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Grape is a staple crop in many parts of Iran which has shown moderate sensitivity to salinity stress. Water and soil salinity is one of the major environmental stresses that strongly affect the production of agricultural products, including grapes. To overcome the harmful effects of salinity, different methods and materials are used, one of which is the use of nitric oxide. In order to explore the impact of nitric oxide on the mitigation of the negative effects of salinity stress on four grape cultivars and rootstocks ('Bidaneh Sefid' (Sultana) and 'Yaghouti' cultivars, and 140Ru and 1103 P rootstocks), a pot experiment was performed in a factorial based on a randomized complete block design with three replications. Plants were subjected to three sodium chloride (NaCl) levels of 0 (control), 25, and 50 mM and three levels of sodium nitroprusside (SNP) of 0 (control), 0.5, and 1 mM. Results indicated that increasing SNP concentration caused an increase in growth indices such as leaf area, shoot and root length, fresh and dry weights of leaves, shoots, and roots, and leaf relative water content (RWC). Furthermore, salinity decreased the concentrations of potassium (K+), calcium (Ca2+), magnesium (Mg2+), and iron (Fe2+) in leaves, while increased the amount of sodium (Na+) and chlorine (Clˉ) as well as the electrolyte leakage (EL). In addition, SNP at 0.5 and 1 mM could increase the growth efficiency and RWC as well as the elements such as K+ and Mg2+ while decreased the absorption of Na+ and Clˉ as well as the EL in plants under salinity. According to the obtained results, SNP at both concentrations (0.5 and 1 mM) had a pronounced effect on reducing the negative effect of salinity in the evaluated grape rootstocks and cultivars. In general, the positive effects of SNP on 'Yaghouti' and 'Bidaneh Sefid' cultivars were higher than those on 140Ru and 1103 P rootstocks. [ABSTRACT FROM AUTHOR]

Introduction: Rice is a vital staple food for many countries, and its yield is known to be significantly affected by various abiotic stresses, which are expected to intensify with climate change, posing a threat to global food security. Abscisic acid (ABA), a crucial plant growth regulator, plays a crucial role in plant responses to these abiotic stresses. It influences several processes, such as seed dormancy, leaf gas exchange, reactive oxygen species (ROS) scavenging, ion toxicity reduction, and root elongation, all of which contribute to enhancing plant survival under stress. Methods: This article reviews recent research on ABA-mediated gene responses and expressions involved in rice plant architecture and its response to abiotic stress. Results and discussion: Abscisic acid responses were primarily driven by changes in gene expression. Expression analyses of the gene related to ABA biosynthesis or catabolism indicated several changes in plant architecture, such as changes in leaf angle, delayed flowering, and modifications in growth regulators. Additionally, tolerance-related mechanisms, such as increased ROS scavenging, reduced membrane leakage, and vacuolar compartmentation of toxic radicals, were activated under single or multiple stress conditions. While these adaptations may improve plant survival and yield sustainability under stress, they may not necessarily enhance yield potential in environments affected by drought, salinity, or heat stress. ABA expression was also associated with improved pollen viability, grain-filling potential, and seed setting under abiotic stresses such as heat, which could enhance seed yield in such challenging environments. [ABSTRACT FROM AUTHOR]

Premise: There are advantages to flowering early in the spring, including greater pollinator fidelity and longer fruit maturation time. But plant phenology has advanced in recent years, making many plants vulnerable to freezing damage from late frosts. Methods: To determine the costs and benefits of flowering early in the growing season, we exposed Prunus pumila plants to two freezing treatments and a delayed flowering treatment in subsequent years. Data were collected on ovary swelling, fruit production, and pollinator visitation on hand‐ and open‐pollinated plants in all treatments. We also measured tissue damage after freeze events. Results: Our results suggest that flowering time and temperature affect reproductive success, with fewer fruits produced after hard freezes. The same was not true for light freezes, which had minimal impact on reproduction. Freezing damage to plants after a hard freeze did affect the number of dipteran pollinators but not the overall pollinator visitation rate. Despite the clear impact of freezing temperatures on plant reproduction, flowering early provided an advantage in that reproductive output decreased with delayed flowering. Conclusions: Our findings suggest that Prunus pumila will retain the ability to attract pollinators and produce viable seeds if exposed to false spring conditions that involve a light freeze, but hard freezes may reduce yield by an order of magnitude. Although the advantages to flowering early may outweigh the risk of freezing damage under current conditions, it is possible that flower viability may be constrained under continued climate warming. [ABSTRACT FROM AUTHOR]

Salinity stress can be deemed as an important challenge extremely affecting crop growth as well as development. Therefore, it is important to improve its tolerance to salinity stress, in arid as well as semiarid regions. Thus, this experiment explored the influence of foliar usage of plant growth-stimulating substances with different concentrations (C: control, melatonin (M 1 : 100, M 2 : 200 and M 3 :400 µM) and silicon (Si 1 : 5.4, Si 2 : 10.8 and Si 3 : 16.2 mM)) on some physiological as well as biochemical attributes of Cyamopsis tetragonoloba L. (guar) seedlings under five salinity levels (S 1 : no-salt treatment, S 2 : 5, S 3 : 10, S 4 : 15 and S 5 : 20 dS m−1). With increasing salinity, shoot dry weight, F v /F m , F ′ v / F ′ m , ΦPSII, qp, qL, Rfd, ETR, photosynthetic pigments, membrane stability index, as well as relative water content were gradually reduced in salt-stressed guar, as comparison is made to the non-saline conditions. However, foliar usage of plant growth-stimulating substances was effective in improving guar tolerance to salinity by elevating the DPPH radical scavenging capacity and anthocyanin, thus enhancing membrane stability index, improving the electron's transport rate, reducing electrolyte leakage and decreasing the damage affecting the reaction center of PSII, as comparison is made with control. Such positive effects were exhibited in elevating growth under salinity stress. Si 3 treatment demonstrated the best response under salinity stress, as compared with the other treatments. Consequently, foliar usage of silicon or melatonin in salt-stressed guar seedlings can serve an efficient method to improve salt tolerance under salinity stress in arid and semiarid regions. [ABSTRACT FROM AUTHOR]

Water stress in agricultural systems may occur slowly or abruptly. Plant reactions to stress differ with regard to its level and duration. The level of plant susceptibility to water deprivation primarily depends on the management of the water content and metabolism adjustments. The aim of this study was to determine the correlation between water-based plant parameters and the yield components of 90 genotypes of winter wheat (Triticum aestivum L.). Since the loss of water is frequently used as a selection criterion to assess drought tolerance, the relationships between the yield and leaf water content, osmotic potential, and gas exchange characteristics were examined. Genotypes 1, 25, 34, 36, 42, 43, 46, 57, 66, 73, and 90 showed 33–45% larger numbers of grains/plant, 19–25% higher weights of grains/plant, and 4% higher thousand grain weights compared to other genotypes. The higher values of the yield components were accompanied by 20–30% lower leaf water content, 39–52% lower osmotic potential, and 4–39% lower water use efficiency. The principal component analysis revealed that the wheat genotypes had noticeable differences in a few physiological parameters that depended on the sowing date. Electrolyte leakage showed a substantial correlation with the sowing date, suggesting that it may not be a suitable factor for the prediction of drought tolerance. The factors that distinguished the examined genotypes the most were the leaf water content, osmotic potential, and water use efficiency. In addition, a significant correlation was observed between the mentioned parameters and yield components. As a result, these parameters may be helpful in genotype characterization in relation to water stress susceptibility, offering a trustworthy plant selection test. [ABSTRACT FROM AUTHOR]

Frost tolerance has evolved many times independently across flowering plants. However, conservation of several frost tolerance mechanisms among distant relatives suggests that apparently independent entries into freezing climates may have been facilitated by repeated modification of existing traits ('precursor traits'). One possible precursor trait for freezing tolerance is drought tolerance, because palaeoclimatic data suggest plants were exposed to drought before frost and several studies have demonstrated shared physiological and genetic responses to drought and frost stress. Here, we combine ecophysiological experiments and comparative analyses to test the hypothesis that drought tolerance acted as a precursor to frost tolerance in cool-season grasses (Pooideae). Contrary to our predictions, we measured the highest levels of frost tolerance in species with the lowest ancestral drought tolerance, indicating that the two stress responses evolved independently in different lineages. We further show that drought tolerance is more evolutionarily labile than frost tolerance. This could limit our ability to reconstruct the order in which drought and frost responses evolved relative to each other. Further research is needed to determine whether our results are unique to Pooideae or general for flowering plants. [ABSTRACT FROM AUTHOR]

Late spring frost is the most hazardous abiotic stress affecting the survival of sugar beet seedlings. Therefore, it is very important to identify frost-tolerant cultivars during the early seedling development stage. In the study, the physiological and morphological responses of ten sugar beet cultivars (Ernestina, Isabella, Orthega, Serenada, Kuno, Taurus, Tuna, Mohican, Rodeo, and Smılodon) to frost stress at different growth stages (V1.1, V2.1, and V3.1) were evaluated. Seedlings were exposed to − 3 °C for 2 h at all stages. Percent damage (%), leaf chlorophyll content (SPAD), leaf surface temperature (°C), electrolyte leakage (%), leaf relative water content (%), and turgidity loss (%) were examined. The results showed that higher damage percentages were observed in earlier growth stages of sugar beet, with recorded values of 29.7% in V1.1, 15.4% in V2.1, and 3.6% in V3.1. A great genotypic variation was observed among the cultivars; electrolyte leakage increased from 15.6% in control to 52.6% in frost stress, and higher electrolyte leakage was obtained from frost-stressed plants. The relative water content of leaves increased only at stage V2.1, although frost decreased turgor loss. Sugar beet showed sensitivity to frost in earlier seedling growth stages, but their tolerance levels increased in later growth stages. The study revealed that electrolyte leakage is a reliable indicator for identifying sugar beet cultivars that exhibit tolerance to frost stress during early development. [ABSTRACT FROM AUTHOR]

In India, about 80% of the potato crop is grown during winter season and thus it often gets exposed to low temperatures which adversely affect its growth and lead to heavy reductions in tuber yield (approximately 40–60%). Overall aim of this study was to generate frost tolerant potato clones through intervarietal hybridization. In the summer 2018, the segregating progenies were developed through hybridization between J-2/19 (frost tolerant) and MS/7-645 (high yielding). In F1C1 generation, the characterization of 168 potato clones was carried out on the basis of leaf morpho-anatomical (LMA) traits viz., stomatal and trichome density on adaxial and abaxial leaf surfaces, stomatal index and palisade thickness. Seventy-six clones possessing LMA traits associated with frost tolerance were exposed to low temperature and their tolerance behaviour was further confirmed through electrolyte leakage in F1C2 generation. The potato clones exhibited a large and significant variability for both the leaf morpho-anatomical traits and electrolyte leakage. The hierarchical clustering analysis distributed the 168 potato clones into 13 cluster groups based on their proximate composition in twelve LMA traits. Moreover, the electrolyte leakage exhibited a negative correlation with stomatal index (−0.43) and stomatal density on adaxial leaf surface (−0.36). Overall, 11 potential clones exhibiting frost tolerant characteristics with desirable horticultural traits were identified and these were recommended for further evaluation. Thus, LMA traits, particularly stomatal index can potentially be used for preliminary screening of potato genetic resources for frost tolerance in breeding programmes specifically during the non-frost years. [ABSTRACT FROM AUTHOR]

IntroductionDrought is one of the most important abiotic stresses that has an undesirable effect on crop production and their quality and leads to osmotic, ionic, and nutritional limitations as well as growth delay, metabolic disorders and oxidative stress in plants. Iran has a dry and semi-arid climate. Due to this problem, there is a possibility of drought stress during the growth period of plants. Presently, the production of legumes in the country is mostly under rainfed conditions and drought stress is one of the main factors reducing the yield of legumes. Mung bean is a small grain of valuable legume. Evaluation of the performance of different cultivars is considered a starting point in identifying drought-resistant cultivars. Cycocel is one of the most important growth retarders for tampering with growth and performance. Therefore, the present study was conducted to investigate the effect of foliar application of cycocel on morphophysiological and biochemical characteristics of mung bean (Vigna radiata L.) genotypes under water deficit conditions. Materials and MethodsThis study was conducted in order to investigate the effect of foliar application of cycocel on the morpho-physiological and biochemical characteristics of mung bean (Vigna radiata L.) genotypes under water deficit conditions, split-split plots based on a randomized complete block design with three replications, in the research farm of Ferdowsi University of Mashhad. Experimental factors included 3 levels of drought (non-stress, mild stress, and severe stress), 3 levels of cycocel foliar spraying (0, 400, and 800 mg.l-1), and 2 levels of mung bean cultivars (Hendi landrace and Zarbakhsh). Statistical analysis was performed using SAS 9.4 and comparing the means was based on the LSD method at a 5% probability level. Results and DiscussionThe experimental results showed that the effect of drought stress, cycocel, genotype, and the interaction of drought stress and cycocel as well as drought stress and genotype on height, stem diameter, relative water content, stomatal conductance, leakage of electrolytes, greenness and chlorophyll content were significant. Severe stress, compared to non-stress conditions, caused a decrease in height (53%), stem diameter (30%), relative water leaf content (29%), stomatal conductance (68%), greenness (37%), chlorophyll a content (25%) and chlorophyll b content (30%) and leakage of electrolytes increased (60%). The results showed that both drought stress and cycocel caused a decrease in the height of the plant. At all levels of drought stress, the Hendi genotype had a higher plant height. Drought stress caused a decrease in the diameter of the stem, while the application of cycocel reduced the decrease in the diameter of the stem due to drought stress. Drought stress caused a decrease in the relative content of leaf water, while the application of cycocel reduced this decrease. Also, Drought stress reduced the stomatal conductance, while the application of cycocel slightly compensated this reduction. At all levels of drought stress, Zarbakhsh genotype had higher stomatal conductance, but the difference between the two genotypes in the treatment of non-stress was not significant. Drought stress increased the leakage of membrane electrolytes, and the use of cycocel reduced the increase in electrolyte leakage due to drought stress, and it was also found that the increase in electrolyte leakage due to drought stress was more intense in the Hendi genotype. Drought stress reduced the greenness of the leaf, while the application of cycocel slightly compensated this reduction. Also, at all levels of drought stress, the Zarbakhsh genotype had higher leaf greenness, but the difference between the two genotypes in the treatment of 100% crop water requirement was not significant. The chlorophyll a content of leaves decreased due to drought stress, while the application of cycocel reduced the severity of this decrease. Also, at all levels of drought stress, the Hendi genotype had lower leaf chlorophyll a content. ConclusionsThe results of this study showed that under drought stress, there was a decrease in plant height, stem diameter, relative water content, stomatal conductance, greenness, chlorophyll a and b content, along with an increase in electrolyte leakage. Among mung bean cultivars, the Zarbakhsh cultivar showed superiority in tolerance to water shortage conditions compared to another one. The use of cycocel reduced the negative effects of drought stress on the plant. It appeared that the use of cycocel under drought stress conditions is effective for improving plant performance.

Abstract Background Cotton (Gossypium hirsutum L.), adapted to tropical and subtropical regions of the world, is highly sensitive to low temperatures throughout its life cycle. The objective of this study was to evaluate the mitigating effects of different doses of animal-derived (0.25%, 0.50%, and 1.00% Isabion® ), seaweed-based (0.165%, 0.330%, and 0.660% Proton®) biostimulants, as well as a copper (Cu)-containing fungicide application, on cotton cultivar Lazer seedlings at the four true leaves (V4) stage. The plants were exposed to a low temperature of 5 °C for 48 h, and the changes in morphological (seedling fresh and dry weight, plant height, and stem diameter) and physiological parameters (leaf temperature, chlorophyll content, relative water content, electrolyte leakage, and relative injury) were examined. Results The results revealed that chilling stress reduced plant growth, while biostimulants helped protect the plants and overcome the adverse effects of chilling. Under chilling stress, there was a considerable reduction in seedling fresh weight (SFW), seedling dry weight (SDW), plant height (PH), stem diameter (SD), leaf temperature (LT), and relative water content (RWC). Cotton seedlings treated with the animal-derived biostimulants showed significantly enhanced SFW, SDW, PH, SD, LT, chlorophyll content (Chl), electrolyte leakage (EL), and relative injury (RI), although there were no positive changes in RWC. No significant differences in the morphological traits were observed among the doses of seaweed biostimulants. For SDW, PH, EL, and RI, the best results were obtained with the application of a fungicide containing copper. Conclusion These results show the efficiency of the biostimulant and fungicide treatments in mitigating low-temperature stress in cotton seedlings. Applying a copper-containing fungicide to cotton seedlings helped to counteract the negative effects of low-temperature stress and to protect the plants from damage by maintaining electrolyte balance. Among the biostimulant applications, all levels of animal-derived biostimulant applications, as well as the 0.660% level of the seaweed-derived biostimulant, led to increased tolerance of cotton plants to chilling stress.

Premise: With growing interest in the impact of false springs on plant reproduction, there is the need to develop reliable, high‐throughput methods for assessing floral freezing damage. Here we present a method for use with floral tissue that will facilitate more comparative work on floral freezing tolerance in the future. Methods and Results: We examined the effectiveness of a modified electrolyte leakage protocol to assess floral freezing damage. By comparing data from temperature response curves to an estimate of visual tissue damage, we optimized the protocol for different floral types and improved the signal‐to‐noise ratio for floral data. Conclusions: Our modified protocol provides a quick and straightforward method for quantifying floral freezing damage that can be standardized across floral types. This method allows for cross‐species comparisons and can be a powerful tool for studying broad patterns in floral freezing tolerance. [ABSTRACT FROM AUTHOR]

A simple method set for assessing biochemical changes associated with osmotic stress responses was developed using coffee (Coffea arabica L.) leaf disks. Stress was induced by polyethylene glycol (PEG) exposure. Quantitative evaluation of tissue physiological stress parameters was carried out using analytical methods to validate the conversion of classic qualitative histochemical tests for localizing lipid peroxidation, hydrogen peroxide, and total xanthine alkaloids into semi-quantitative assays. Relative electrolyte leakage (EL%) and chlorophyll content (SPAD index) were also recorded. EL% levels of treated disks were higher than those of control ones, whereas SPAD indexes were comparable. Histochemical localization indicated that levels of lipid peroxidation, H2O2, and total xanthines were also higher under osmotic stress than in control conditions. Semi-quantitative data obtained by image processing of histochemical staining consistently matched quantitative evaluations. Chromatographic analyses revealed that theophylline and caffeine concentrations increased in the presence of PEG, whereas theobromine remained constant in relation to the control. The methods herein described can be useful to rapidly acquire initial data regarding biochemical osmotic stress responses in coffee tissues based on simple staining and imaging steps. Moreover, it is likely that the same method may be applicable to other types of stresses and plant species upon minor adjustments. [ABSTRACT FROM AUTHOR]

Sugarbeets are largely produced without irrigation, making drought stress inevitable when rainfall is insufficient. Whether drought stress impacts root storage, however, is currently unknown. Research was conducted to determine the effect of preharvest water stress on postharvest sugarbeet root respiration rate and susceptibility to storage rots as these traits are the primary determinants for sucrose loss and quality deterioration. Greenhouse‐grown plants were subjected to four levels of water deficit by discontinuing watering for 0, 7, 14 or 21 days prior to harvest. Plants receiving water‐restrictive treatments displayed physiological stress by leaf epinasty, reductions in net photosynthetic rate and leaf relative water content and increases in leaf temperature, whereas the water content of roots harvested from these plants progressively decreased with the severity of the preharvest water‐deficit treatment. Harvested roots from all watering treatments were stored at 10°C and 95% relative humidity for up to 12 weeks and evaluated for respiration rate and susceptibility to storage rot. Root respiration rate during storage was inversely related to root water content at harvest by second‐order equations, such that respiration was not significantly affected by minor reductions in root water content but increased exponentially for roots obtained from severely drought‐stressed plants with water contents at harvest of ≤75%. Similarly, roots with water contents ≤75% had elevated levels of electrolyte leakage, a measure of cellular membrane damage, and were more susceptible to dehydration and fungal infection during storage. In separate experiments, roots harvested from water‐stressed plants were inoculated with Botrytis cinerea or Penicillium vulpinum, two causal agents for storage rots. In these experiments, preharvest water stress quantitatively increased root rot and qualitatively altered symptoms of their infection. Overall, these results demonstrate that severe preharvest drought stress is likely to significantly increase sugarbeet root storage losses caused by root respiration and storage rots and that storage losses are likely to accelerate with time in storage. However, mild‐to‐moderate drought conditions prior to harvest are expected to have no or minimal effect on storage losses from root respiration or storage rots. [ABSTRACT FROM AUTHOR]

Heat stress is a major environmental stress that affects the growth and development of plants. Korean fir (Abies koreana), a rare species endemic to South Korea, is sensitive to global climate change. The effect of exogenous methyl jasmonate (MeJA) on heat stress tolerance was, therefore, investigated in this species. During heat stress, the expression levels of eight genes (AkNAC19, AkMPK6, AkERF4, AkEFP, AkNAC2, AkbHLH, AkHSP17.6, and AkMYB123) were assessed in needles of A. koreana following treatment with 0, 0.1, 1.0, or 2.0 mM MeJA. Optimal upregulation of expression of most genes was observed 24 h post-treatment with 2.0 mM MeJA. Similar results were obtained when gene expression was analyzed 1, 2, 4, and 8 days post-treatment with 2.0 mM MeJA. Under heat stress conditions, plants treated with 2.0 mM MeJA initially showed a rapid decline in electrolyte leakage and higher chlorophyll content after 28 days of heat stress; however, opposite trends were observed in untreated plants, indicating that MeJA mediated tolerance to heat stress. Higher levels of expression of AkERF4, AkNAC2, and AkHSP17.6 were observed in MeJA-treated needles than in untreated needles, indicating these genes were strongly associated with MeJA-mediated heat tolerance. Therefore, these results suggest that the ability of Korean fir to tolerate abiotic stress is associated with endogenous MeJA synthesis or signaling, and identifies AkERF4, AkNAC2, and AkHSP17.6 as potential candidates for genes involved in the stress-tolerance mechanism. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) is a multifunctional signalling molecule involved in the regulation of plant ontogenesis and adaptation to different adverse environmental factors, in particular to osmotic stress. Understanding NO-induced plant protection is important for the improvement of plant stress tolerance and crop productivity under global climate changes. The root system is crucial for plant survival in a changeable environment. Damages that it experiences under water deficit conditions during the initial developmental periods seriously affect the viability of the plants. This work was devoted to the comparative analysis of the pretreatment of wheat seedlings through the root system with NO donor sodium nitroprusside (SNP) for 24 h on various parameters of redox homeostasis under exposure to osmotic stress (PEG 6000, 12%) over 0.5–24 h. The active and exhausted solutions of SNP, termed as (SNP/+NO) and (SNP/−NO), respectively, were used in this work at a concentration of 2 × 10−4 M. Using biochemistry and light microscopy methods, it has been revealed that osmotic stress caused oxidative damages and the disruption of membrane cell structures in wheat roots. PEG exposure increased the production of superoxide (O2•−), hydrogen peroxide (H2O2), malondialdehyde (MDA), and the levels of electrolyte leakage (EL) and lipid peroxidation (LPO). Stress treatment enhanced the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), the excretion of proline, and the rate of cell death and inhibited their division. Pretreatment with (SNP/+NO) decreased PEG-induced root damages by differently regulating the antioxidant enzymes under stress conditions. Thus, (SNP/+NO) pretreatment led to SOD, APX, and CAT inhibition during the first 4 h of stress and stimulated their activity after 24 h of PEG exposure when compared to SNP-untreated or (SNP/−NO)-pretreated and stress-subjected plants. Osmotic stress triggered the intense excretion of proline by roots into the external medium. Pretreatment with (SNP/+NO) in contrast with (SNP/−NO) additionally increased stress-induced proline excretion. Our results indicate that NO is able to mitigate the destructive effects of osmotic stress on the roots of wheat seedlings. However, the mechanisms of NO protective action may be different at certain periods of stress exposure. [ABSTRACT FROM AUTHOR]

The accumulation of cadmium (Cd) in plants poses a major risk to consumer health, in addition to affecting plant growth, development and quality. The study aimed to examine the effects of cadmium on the plants' ability for photosynthesis and antioxidant enzyme activity. In this study, radishes were planted in Petri dishes and pots containing soil supplemented with different concentrations of cadmium sulphate (25, 50, and 100 mg Cd kg-1 soil). The results showed that the percentage of germination, seedlings length, and fresh and dry matter significantly declined its increasing cadmium concentrations. In addition, cadmium hindered plant growth, as evidenced by the fresh and dried weight of radish roots and leaves after a 100 mg Cd kg-1 soil treatment. There was also a notable decrease in chlorophyll a and chlorophyll b, total chlorophyll, and total leaf area per plant. The leaves of radish plant exhibited a significant increase in lipid peroxidation and electrolyte leakage contents under Cd stress, while, the relative water content (RWC) decreased. However, leaves and roots of radish plant showed a considerable increase in antioxidant enzymes (catalase; CAT, peroxidase; POD, and superoxide dismutase; SOD). Furthermore, radish showed a significant increase in Cd accumulation in all applications, however, there were no obvious symptoms of Cd toxicity following the 25 and 50 mg Cd kg-1 soil applications. In conclusion, the radish plants accumulated cadmium at higher concentrations (100 mg Cd kg-1 soil). So, we recommended cultivating the radish plants in soil that has low concentrations of cadmium. [ABSTRACT FROM AUTHOR]

Background: Cotton (Gossypium hirsutum L.), adapted to tropical and subtropical regions of the world, is highly sensitive to low temperatures throughout its life cycle. The objective of this study was to evaluate the mitigating effects of different doses of animal-derived (0.25%, 0.50%, and 1.00% Isabion®), seaweed-based (0.165%, 0.330%, and 0.660% Proton®) biostimulants, as well as a copper (Cu)-containing fungicide application, on cotton cultivar Lazer seedlings at the four true leaves (V4) stage. The plants were exposed to a low temperature of 5 °C for 48 h, and the changes in morphological (seedling fresh and dry weight, plant height, and stem diameter) and physiological parameters (leaf temperature, chlorophyll content, relative water content, electrolyte leakage, and relative injury) were examined. Results: The results revealed that chilling stress reduced plant growth, while biostimulants helped protect the plants and overcome the adverse effects of chilling. Under chilling stress, there was a considerable reduction in seedling fresh weight (SFW), seedling dry weight (SDW), plant height (PH), stem diameter (SD), leaf temperature (LT), and relative water content (RWC). Cotton seedlings treated with the animal-derived biostimulants showed significantly enhanced SFW, SDW, PH, SD, LT, chlorophyll content (Chl), electrolyte leakage (EL), and relative injury (RI), although there were no positive changes in RWC. No significant differences in the morphological traits were observed among the doses of seaweed biostimulants. For SDW, PH, EL, and RI, the best results were obtained with the application of a fungicide containing copper. Conclusion: These results show the efficiency of the biostimulant and fungicide treatments in mitigating low-temperature stress in cotton seedlings. Applying a copper-containing fungicide to cotton seedlings helped to counteract the negative effects of low-temperature stress and to protect the plants from damage by maintaining electrolyte balance. Among the biostimulant applications, all levels of animal-derived biostimulant applications, as well as the 0.660% level of the seaweed-derived biostimulant, led to increased tolerance of cotton plants to chilling stress. [ABSTRACT FROM AUTHOR]

Low freezing tolerance threatens the survival and productivity of perennial ryegrass under northern climate. In this study, we aimed to identify transcriptional changes in plants subjected to low and freezing temperatures as well as to elucidate differences between tolerant and sensitive genotypes. Response to freezing stress was evaluated in a panel of 160 perennial ryegrass genotypes by measuring electrolyte leakage after exposure to -12 °C and -14 °C for 24 h. Two tolerant and two sensitive genotypes were selected for the transcriptome analysis. Crown tissue samples were collected at six treatments: before the start of cold acclimation (control point), at the start of acclimation, after one week of acclimation, after three weeks of acclimation, after freezing at -5 °C and freezing at -10 °C. A total of 11,125 differentially expressed genes (DEGs) were identified in the sensitive and 12,937 DEGs in the tolerant genotypes, when comparing the control vs. each of the acclimation and freezing treatments, as well as the end of acclimation vs. freezing treatments. Among the identified DEGs 3323 were unique to the sensitive genotypes, 5135 were unique to the tolerant genotypes and 7802 were shared. Genes upregulated during cold acclimation and freezing stress were linked to the MAPK signalling pathway, circadian rhythm, starch and sucrose metabolism, plant-pathogen interaction, carbon fixation, alpha-linoleic acid metabolism, carotenoid metabolism, glyoxylate and dicarboxylate metabolism pathways. Downregulated genes were linked to ATP-dependent chromatin remodelling, fatty acid elongation and DNA replication. The downregulation of fatty acid elongation and glutathione metabolism DEGs could indicate that the studied genotypes respond to cold stress in a novel or not yet well-characterized manner.

IntroductionRice is a vital staple food for many countries, and its yield is known to be significantly affected by various abiotic stresses, which are expected to intensify with climate change, posing a threat to global food security. Abscisic acid (ABA), a crucial plant growth regulator, plays a crucial role in plant responses to these abiotic stresses. It influences several processes, such as seed dormancy, leaf gas exchange, reactive oxygen species (ROS) scavenging, ion toxicity reduction, and root elongation, all of which contribute to enhancing plant survival under stress.MethodsThis article reviews recent research on ABA-mediated gene responses and expressions involved in rice plant architecture and its response to abiotic stress.Results and discussionAbscisic acid responses were primarily driven by changes in gene expression. Expression analyses of the gene related to ABA biosynthesis or catabolism indicated several changes in plant architecture, such as changes in leaf angle, delayed flowering, and modifications in growth regulators. Additionally, tolerance-related mechanisms, such as increased ROS scavenging, reduced membrane leakage, and vacuolar compartmentation of toxic radicals, were activated under single or multiple stress conditions. While these adaptations may improve plant survival and yield sustainability under stress, they may not necessarily enhance yield potential in environments affected by drought, salinity, or heat stress. ABA expression was also associated with improved pollen viability, grain-filling potential, and seed setting under abiotic stresses such as heat, which could enhance seed yield in such challenging environments.

IntroductionThe increasing demands for pulse crops and the lack of water resources in most parts of Iran, especially in dry areas, need to employ new strategies to increase water productivity of pulse crops. One of the new methods in managing water and soil resources is the use of zeolite as a storage tank, which prevents wastage and increases the efficiency of irrigation water particularly in light soils. The purpose of this research was to determine the effect of different amounts of zeolite and irrigation interval on growth and yield indices in Pak cultivar of white beans (Phaseolus vulgaris L.). Materials and MethodsThis research was conducted in order to investigate the effect of different amounts of zeolite and irrigation interval on the growth and grain yield in Pak cultivar of white bean (Phaseolus vulgaris L.), in a split plot design based on randomized complete block design with three replications in a farm located in the bojnord city - north Khorasan in the agronomic year 2023-2024. The study factors included 7, 10 and 13 days irrigation interval in the main plot and three levels of zeolite in the soil (0 (no use), 5 and 10 t.ha-1) in the sub plots. Data were analyzed using SAS 9.4 statistical package and figures were drawn by Excel program. Mean comparison were arranged by least significant differences in the 95% probability. Results and DiscussionThe results revealed that the white bean plants attained their shortest height across all three irrigation levels when zeolite was not applied in the plots. Conversely, when a zeolite level of 10 t.ha-1 was introduced, there was an observed increase of 18.15% in the number of nodes per plant compared to scenarios where no zeolite was utilized. The highest level of zeolite consumption caused an increase of 13.88% in the seed weight compared to the level of no zeolite consumption. The highest seed yield of 4651.5 kg.ha-1was recorded in the 7 day irrigation interval and zeolite consumption of 10 t.ha-1. The lowest amount of electrolyte leakage related to irrigation interval of 10 and 7 days and consumption of 10 t.ha-1 of zeolite was 14.8 and 12.34%, respectively. The consumption of 10 t.ha-1 of zeolite caused a 21% increase in protein compared to the non-use of zeolite in white beans, and with the increase of the irrigation frequency from 7 to 10 days, although the amount of seed protein decreased, it did not have a significant difference with the level of irrigation once every 7 days. And when the irrigation cycle reached once every 13 days, the amount of seed protein decreased significantly by 6.8% compared to the irrigation cycle once every 7 days. It was also found that the addition of 10 tons of zeolite per hectare to the soil caused a 41.5% decrease in the amount of proline in white bean leaves compared to the absence of zeolite. In this research, it was found t.hat the level of 10 t.ha-1 the highest biological yield of 13475 kg.ha-1 recorded and it increased by 29.2% compared to the no zeolite consumption. By reducing the irrigation interval to 10 and 7 days, with the increase of zeolite consumption, the harvest index increased, and in the meantime, the highest index related to the irrigation cycle of 7 days and zeolite consumption of 10 tons was 35.5%. ConclusionsBased on the obtained results, it can be concluded that water stress resulted in a reduction in the growth characteristics and overall performance of white bean plants. The lowest values ​​of parameters calculated in this research were observed at the level of no zeolite consumption and irrigation cycle of 13 days, and their highest values ​​were observed at the level of zeolite of 10 t.ha-1 and irrigation cycle of 7 days, which shows that Zeolite, help more water absorption and water return when the plant needs water, and increase the growth of different plant tissues and production of more products. Overall, it can be inferred that applying zeolite at a rate of 10 t.ha-1, particularly in conjunction with a 7-day irrigation cycle, can optimize the yield and growth characteristics of white beans, specifically the Pak cultivar. However, we recommend further investigation into higher levels of zeolite application across various soil textures to enhance our understanding and refine cultivation practices.

Abstract High temperature stress influences plant growth, seed yield, and fatty acid contents by causing oxidative damage. This study investigated the potential of thiourea (TU) to mitigate oxidative stress and restoring seed oil content and quality in canola. The study thoroughly examined three main factors: (i) growth conditions—control and high temperature stress (35 °C); (ii) TU supplementation (1000 mg/L)—including variations like having no TU, water application at the seedling stage, TU application at seedling stage (BBCH Scale-39), water spray at anthesis stage, and TU application at anthesis stage (BBCH Scale-60); (iii) and two canola genotypes, 45S42 and Hiola-401, were studied separately. High temperature stress reduced growth and tissue water content, as plant height and relative water contents were decreased by 26 and 36% in 45S42 and 27 and 42% Hiola-401, respectively, resulting in a substantial decrease in seed yield per plant by 36 and 38% in 45S42 and Hiola-401. Seed oil content and quality parameters were also negatively affected by high temperature stress as seed oil content was reduced by 32 and 35% in 45S42 and Hiola-401. High-temperature stress increased the plant stress indicators like malondialdehyde, H2O2 content, and electrolyte leakage; these indicators were increased in both canola genotypes as compared to control. Interestingly, TU supplementation restored plant performance, enhancing height, relative water content, foliar chlorophyll (SPAD value), and seed yield per plant by 21, 15, 30, and 28% in 45S42; 19, 13, 26, and 21% in Hiola-401, respectively, under high temperature stress as compared to control. In addition, seed quality, seed oil content, linoleic acid, and linolenic acid were improved by 16, 14, and 22% in 45S42, and 16, 11, and 23% in Hiola-401, as compared to control. The most significant improvements in canola seed yield per plant were observed when TU was applied at the anthesis stage. Additionally, the research highlighted that canola genotype 45S42 responded better to TU applications and exhibited greater resilience against high temperature stress compared to genotype Hiola-401. This interesting study revealed that TU supplementation, particularly at the anthesis stage, improved high temperature stress tolerance, seed oil content, and fatty acid profile in two canola genotypes.

Cadmium (Cd) is the most toxic element which may cause serious consequences to microbial communities, animals, and plants. The use of green technologies like phytoremediation employs plants with high biomass and metal tolerance to extract toxic metals from their rooting zones. In the present work, Hydrocotyle umbellata was exposed to five Cd concentrations (2, 4, 6, 8, and 10 µmol) in triplicates to judge its phytoextraction ability. Effects of metal exposure on chlorophyll (Chl), bio-concentration factor (BCF), translocation factor (TF), and electrolyte leakage (EL) were analyzed after 10 days of treatment. Metal-responding genes were also observed through transcriptomic analysis. Roots were the primary organs for cadmium accumulation followed by stolon and leaves. There was an increase in EL. Plants showed various symptoms under increasing metal stress namely, chlorosis, browning of the leaf margins, burn-like areas on the leaves, and stunted growth, suggesting a positive relationship between EL, and programmed cell death (PCD). Metal-responsive genes, including glutathione, expansin, and cystatin were equally expressed. The phytoextraction capacity and adaptability of H. umbellata L. against Cd metal stress was also demonstrated by BCF more than 1 and TF less than 1. The results of the current study demonstrated that Hydrocotyle umbellata is a good choice for environmental cleanup in areas with mild Cd contamination. According to TF and BCF, the plant demonstrated a considerable uptake of Cd. Additionally, H. umbellata's eligibility as a phytoremediation agent for Cd was supported by the transcription of numerous metal-responsive genes, including glutathione, expansin, cystatin, and other genes associated with growth. [ABSTRACT FROM AUTHOR]

An understudied problem in plant heavy metal biology is the effects of acute versus gradual or chronic metal exposure. The aim of the present study was to compare the growth and physiological responses of Rumex hydrolapathum Huds. plants subjected to gradual or acute Mn stress treatment in controlled conditions. Heavy metal was applied to substrate either as one 1.00 g L−1 Mn dose (acute treatment) or the same dose in four steps of increasing amounts within 12 days (gradual treatment). Peroxidase activity in actively photosynthesizing leaves was used for monitoring induced biochemical changes resulting from Mn treatment. The number of leaves per plant significantly increased in the case of gradual treatment with Mn, but this effect was not statistically significant for acute treatment. Leaf fresh mass significantly decreased in both cases due to the decrease in leaf water content, but dry biomass of leaves was not affected, with no significant differences between the two types of treatments. A significantly lower chlorophyll fluorescence parameter Performance Index in large leaves of plants under the acute Mn treatment than in plants under the gradual treatment was evident. An increase in leaf peroxidase activity by Mn treatment was proportional to the metal dose received, but plants in the acute treatment with 1.00 g L−1 Mn had a significantly lower peroxidase response in comparison to the gradual treatment with 1.00 g L−1 Mn. In conclusion, under gradual treatment, biochemical changes related to the induction of tolerance to the heavy metal are expressed, as indicated by the continuous increase in leaf peroxidase activity after each treatment step. [ABSTRACT FROM AUTHOR]

IntroductionThe increasing demands for pulse crops and the lack of water resources in most parts of Iran, especially in dry areas, need to employ new strategies to increase water productivity of pulse crops. One of the new methods in managing water and soil resources is the use of zeolite as a storage tank, which prevents wastage and increases the efficiency of irrigation water particularly in light soils. The purpose of this research was to determine the effect of different amounts of zeolite and irrigation interval on growth and yield indices in Pak cultivar of white beans (Phaseolus vulgaris L.). Materials and MethodsThis research was conducted in order to investigate the effect of different amounts of zeolite and irrigation interval on the growth and grain yield in Pak cultivar of white bean (Phaseolus vulgaris L.), in a split plot design based on randomized complete block design with three replications in a farm located in the bojnord city - north Khorasan in the agronomic year 2023-2024. The study factors included 7, 10 and 13 days irrigation interval in the main plot and three levels of zeolite in the soil (0 (no use), 5 and 10 t.ha-1) in the sub plots. Data were analyzed using SAS 9.4 statistical package and figures were drawn by Excel program. Mean comparison were arranged by least significant differences in the 95% probability. Results and DiscussionThe results revealed that the white bean plants attained their shortest height across all three irrigation levels when zeolite was not applied in the plots. Conversely, when a zeolite level of 10 t.ha-1 was introduced, there was an observed increase of 18.15% in the number of nodes fa plant compared to scenarios where no zeolite was utilized. The highest level of zeolite consumption caused an increase of 13.88% in the seed weight compared to the level of no zeolite consumption. The highest seed yield of 4651.5 kg.ha-1was recorded in the 7 day irrigation interval and zeolite consumption of 10 t.ha-1. The lowest amount of electrolyte leakage related to irrigation interval of 10 and 7 days and consumption of 10 t.ha-1 of zeolite was 14.8 and 12.34%, respectively. The consumption of 10 t.ha-1 of zeolite caused a 21% increase in protein compared to the non-use of zeolite in white beans, and with the increase of the irrigation frequency from 7 to 10 days, although the amount of seed protein decreased, it did not have a significant difference with the level of irrigation once every 7 days. And when the irrigation cycle reached once every 13 days, the amount of seed protein decreased significantly by 6.8% compared to the irrigation cycle once every 7 days. It was also found that the addition of 10 tons of zeolite fa hectare to the soil caused a 41.5% decrease in the amount of proline in white bean leaves compared to the absence of zeolite. In this research, it was found t.hat the level of 10 t.ha-1 the highest biological yield of 13475 kg.ha-1 recorded and it increased by 29.2% compared to the no zeolite consumption. By reducing the irrigation interval to 10 and 7 days, with the increase of zeolite consumption, the harvest index increased, and in the meantime, the highest index related to the irrigation cycle of 7 days and zeolite consumption of 10 tons was 35.5%. ConclusionsBased on the obtained results, it can be concluded that water stress resulted in a reduction in the growth characteristics and overall faformance of white bean plants. The lowest values ​​of parameters calculated in this research were observed at the level of no zeolite consumption and irrigation cycle of 13 days, and their highest values ​​were observed at the level of zeolite of 10 t.ha-1 and irrigation cycle of 7 days, which shows that Zeolite, help more water absorption and water return when the plant needs water, and increase the growth of different plant tissues and production of more products. Overall, it can be inferred that applying zeolite at a rate of 10 t.ha-1, particularly in conjunction with a 7-day irrigation cycle, can optimize the yield and growth characteristics of white beans, specifically the Pak cultivar. However, we recommend further investigation into higher levels of zeolite application across various soil textures to enhance our understanding and refine cultivation practices. [ABSTRACT FROM AUTHOR]

Soil salinity and poor-quality irrigation water in Florida, USA, have become major issues for agricultural crops. Since Florida is one of the major producers of cabbage in the country, soil salinization may significantly impact this industry. Chinese cabbage varieties are very popular in the farming community of Florida and are widely cultivated. In the present study, four Chinese cabbage varieties ('Bilko', 'Red Dragon', 'Rubicon', and 'Minuet') were tested for their tolerance, agronomic, physiological, and nutritional responses to irrigation with 0, 100, and 200 mM NaCl solutions. The results showed that NaCl irrigation has decreased the growth of the tested plants, with 'Bilko' being the most tolerant one, showing higher production in both control and salt stress conditions. Although NaCl stress has increased electrolyte leakage in plant leaves, it has no significant effect on proline contents, and chlorophyll contents tend to increase with salinity stress, highlighting the physiological responses of all tested varieties. Among nutritional contents, there were no significant differences, but a few treatment groups showed a significant increase and decrease in nutrient contents. The higher NaCl treatments have caused a higher accumulation of Na and Cl elements in plants, making it a major factor for the decrease in plant growth. [ABSTRACT FROM AUTHOR]

The identification of reliable physiological and biochemical indicators for assessing tomato salt tolerance can increase the efficiency of plant breeding to create new varieties and lines. The purpose of our study was to identify available physiological and biochemical relevant characteristics for assessing the sensitivity to sodium chloride salinity of different tomato genotypes at the seedling stage. A complex analysis was carried out based on indicators such as biomass growth, water content of plant tissues, content of readily soluble salts, sodium and chlorine ions, photosynthetic pigments, carotenoids, phenolic compounds and flavonoids. Additionally, the stomata area of the upper and lower epidermis was taken into account. The comprehensive assessment carried out made it possible to reliably divide the eight studied tomato varieties into two groups: sensitive (Belyij Naliv, Geya, YaLF, Paradigma) and tolerant (Recordsmen, Yuryevskij, Bych'e Serdce, Astrakhanskij). Tomato genotypes that can be classified as sensitive (in order of increasing sensitivity to high concentrations of NaCl (150 mM)) were Belyij Naliv > Geya > YaLF ≥ Paradigma. Tomato genotypes that can be classified as resistant to salt stress (in order of increasing tolerance to high concentrations of NaCl (150 mM)) were Recordsmen < Yuryevskij < Bych'e Serdce < Astrakhanskij. The advisability of only using complex physiological and biochemical indicators to obtain relevant assessments for salinity tolerance at the early stages of tomato plant development has been demonstrated. [ABSTRACT FROM AUTHOR]

Salinity, as an important abiotic parameter, has a negative influence on crop productivity. The application of plant growth-promoting rhizobacteria and iron-silicon nanoparticles has been found to enhance plant growth and grain yield while also increasing its resistance to abiotic stresses. In this regard, a factorial experiment was carried out based on randomized complete block design with three repetitions under greenhouse conditions in 2021. Experimental factors included salinity in three levels (no salinity as control, salinity 35 and 70 mM) by NaCl, four plant growth-promoting rhizobacteria levels (no application as control, application of Azospirilum, Pseudomonas, both application of Azospirilum and Pseudomonas), and nanoparticles foliar application in four levels (foliar application with water as control, nano Fe, nano Si, foliar application of iron-silicon nanoparticles). The findings demonstrated that under salinity 70 mM, chlorophyll index (27.71%), quantum yield (23.8%), relative water content (43.69%) and grain yield (12.83%) increased in the dual application of plant growth-promoting rhizobacteria and nanoparticles foliar application compared to control level (no application of plant growth-promoting rhizobacteria and nanoparticles) in the same salinity level. However, under such conditions, electrolyte leakage, hydrogen peroxide and malondialdehyde content decreased by 38.93%, 35.34% and 35.13%, respectively, in comparison to the lack of plant growth-promoting rhizobacteria and nanoparticles applications under salinity 70 mM. Also, the usage of plant growth-promoting rhizobacteria and nanoparticles under 70 mM salinity increased the activity of catalase and peroxidase enzymes (42.1% and 73.14%, respectively), as well as proline and soluble sugar content (55.41% and 64.08%, respectively) in comparison to lack of plant growth-promoting rhizobacteria and nanoparticles applications under non-salinity conditions. According to the results of the current study, the application of plant growth-promoting rhizobacteria and nanoparticles could increase the grain yield of triticale under the highest salinity level due to improving physiological and biochemical traits. [ABSTRACT FROM AUTHOR]

A crop pretreatment with silicon was combined with passive modified atmosphere packaging (PMAP) in a thermoformed recycled PET packaging format as a novel approach to minimize the quality degradation in mushrooms. This study was aimed to evaluate the effects of (a) two preharvest treatments, namely preharvest control (PHTC) and preharvest silicon treatment (PHTS) and (b) four packaging lid formats, namely PMAP1: a single hole of 1.1 mm size, PMAP2: two holes of 0.53 mm size, PMAP3: three holes of 0.53 mm size, and PMAPC: OMNI-PW micro perforated cling film as a control on the quality and shelf life of mushrooms during five days of storage at 4 °C and 99.9% RH. The results of the analysis of variance showed that packaging type, storage days, and the double interaction effects of storage days × packaging type had significant effects (p < 0.0001) on the changes in O2, CO2, colour L* and a* values, ΔE, total soluble solids (TSS), and the density of mushrooms. Density, electrolyte leakage (EL), and TSS were significantly affected by the double interaction effects of preharvest treatment × packaging type. Overall, PMAP1, PMAP2, and PMAP3 resulted in lower O2 + higher CO2 within packages compared with the conventional control. A preharvest silicon treatment had little overall effect. PMAP 1, 2 and 3 had a significantly lower ΔE (=better quality) after 5 days storage compared to PMAPC which had the highest ΔE (lowest quality) overall. PMAP1 and PMAP2 had the lowest EL values compared to PMAP3 and PMAPC. PMAP1, PMAP2, and PMAP3 all gave better TSS levels and density compared to PMAPC. Notably, this study proved that a perforation-mediated MAP design for mushrooms packaged in a thermoformed recycled PET packaging format maintained improved CO2, lowered O2, and reduced EL while maintaining TSS and the density of the mushrooms during the storage period. [ABSTRACT FROM AUTHOR]

The effect of plant growth regulators and Methylobacterium oryzae CBMB20 treatment on the growth and stress responses of red pepper was evaluated under in vitro and green house conditions. The highest increase (50%) in wet weight of 1279.2 mg explant− 1 and dry weight of 37.9 mg explant− 1 was observed with the combination of 6-Benzylaminopurine (BAP) and Indole-3-butyric acid (IBA) treatment. Among the different combinations tested, BAP + 2,4-Dichlorophenoxyacetic acid (2,4-D) treatment showed the highest number of shoots per explant, shoot length, and rooting response. The combination of CBMB20 (M. oryzae CBMB20) and IBA recorded the highest rooting response in red pepper plants. Colonization in xylem vessels by CBMB20 in red pepper plants can be observed based on the electron microscopic photographs. CBMB20-treated red pepper plants recorded less Malondialdehyde (MDA) content (30–43%), less proline content (52 − 43%), and less electrolyte leakage (38–72%), when compared to plants devoid of CBMB20 treatment. CBMB20 inoculated plants recorded less ethylene emission of 27–57%, 1-aminocyclopropane-1-carboxylic acid (ACC) content of 43–47%, and 1-Aminocyclopropane-1-carboxylic acid oxidase (ACO) activity of 23–25% were recorded in micropropagated plants inoculated with CBMB20 compared to the plants without inoculation. CBMB20-treated red pepper plants recorded a higher survivability of 11–18%, when compared to plants without CBMB20 inoculation. CBMB20 treated micropropagated-red-pepper plants showed a 28–30% increase in plant dry weight compared to micropropagated plants with CBMB20 inoculation. [ABSTRACT FROM AUTHOR]

High temperature stress influences plant growth, seed yield, and fatty acid contents by causing oxidative damage. This study investigated the potential of thiourea (TU) to mitigate oxidative stress and restoring seed oil content and quality in canola. The study thoroughly examined three main factors: (i) growth conditions—control and high temperature stress (35 °C); (ii) TU supplementation (1000 mg/L)—including variations like having no TU, water application at the seedling stage, TU application at seedling stage (BBCH Scale-39), water spray at anthesis stage, and TU application at anthesis stage (BBCH Scale-60); (iii) and two canola genotypes, 45S42 and Hiola-401, were studied separately. High temperature stress reduced growth and tissue water content, as plant height and relative water contents were decreased by 26 and 36% in 45S42 and 27 and 42% Hiola-401, respectively, resulting in a substantial decrease in seed yield per plant by 36 and 38% in 45S42 and Hiola-401. Seed oil content and quality parameters were also negatively affected by high temperature stress as seed oil content was reduced by 32 and 35% in 45S42 and Hiola-401. High-temperature stress increased the plant stress indicators like malondialdehyde, H2O2 content, and electrolyte leakage; these indicators were increased in both canola genotypes as compared to control. Interestingly, TU supplementation restored plant performance, enhancing height, relative water content, foliar chlorophyll (SPAD value), and seed yield per plant by 21, 15, 30, and 28% in 45S42; 19, 13, 26, and 21% in Hiola-401, respectively, under high temperature stress as compared to control. In addition, seed quality, seed oil content, linoleic acid, and linolenic acid were improved by 16, 14, and 22% in 45S42, and 16, 11, and 23% in Hiola-401, as compared to control. The most significant improvements in canola seed yield per plant were observed when TU was applied at the anthesis stage. Additionally, the research highlighted that canola genotype 45S42 responded better to TU applications and exhibited greater resilience against high temperature stress compared to genotype Hiola-401. This interesting study revealed that TU supplementation, particularly at the anthesis stage, improved high temperature stress tolerance, seed oil content, and fatty acid profile in two canola genotypes. [ABSTRACT FROM AUTHOR]

In transportation and operation, lithium-ion batteries can be exposed to environments where the temperature exceeds 75 °C, compromising seal integrity and leading to electrolyte leakage and safety issues. Standards introduced by regulatory bodies require temperature testing, including temperature cycling tests. This study examines cylindrical battery electrolyte leakage due to temperature cycling between 25 °C and 80 °C through capacity tests, electrochemical impedance spectroscopy, computed tomography scans, and thermal analysis. Different thermal expansions among battery cap elements were identified as the cause of leakage. The thermal test parameters and requirements in the UN Manual of Tests and Criteria Section 38.3 were reviewed, revealing the 72 °C upper-temperature limit and the 24 h storage period after temperature cycling fail to effectively qualify lithium-ion batteries for real-world applications. [ABSTRACT FROM AUTHOR]

Introduction and Objective: Salinity stress is one of the most important limitations of rice cultivation worldwide. On the other hand, the use of physical and chemical mutagens can be very important not only to the development and combination of new genes or alleles with agricultural importance but also to introduce genotypes more adaptable and stable to adverse weather and soil conditions. For this reason, with the development and progress of rice varieties that are tolerant and adapted to salinity, it is possible to increase the sustainable production of this stable food. Therefore, the present study was conducted with the aim of investigating the response of the tenth generation (M10) of rice mutants to salinity stress in the reproductive stage using agronomic and biochemical characteristics. Material and Methods: In this research, 13 mutant lines of Seng-e-Tarem, Hashemi and Khazar cultivars using gamma ray irradiation from Cobalt 60 which have been previously identified as tolerant lines in molecular studies were used along with the tolerant cultivars of Nonabukra and Deylamani and sensitive cultivars of IR29 and Sepidrood. The genotypes were exposed to three levels of salinity (0, 4 and 8 dS/m) from the source of sodium chloride. A factorial experiment based a randomized complete block design (RCBD) and a factorial split based a RCBD with three replicates were used to evaluate agronomic traits along with yield and biochemical traits, respectively. The measured parameters were tillers number (TN), the number of filled (NFG) and unfilled grains (NUG), 1000 grains weight (TGW), plant height (PH), Days to 50% of flowering (DTF) and the paddy yield (PY), and for the biochemical traits, the activity of catalase (CAT) and superoxide dismutase (SOD), protein (PN), proline (PR) and malondialdehyde (MDA) contents and electrolyte leakage (EL) percentage. Results: The results of the variance analysis showed that the effect of salinity and genotype and their interactions were significant for all the measured traits. A wide range of genetic diversity was observed among the genotypes for the agronomic and biochemical traits. Among the traits, PY was identified as the best and the most indicative trait to classify the tolerant genotype under salt stress conditions. Among the investigated mutants at different levels of salinity, the highest PY was recorded in MP6, MP10 and Deylamani genotypes, respectively. PY value in MP10 mutant at the salinity level of 8 dS/m was closed to Deylamani variety (tolerant check). With the increase of salinity from zero to 8 dS/m, the measured traits adversely affected. The cluster analysis diagram of studied genotypes based on agronomic traits and PY at a salinity level of 4 dS/m classified the genotypes into three separate groups. The genotypes MP2, MP3, MP4, MP9, and MP10 were grouped in the second group, in which Deylamani cultivar was also present as a tolerant check. The cluster analysis diagram of agronomic traits and PY at the salinity stress level of 8 dS/m divided the genotypes into four different groups. In the third group, two genotypes of MP9 and MP10 were included with Tarem Deylamani variety (tolerant check). The correlation coefficient between agronomic traits in 8 dS/m of salt conditions showed that PY had a positive and significant correlation with PH (r=0.51), the NFG (r=0.88) and TGW (r=0.63). Also, there is a negative correlation between DTF with PH (r=-0.70) and NFG (r=-0.62) and a positive and significant correlation with TN (r=0.60). Biplot analysis divided the studied lines into four groups based on agronomic traits at a salinity level of 4 dS/m. The first group includes six mutant lines as very sensitive group, the second group includes two mutant lines as sensitive group, the third group with three genotypes including lines MP9, MP10 and Tarem Deylamani variety (tolerant check) as tolerant group and the fourth group with six genotypes included lines MP11, MP12, MP13 and Nonabukra variety (international tolerant check) as well as Sepidrood and IR29 varieties as high salt tolerant group. Also, biplot analysis based on agronomic traits at a salinity level of 8 dS/m divided the studied lines into four groups. The first group consisted three mutant lines as very sensitive group, the second group included six lines as sensitive group, the third group involved five genotypes including MP11 and MP13 lines and Nonabukra varieties (tolerant check), Sepidrood and IR29 as the tolerant group and the fourth group with three genotypes included MP9 and MP10 lines and Tarem Deylamani variety (native tolerant check) as high salt tolerant group. For biochemical traits at 8 dS/m of salt stress, the highest amount of SOD was recorded in Deylamani cultivar (tolerant check), PN for MP2 mutant, PR for MP3 mutant, and the lowest amount of EL and MDA was recorded for MP2 and MP10 mutants, respectively. Conclusion: In general, PY of MP10 mutant line in salt stress conditions was closed to Deylamani as a native salt tolerant cultivar, therefore could be introduced as a superior line for further research in saline conditions. [ABSTRACT FROM AUTHOR]

Due to increased consumption, artificial sweeteners are often present in the environment but their effects on plants are largly unknown. In this research, the effects of four artificial sweeteners on plant stress markers in Triticum aestivum L. were investigated. Wheat seedlings were grown from seeds in soil containing artificial sweeteners (saccharin, sodium cyclamate, sucralose, aspartame) in different concentrations (0, 25, 50, 100 mg kg-1). Plants were irrigated at regular intervals to maintain field capacity moisture and harvested after 15 days of growth. Electrolyte leakage, chlorophyll and carotenoid content, and antioxidant enzyme (superoxide dismutase, peroxidase, catalase) activities were determined in harvested leaves. Comparisons between control samples and test samples were statistically evaluated at a 95% confidence interval to determine significant differences. Overall, significant increases in chlorophyll and carotenoid content, and some antioxidant enzyme activities were observed in wheat plants exposed to artificial sweeteners in the soil. A significant increase in electrolyte leakage was observed with saccharin and aspartame treatment, indicating that these sweeteners can cause membrane damage in wheat. Chlorophyll a and POX activity were the most sensitive stress parameters in wheat. This study showed the importance of evaluating the potential impact of anthropogenic pollutants that may be present in treated wastewater and consequently affect plants. [ABSTRACT FROM AUTHOR]

Globally, urban areas are facing a rising issue of industrial pollution particularly due to heavy metals like Cadmium (Cd), which pose a threat to both plants and humans. However, plants response to Cd exposure varies based on factors like species, genetics, and growing conditions such as the type of soil and cultivation methods. This study focused on young tomato seedlings subjected to different Cd concentrations (0, 100, 200, and 300 ppm) through a pot experiment, aiming to understand the impact of Cd on various morpho-physiological traits of the "MAYAR F1" tomato cultivar. The results exhibited amazing findings that the chlorophyll contents (21.93 nmol/mg), relative water contents (0.84%), electrolyte leakage (135.5 uS/cm) and leaf area (6.37 cm2) were highest at 300 ppm followed by control. While the maximum number of leaves (11) were noticed in control. Consequently, the study suggests that cultivating tomatoes in urban agriculture soils contaminated with Cd could be a viable option. Nonetheless, it emphasizes the importance of exercising caution and conducting further research to fully comprehend the potential long-term implications and associated risks of Cd exposure in urban agriculture. [ABSTRACT FROM AUTHOR]

The accumulation of cadmium (Cd) in plants poses a major risk to consumer health, in addition to affecting plant growth, development and quality. The study aimed to examine the effects of cadmium on the plants' ability for photosynthesis and antioxidant enzyme activity. In this study, radishes were planted in Petri dishes and pots containing soil supplemented with different concentrations of cadmium sulphate (25, 50, and 100 mg Cd kg-1 soil). The results showed that the percentage of germination, seedlings length, and fresh and dry matter significantly declined its increasing cadmium concentrations. In addition, cadmium hindered plant growth, as evidenced by the fresh and dried weight of radish roots and leaves after a 100 mg Cd kg-1 soil treatment. There was also a notable decrease in chlorophyll a and chlorophyll b, total chlorophyll, and total leaf area per plant. The leaves of radish plant exhibited a significant increase in lipid peroxidation and electrolyte leakage contents under Cd stress, while, the relative water content (RWC) decreased. However, leaves and roots of radish plant showed a considerable increase in antioxidant enzymes (catalase; CAT, peroxidase; POD, and superoxide dismutase; SOD). Furthermore, radish showed a significant increase in Cd accumulation in all applications, however, there were no obvious symptoms of Cd toxicity following the 25 and 50 mg Cd kg-1 soil applications. In conclusion, the radish plants accumulated cadmium at higher concentrations (100 mg Cd kg-1 soil). So, we recommended cultivating the radish plants in soil that has low concentrations of cadmium.

Abstract Premise With growing interest in the impact of false springs on plant reproduction, there is the need to develop reliable, high‐throughput methods for assessing floral freezing damage. Here we present a method for use with floral tissue that will facilitate more comparative work on floral freezing tolerance in the future. Methods and Results We examined the effectiveness of a modified electrolyte leakage protocol to assess floral freezing damage. By comparing data from temperature response curves to an estimate of visual tissue damage, we optimized the protocol for different floral types and improved the signal‐to‐noise ratio for floral data. Conclusions Our modified protocol provides a quick and straightforward method for quantifying floral freezing damage that can be standardized across floral types. This method allows for cross‐species comparisons and can be a powerful tool for studying broad patterns in floral freezing tolerance.

IntroductionGrasses are narrow-leaved plants that are used as cover plants in landscape. These plants are one of the basic and necessary components of the green cover of most gardens, parks and as the background color of landscape. In Iran, due to the high costs of planting and management of grass, high water requirements, climatic incompatibility and damage to water and soil salinity, it is recommended to remove from the green space in some cities, especially in areas with low water and water and soil saline. If it is possible to benefit from the role and influence of these plants by observing the technical points and choosing the best species for each area. Salinity stress is the second limiting factor for the growth of plants in the world after drought, which affects the efficiency and performance of plants. Increase in salinity causes a decrease in the water potential in the soil. In this condition, the plant spends most of its energy to maintain the water potential, cell mass, and water absorption to have minimal growth. The aim of this research is the effect of external application of glycine betaine on the accumulation of osmolality compounds and the antioxidant system of sports grass under salt stress. Materials and MethodsThis research was done in factorial form in completely randomized design with 3 replications on Rashid variety cucumber. The factors included 4 levels of temperature (25, 30, 35 and 40 degrees Celsius) and 3 levels of salicylic acid (0, 0.5 and 1 mM). When the seedlings reached the two-leaf stage, they were sprayed with different concentrations of salicylic acid two times with an interval of five days. One week after the application of salicylic acid, temperature treatment was gradually applied. After applying each heat treatment, the corresponding pots were transferred to the greenhouse with a temperature of 25 degrees Celsius. Then, fresh and dry weight of root and shoot, leaf surface, chlorophyll index, electrolyte leakage, proline, polyphenol oxidase enzyme activity and superoxide dismutase enzyme activity were measured. Results and Discussion The results showed that salinity stress decreased all the study morphological, physiological and biochemical parameters including plant height, shoot fresh and dry weight, number of tiller, leaf area, chlorophyll content, protein and total antioxidant capacity in the studied plants. It also increased peroxidase enzyme, H2O2 and proline in plants, but glycine betaine application significantly improved the morpho-physiological characteristics of plants compared to the control under salt stress conditions. Thus, the highest height, shoot fresh and dry weight, leaf area, number of tiller, chlorophyll content, and protein and antioxidant capacity were observed in plants sprayed with glycine betaine. Also, the highest content of glycine betaine and activity of catalase and peroxidase enzymes and the lowest content of glycine betaine and H2O2 were observed in in plants sprayed with glycine betaine and 10 mM glycine betaine was more effective than 5 mM. The occurrence of salinity in plants disrupts the absorption of ions and causes the reduction of nutrients and increases sodium ions. One of the effects of salinity in plants is the reduction of photosynthetic activity, which results in the reduction of chlorophyll, carbon dioxide absorption, photosynthetic capacity, plant height, shoot fresh and dry weight, number of tiller and leaf area. One of the most strategies to deal with stress is accumulation of osmolyte and increasing the antioxidant activity, which makes plants resistant to environmental stresses. Salinity, through the toxic effect of Na+ and Cl- ions, affects the growth and performance of the plant by reducing the soil water potential, disrupting water absorption and imbalance of nutrients in the plant. The results obtained from comparing the average results of glycine betaine show that glycine betaine increased plant height, shoot fresh and dry weight, number of tiller, leaf area, chlorophyll content, total protein and antioxidant capacity, but on the other hand, it increased proline and H2O2 decreased, which is due to the accumulation of glycine betaine as a protector in plants under salt stress conditions. In stress conditions, glycine betaine can protect photosynthetic activities including photosynthetic enzymes, proteins and lipids in thylakoid membranes in the combination of photosystem II, and also the task of protecting cell membranes against osmotic stresses in the plant. ConclusionThe results obtained from this research showed that salinity stress reduced all the morphological, physiological and biochemical characteristics in the sport grass plants, but glycine betaine application played a positive role in reducing salinity damage and maintaining plant quality. Glycine betaine is known as one of the effective molecules in stress signaling, so it can protect the plant cells against stress by reducing the destruction of the membrane and by increasing the salt tolerance mechanisms. Also, glycine betaine 10 mM is introduced as the best treatment to reduce salinity damage in sport grass during present study.

An understudied problem in plant heavy metal biology is the effects of acute versus gradual or chronic metal exposure. The aim of the present study was to compare the growth and physiological responses of Rumex hydrolapathum Huds. plants subjected to gradual or acute Mn stress treatment in controlled conditions. Heavy metal was applied to substrate either as one 1.00 g L−1 Mn dose (acute treatment) or the same dose in four steps of increasing amounts within 12 days (gradual treatment). Peroxidase activity in actively photosynthesizing leaves was used for monitoring induced biochemical changes resulting from Mn treatment. The number of leaves per plant significantly increased in the case of gradual treatment with Mn, but this effect was not statistically significant for acute treatment. Leaf fresh mass significantly decreased in both cases due to the decrease in leaf water content, but dry biomass of leaves was not affected, with no significant differences between the two types of treatments. A significantly lower chlorophyll fluorescence parameter Performance Index in large leaves of plants under the acute Mn treatment than in plants under the gradual treatment was evident. An increase in leaf peroxidase activity by Mn treatment was proportional to the metal dose received, but plants in the acute treatment with 1.00 g L−1 Mn had a significantly lower peroxidase response in comparison to the gradual treatment with 1.00 g L−1 Mn. In conclusion, under gradual treatment, biochemical changes related to the induction of tolerance to the heavy metal are expressed, as indicated by the continuous increase in leaf peroxidase activity after each treatment step.

IntroductionSalinity stress is one of the most vital abiotic stresses which limits the production of crops. In recent decades, the area under chickpea cultivation in Iran has tripled, but unfortunately, its yield has decreased from 610 to 500 Kg per hectare. The main reason for this reduction is the allocation of marginal lands under rain-fed conditions to chickpea cultivation. However, environmental stresses are the most critical factors of yield loss that can decrease chickpeas production significantly. The growth of chickpea is susceptible to salinity, and salinity stress affects their yield by affecting plant growth and symbiotic bacteria. Considering the current extent of salt-affected lands in Iran and in order to maintain and increase the area under chickpea cultivation, it is necessary to select the salt-tolerant genotypes. Therefore, this study was carried out to determining the salinity tolerance threshold of Kabuli -type chickpea genotypes. Materials and MethodsThe experiment was a split-plot randomized complete block design (RCBD) with three replicates at the research greenhouse of the faculty of agriculture of Ferdowsi University of Mashhad, Iran, in 2020. Chickpea germplasm, including 70 Kabuli type chickpea genotypes, were provided from the Mashhad chickpea collection at the Research Center for Plant Science, Ferdowsi University of Mashhad. Two weeks after seed planting, the salinity treatments included 12 and 16 dS.m-1 sodium chloride and 0.5 dS.m-1 (tap water) as control was applied. The recirculating nutrient system was applied, the nutrient solution was replaced weekly, and the salinity of nutrient solution was adjusted daily, but no acidity adjustments were made in the Hoagland solution. The plant height was measured before and after four weeks of applying salinity stress, and then the difference in plant height was calculated. Four weeks after salinity application, survival percentage, leaves survival, plant height, leaf electrolyte leakage, osmotic potential, shoot dry weight, and Na to K ratio were measured. Salinity tolerance indexes, including stress tolerance (TOL), mean productivity (MP), stress susceptibility index (SSI), geometric mean productivity (GMP), and stress tolerance index (STI), were calculated based on the shoot dry weight and separately for 12 and 16 dS.m-1 compared to the control treatment. Data were analyzed using Minitab 16 software, and the mean comparison was performed by Duncan Multiple Range Test (DMRT) at a 5% probability level. Interrelationship among different traits was calculated using Pearson's correlation analysis. STATISTICA 8.0 and SPSS 27 soft wares also performed a cluster analysis (based on Euclidean distance) and principal component analysis (PCA). Results and DiscussionThe results showed that for the salinity levels of 12 and 16 dS.m-1, 65 and 28 genotypes had a survival between 76 -100%, respectively. With the decrease in the survival percentage in 16 dS.m-1, the average percentage of leaf survival also decreased. With increased salinity levels from 12 to 16 dS.m-1, electrolyte leakage in the survival range of 76 -100, 51 -75, and 26 -50% increased by 8, 25, and 12%, respectively. With increased salinity levels from 12 to 16 dS.m-1, in survival ranges of 0 -25, 26 -50, 51 -75, and 76 -100%, shoot dry weight decreased by 15, 11, 36, and 14%. With increased salinity levels from 12 to 16 dS.m-1, the shoot Na to K ratio in the survival range of 26-50% did not change, and in the survival range of 0 -25, 51 -75 and 76 -100%, it increased two and nine times and 22% respectively. The highest average shoot Na to K ratio was also observed within the survival range of 0 -25%. In 12 and 16 dS.m-1, two genotypes, MCC1467 and MCC1394, were superior to other genotypes in most studied traits. The genotypes of the third cluster had a higher relative advantage for salinity tolerance. ConclusionsIn general, the results showed the diversity between chickpea genotypes under salinity stress. In 12 and 16 dS.m-1 salinity, MCC1467 and MCC1394 were superior to other genotypes in most studied traits. In saline conditions plant survival had a positive and strong correlation with leaf survival. In the saline condition, genotypes that can maintain their normal physiological function can maintain and expand more leaf area, which ultimately leads to more biomass production. The genotypes of the third cluster had a more advantage for salinity tolerance. Due to this study being conducted in greenhouse conditions, it is recommended to check the salinity tolerance of superior genotypes in field conditions.

Abstract Background Onion seeds have limited storage capacity compared to other vegetable seeds. It is crucial to identify the mechanisms that induce tolerance to storage conditions and reduce seed deterioration. To address this goal, an experiment was conducted to evaluate changes in germination, biochemical, physiological, and molecular characteristics of onion seed landraces (Horand, Kazerun landraces and Zargan cultivar) at different aging levels (control, three-days and six-days accelerated aging, and natural aging for one year). Results The findings suggest that there was an increase in glucose, fructose, total sugar, and electrolyte leakage in the Horand (HOR), Kazerun (KAZ) landraces, and Zarghan (ZAR) cultivar, with Kazerun exhibiting the greatest increase. The percentage and rate of germination of Kazerun decreased by 54% and 33%, respectively, in six-day accelerated aging compared to the control, while it decreased by 12% and 14%, respectively, in Horand. Protein content decreased with increasing levels of aging, with a decrease of 26% in Kazerun landrace at six days of aging, while it was 16% in Horand landrace. The antioxidant activities of catalase, superoxide dismutase, and glutathione peroxidase decreased more intensively in Kazerun. The expression of AMY1, BMY1, CTR1, and NPR1 genes were lower in Kazerun landraces than in Horand and Zargan at different aging levels. Conclusions The AMY1, BMY1, CTR1, and NPR1 genes play a pivotal role in onion seed germination, and their downregulation under stressful conditions has been shown to decrease germination rates. In addition, the activity of CAT, SOD, and GPx enzymes decreased by seed aging, and the amount of glucose, fructose, total sugar and electrolyte leakage increased, which ultimately led to seed deterioration. Based on the results of this experiment, it is recommended to conduct further studies into the molecular aspects involved in onion seed deterioration. More research on the genes related to this process is suggested, as well as investigating the impact of different priming treatments on the genes expression involved in the onion seed aging process.

Water stress in agricultural systems may occur slowly or abruptly. Plant reactions to stress differ with regard to its level and duration. The level of plant susceptibility to water deprivation primarily depends on the management of the water content and metabolism adjustments. The aim of this study was to determine the correlation between water-based plant parameters and the yield components of 90 genotypes of winter wheat (Triticum aestivum L.). Since the loss of water is frequently used as a selection criterion to assess drought tolerance, the relationships between the yield and leaf water content, osmotic potential, and gas exchange characteristics were examined. Genotypes 1, 25, 34, 36, 42, 43, 46, 57, 66, 73, and 90 showed 33–45% larger numbers of grains/plant, 19–25% higher weights of grains/plant, and 4% higher thousand grain weights compared to other genotypes. The higher values of the yield components were accompanied by 20–30% lower leaf water content, 39–52% lower osmotic potential, and 4–39% lower water use efficiency. The principal component analysis revealed that the wheat genotypes had noticeable differences in a few physiological parameters that depended on the sowing date. Electrolyte leakage showed a substantial correlation with the sowing date, suggesting that it may not be a suitable factor for the prediction of drought tolerance. The factors that distinguished the examined genotypes the most were the leaf water content, osmotic potential, and water use efficiency. In addition, a significant correlation was observed between the mentioned parameters and yield components. As a result, these parameters may be helpful in genotype characterization in relation to water stress susceptibility, offering a trustworthy plant selection test.

Reducing fertilizer input is a goal for helping greenhouse farming to achieve higher sustainability in the production process while preserving overall crop performance and quality. Wild rocket plants were cultivated in a plastic greenhouse divided into two independent sectors, one for soil-bound (SbS) cultivation and another equipped for soilless (ScS) cultivation systems. In both SbS and ScS, the crop was subjected to treatments consisting of a high- and a low-input fertilization program (HF and LF treatment, respectively). Water use efficiency (WUE) and partial factor productivity (PFP) for nutrients (N, P, K, Ca, and Mg for ScS, and N for SbS) were measured. Rocket leaves, separated for the cultivation system and fertilization program and collected at different cuts during the growing cycle, were cold stored at 10 °C until 16 d. On each sampling day (at harvest and during storage), the sensory parameters, respiration rate, dry matter, color, electrolyte leakage, antioxidant activity, total phenols, total chlorophyll and ammonia content were evaluated. In ScS, the PFP for all nutrients supplied as fertilizers showed a significant increase with the LF treatment, with values higher than 30% recorded for N, K, and Ca. As for the postharvest performance, rocket leaves cultivated in ScS showed better qualitative traits than those cultivated in SbS, as suggested by the lower values of ammonia content and electrolyte leakage recorded at the end of storage period in samples grown in ScS. Moreover, in ScS, the data showed lower membrane damage in LF than HF rocket leaves. Finally, regarding total chlorophyll content, even if no effect of each treatment was recorded in SbS, rocket cultivated in ScS showed a better retention of this parameter by applying LF rather than HF treatment. In addition to this, a PLS model (R2 = 0.7) able to predict the cultivation system, using as a variable non-destructively measured total chlorophyll content, was implemented. Low fertilization input, both in SbS and in ScS, allowed satisfying production levels and more sustainable management of nutrients. LF treatment applied to ScS also had in positive effects on the postharvest quality of fresh-cut rocket leaves. [ABSTRACT FROM AUTHOR]

Climate change is affecting the production of temperate fruit crops. Freeze damage, particularly in spring, has resulted in significant economic losses in peach production in the southeastern United States. Research efforts in peach and other Prunus species have primarily focused on dormancy-related traits associated with bloom time, such as chill and heat requirement, with fruitlet freeze tolerance not equally represented. This study reports fruitlet freeze tolerance in 75 peach and nectarine accessions at six freezing temperatures (0 to −10 °C) using electrolyte leakage method over two seasons (2022–2023). Fruitlet freeze tolerance ranged from −3.9 to −10.2 °C with an estimated freeze damage ranging from 16–48% of fruitlet tissue with the majority of the accessions showing tolerance to cold temperatures in the −4 to −6 °C and 25–35% range. Variability in tolerance was noted across years, including some inconsistencies between tolerance group assignments. Grouping based on the estimated damage showed better stability and some accessions changed their grouping from the extremes to an intermediate tolerance group. Interestingly, nectarine accessions were among the most tolerant in both seasons. Broad-sense heritability of 0.52 and 0.85, estimated for freeze tolerance and % tissue damage, respectively, suggested genetic control of this trait with a potential for improvement via breeding. [ABSTRACT FROM AUTHOR]

Osteospermum ecklonis DC. NORL. is native to South Africa and is fully adapted to the Mediterranean climate. The aim of the study was to elucidate morphological and developmental changes in O. ecklonis plants associated with drought resistance in response to low doses of UV-C. Growth responses under three levels of drought stress (NW: normal watering, MD: moderate drought stress and SD: severe drought) were recorded. The results showed that 1 kJ m−2 UV-C significantly (p < 0.05) increased resistance to water stress without affecting growth and development or damaging photosystem II. Fresh weights of the upper parts and the root system of the irradiated plants were maintained at similar levels to those of the non-irradiated control plants. Fv/Fm values in the irradiated plants ranged from 0.73 to 0.82 depending on the stress level, while in the non-irradiated plants, the values ranged from 0.69 to 0.83. Differences between UV-C irradiated and non-irradiated plants were recorded in electrolyte leakage (EL), in malondialdehyde (MDA) and in relative water content (RWC) at all drought levels. The EL percentage of the non-irradiated plants at SD was 19.7%, while in the irradiated plants, it was 17.8%. RWC rates in the irradiated plants ranged between 60.6 and 76.4%, while in the non-irradiated plants, they ranged from 54.2 to 63.6%. Superoxide dismutase (SOD) and catalase (CAT) activities increased with UV-C irradiation, suggesting that antioxidant responses were induced and protected cell membranes from lipid peroxidation and damage. The results of the present study showed that UV-C irradiation at 1 kJ m−2 alleviated the drought symptoms of O. ecklonis by reducing oxidative stress and membrane lipid peroxidation. [ABSTRACT FROM AUTHOR]

The growth of crop plants is greatly affected by the increased toxicity of metals. Luckily, certain beneficial bacteria can potentially reduce the effects of metal stress and promote the growth of the host plants. Many species of bacteria were reported as heavy metal tolerant and plant growth promoting, with very little or no report available concerning Enterobacter tabaci as heavy metal tolerant plant growth promoting. The present study aimed to evaluate the potential of Cadmium (Cd) tolerant Enterobacter tabaci 4M9 (CCBMBL 5004) to alleviate heavy metals stress and enhance the growth of rice seedlings grown under Cd stress conditions. Rice seedlings were grown in Yoshida medium supplemented with different concentrations of Cd and inoculated with 4M9. The results showed that the inoculum tested successfully reduced oxidative stress in the seedlings by reducing the electrolyte leakage (EL) and increasing catalase (CAT) and superoxide dismutase (SOD) activities in the inoculated seedlings compared to the control counterparts. The results also revealed a significant increase in plant growth, biomass, and chlorophyll content of inoculated rice seedlings compared to the control. In general, the Cd tolerant E. tabaci 4M9 confers heavy metal alleviation and thereby improves the growth and survival of rice seedlings under Cd stress conditions. Therefore, the findings stated the potential of 4M9 for alleviating heavy metal stress and promoting the development of inoculated rice seedlings if accidentally grown under Cd-contaminated conditions. [ABSTRACT FROM AUTHOR]

The cyclic nucleotide cyclic guanosine monophosphate (cGMP) is a powerful cell signaling molecule involved in biotic and abiotic stress perception and signal transduction. In the model plant Arabidopsis thaliana, salt and osmotic stress rapidly induce increase in cGMP which plays role by modulating the activity of monovalent cation transporters, possibly by direct binding to these proteins and by altering the expression of many abiotic stress responsive genes. In a recent study, a membrane permeable analogue of cGMP (8-bromo-cGMP) was found to have a promotive effect on soluble sugar, flavonoids and lignin content, and membrane integrity in Solanum lycopersicum seedlings under salt stress. However, it remains to be elucidated how salt stress affects the endogenous cGMP level in S. lycopersicum and if Br-cGMP-induced improvement in salt tolerance in S. lycopersicum involves altered cation fluxes. The current study was conducted to answer these questions. A rapid increase (within 30 s) in endogenous cGMP level was determined in S. lycopersicum roots after treatment with 100 mM NaCl. Addition of membrane permeable Br-cGMP in growth medium remarkably ameliorated the inhibitory effects of NaCl on seedlings' growth parameters, chlorophyll content and net photosynthesis rate. In salt stressed plants, Br-cGMP significantly decreased Na+ content by reducing its influx and increasing efflux while it improved plants K+ content by reducing its efflux and enhancing influx. Furthermore, supplementation with Br-cGMP improved plant's proline content and total antioxidant capacity, resulting in markedly decreased electrolyte leakage under salt stress. Br-cGMP increased the expression of Na+/H+ antiporter genes in roots and shoots of S. lycopersicum growing under salt stress, potentially enhancing plant's ability to sequester Na+ into the vacuole. The findings of this study provide insights into the mechanism of cGMP-induced salt stress tolerance in S. lycopersicum. [ABSTRACT FROM AUTHOR]