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Lettuce (Lactuca sativa L.) is salt-sensitive, and salinity level can negatively affect yield. The study was conducted to investigate effect of water enriched with seaweed extract to overcome effects of salinity in 'New Red Fire' leafy lettuce cultivation. The highest and lowest leaf free proline content was in plants irrigated with saline water at EC 7 and 1.37 dS m−1. Increasing water EC level from 2.5 to 4 dS m−1 resulted in 9.3% increase in leaf total soluble solid content. The highest leaf vitamin C content was in plants treated by Chlorella vulgaris seaweed solution. Salinity levels could be classified into three groups: 1.37 and 2.5 dS m−1 (least damaging), 4 and 5 dS m−1 (tolerance threshold) and 7 dS m−1 (most damaging). Chlorella vulgaris seaweed solution appeared to neutralize adverse effects of salinity on plant fresh weight, free proline content, total soluble solid content, photosynthetic pigments content, radical scavenging activity, anthocyanin content, phenol and flavonoid content, peroxidase enzyme activity and leaf vitamin C content. Irrigation 'New Red Fire' with water enriched with Chlorella vulgaris seaweed extract is strongly recommended to overcome effects of salinity on lettuce morphological and physiological characteristics. Salinity levels higher than 5 dS m−1 can seriously damage 'New Red Fire' qualitative and quantitative properties. [ABSTRACT FROM AUTHOR]

Soil application of farmyard manures and moisture-absorbing materials such as natural zeolite is considered a simple and cheap way to conserve soil moisture in arid areas and light soils. To study the effect of two soil amendments on the physiological properties of "Bidaneh Sefid" grapevines under drought stress, an experiment was conducted in factorial based on a randomized block design in the research vineyard of Malayer University, Hamadan, Iran during the 2022 and 2023 growing seasons. The treatments included two levels of irrigation cycle (7 and 21 d intervals) and four levels of soil amendments (control, 12 kg zeolite vine-1, 15 kg sheep manure vine-1, a combination of 12 kg zeolite + 15 kg sheep manure vine-1). Results showed that the drought stress led to a decrease in chlorophyll content, leaf relative water content, and leaf water potential. Drought stress also led to an increase in electrolyte leakage and the activity of antioxidant enzymes. Application of farmyard manure and zeolite moderated all the investigated indicators, due to their ability to absorb and retain water in the soil. The results of the study showed that it is possible to mitigate the adverse effects of drought stress on grapevine by retaining the moisture of light soils by the application of natural zeolite, alone or in combination with farmyard manure. [ABSTRACT FROM AUTHOR]

There is an urgent need to reduce the intensive use of chemical fungicides due to their potential damage to human health and the environment. The current study investigated whether nano-selenium (nano-Se) and nano-silica (nano-SiO2) could be used against the leaf spot disease caused by Alternaria alternata in a common bean (Phaseolus vulgaris L.). The engineered Se and SiO2 nanoparticles were compared to a traditional fungicide and a negative control with no treatment, and experiments were repeated during two successive seasons in fields and in vitro. The in vitro study showed that 100 ppm nano-Se had an efficacy rate of 85.1% on A. alternata mycelial growth, followed by the combined applications (Se + SiO2 at half doses) with an efficacy rate of 77.8%. The field study showed that nano-Se and the combined application of nano-Se and nano-SiO2 significantly decreased the disease severity of A. alternata. There were no significant differences among nano-Se, the combined application, and the fungicide treatment (positive control). As compared to the negative control (no treatment), leaf weight increased by 38.3%, the number of leaves per plant by 25.7%, chlorophyll A by 24%, chlorophyll B by 17.5%, and total dry seed yield by 30%. In addition, nano-Se significantly increased the enzymatic capacity (i.e., CAT, POX, PPO) and antioxidant activity in the leaves. Our current study is the first to report that the selected nano-minerals are real alternatives to chemical fungicides for controlling A. alternata in common beans. This work suggests the potential of nanoparticles as alternatives to fungicides. Further studies are needed to better understand the mechanisms and how different nano-materials could be used against phytopathogens. [ABSTRACT FROM AUTHOR]

Low emergence and vigor of canola seeds are common problems encountered by canola growers. Seed coating is a good way to solve this problem. The objective of this study was to find the best combination of nano-organic to be used as a coating for seeds for strengthening the absorption of water and emergence seed of low vigor canola. The treatments in the first experiment included six levels of organic coatings: 20% vermicompost with 80% bentonite, 30% vermicompost with 70% bentonite, 40% vermicompost with 60% bentonite, 40% residues of canola with 60% bentonite, 30% residues of canola with 70% bentonite, and 20% resides of canola with 80% bentonite. The results indicated that 20% residues of canola and 20% vermicompost had the highest moisture under the saturation conditions and kept moisture for a longer time. Subsequently, the factors of the second experiment included three levels of water stress (100, 75, and 50% field capacity (FC)), three levels of seed coating (control, vermicompost, and canola residues), and three levels of titanium dioxide nanoparticles (0, 0.5, and 1 mM). The results showed that nano-organic coating improved emergence percentage and seedling traits while increasing superoxide dismutase, peroxidase, and catalase activities and decreasing electrolyte leakage. The highest ratios for emergence percentage (74.67), seedling vigor index (264.58), and leaf area (418) were obtained at the highest level of nano-titanium (1 mM). The highest rates of superoxide dismutase (53.44), peroxidase (30.68), catalase (5.35), chlorophyll content (51.05), and lowest electrolyte leakage (42.39) were observed in the highest level of nano-titanium (1 mM). Based on the results, we suggest the use of rapeseed residues with nano titanium oxide for rapeseed coating. The use of nanoparticles in current seed coatings is useful for reducing stresses in the germination and emergence stages. [ABSTRACT FROM AUTHOR]

The effect of 10% CO2 pre-storage treatment for 12, 24, and 48 h alongside modified atmosphere packaging (MAP) on chilling injury was determined in this study. This study found significant interactions between chilling injuries and cell membrane damage indicators. The results show that chilling injuries can be somewhat reduced by the use of CO2 treatment for sweet peppers. It was noticed that the fruit's respiration rate increased as the treatment duration increased immediately after the treatments, while the resultant did not affect the ethylene production rate, electrolyte leakage, or malondialdehyde. Similarly, after cold storage and on the final day, no really significant differences were shown in all those parameters except for the weight loss rate, chilling injury, calyx browning, and firmness, which were at the poorest state in the control group. Of all the treatments in this study, MAP appeared to be the best treatment, and preference may be given to the 24 h treatment of pretreated fruits. Weight loss, firmness, calyx browning, and chilling injury were maintained best in MAP due to the presence of CO2 and high humidity. [ABSTRACT FROM AUTHOR]

Chromium [Cr(VI)] pollution is a major environmental risk, reducing crop yields. 5-Aminolevunic acid (5-ALA) considerably improves plant abiotic stress tolerance by inducing hydrogen peroxide (H2O2) and nitric oxide (NO) signalling. Our investigation aimed to uncover the mechanism of tomato tolerance to Cr(VI) toxicity through the foliar application of 5-ALA for three days, fifteen days before Cr treatment. Chromium alone decreased plant biomass and photosynthetic pigments, but increased oxidative stress markers, i.e., H2O2 and lipid peroxidation (as MDA equivalent). Electrolyte leakage (EL), NO, nitrate reductase (NR), phytochelatins (PCs), glutathione (GSH), and enzymatic and non-enzymatic antioxidants were also increased. Foliar application of 5-ALA before Cr treatment improved plant growth and photosynthetic pigments, diminished H2O2, MDA content, and EL, and resulted in additional enhancements of enzymatic and non-enzymatic antioxidants, NR activity, and NO synthesis. In Cr-treated tomato seedlings, 5-ALA enhanced GSH and PCs, which modulated Cr sequestration to make it nontoxic. 5-ALA-induced Cr tolerance was further enhanced by sodium nitroprusside (SNP), a NO donor. When sodium tungstate (ST), a NR inhibitor, was supplied together with 5-ALA to Cr-treated plants, it eliminated the beneficial effects of 5-ALA by decreasing NR activity and NO synthesis, while the addition of SNP inverted the adverse effects of ST. We conclude that the mechanism by which 5-ALA induced Cr tolerance in tomato seedlings is mediated by NR-generated NO. Thus, NR and NO are twin players, reducing Cr toxicity in tomato plants via antioxidant signalling cascades. [ABSTRACT FROM AUTHOR]

Gypsophila paniculata L. is one of the most important commercial cut flowers worldwide. The plant is sterile and propagated mainly by in vitro culture techniques. However, hyperhydricity hinders its micropropagation and increases mortality during ex vitro acclimatization. Hyperhydric shoots of G. paniculata were proliferated from nodal explants on MS medium without growth regulators that contained 30 g L−1 sucrose, and gelled with 6.0 g L−1 agar. Medium components and environmental culture conditions were optimized to revert hyperhydricity in G. paniculata microshoots and develop an efficient micropropagation protocol for commercial production. Multiple shoots with high quality were successfully regenerated on MS medium fortified with potassium and ammonium nitrate at full concentration, 2.0 mg L−1 paclobutrazol, solidified with 9.0 g L−1agar in Magenta boxes of 62.87 gas exchange/day and incubated under light density of 60 µmol m−2s−1. We recorded 4.33 shoots, 40.00 leaves, 6.33 cm, 2.50 g and 95.00% for number of shoots/explant, number of leaves/shoot, shoot length, shoot fresh weight and normal shoots percentage, respectively. Well-rooted plantlets of G. paniculata were developed from the reverted microshoots, with the rooting percentage (95.00%) on MS medium augmented with 1.0 mg L−1 IBA in Magenta boxes of 62.87 gas exchange/day and 60 µmol m−2s−1 light density. In vitro-rooted plantlets exhibited reduced electrolyte leakage, and enhanced antioxidant enzymes activity of peroxidase, catalase, and polyphenol oxidase due to good ventilation at the highest gas exchange rate of the culture vessels. [ABSTRACT FROM AUTHOR]

Sugarcane (Saccharum spp.) growth and yield decrease in acidic soil (low pH and high Al content) conditions owing to impaired nutrient and water absorption. An efficient method to evaluate acid tolerance needs to be developed to utilize Erianthus arundinaceus to improve acid tolerance in sugarcane. Herein, we performed a root electrolyte leakage assay to quantitatively evaluate and compare the acid tolerance of the roots of sugarcane cultivar NiF8 and E. arundinaceus accession JW630 under various treatments of acid solutions in laboratory. Additionally, cellular damage of root was observed anatomically and their growth in acidic soil was verified by pot cultivation. To detect the interspecific difference in injury index of root by measuring electrolyte leakage, the following method was found suitable: initial washing for 15 min, acid stress treatment with 3% Al2(SO4)3 solution for 2 h, and leaking electrolyte from the damaged cells in ultrapure water for 2-4 h. The index was aligned with the relative growth rate (RGR) under acidic soil (pH 5.0), as E. arundinaceus with a lower index value exhibited a higher RGR. Callose, indicative of cellular damage, was deposited both after exposure to short-term and long-term acid stress in the exodermis of sugarcane, which showed higher injury index and lower RGR than those of E. arundinaceus, whereas callose deposition was not observed in E. arundinaceus even after acid stress treatments. Our results strongly suggest that the injury index measurements can be used to quantitatively evaluate differences in acid tolerance between sugarcane and Erianthus roots. [ABSTRACT FROM AUTHOR]

Anthropogenic pollution of the environment by fluoride (F) can lead to abnormality symptoms in some species of plants even at relatively low impact levels. Currently, an active accumulation of data on the effect of F on plant functions take place. The purpose of the present work was complex investigation of influence of different F concentrations in soil on growth, morphological and biochemical parameters and elemental composition of the wheat plants (Triticum aestivum L.). Seed germination, survivorship rate, external appearance, length and thickness of leaf blade, chlorophyll, electrolyte leakage, catalase and acid phosphatase activity and elemental composition (As, Ba, Ca, Cd, Co, Cr, F, Fe, K, Mg, Na, Ni, Pb, Se, Sr, Ti, V, Y, Zn and rare-earth elements) were studied at different levels of F in soil in range of 100 - 7600 mg/kg. Methods of spectrophotometry, conductometry, inductively coupled plasma mass-spectrometry and atomic absorption spectrometry were used. The most sensitive biochemical markers for estimation of the plant F stress were found to be electrolyte leakage and acid phosphatase activity. Noticeable change of these parameters started at F soil concentration of 600 and 1100 mg/kg respectively. Concentration of Mg, Ca and Sr in the plants was established to decrease at increasing F in soil. Distribution of concentration Al, As, Ba, Co, Cr, Fe, K, Ni, Pb, Sb, Th, Ti, V, Y, and light rare-earth elements was described by curve with maxima at 1100 mg/kg; maximum concentration of Fe, K, and Ni was observed at 2100 mg/kg of F in soil. Possible 3-stage's scheme for the development F stress in wheat plant was suggested. Both the decrease of the F bioaccumulation factor, electrolyte leakage, acid phosphatase activity and the increase of the content of molybdenum that is a component of plant enzymes catalyzing key stages of nitrogen, carbon, and sulfur metabolism at high F soil levels could be parts of adaptation mechanism of the wheat plants (Triticum aestivum L.) to F stress. [ABSTRACT FROM AUTHOR]

Early detection of electrolyte leakage is crucial to prevent thermal runaway in lithium-ion batteries (LIBs). Gas sensors offer a potential solution, however, designing sensing materials that can sensitively identify organic molecules from electrolyte leakage remains a great challenge. Herein, the heterostructured NiO/Si-NiWO 4 /WO 3 nanofibers (NFs) were achieved as a sensing material for highly sensitive detection of 1, 2-dimethoxyethane (DME), a typical electrolyte organic molecule. This was accomplished using the highly negatively charged lacunary polyoxometalates (POMs) TBA 4 H 6 [SiW 9 O 34 ]·2 H 2 O (α-SiW 9) and Ni2+ as precursors, resulting in a series of uniform Si-NiWO 4 /WO 3 decorated NiO NFs synthesized through a two-step process involving electrospinning followed by thermal oxidation. By utilizing the synergistic effect of abundant active interfaces, rapid carrier transfer, and a large specific surface area inherent to NFs, the sensor shows high sensitivity (1.87–300 ppb DME), reliable reproducibility and stability, and superior selectivity. Moreover, the sensor is highly responsive to electrolyte leakage simulations, making it a strong candidate for safety systems of LIBs. The study outlines a cost-effective method for preparing NiO/Si-NiWO 4 /WO 3 NFs, setting a foundation for developing various heterostructured nanomaterials with POMs as precursors. [Display omitted] • Obtaining NiO/Si-NiWO 4 /WO 3 NFs by lacunary POMs-Driven in-situ growth method. • NiO/Si-NiWO 4 /WO 3 NFs showed high 1, 2-dimethoxyethane sensitivity and selectivity. • NiO/Si-NiWO 4 /WO 3 NFs showed significant promise for practical electrolyte sensing. • Abundant heterostructure interface in NFs enhances the sensing properties. [ABSTRACT FROM AUTHOR]

Postharvest peel browning is one of the primary issues accountable for the subdued consumer acceptability and market value of guava fruit. However, postharvest treatment with brassinosteroid can reduce the peel browning to some extent through various modes of action. In current study, the influence of exogenous 24-epibrassinolide (EBL) application on antioxidant system and chilling injury (CI) characteristics of guavas during cold storage at 10 ± 1 ℃ were assessed. The mature green fruit exposed to various concentrations (15, 30, 45, 60 and 75 µg kg−1) of EBL displayed a notably lower fruit weight loss, respiration rate, electrolyte leakage and CI index, while higher consumer acceptability. Further, treatment with EBL has recorded lower amassing of hydrogen peroxide and malondialdehyde by suppressing lipoxygenase activity. Postharvest EBL application also heightened the content of total phenolics, ascorbic acid, total flavonoids and total antioxidant capacity. The enhanced activities of ascorbate peroxidase, catalase, superoxide dismutase and peroxidase due to EBL application impede the burst of reactive oxygen species. Moreover, correlation and regression analysis of tested biochemical parameters including enzymatic and non-enzymatic antioxidants exhibited a strong association and contributed 98.24–99.88 % variability in fruit weight loss, respiration rate, electrolyte leakage, CI index and consumer acceptability. Among different concentrations tested, 60 µg kg−1 EBL-treated guavas exhibited the desirable qualities and least CI index. From the study, it is concluded that the novelty of EBL can be gainfully harnessed in a postharvest handling system to induce cold tolerance and widen the storage life of cold-stored guava fruit. [Display omitted] • EBL concentration of 60 µg kg−1 alleviates chilling injury, EL and peel browning. • EBL application reduces the accumulation of intracellular MDA and H 2 O 2. • EBL treatment enhances the AsA, TPC, TFC and TAC in cold stored guava fruit. • EBL treatment increases SOD, CAT, APX and POD activities in guava fruit. • Regression suggested 98.24–99.88 % variability in chilling injury attributes. [ABSTRACT FROM AUTHOR]

Eight wheat cultivars, Sakha-94, Giza-171, Sids-1, Sids-12, Sids-13, Shandweel-1, Misr-1, and Misr-2, were evaluated for leaf rust at the seedling and adult stages in the 2021 and 2022 seasons. Biochemical, histological, and genetic analyses were performed to determine the link between cultivars that were either sensitive or resistant to the disease. Misr-2 and Giza-171 cultivars had the highest levels of resistance to leaf rust races in 2021 (LTCGT, STSJT, and TTTST) and 2022 (MBGJT, TTTKS, and TTTTT) at the seedling stage. However, at the adult stage, Sakha-94, Giza-171, Misr-1, and Misr-2 cultivars had the highest levels of resistance; consequently, they had the lowest final disease severity and the lowest values of AUDPC. The correlation between the seedling reaction and adult reaction was non-significant, with values of 0.4401 and 0.4793 in the 2021 and 2022 seasons, respectively. Throughout the biochemical, histological, and genetic analyses, it was observed that catalase, peroxidase, and polyphenol oxidase activities significantly increased in the resistant cultivars. The discoloration of superoxide (O2-) and hydrogen peroxide (H2O2) significantly decreased in resistant and moderately resistant wheat cultivars (Sakha-94, Giza-171, Misr-1, and Misr-2); higher hydrogen peroxide (H2O2) and superoxide (O2-) levels were recorded for the susceptible cultivars compared to the resistant cultivars. Molecular markers proved that the Lr50 gene was detected in the resistant cultivars. Puccinia triticina infections negatively affected most histological characteristics of flag leaves, especially in susceptible cultivars. The thickness of the blade (µ), the thickness of the upper and lower epidermis (UE and LE), the thickness of mesophyll tissue (MT), and bundle length and width in the midrib were decreased in susceptible cultivars such as Sids-1, Sids-13, and Shandwel-1 compared with resistant cultivars.

Effect of chemical- and bio-fertilizers (Nitroxin) on growth parameters, physiological and biochemical attributes, and yield of cantaloupe (Cucumis melo L.) under water stress conditions has been studied. Irrigation was done at 3 levels including 50, 75, and 100% of the water requirement of the cantaloupe plant. Water stress had an adverse effect on plant growth and the application of 120 kg ha−1 chemical fertilizer with Nitroxin in 100% water requirement had the highest growth parameters including fruit weight (1.84 kg) and fruit length (20.71 cm). The highest Malondialdehyde content was observed at 60 kg ha−1 of chemical fertilizer using Nitroxin. Application of Nitroxin had a significant effect on electrolyte leakage, proline content, relative water content, colour, vitamin C, titratable acidity, firmness, and total soluble solids (TSS) during water stress. The highest content of total chlorophyll (5.81 mg g−1 fresh weight) was observed at 100% field capacity with 180 kg ha−1 of chemical fertilizer with Nitroxin. The total phenol content of fruit enhanced by increasing drought stress and a significant difference was observed by application of biological and chemical fertilizers compared to control. Antioxidant enzyme activity including ascorbate peroxidase, catalase, superoxide dismutase and peroxidase increased during water stress and the application of chemical fertilizer with Nitroxin enhanced antioxidant enzyme activity during stress. Overall, the application of chemical fertilizers and Nitroxin improved growth parameters, physiological and biochemical attributes and yield of cantaloupe plants during water stress.

This study investigated the effect of mechanical damage of different impact energies (0.074 J, 0.160 J, 0.273 J) generated by a pendulum impactor and evaluated the bruise intensity and quality changes of bananas after 12 days of storage at 5, 13, and 22 °C. The bruise area (BA) and bruise susceptibility (BS) in the banana fruit were significantly increased as impact damage increased. The results of weight loss % and electrolyte leakage (EL%) were highly dependent on all studied factors; in the order of storage temperature > storage days > impact level. Storage temperature and impact damage accelerated the incidence of transpiration rate (TRm) during storage. Regarding color measurements, the results of image processing emphasized that storage at 13 °C exhibited the ideal color change in bruised fruit, which revealed a slow increment in lightness (L*) and yellowness (b*) until the last day of storage. The ethylene production rate (EPR) was recorded at its maximum peak on days 2 and 12 with values of 3.85 × 10−3 and 3.08 × 10−3 mg kg−1h−1 in banana fruit bruised by high-impact (0.273 J) and stored at 22 °C. Regardless of impact level, all size measurements reduction % including, surface area (As), geometric mean diameter (Dg), and fruit volume (Vf) of bruised bananas were higher at ambient storage conditions than those stored at 5 and 13 °C. The results of regression analysis can confirm the possibility of bruise susceptibility (BS) to estimate the quality changes of bruised fruit during storage.

Poor organic matter and nitrogen (N) deficiency along with salinity in arid and semiarid region soils are major hurdles to optimization of cereal's yield. In different cereals, maize productivity is significantly decreased due to less availability of N in low organic matter soils. Scientists suggest the incorporation of organic fertilizers to overcome this issue. That’s why the current study was conducted to explore the effectiveness of chemically produced nitrate blended acidified carbon (NBC). There were 3 levels of NBC i.e., 0, 0.50 and 1.00% applied under naturally normal and saline soils having EC 2.75 and 6.19 dS/m respectively. Results showed that the addition of 1.00NBC was significantly better compared to 0NBC for improvement in maize growth attributes i.e., root (32.86 and 77.84%) and shoot (74.17 and 67.57%) length, shoot fresh (53.98 and 97.42%) and dry weight (53.20and 84.20%), root dry (45.97 and 53.66%) and fresh weight (45.62 and 25.14%) in normal and saline conditions respectively. A significant enhancement in chlorophyll a, b, total and carotenoids of maize leaves also validated the imperative role of 1.00NBC than 0NBC in saline and normal soil. Application of 1.00BC also significantly decreases leaves electrolyte leakage and Na concentration in root and leaves over 0NBC in saline soils. In conclusion, 1.00NBC is an effective amendment to improve maize growth in saline soil. More investigations are suggested on different cereal crops under variable agroclimatic zones to declare 1.00NBC as the most effective amendment for alleviation of salinity stress.

The current experiment was designed to evaluate the effect of salicylic acid (SA) on the growth, physiological, biochemical, antioxidant and agronomic parameters of black gram Vigna mungo (L.) Hepper under salinity stress. One group of experimental plants of V. mungo varieties ADT-5 was treated with 75 mM NaCl, and the other group was kept without NaCl as control. Various concentrations of SA (0.5, 0.75, and 1 mM) were sprayed on the experimental plant to test its effect. Under salinity stress, the morpho-biochemical parameters were significantly reduced in the salt-treated plant. The results revealed that SA foliar spray mitigated the salinity-induced adverse effect on plant. The apparent increase in chlorophyll a by 81%, chlorophyll b by 63%, carotenoid by 25%, decreased malondialdehyde by 5% and electrolyte leakage by 29% was reported using SA (0.5 mM) foliar spray under salt stress. Foliar application of SA enhanced proline content and enzymatic antioxidants enzymes viz., catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and glutathione reductase (GR) activity of V. mungo by 18, 29, 46, 37, and 38%, respectively, compared to the control group. It was revealed that foliar application of SA could enhance the yield of the V. mungo under salt stress conditions. Our results demonstrated that SA mitigated the deleterious impact of salt stress and may be used as a tool to enhance food production under global climate change. [ABSTRACT FROM AUTHOR]

Humboldtia vahliana Wight. is an endangered species belonging to the family Leguminosae (subfamily Caesalpinioideae). Though the plant propagates through seeds, low seed setting, seed infestation, poor viability of seed, reduction in natural regeneration of seedlings as well as anthropogenic activities like overexploitation, habitat destruction and fragmented distribution in localities are the major factors hindering the survival of the species. Hence, strategies must be devised urgently for the conservation of this species as these recalcitrant seeds do not contribute significantly to the seed bank. The present attempt was to understand the seed physiology and biochemistry during embryogenesis and embryo desiccation. H. vahliana seeds took 120 days after anthesis to acquire full maturity. Immature seeds had higher moisture content (87.40%) which gradually reduced during maturity and reached 55.42% at the time of seed shed a true recalcitrant behavior of the seeds. Freshly fallen mature seeds showed an optimal germination percentage of 82.32% which was severely affected by the decrease in seed moisture content and the critical moisture content was found to be 33.63% in which the percentage of germination was only 30%. Cell membrane damage of seed was found to cause quick loss of seed viability. The LC-MS/MS analysis showed insignificant amounts of ribose, arabinose and trehalose but a significant accumulation of fructose in the mature embryos rather than glucose and sucrose. Embryo drying significantly reduced the level of these sugars including the stress related trehalose indicating the lack of biosynthetic machinery to counter desiccation stress in these recalcitrant seeds. [ABSTRACT FROM AUTHOR]

Many root diseases can cause serious damage to tomato (Solanum lycopersicum L.) production during the seedling growth period, particularly Rhizoctonia solani, Pythium spp., and Alternaria spp. Paclobutrazol (PBZ) has proved to reduce the damage of the Alternaria blight disease on tomato seedlings. The present investigation was designated to evaluate the growth of infected tomato seedlings with R. solani under applications of Trichoderma harzianum alone, PBZ alone, both PBZ and T. harzianum, and comparing with applied fungicide. PBZ enhanced the chlorophyll system in tomato seedlings, enzymatic antioxidants, and the total antioxidants, besides the vegetative parameters. The combined application of both PBZ and Trichoderma significantly improved growth parameters, decreased the damping off percent of R. solani, as well as increased the enzymatic antioxidants and the total antioxidants of tomato seedlings. It was found that applying 100 mg L−1 PBZ did not affect the effectiveness of the biocontrol agent of T. harzianum. The images of the scanning electron microscope (SEM) confirm that PBZ showed twisting, shrinking, and collapsing of lysis and hyphae in cultures of R. solani. This is the first report that confirms the biochemical control of R. solani on tomato seedlings using the combined application of PBZ and T. harzianum. Further studies are still needed to test more Trichoderma species and different phytopathogens. [ABSTRACT FROM AUTHOR]

Common bean (Phaseolus vulgaris L.) is the most widespread legume in Croatia and its production is based on landraces of great morphological diversity. Landraces morphologically differ the most in the seed coat color and size. Because plant emergence and crop establishment represent the most sensitive stage in crop development, the aim of this study was to determine whether the seed coat color and seed size of Croatian common bean landraces affect the water absorption rate, seed germination, emergence and phenotypic characteristics of the seedlings. In this study seeds of four common bean landraces with different seed color and size, 'Biser' (white-colored, small-seeded), 'Bijeli' (white-colored, large-seeded), 'Kornjača' (dark-colored, small-seeded) and 'Trešnjevac' (dark-colored, large-seeded) were evaluated in three different experiments: (i) water uptake, (ii) seed germination and (iii) emergence and seedling phenotypic characterization. The results show that white-colored seeds have a higher absorption rate and release more electrolytes compared to dark-colored seeds of similar size (and weight). The germination results show that white-colored and smaller seeds germinate faster compared to dark-colored and large seeds. On the other hand, the white-colored landrace 'Bijeli' took the longest time to emerge, probably due to cell damage that occurred during the fast initial water absorption. Using multispectral imaging, chlorophyll fluorescence imaging and stomatal conductance analysis, the seedlings of the dark-colored and large-seeded landraces were found to contain more photosynthetic pigments and have higher light absorption. In contrast, seedlings of white-colored and large seeds have lower stomatal conductance and transpiration and higher photochemical efficiency (despite possible cell damage during water absorption and germination). Results suggest that dark-colored seeds could survive better under unfavorable soil conditions without absorbing water, swelling, emergence or molding than white-colored seeds. Despite all this, white-colored common bean landraces remain popular in human diets and are often grown on small-scale farms. [ABSTRACT FROM AUTHOR]

A N2O2 donor Schiff base polydentate ligand was synthesized by the condensation of benzidine and benzil in ethanolic medium. The formed ligand was condensed further with VOSO4.xH2O to get the corresponding vanadyl complex. Both the ligand and the complex were characterized by spectroscopic and elemental analyses. Mung bean (Vigna radiata L.) was selected as a plant material. Various morphological and biochemical parameters, e.g. leaf senescence assay, chlorophyll content, and different reactive oxygen species (ROS) were estimated and were compared to those with ammonium vanadate. Outcomes of the experiments revealed that the Schiff base complex has less toxic effects than ammonium vanadate on mung bean seedlings and provide better tolerance to vanadium toxicity. Though different stress marker and ROS accumulation were less and minimum pigment damage was noticed in the Schiff base complex-treated seedlings but the optimum positive impact largely depends on the dose. Beyond certain concentration, the complex may show inhibitory effects on the plants. Therefore, the present study revealed that heavy metal Schiff base complexes can be used as potential supplement to meet up micronutrient deficiency and at the same time such complexes can minimize the toxicity generated by application of different heavy metals. [ABSTRACT FROM AUTHOR]

Salinity is among the most significant threats hindering global food security. The impact of Trichoderma, biochar, and combination on Spinach plants under salt stress conditions was investigated. Our results confirmed that salt stress (75, 150 mM) negatively affected morphological and physiological parameters of Spinach plants such as shoot (26.4%, 45.9%), and root length (16.1%, 51.2%), fresh and dry weights of root and shoot, membrane stability index (9.8%, 18.5%), relative water content(4.5%, 16.8%), chlorophyll content, mineral contents, endogenous phytohormones (auxin, gibberellins, abscisic acid, jasmonic acid, and salicylic acid) and total soluble protein content. However, electrolyte leakage, lipid peroxidation, reactive oxygen species production (such as hydrogen peroxide and hydroxyl radical), sodium, soluble sugars, proline contents, and antioxidant enzymes activities (peroxidase, catalase, and superoxide dismutase) significantly increased as a response to salt stress. The use of Trichoderma, biochar, and combination led to significant increases in all the above parameters; nevertheless, these treatments led to significant decreases in EL%, MDA, ROS, and sodium content in the stressed plants. The results proved the combination of Trichoderma and biochar is the most effective in alleviating the damaging impacts of salt on Spinach plants by increasing the up-regulation of antioxidants and decreasing membrane leakage and ROS. [ABSTRACT FROM AUTHOR]

Drought is believed to be one of the most important abiotic stresses, which drastically affects wheat production worldwide. Jasmonates, as plant growth regulators, could modify the effects of environmental stresses. Therefore, we conducted the present study to investigate the physiological responses of wheat cultivars to exogenous methyl jasmonate (MeJA) under drought stress during two crop years of 2015–2017. The results revealed that the irrigation cut-off regime at the booting decreased Fv/Fm, RWC, peroxidase activity, and grain yield; whereas it increased proline, malondialdehyde content, protein, and electrolyte leakage. The drought-tolerant cultivar, Sirvan had 13.7% higher grain yield than Pishtaz cultivar in drought stress owing to higher Fv/Fm, proline, RWC, peroxidase activity, and lower electrolyte leakage and MDA. Spraying 50 μM of MeJA increased chlorophyll and carotenoids (8.7% and 6.93%), proline (26.8%), and peroxidase activity (31.4%); whereas 100 μM of MeJA increased the RWC (2.5%), Fv/Fm (9.3%) and decreased membrane electrolyte leakage (6.7%) compared to hormone-free conditions. According to the results drought stress decreased certain physiological traits, the foliar application with 100 μM of MeJA could increase the grain yield (9.2% in irrigation cut-off at booting and 6.8% at the milk stage) and then partially compensate for the reduction caused by drought stress. Therefore, for minimizing the effect of drought stress, we could recommend the use of MeJA and drought-tolerant cultivar. [ABSTRACT FROM AUTHOR]

Drought stress is one of the important non-biological stresses for plants such as beans because it affects the growth, development and yield of the plant. Therefore, identification of drought tolerant genotypes is very important. One of the effective ways in identifying drought tolerant genotypes is biochemical investigation and relative genes expression involved in drought stress. Therefore, the present study was performed on a number of bean genotypes including Khomein, COS-16, D81083 and KS-10012 as factorial complete randomized block design. Drought stress was applied at the levels of severe stress (25% field capacity), mild stress (75% field capacity) and normal irrigation (100% field capacity) and then the relative water content, electrolyte leakage, proline, malondialdehyde and gene expression (nced, cdpk1, pip1 and nac) were evaluated. Results showed that the highest and lowest electrolyte leakage traits belonged to Khomein genotypes with 77.66% and COS-16 with 25%, respectively. The highest relative water content of leaf belonged to COS-16 genotype at mild stress of 80.66% and the lowest to khomein genotype at severe stress of 25%. Increasing trend of proline content was observed in all genotypes from 100% of irrigation to mild and severe stresses. Also, increasing trend of malondialdehyde was observed in severe stress compared to control, on the other hand, Khomein genotype with the highest malondialdehyde rank a and COS-16 genotype with the lowest malondialdehyde genotype f were considered with Tukey test. Relative increase of nCEd, nac and cdpk1 gene expression was observed in severe stress compared to mild stress. Different relative expression of pip1 gene was also observed at different stress levels (75% and 25% of field capacity). In general, it can be concluded that among the genotypes studied, COS-16 had the highest and Khomein genotype had the least tolerance to drought stress. [ABSTRACT FROM AUTHOR]

In light of global warming, adapting plants to a new area may reduce the damage of climatic changes. Indian almond seedlings were planted in pots subjected to calcium and potassium (250 and 500 mg l-1) to reduce the negative impact of high field temperature. Compared with the control, all treatments improved the height plant, branch numbers, leaf numbers, and leaf area. The treatments increased total chlorophyll and carotenoid. However, the treatments modulated proline, total soluble carbohydrate, phenolic, and ascorbic acid contents. Heat stress increased abscisic acid content and electrolyte leakage percentage, whereas calcium and potassium treatments decreased abscisic acid and electrolyte leakage. The treatments modulated protein profile in the number of proteins separated into bands on the gel. The thickness and density of these bands indicate differences in the molecular weights of proteins by treatments. The seedlings responded to heat stress during the second week of July, and the untreated plants were more responsive to the temperature rise than the treated plants. The adaptability of the Indian almond during the summer in semi-tropical regions to high temperatures by using calcium and potassium to reduce heat stress damage on the plant. [ABSTRACT FROM AUTHOR]

Cold-acclimated and non-acclimated contrasting Camelina (Camelina sativa L.) biotypes were investigated for changes in stress-associated biomarkers, including antioxidant enzyme activity, lipid peroxidation, protein, and proline content. In addition, a well-known freezing tolerance pathway participant known as C-repeat/DRE-binding factors (CBFs), an inducer of CBF expression (ICE1), and a cold-regulated (COR6.6) genes of the ICE-CBF-COR pathway were studied at the transcriptional level on the doubled-haploid (DH) lines. Freezing stress had significant effects on all studied parameters. The cold-acclimated DH34 (a freezing-tolerant line) showed an overall better performance under freezing stress than non-acclimated plants. The non-cold-acclimated DH08 (a frost-sensitive line) showed the highest electrolyte leakage after freezing stress. The highest activity of antioxidant enzymes (glutathione peroxidase, superoxide dismutase, and catalase) was also detected in non-acclimated plants, whereas the cold-acclimated plants showed lower enzyme activities upon stress treatment. Cold acclimation had a significantly positive effect on the total protein and proline content of stressed plants. The qRT-PCR analysis revealed significant differences in the expression and cold-inducibility of CsCBF1-3, CsICE1, and CsCOR6.6 genes among the samples of different treatments. The highest expression of all CBF genes was recorded in the non-acclimated frost-tolerant biotype after freezing stress. Interestingly a significantly higher expression of COR6.6 was detected in cold-acclimated samples of both frost-sensitive and -tolerant biotypes after freezing stress. The presented results provide more insights into freezing tolerance mechanisms in the Camelina plant from both a biochemical point of view and the expression of the associated genes. [ABSTRACT FROM AUTHOR]

Strawberry is a delicate fruit with a short shelf life after harvest. High metabolic activities and fungal decay deteriorate its quality. In an attempt to extend its shelf life and maintain its quality while retaining its antioxidant potential, the harvested fruits of strawberry cv. Chandler were dipped in 30% eucalyptus leaf extract (ELE). Weight loss, fungal decay index, percentage of decayed fruits, respiration rate, and electrolyte leakage were all reduced in ELE-treated strawberries. The enzymatic activities of catalase in fruits increased initially until the fifth day of storage but then started to decline during the later period while superoxide dismutase and peroxidase activities continued to rise until the 10th day and then declined. With higher contents of total phenolics, ascorbic acid, total antioxidants, and anthocyanin, the application of ELE maintained the general acceptance, firmness, flavor, and marketable fruit percentage. Titrable acidity (TA) and sugar–acid ratio (SAR) were also significantly affected by ELE application. A declining trend was observed in TA during storage, along with an increase in SAR. The pH and soluble solid contents of strawberry juice were not significantly changed by the application of ELE; however, both attribute scores were greater than those for the control. In conclusion, ELE could be used as an environmentally safe method to postpone senescence and maintain postharvest quality for up to 15 days. [ABSTRACT FROM AUTHOR]

While salinity is increasingly becoming a prominent concern in arable farms around the globe, various treatments can be used for the mitigation of salt stress. Here, the effective presence of Azotobacter sp. inoculation (A1) and absence of inoculation (A0) was evaluated on Iranian licorice plants under NaCl stress (0 and 200 mM) (S0 and S1, respectively). In this regard, 16 Iranian licorice (Glycyrrhiza glabra L.) accessions were evaluated for the effects on photosynthesis and chlorophyll fluorescence. Leaf samples were measured for photosynthetic pigments (via a spectrophotometer), stomatal and trichome-related features (via SEM), along with several other morphological and biochemical features. The results revealed an increase in the amount of carotenoids that was caused by bacterial inoculation, which was 28.3% higher than the non-inoculated treatment. Maximum initial fluorescence intensity (F0) (86.7) was observed in the 'Bardsir' accession. Meanwhile, the highest variable fluorescence (Fv), maximal fluorescence intensity (Fm), and maximum quantum yield (Fv/Fm) (0.3, 0.4, and 0.8, respectively) were observed in the 'Eghlid' accession. Regarding anatomical observations of the leaf structure, salinity reduced stomatal density but increased trichome density. Under the effect of bacterial inoculation, salinity stress was mitigated. With the effect of bacterial inoculation under salinity stress, stomatal length and width increased, compared to the condition of no bacterial inoculation. Minimum malondialdehyde content was observed in 'Mahabad' accession (17.8 mmol/g FW). Principle component analysis (PCA) showed that 'Kashmar', 'Sepidan', 'Bajgah', 'Kermanshah', and 'Taft' accessions were categorized in the same group while being characterized by better performance in the aerial parts of plants. Taken together, the present results generally indicated that selecting the best genotypes, along with exogenous applications of Azotobacter, can improve the outcomes of licorice cultivation for industrial purposes under harsh environments. [ABSTRACT FROM AUTHOR]

Silicon (Si) is the most abundant element on earth after oxygen and is very important for plant growth under stress conditions. In the present study, we inspected the role of Si in the mitigation of the negative effect of salt stress at three concentrations (40 mM, 80 mM, and 120 mM NaCl) in two wheat varieties (KRL-210 and WH-1105) with or without Si (0 mM and 2 mM) treatment. Our results showed that photosynthetic pigments, chlorophyll stability index, relative water content, protein content, and carbohydrate content were reduced at all three salt stress concentrations in both wheat varieties. Moreover, lipid peroxidation, proline content, phenol content, and electrolyte leakage significantly increased under salinity stress. The antioxidant enzyme activities, like catalase and peroxidase, were significantly enhanced under salinity in both leaves and roots; however, SOD activity was drastically decreased under salt stress in both leaves and roots. These negative effects of salinity were more pronounced in WH-1105, as KRL-210 is a salt-tolerant wheat variety. On the other hand, supplementation of Si improved the photosynthetic pigments, relative water, protein, and carbohydrate contents in both varieties. In addition, proline content, MDA content, and electrolyte leakage were shown to decline following Si application under salt stress. It was found that applying Si enhanced the antioxidant enzyme activities under stress conditions. Si showed better results in WH-1105 than in KRL-210. Furthermore, Si was found to be more effective at a salt concentration of 120 mM compared to low salt concentrations (40 mM, 80 mM), indicating that it significantly improved plant growth under stressed conditions. Our experimental findings will open a new area of research in Si application for the identification and implication of novel genes involved in enhancing salinity tolerance. [ABSTRACT FROM AUTHOR]

Abstract Cotton is a tropical/subtropical crop and is innately susceptible to cold. Using an approach that integrates morphological, biochemical, and transcriptome analyses, the study aimed to understand the molecular underpinnings of phenotypic adjustments in cotton seedlings under cold stress. Exposure of six cotton accessions to 15°C during the seedling stage significantly reduced chlorophyll content, stomatal conductance, plant height, and biomass, but increased malondialdehyde and proline production. Comparative transcriptome profiling of the cold‐sensitive accession SA 3781 grown under low and normal temperatures showed the upregulation of genes related to the production of reactive oxygen species (ROS) under cold stress. Despite a similar upregulation of genes encoding metabolites that can scavenge ROS and provide osmoprotection for the cell, the stressed plants still exhibited oxidative stress in terms of lipid peroxidation. This may be due in part to the upregulation of abscisic acid synthesis genes and downregulation of chlorophyll synthesis genes effecting lower stomatal conductance and chlorophyll contents, respectively. Additionally, stomatal closure which is required to avoid the cooling effect and dehydration under cold conditions may have contributed in reducing the net photosynthetic rates in plants exposed to low temperature. These findings provide an insight into the expression of key genes regulating the phenotypic changes observed in cotton in response to cold stress.

This study aimed to determine a useful selection criterion for salt tolerance during the early development stage of sugar beet. Four sugar beet cultivars (Orthega, Valentina, FD Shoot, and Mohican) were exposed to NaCl stresses (Control, 5, 10, and 15 dS m-1), and morphological and physiological characteristics were investigated. Germination percentage, mean germination time (MGT), seedling length, and seedling fresh weight (SFW) in germination test; emergence percentage, mean emergence time (MET), root length, shoot length, plant fresh weight, relative chlorophyll content (Chl), relative water content (RWC) and electrolyte leakage of the plants grown in pod experiment were measured. The results showed that the maximum germination at control was recorded in FD Shoot, but it gave the lowest germination at 15 dS m-1. In the pod experiment, the highest emergence rate was detected in Orthega and Mohican at all levels of NaCl. Increased salinity delayed MET and led to reduction in shoot length, root length, and RWC of sugar beet cultivars. Relative Chl content and electrolyte leakage enhanced from 32.7 SPAD and 21.6% in control to 38.5 SPAD and 35.6% in 10 dS m-1, respectively. In general, there were significant differences among sugar beet cultivars, and they could keep the salinity up to 5 dS m-1 in terms of the investigated traits. It was concluded that relative Chl content and electrolyte leakage should be used a promising clue for selection of tolerant or sensitive sugar beet cultivars for salinity.

While salinity is increasingly becoming a prominent concern in arable farms around the globe, various treatments can be used for the mitigation of salt stress. Here, the effective presence of Azotobacter sp. inoculation (A1) and absence of inoculation (A0) was evaluated on Iranian licorice plants under NaCl stress (0 and 200 mM) (S0 and S1, respectively). In this regard, 16 Iranian licorice (Glycyrrhiza glabra L.) accessions were evaluated for the effects on photosynthesis and chlorophyll fluorescence. Leaf samples were measured for photosynthetic pigments (via a spectrophotometer), stomatal and trichome-related features (via SEM), along with several other morphological and biochemical features. The results revealed an increase in the amount of carotenoids that was caused by bacterial inoculation, which was 28.3% higher than the non-inoculated treatment. Maximum initial fluorescence intensity (F0) (86.7) was observed in the ‘Bardsir’ accession. Meanwhile, the highest variable fluorescence (Fv), maximal fluorescence intensity (Fm), and maximum quantum yield (Fv/Fm) (0.3, 0.4, and 0.8, respectively) were observed in the ‘Eghlid’ accession. Regarding anatomical observations of the leaf structure, salinity reduced stomatal density but increased trichome density. Under the effect of bacterial inoculation, salinity stress was mitigated. With the effect of bacterial inoculation under salinity stress, stomatal length and width increased, compared to the condition of no bacterial inoculation. Minimum malondialdehyde content was observed in ‘Mahabad’ accession (17.8 μmol/g FW). Principle component analysis (PCA) showed that ‘Kashmar’, ‘Sepidan’, ‘Bajgah’, ‘Kermanshah’, and ‘Taft’ accessions were categorized in the same group while being characterized by better performance in the aerial parts of plants. Taken together, the present results generally indicated that selecting the best genotypes, along with exogenous applications of Azotobacter, can improve the outcomes of licorice cultivation for industrial purposes under harsh environments.

The impact of heat and drought stresses, either individually or combined, on physiological and biochemical parameters of four eggplant varieties (Solanum melongena L.) was investigated. The results showed that associated stress generated the highest increment in proline content, MDA concentration, and H2O2 accumulation and generated the lowest increment in RWC. In addition, 'Bonica' and 'Galine' exhibited higher starch accumulation and lower electrolyte leakage (EL) under combined stress. Moreover, drought and heat stresses applied individually contributed to a substantial decline in Chla, Chlb, total Chl, Chla/b, and carotenoids (p > 0.05) in 'Adriatica' and 'Black Beauty'. The decreasing level of pigments was more substantial under associated drought and heat stresses. The simultaneous application of drought and heat stresses reduced PSII efficiency (Fv/Fm), quantum yield (ΦPSII), and photochemical efficiency (qp) and boosted non-photochemical quenching (NPQ) levels. However, the change recorded in the chlorophyll fluorescence parameters was less pronounced in 'Bonica' and 'Galine'. In addition, the gas exchange parameters, transpiration rate (E), CO2 assimilation rate (A), and net photosynthesis (Pn) were decreased in all varieties under all stress conditions. However, the reduction was more pronounced in 'Adriatica' and 'Black Beauty'. Under associated stress, antioxidant enzymes, SOD, APX, CAT, and GR exhibited a significant increment in all eggplant cultivars. However, the rising was more elevated in 'Bonica' and 'Galine' (higher than threefold increase) than in 'Adriatica' and 'Black Beauty' (less than twofold increase). Furthermore, 'Bonica' and 'Galine' displayed higher non-enzyme scavenging activity (AsA and GSH) compared to 'Adriatica' and 'Black Beauty' under associated stress. Under stressful conditions, nutrient uptake was affected in all eggplant cultivars; however, the root, stem, and leaf N, P, and K contents, in 'Adriatica' and 'Black Beauty' were lower than in 'Bonica' and 'Galine', thereby showing less capacity in accumulating nutrients. The coexistence of drought and heat stresses caused more damage on eggplant varieties than the single appearance of drought or heat stress separately. 'Bonica' and 'Galine' showed better distinguished performance compared to 'Adriatica' and 'Black Beauty'. The superiority of 'Bonica' and 'Galine' in terms of tolerance to heat and drought stresses was induced by more effective antioxidant scavenging potential, enhanced osmolyte piling-up, and prominent ability in keeping higher photosynthetic efficiency and nutrient equilibrium compared with 'Adriatica' and 'Black Beauty'. [ABSTRACT FROM AUTHOR]

In order to study the freezing resistance of some barley varieties using rates of electrolyte leakage this experiment was carried out on three barley variety, including Reyhan, kavir, and Nosrat. These varieties are the most important varieties that cultivated in Semnan province. For this experiment, barely seeds were sown in small containers. The current experiment was carried out as Factorial experimental design plan based on completely randomized design (CRD). The first factor in this study was barley variety in three levels. The second factor was temperature in 5 levels including +4°C, -4°C, -8°C, -12°C and -15°C. Seedlings in the stage of tillering, was sprayed by water and then were put in the incubator for two hours. Then two gram samples were selected and 20 mm deionized water was added and shakes for 24 hours. Then every day for a week EC in solution was measured. Analysis of variance (ANOVA) was used to determine significant (p < 0.01 and p < 0.05) differences between barley genotypes. The differences between means of barley varieties were inspected using Duncan test. The results showed that the percentage of ion leakage between the three cultivars had significant differences. The effect of temperature on the percentage of ion leakage in all days, had significant difference. The highest percentage of ion leakage measurements on all days was at the -15°C and the lowest percentage of leakage occurred at 4°C. Kavir variety in comparison with other varieties had lower cold tolerance. Interaction of temperature and genotype factors on ion leakage measurements showed that all varieties had significant differences. [ABSTRACT FROM AUTHOR]

In order to investigate the effects of nanoparticles nano Fe-Si oxide and biofertilizers (Azospirillum lipoferum and Pseudomonas putida) on chlorophyll fluorescence components and some physiological traits of triticale at different levels of irrigation, an experimental as the factorial study was conducted based on randomized complete block design with three replications. The studied factors included three levels of irrigation (full irrigation as control, irrigation withholding at 50% of booting and heading stages as severe, and moderate water limitation, respectively), application of biofertilizers (Azospirillum lipoferum and Pseudomonas putida) in four levels, and nanoparticles foliar application (nano iron oxide and nano silicon oxide) at four levels. Both applications of plant growth-promoting rhizobacteria and nanoparticle foliar application under full irrigation increased chlorophyll index (50.23%), relative water content (43.97%), stomatal conductance (36.78%), quantum yield (47.38%), maximum fluorescence (34.84%), variable fluorescence (98.49%), and grain yield (43.28%) in comparison to no application of biofertilizers and nanoparticles under irrigation withholding at booting stage. Both applications of plant growth-promoting rhizobacteria and nanoparticles increased the chlorophyll index, relative water content, stomatal conductance, quantum yield, maximum fluorescence, variable fluorescence and grain yield in both levels of full irrigation and severe water limitation, but decreased electrolyte leakage and minimum fluorescence. In addition, severe water limitation or irrigation withholding at the booting stage increased chlorophyll index (7.74%), relative water content (10.99%), stomatal conductance (22.46%), quantum yield (15.2%), maximum fluorescence (26.54%), variable fluorescence (75.61%) and grain yield (28.59%) in comparison to no application of biofertilizers and nanoparticles at the same irrigation level. Generally, the application of biofertilizers and nanoparticles showed a better performance at different irrigation levels due to the improvement of physiological traits. [ABSTRACT FROM AUTHOR]

Due to arid and semi-arid climates, identification of water deficit stress tolerant genotypes is really important in Iran. To select tolerant genotypes, it is necessary to use important and practical indicators. In this regard, this study was conducted to studying the effect of water deficit stress on 27 sugar beet genotypes in a split plots based on randomized complete block design in three replications at the University of Tabriz in 2019. The main factor included two irrigation levels (optimal and water deficit), and the sub-factor included 27 sugar beet genotypes. In this experiment, sugar beet seeds were planted in the PVC tubes. Studied traits included transpirational cooling before and after irrigation, relative water loss (RWL), relative water content (RWC), root weight (RW), electrolyte leakage (EL), initial fluorescence (F0), maximum fluorescence (Fm), and quantum yield of photosystem II. Based on the analysis of variance, irrigation, genotype, and irrigation × genotype interaction effects were significant for all studied traits at 1% of probability level. Also, the relative lost water, relative water content, maximum fluorescence, and quantum yield of photosystem II were significantly reduced due to water deficit stress. In terms of transpirational cooling indices after irrigation, relative water content, root weight, electrolyte leakage, initial fluorescence, and quantum yield of photosystem II, Full sib S1- 10- 8001 genotype was identified as the tolerant genotype. [ABSTRACT FROM AUTHOR]

Accumulation of oxidative damage is a major contributor to aging; however, whether the capacity of cellular mechanisms that protect against oxidative damage differs between annuals and perennials remains unknown. We undertook three approaches to evaluate this question. For our first approach, using an electrolyte leakage assay, we showed that leaves from deciduous and evergreen perennials had a significantly lower rate of cellular damage from exogenous H2O2 than those from annuals. For our second approach, we demonstrated that seeds from deciduous perennials – but not biennials or evergreens – required a higher H2O2 concentration to maximize germination rate than seeds from annuals. For our third approach, we showed that chlorophyll b was more susceptible to oxidative damage from exogenous H2O2 than chlorophyll a but that chlorophyll a/b ratios did not differ between annuals and perennials. Overall, our results showcase that perennial species have greater defences against exogenous H2O2, allowing them to survive over multiple years. The mechanisms responsible for this increased H2O2 tolerance were not fully elucidated by this study, but they do not involve changes to chlorophyll a/b ratios, likely because such changes could disrupt photosynthesis. Perennials may have higher levels of antioxidants, but this remains unconfirmed. Developmental onset of protective mechanisms is delayed in evergreens, which reflects that these plants are ancestral and likely prioritized rapid colonization of the land, which requires faster germination rates induced by higher H2O2 levels. Annuals reduced the magnitude of inherited protective mechanisms, likely to permit faster growth and reproduction. [ABSTRACT FROM AUTHOR]

Low temperature stress decreases yield and quality of tomato in greenhouse conditions. For successful tomato cultivation under the cold stress, cultivars performances are extremely important both vegetative and reproductive growth stage. In this study, 20 tomato pure lines and 3 commercial cultivars (Cigdem F1, Anit F1 and Bestona F1) and also Solanum hirsutum (LA 1777) known as tolerant genotypes were evaluated at vegetative and reproductive stage. The studies were conducted under both the cold stress in growth chamber and the optimal temperature condition (control) in the greenhouse. They were evaluated by measuring malondialdehyde (MDA), electrolyte leakage (EL) and dry matter yield (DM) at vegetative stage. The results showed that EL rate and MDA content increased while DM decreased under the cold stress when compared with leaves of plants grown at optimal temperature. In reproductive stage, pollen viability and pollen germination were evaluated under both cold stress and control conditions for all genotypes. All the sensitive genotypes exhibited low pollen viability and pollen germination. Consequently, three pure lines were identified with lowtemperature tolerant in vegetative and reproductive growth stage. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the membrane integrity and some physiological responses of rootstock citrus calli under exposure to different concentrations of NaCl. Selected salt-tolerant cell lines were compared with salt-sensitive calli of Troyer's citrange (Citrus sinensis [L.] x Citrus trifoliata [L.] Raf.) (TC) with respect to growth, water content, Na+, K+ and Cl− ion content as well as cell membrane stability under exposure to different NaCl concentrations. The results show that the stressed sensitive lines have a consistently high ion efflux. The values recorded for these sensitive calli are 3 to 6 times higher than those of the tolerant calli. Thus, only selected halotolerant calli were able to maintain the integrity of their membranes under salt stress conditions. In the sensitive calli, NaCl always induces a slowing down of growth even from 4 g L−1, and the reduction in the relative growth rate is higher than 50% and reaches more than 90% for the three culture durations at 8 g L−1 NaCl. For the salt-tolerant selected lines, the relative growth rate seems to be slightly slowed down until the second month of culture but becomes equal to that of the control at the third month, whether at 4 or 8 g L−1 NaCl. At the end of the third month, the relative growth rate of the selected calli is 100% at 8 g L−1 NaCl. The water content is twice as high in the selected tolerant calli as in the sensitive ones after three months of salt treatment at 8 g L−1 NaCl. After long-term culture, the halotolerant calli absorbed similar or even higher amounts of Na+ and Cl− than the salt-sensitive lines. However, by the 3rd month, the recorded accumulation rate dropped in the unselected but continued to increase in the tolerant calli (4-fold higher at 12 g L−1 NaCl than the control). Furthermore, exposure of both types of calli (salt-sensitive and salt-tolerant) to equal concentrations of NaCl resulted in greater loss of K+ by the NaCl-sensitive lines. However, for tolerant lines, K+ uptake is not affected at 4 g L−1 NaCl and the decrease in tissue content is less than 25% at 8 g L−1 NaCl. From this observation, it can be concluded that growth and the ability to retain high levels of internal K+ are correlated. [ABSTRACT FROM AUTHOR]

Silicon (Si) application has great potential to improve salt tolerance in a variety of crop plants. However, it is unclear how Si influences the responses of contrasting rice cultivars when exposed to excessive salt. Here, we investigated the functions of Si in alleviating the negative effects of salt stress on two contrasting rice cultivars, namely BRRI dhan48 (salt-sensitive) and Binadhan-10 (salt-tolerant). Rice seedlings was pre-treated with three doses of Si (as silicic acid; 0, 1 and 2 mM) for 14 days at one-day interval before being exposed to salt stress (10 dSm−1) in a sustained water bath system. The results demonstrated that the seedlings of BRRI dhan48 and Binadhan-10, respectively exhibited substantial reductions in shoot height (16 and 9%), shoot fresh weight (64 and 43%) and shoot dry weight (50 and 39%) under salinity. Intriguingly, BRRI dhan48 pre-treated with 1 and 2 mM Si, respectively, showed a higher increase in shoot height (SH) (by 25.90 and 26.08%) as compared with Binadhan-10 (by 3 and 8%) under salt stress compared with their respective controls. Data revealed that a comparatively higher improvement in the growth performances of the salt-induced Si pre-treated BRRI dhan48 than that of Binadhan-10. For example, 1 and 2 mM of Si treatments significantly attributed to elevated leaf relative water content (RWC) (13 and 22%), proline (138 and 165%), chlorophyll a (42 and 44%), chlorophyll b (91 and 72%), total chlorophyll (58 and 53%) and carotenoids (33 and 29%), and recovery in the reductions of electrolyte leakage (13 and 21%), malondialdehyde content (23 and 30%) and shoot Na+/K+ ratio (22 and 52%) in BRRI dhan48 compared with Si-untreated control plants under salt stress. In addition, we found salt-tolerant Binadhan-10 also had enhanced RWC (9 and 19%), proline (12 and 26%) with pre-treatment with 1 and 2 mM of Si, respectively, under salt stress, while no significant differences were noticed in the case of photosynthetic pigments and Na+/K+ ratio. Our results showed that Si supplementation potentiated higher salt-tolerance ability in the salt-sensitive BRRI dhan48 as compared with salt-tolerant Binadhan-10. Thus, Si application could be highly beneficial in the growth recovery of the salinity-affected salt-sensitive high yielding rice cultivars in the saline-prone areas. [ABSTRACT FROM AUTHOR]

Orthodox seeds deteriorate even when stored in the best of conditions; hence, it is very important to monitor germination in stored seeds. To assess orthodox seed deterioration, a germination test is usually employed. This study assessed and compared seed deterioration in five orthodox species using electrolyte leakage and Fourier transform infrared spectroscopy (FTIR). The study also compared water imbibition by the test orthodox seeds. To achieve this, the seeds from three wild (Bolusanthus speciosus; Combretum erythrophyllum; Erythrina caffra) and two agricultural (Pisum sativum and Cucurbita pepo) species were imbibed between 20 layers of single-ply paper towel. The other set was subjected to controlled deterioration at 40 °C and 100% relative humidity for 32 d, with samples taken for germination and electrolyte leakage measurement at 4 d intervals. FTIR measurements were performed at 0, 20, and 32 d of controlled deterioration. The results indicated that there were some significant interspecies differences in the imbibition times and seed water contents but these were not large. In all species, uptake of water was complete between about 15 and 25 h. The wild species showed higher sensitivity to controlled deterioration. Complete loss of germinability occurred much earlier in the wild species (20 d in B. speciosus and E. caffra, and 16 d in Co. erythrophyllum) compared with 36 d for the agricultural species P. sativum and Cu. pepo. There was a negative correlation between electrolyte leakage and seed germination in all wild and agricultural species. A strong positive correlation was observed between the time of controlled deterioration, electrolyte leakage, and FTIR transmission in all the species. While controlled deterioration may help in decisions relating to the storage of orthodox seeds, the water imbibition results from this study will help to set the priming time of the species. The study reaffirms electrolyte leakage as an indicator of seed viability in P. sativum and Cu. pepo; it also recommends the use of electrolyte leakage as an indicator of seed deterioration in B. speciosus, Co. erythrophyllum, and E. caffra. The study also recommends FTIR as a tool for monitoring the germination of stored seeds of all the test species. [ABSTRACT FROM AUTHOR]

The infection of Pseudomonas syringae pv. actinidiae in kiwifruit is currently assessed by numerous methodologies, each with their own limitations. Most studies are based on either a laborious method of growth quantification of the pathogen or qualitative assessments by visual scoring following stem or cutting inoculation. Additionally, when assessing for resistance against specific pathogen effectors, confounding interactions between multiple genes in the pathogen can make mapping resistance phenotypes nearly impossible. Here, we present robust alternative methods to quantify pathogen load based on rapid bacterial DNA quantification by PCR, the use of Pseudomonas fluorescens, and a transient reporter eclipse assay for assessing resistance conferred by isolated bacterial avirulence genes. These assays compare well with bacterial plate counts to assess bacterial colonization as a result of plant resistance activation. The DNA-based quantification, when coupled with the P. fluorescens and reporter eclipse assays to independently identify bacterial avirulence genes, is rapid, highly reproducible, and scalable for high-throughput screens of multiple cultivars or genotypes. Application of these methodologies will allow rapid and high-throughput identification of resistant cultivars and the bacterial avirulence genes they recognize, facilitating resistance gene discovery for plant breeding programs.[Graphic: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Field winterhardiness is a critical trait in rose cultivars (Rosa ×hybrida) grown in northern climates. Although the molecular basis of cold hardiness has been well documented in model organisms such as Arabidopsis thaliana, little is known about the genetics and mechanisms underlying winterhardiness in roses. This research aims to explore the genetic control of winterhardiness for application in breeding programs using quantitative trail loci (QTL) analysis in two biparental rose populations derived from cold-hardy roses of the Canadian Explorer Series Collection. Field winterhardiness was assessed as a complex trait with winter damage and regrowth recorded in multiyear and multilocation trials in Ontario and Saskatchewan, Canada. In addition, this research explored the relationship between field measurements and electrolyte leakage recorded under artificial conditions. Electrolyte leakage had limited utility for application in rose breeding programs as a substitute for field evaluation, but did enable identification of QTL associated with potential cold hardiness candidate genes. A QTL for electrolyte leakage mapped to a genomic region that harbors a CBF1-like transcription factor. A total of 14 QTLs associated with field winter damage and regrowth were discovered, and they explained between 11% and 37% of the observed phenotypic variance. Two QTL associated with winter damage and regrowth overlapped with a known QTL for black spot (Diplocarpon rosae) disease resistance, Rdr1, in an environment under high disease pressure. Due to the complexity of field winterhardiness and its direct reliance on intertwined factors, such as overall plant health, moisture status, snow cover, and period of prolonged sub-zero temperatures, field trials are the ultimate measurement of field winterhardiness. Transgressive segregation was observed for all traits, and it was most likely due to complementary gene action. Field winter damage and regrowth were highly heritable in single environments, but they were subject to genotype × environment interaction resulting from pest pressure and severe climatic conditions.

Fusaric acid (FA) is one of the potential toxins produced by pathogenic Fusarium species which exerts oxidative stress and cell death in plants. In this work, the effects of different concentrations of FA were investigated on the photosynthetic activity in leaves of wild type and Never ripe (Nr) tomato plants to reveal the potential role of ethylene under mycotoxin exposure. FA induced a significant ethylene emission from leaves in a concentration- and time-dependent manner. FA (1 mM) decreased the maximal and effective quantum yields of PSII and PSI in both tomato genotypes but photoprotective processes, such as the nonphotochemical quenching and the cyclic electron flow, were activated more effectively in Nr plants. However, the lipid peroxidation was higher in leaves of Nr. Our result confirmed that Nr plants were more sensitive to FA phytotoxicity suggesting the key role of ethylene in the activation of defense responses.

Abstract Background Organic mulches are widely used in crop production systems. Due to their benefits in improving soil fertility, retention of soil moisture and weed control. Field experiments were conducted during wheat growing seasons of 2018–2019 and 2019–2020 to evaluate the effects of Jatropha leaves mulch on the growth of wheat varieties ‘Wadan-17’ (rainfed) and ‘Pirsabaq-2013’ (irrigated) under well irrigated and water stress conditions (non-irrigated maintaining 40% soil field capacity). Jatropha mulch was applied to the soil surface at 0, 1, 3 and 5 Mg ha−1 before sowing grains in the field. Under conditions of water stress, Jatropha mulch significantly maintained the soil moisture content necessary for normal plant growth. Results We noted a decrease in plant height, shoot and root fresh/dry weight, leaf area, leaf relative water content (LRWC), chlorophyll, and carotenoid content due to water stress. However, water stress caused an increase in leaf and root phenolics content, leaf soluble sugars and electrolytes leakage. We observed that Jatropha mulch maintained LRWC, plant height, shoot and root fresh/dry weight, leaf area and chlorophyll content under water stress. Moreover, water stress adverse effects on leaf soluble sugar content and electrolyte leakage were reversed to normal by Jatropha mulch. Conclusion Therefore, it may be concluded that Jatropha leaves mulch will minimize water stress adverse effects on wheat by maintaining soil moisture and plant water status.