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The present study was conducted to examine the potential role of Plantago ovata Forsk leaf extract (POLE) which was applied at various concentration levels (control, hydropriming, 10, 20, 30, and 40% POLE) to the wheat (Triticum aestivum L.) seedlings. Drought stressed was applied at 60% osmotic potential (OM) to the T. aestivum seedlings to study various parameters such as growth and biomass, photosynthetic pigments and gas exchange characteristics, oxidative stress and response of various antioxidants and nutritional status of the plants. Various growth parameters such as gaseous exchange attributes, antioxidants and nutritional status of T. aestivum were investigated in this study. It was evident that drought-stressed condition had induced a negative impact on plant growth, photosynthetic pigment, gaseous exchange attributes, stomatal properties, and ion uptake by different organs (roots and shoots) of T. aestivum. The decrease in plant growth resulted from oxidative stress and overcome by the antioxidant (enzymatic and non-enzymatic) compounds, since their concentration increased in response to dehydration. Seed priming with POLE positively increased plant growth and photosynthesis, by decreasing oxidative stress indicators and increasing activities of antioxidant (enzymatic and non-enzymatic) compounds, compared to the plants which were grown without the application of POLE. Our results also depicted that optimum concentration of POLE for T. aestivum seedlings under drought condition was 20%, while further increase in POLE (30 and 40%) induced a non-significant (P < 0.05) effect on growth (shoot and root length) and biomass (fresh and dry weight) of T. aestivum seedling. Here we concluded that the understanding of the role of seed priming with POLE in the increment of growth profile, photosynthetic measurements and nutritional status introduces new possibilities for their effective use in drought-stressed condition and provides a promising strategy for T. aestivum tolerance against drought-stressed condition. [ABSTRACT FROM AUTHOR]

In the present study, ameliorative capabilities of wuxal amino (bio stimulant) under salt stress has been investigated through adaptive mechanisms and antioxidant potential in tomato plants. In the experiment, two different concentrations (2 cm L-1 and 3 cm L-1) of wuxal amino through foliar application and soil irrigation were applied to the salt (150 mM) treated tomato plants and then morphological traits, photosynthetic pigments, osmolytes, secondary metabolites, oxidative stress and antioxidant enzymes activity were assessed at 60 days after planting. The results revealed that salt stress decreased the growth parameters, photosynthetic pigments, soluble sugars and soluble protein whereas, content of proline, ascorbic acid, total phenols, malondialdehyde, hydrogen peroxide and the activity of antioxidant enzymes activity increased under salt stress. Moreover, Wuxal amino application through foliar or soil to salt stressed plants improved morphological traits, photosynthetic pigments, osmolytes, total phenol and antioxidant enzymes activity. Interestingly, the deleterious impact of salinity on tomato plants were significantly reduced and it can be evident from reduced MDA and H 2 O 2 levels. These responses varied with the mode (foliar or soil) of application of Wuxal amino under different concentrations (2 cm L-1 and 3 cm L-1). It was concluded that application of Wuxal amino (2 cm L-1, foliar) and (3 cm L-1; soil) proved best and could be commercially used as eco-friendly tool for the protection of tomato plants grown under salinity stress. [ABSTRACT FROM AUTHOR]

Brassinosteroids (BRs) are well recognized for their defensive role in plants under abiotic stress conditions, but 28-homobrassinolide (HBR)-induced tolerance to drought stress has not been reported in soybean (Glycine max L.). The present study investigated the effect of HBR on soybean seedlings under drought stress. Drought stress suppressed growth and photosynthetic systems while increased the proline, glycine betaine (GB), anthocyanin, total phenolic (TP), and total flavonoid (TF) levels in soybean seedlings. HBR restricted reactive oxygen species (ROS) accumulation and decreased the hydrogen peroxide (H2O2) and malondialdehyde (MDA) content by triggering the antioxidant systems. HBR acts as a shield in soybean, protecting the plant against the harmful effects of methylglyoxal (MG) effects by upregulating the enzymes glyoxalase I, (Gly I;15%) and glyoxalase II (Gly II;29.1%) compared to the levels in drought stressed seedlings. Overall, HBR improved drought tolerance in soybean seedlings by modulating osmolytes, the AsA–GSH cycle, and enzyme activities. [ABSTRACT FROM AUTHOR]

Salinity is considered as one of the devastating abiotic stress factors and global climate change has further worsened the situation. Present experiments were aimed to evaluate the role of calcium (Ca) availability on growth and salinity tolerance mechanisms in soybean. Seedlings were grown with (2 mM Ca) and without Ca supplementation and modulation in key physiological and biochemical parameters were studied. Salinity (100 mM NaCl) stress resulted in growth reduction in terms of height and biomass accumulation, which was more pronounced in Ca-deficient plants. Relative to control (Ca deficient) and NaCl stressed plants, Ca supplemented seedlings exhibited higher relative water content, pigment synthesis and the photosynthetic efficiency. Ca availability affected the synthesis of proline, glycine betaine and soluble sugars under normal and saline growth conditions. Optimal Ca supplementation up-regulated the activities of antioxidant enzymes assayed and the contents of non-enzymatic antioxidants (ascorbate, glutathione, and tocopherol) thereby reflecting in amelioration of NaCl induced oxidative damage. Moreover, increased accumulation of phenols due to Ca supplementation and the amelioration of NaCl mediated decline if nitrate reductase activity was observed. More importantly, Ca availability reduced the accumulation of Na under control and NaCl stressed conditions restricting the damging effects on metabolism. Availability of optimal Ca potentially regulates the salinity tolerance mechanisms in soybean by maintaining osmoregulation and antioxidant metabolism. [ABSTRACT FROM AUTHOR]

Excess selenium (Se) causes toxicity, and nitric oxide (NO)'s function in spermine (Spm)-induced tolerance to Se stress is unknown. Using wheat plants exposed to 1 mM sodium selenate—alone or in combination with either 1 mM Spm, 0.1 mM NO donor sodium nitroprusside (SNP) or 0.1 mM NO scavenger cPTIO—the potential beneficial effects of these compounds to palliate Se-induced stress were evaluated at physiological, biochemical and molecular levels. Se-treated plants accumulated Se in their roots (92%) and leaves (95%) more than control plants. Furthermore, Se diminished plant growth, photosynthetic traits and the relative water content and increased the levels of malondialdehyde, H2O2, osmolyte and endogenous NO. Exogenous Spm significantly decreased the levels of malondialdehyde by 28%, H2O2 by 37% and electrolyte leakage by 42%. Combined Spm/NO treatment reduced the Se content and triggered plant growth, photosynthetic traits, antioxidant enzymes and glyoxalase systems. Spm/NO also upregulated MTP1, MTPC3 and HSP70 and downregulated TaPCS1 and NRAMP1 (metal stress-related genes involved in selenium uptake, translocation and detoxification). However, the positive effects of Spm on Se-stressed plants were eliminated by the NO scavenger. Accordingly, data support the notion that Spm palliates selenium-induced oxidative stress since the induced NO elicits antioxidant defence upregulation but downregulates Se uptake and translocation. These findings pave the way for potential biotechnological approaches to supporting sustainable wheat crop production in selenium-contaminated areas. [ABSTRACT FROM AUTHOR]

The study examined the effects of jasmonic acid (100 nmol, JA) priming and foliar application of spermidine (1 mM, Spd), both individually and combined, on mitigating cadmium (100 μM, Cd) stress- induced oxidative damage in wheat. Cadmium stress reduced plant height and dry mass, but JA priming and/or Spd treatment increased resistance. Cd stress significantly decreased carotenoids, total chlorophylls, glutamate 1-semialdehyde (GSA), and δ-aminolevulinic acid (ALA), but JA and Spd treatments counteracted these reductions. Photosynthetic parameters improved under JA and Spd treatments, with combined treatment showing greater alleviation. Cd exposure increased lipid peroxidation, hydrogen peroxide, electrolyte leakage, and superoxide, but these oxidative stress indicators were significantly reduced after JA and Spd treatment. Antioxidant enzyme activity was upregulated by JA priming and Spd application, both under unstressed and Cd-stressed conditions. JA and/or Spd treatments also increased ascorbic acid, lowered glutathione concentration, and upregulated glyoxylase activity, reducing methylglyoxal accumulation. Additionally, secondary compounds (phenols and flavonoids) and osmolytes (proline and glycine betaine) levels improved. Proline oxidase activity decreased, indicating controlled proline buildup, while γ-glutamyl kinase activity increased. JA and/or Spd treatments significantly reduced Cd accumulation in seedlings. The study concluded that JA and Spd treatments enhance the plant's defensive mechanisms against oxidative stress by boosting antioxidant enzymes and secondary metabolism. [ABSTRACT FROM AUTHOR]

Chromium (Cr) is among the most widespread toxic trace elements found in agricultural soils resulting from various anthropogenic activities. However, the role of micronutrient-amino acid chelates in reducing Cr toxicity in crop plants has recently been suggested. The present study was conducted to explore the effect of iron (Fe) chelated with lysine (lys) on plant growth, biomass, gaseous exchange attributes, oxidative stress indicators, antioxidant response, and Cr uptake in rapeseed (Brassica napus L.) plants irrigated with different levels of tannery wastewater in soil collected from District Kasur of Pakistan. B. napus seedlings (thirty-day-old) were shifted to pots irrigated with different levels of tannery wastewater. After two weeks, foliar application of Fe–lys (5 mM) was carried out for four successive weeks, and plants were harvested carefully post ten weeks of cultivation in tannery wastewater, under controlled conditions. Toxic levels of Cr in the soil significantly decreased plant height, fresh biomass of roots and leaves, dry biomass of roots and leaves, root length, number of leaves, leaf area, total chlorophyll contents, carotenoid contents, transpiration rate (E), stomatal conductance (g s), net photosynthesis (P N), and water use efficiency (WUE). Toxic Cr levels in the soil also increased oxidative stress in the roots and leaves of B. napus plants, which were overcome by the activities of various antioxidant enzymes, such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX). Moreover, increasing levels of Cr in the soil caused a significant increase in the Cr content of the roots and shoots of B. napus plants. The negative effects of Cr toxicity could be overturned by Fe–lys application, significantly increasing plant growth, biomass, chlorophyll content, and gaseous exchange attributes by reducing oxidative stress (H 2 O 2 , MDA, EL) and enhancing antioxidant enzyme activities. Furthermore, foliar application of Fe–lys reduced the Cr concentration and increased essential micronutrients (Fe contents) in the roots and shoots of B. napus plants. These results shed light on the effectiveness of Fe–lys in improving the growth and up-regulation of antioxidant enzyme activities of B. napus in response to Cr stress. However, further studies at field levels are required to explore the mechanisms of Fe–lys-mediated reduction of the toxicity of not only Cr, but possibly also other heavy metals in plants. Image 1 • Cr toxicity reduced morpho-physiological traits of B. napus plant when cultivated in tannery wastewater. • Cr toxicity also induced oxidative stress in the plant. • Application of Fe-lys alleviates Cr toxicity. • Application of Fe-lys also increased Fe contents while decreased Cr contents. [ABSTRACT FROM AUTHOR]

Being a primary toxic heavy metal, lead (Pb) contamination presents an imposing environmental and public health concern worldwide. A Bacillus subtilis PbRB3, displaying higher Pb tolerance, was isolated from the textile effluent. The bacterial culture was able to remove >80% of Pb from culture solution. Upon screening in the presence of Pb, PbRB3 strain exhibited significant plant growth promoting potential. A 3 weeks long pot experiment was established to examine the capability of PbRB3 strain for physiological and biochemical traits, and Pb accumulation tendency of mung bean at 250 and 500 mg kg−1 of Pb toxicity, respectively. With respect to control treatments, photosynthetic pigments, protein synthesis, net assimilation rate, transpiration rate and stomatal conductance were significantly constrained by Pb toxicity levels. Intrinsic and instantaneous water use efficiencies were considerably improved in inoculated plants under Pb toxicity. Compared to inoculated control, significantly higher superoxide dismutase activity in both Pb toxicity treatments, while higher malondialdehyde contents only at Pb500 treatment was recorded with PbRB3 inoculation. Catalase activity between Pb250 and Pb500 treatments was comparable at both inoculation level. Moreover, PbRB3 inoculation led to significantly higher peroxidase activity under Pb toxicity treatments compared to inoculated control. The PbRB3 inoculation led to comparable differences in root Pb content between Pb250 and Pb500 treatments. These results suggest that inoculation of Pb tolerant, Bacillus subtilis PbRB3, could be employed to improve mung bean growth potential and adaptation against Pb toxicity, and thereby accelerated Pb rhizoaccumulation from metal contaminated environment. • A Bacillus subtilis PbRB3 was isolated from textile effluent. • PbRB3 removed >80% of Pb from spiked culture solution. • Photosynthetic pigments impaired by Pb toxicity even upon inoculation. • PbRB3 improved plant water use efficiency at Pb250 and Pb500. • PbRB3 mediated Pb translocation from root to aerial part. [ABSTRACT FROM AUTHOR]

Climate change has become the global concern due to its drastic effects on the environment. Agriculture sector is the backbone of food security which remains at the disposal of climate change. Heat stress is the is the most concerning effect of climate change which negatively affect the plant growth and potential yields. The present experiment was conducted to assess the effects of exogenously applied β-sitosterol (Bs at 100 mg/L) and eucalyptus biochar (Eb at 5%) on the antioxidants and nutritional status in Thymus vulgaris under heat stressed conditions. The pot experiment was conducted in completely randomize design in which thymus plants were exposed to heat stress (33 °C) and as a result, plants showed a substantial decline in morpho-physiological and biochemical parameters e.g., a reduction of 59.46, 75.51, 100.00, 34.61, 22.65, and 38.65% was found in plant height, shoot fresh weight, root fresh weight, dry shoot weight, dry root weight and leaf area while in Bs + Eb + heat stress showed 21.16, 56.81, 67.63, 23.09, 12.84, and 35.89% respectively as compared to control. In the same way photosynthetic pigments, transpiration rate, plant nutritional values and water potential increased in plants when treated with Bs and Eb in synergy. Application of Bs and Eb significantly decreased the electrolytic leakage of cells in heat stressed thymus plants. The production of reactive oxygen species was significantly decreased while the synthesis of antioxidants increased with the application of Bs and Eb. Moreover, the application Bs and Eb increased the concentration of minerals nutrients in the plant body under heat stress. Our results suggested that application of Bs along with Eb decreased the effect of heat stress by maintaining nutrient supply and enhanced tolerance by increasing the production of photosynthetic pigments and antioxidant activity. [Display omitted] • Heat stress significantly decreased the yield of thyme plant. • Eucalyptus biochar (Eb) and β-sitosterol (Bs) synergize the tolerance in thyme plant. • Photosynthates, antioxidants and mineral nutrients increased with the co-application of Eb and Bs under heat stress. [ABSTRACT FROM AUTHOR]

Soil in mining areas is typically highly contaminated with heavy metals and lack essential nutrients for plants. Phosphorus reduces oxidative stress, improves plant growth, composition, and cellular structure, as well as facilitates the phytoremediation potential of fibrous crop plant species. In this study, we investigated two jute (Corchorus capsularis) varieties HongTieGuXuan and GuBaChangJia cultivated in copper (Cu)-contaminated soil (2221 mg kg−1), under different applications of phosphorus (0, 30, 60, and 120 kg ha−1) at both anatomical and physiological levels. At the same Cu concentration, the tolerance index of HongTieGuXuan was higher than that of GuBaChangJia, indicating that HongTieGuXuan may be more tolerant to Cu stress. Although the normal concentration of P (60 kg ha−1) in the soil improved plant growth, biomass, chlorophyll content, fibre yield and quality, and gaseous exchange attributes. However, high concentration of P (120 kg ha−1) was toxic to both jute varieties affected morphological and physiological attributes of the plants under same level of Cu. Moreover, Cu toxicity increased the oxidative stress in the leaves of both jute varieties was overcome by the activities of antioxidant enzymes. Furthermore, the high concentration of Cu altered the ultrastructure of chloroplasts, plastoglobuli, mitochondria, and many other cellular organelles in both jute varieties. Thus, phytoextraction of Cu by both jute varieties increased with the increase in P application in the Cu-contaminated soil. This suggests that P application enhanced the phytoremediation potential jute plants and can be cultivated as fibrous crop in Cu-contaminated sites. Image 1 • External application of P is pre-requisite for the better growth in jute under stress condition. • The variety HongTieGuXuan was proved more tolerant as compared to GuBaChangJia. • Application of P assisted phytoextraction of Cu in both jute varieties. • Phytotoxicity of Cu destroy ultra-structure of chloroplast. • Plant has strong antioxidant defence system to tolerate Cu-stress. [ABSTRACT FROM AUTHOR]

• Waterlogging (WL) inhibited plant growth and oxidative stress. • Trichoderma harzianum (TH) improved plant physiology and metabolism under WL. • TH maintains plant nutrient status and improves the content of photosynthetic pigments under WL. • TH upregulates antioxidant defense system and decreases oxidative stress under WL. • TH upregulates gene expression related to sugar and alcohol metabolism as well as aquaporin. We studied the role of Trichoderma harzianum (TH) in improving the physiological, biochemical, hormonal, and molecular parameters of tomato seedlings grown under waterlogging (WL, for 14 and 28 days). Pretreatment with TH significantly improved the growth of tomato by enhancing the chlorophyll synthesis and uptake of essential ions, including nitrogen, phosphorus, and potassium. A reduction in anthocyanin content was also ameliorated significantly by TH pretreatment. TH significantly mitigated the WL-induced decline in height and in fresh and dry biomass accumulation. Accumulation of proline, flavonoids, anthocyanin, sugars, and soluble protein increased with TH pretreatment. At both growth periods (14 and 28 days after treatment [DAT]), the accumulation of secondary metabolites, including total phenols and flavonoids, and the redox components (tocopherols) were increased significantly by TH pretreatment. Increased synthesis of metabolites maintained the antioxidant status of tomato, resulting in amelioration of WL-induced oxidative effects on membranes. WL and TH treatments significantly increased ethylene production and decreased abscisic acid content at both growth periods. The accumulation of reactive oxygen species, like hydrogen peroxide, in TH treated seedlings was correlated with the upregulation of the Fe-SOD gene. WL stress triggered the activity of sucrose synthase (SUS), lactate dehydrogenase (LDH), and pyruvate decarboxylase (PDC), which reached a maximum at 14 DAT, and TH pretreatment resulted in further enhancement above control and WL-stressed levels. Quantitative RT-PCR revealed differential expression of genes, where Fe-SOD and ADH were upregulated due to TH treatment and ARE, ACO, ERF, and aquaporin were downregulated relative to control plants. Pretreatment of tomato seedlings with TH improved tolerance to WL by maintaining the antioxidant status, sugar metabolism, and expression of critical genes. These results suggest that TH pretreatment is an effective way to improve WL tolerance in tomato at vegetative stage. [ABSTRACT FROM AUTHOR]