Foliar Spray of Alpha-Tocopherol Modulates Antioxidant Potential of Okra Fruit under Salt Stress

As an antioxidant, alpha-tocopherol (α-Toc) protects plants from salinity-induced oxidative bursts. This study was conducted twice to determine the effect of α-Toc as a foliar spray (at 0 (no spray), 100, 200, and 300 mg L−1) to improve the yield and biochemical constituents of fresh green capsules of okra (Abelmoschus esculentus L. Moench) under salt stress (0 and 100 mM). Salt stress significantly reduced K+ and Ca2+ ion concentration and yield, whereas it increased H2O2, malondialdehyde (MDA), Na+, glycine betaine (GB), total free proline, total phenolics, and the activities of catalase (CAT), guaiacol peroxidase (GPX), and protease in both okra varieties (Noori and Sabzpari). Foliar application of α-Toc significantly improved the yield in tested okra varieties by increasing the activity of antioxidants (CAT, GPX, SOD, and ascorbic acid), accumulation of GB, and total free proline in fruit tissues under saline and non-saline conditions. Moreover, α-Toc application as a foliar spray alleviated the adverse effects of salt stress by reducing Na+ concentration, MDA, and H2O2 levels and improving the uptake of K+ and Ca2+. Among the tested okra varieties, Noori performed better than Sabzpari across all physio-biochemical attributes. Of all the foliar-applied α-Toc levels, 200 mg L−1 and 300 mg L−1 were more effective in the amelioration of salinity-induced adverse effects in okra. Thus, we concluded that higher levels of α-Toc (200 mg L−1 and 300 mg L−1) combat salinity stress more effectively by boosting the antioxidant potential of okra plants.

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Ion and mineral concentrations in roots and leaves of two grapevine cultivars as affected by nitric oxide foliar application under NaCl stress

OENO One ◽

10.20870/oeno-one.2015.49.3.85 ◽

2015 ◽

Vol 49 (3) ◽

pp. 155

Author(s):

Jafar Amiri ◽

Saeid Eshghi

Keyword(s):

Nitric Oxide ◽

Adverse Effects ◽

Foliar Application ◽

Foliar Spray ◽

Nacl Stress ◽

Nitric Oxide Donor ◽

Nutrient Element ◽

Mineral Concentration ◽

Environmental Threats ◽

Element Uptake

Aim: The present study was conducted to investigate the effects of SNP (sodium nitroprusside, as nitric oxide donor) on mineral concentration in two grapevine (Vitis vinifera L.) cultivars, Qarah Shani and Thompson Seedless, under different levels of NaCl stress.Methods and results: The plants were exposed to NaCl at the rate of 0, 25, 50, 75 and 100 mM in nutrient solution and foliar spray of SNP at 0, 0.5, 1 and 1.5 mM under an open hydroponic system. Results indicated that with increasing salinity levels, the Cl- and Na+ concentrations increased and the K+, Ca2+, Mg2+, NO3-N, Zn2+, Fe2+ concentrations and K+/Na+ ratio decreased in both cultivars. However, application of SNP mitigated the Cl- and Na+ concentrations and improved the K+, Ca2+, Mg2+ and NO3-N concentrations in leaves and roots of both cultivars. The application of SNP did not significantly affect Zn2+ and Fe2+ concentrations under 100 mM NaCl.Conclusion: The adverse effects of NaCl stress in nutrient element uptake were ameliorated by the exogenous application of SNP in grapevine.Significance and impact of the study: Salinity of soil and water sources is one of the most serious environmental threats in Iran. Iran ranks tenth among grape-producing countries in the world. Therefore, the application of SNP can serve as an important component to reduce the adverse effects of salinity stress in nutrient element uptake in grapevine.

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Effects of Foliar Application of Gibberellic Acid on the Salt Tolerance of Tomato and Sweet Pepper Transplants

Horticulturae ◽

10.3390/horticulturae6040093 ◽

2020 ◽

Vol 6 (4) ◽

pp. 93

Author(s):

Alessandro Miceli ◽

Filippo Vetrano ◽

Alessandra Moncada

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Gibberellic Acid ◽

Foliar Application ◽

Saline Water ◽

Foliar Spray ◽

Sweet Pepper ◽

Limiting Factor ◽

Growth Stages ◽

Promoting Effect

Seed germination and early seedling growth are the plant growth stages most sensitive to salt stress. Thus, the availability of poor-quality brackish water can be a big limiting factor for the nursery vegetable industry. The exogenous supplementation of gibberellic acid (GA3) may promote growth and vigor and counterbalance salt stress in mature plants. This study aimed to test exogenous supplementation through foliar spray of 10−5 M GA3 for increasing salt tolerance of tomato and sweet pepper seedlings irrigated with increasing salinity (0, 25, and 50 mM NaCl during nursery growth. Tomato and sweet pepper seedlings suffered negative effects of salinity on plant height, biomass, shoot/root ratio, leaf number, leaf area, relative water content, and stomatal conductance. The foliar application of GA3 had a growth-promoting effect on the unstressed tomato and pepper seedlings and was successful in increasing salinity tolerance of tomato seedlings up to 25 mM NaCl and up to 50 mM NaCl in sweet pepper seedlings. This treatment could represent a sustainable strategy to use saline water in vegetable nurseries limiting its negative effect on seedling quality and production time.

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Effects of foliar spray of two kinds of zinc oxide on the growth and ion concentration of sunflower cultivars under salt stress

Journal of Plant Nutrition ◽

10.1080/01904167.2015.1009107 ◽

2015 ◽

Vol 39 (2) ◽

pp. 172-180 ◽

Cited By ~ 42

Author(s):

Shahram Torabian ◽

Morteza Zahedi ◽

Amir Hossein Khoshgoftar

Keyword(s):

Zinc Oxide ◽

Salt Stress ◽

Foliar Spray ◽

Ion Concentration

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Exogenous Application of Chitosan Alleviate Salinity Stress in Lettuce (Lactuca sativa L.)

Horticulturae ◽

10.3390/horticulturae7100342 ◽

2021 ◽

Vol 7 (10) ◽

pp. 342

Author(s):

Geng Zhang ◽

Yuanhua Wang ◽

Kai Wu ◽

Qing Zhang ◽

Yingna Feng ◽

...

Keyword(s):

Salt Stress ◽

Plant Growth ◽

Foliar Application ◽

Abiotic Stress Tolerance ◽

Soluble Sugar ◽

Dry Weight ◽

Membrane Lipid ◽

Ion Concentration ◽

Leaf Chlorophyll ◽

Major Factors

Soil salinity is one of the major factors that affect plant growth and decrease agricultural productivity worldwide. Chitosan (CTS) has been shown to promote plant growth and increase the abiotic stress tolerance of plants. However, it still remains unknown whether the application of exogenous CTS can mitigate the deleterious effects of salt stress on lettuce plants. Therefore, the current study investigated the effect of foliar application of exogenous CTS to lettuce plants grown under 100 mM NaCl saline conditions. The results showed that exogenous CTS increased the lettuce total leaf area, shoot fresh weight, and shoot and root dry weight, increased leaf chlorophyll a, proline, and soluble sugar contents, enhanced peroxidase and catalase activities, and alleviated membrane lipid peroxidation, in comparison with untreated plants, in response to salt stress. Furthermore, the application of exogenous CTS increased the accumulation of K+ in lettuce but showed no significant effect on the K+/Na+ ratio, as compared with that of plants treated with NaCl alone. These results suggested that exogenous CTS might mitigate the adverse effects of salt stress on plant growth and biomass by modulating the intracellular ion concentration, controlling osmotic adjustment, and increasing antioxidant enzymatic activity in lettuce leaves.

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Exogenous application of glutamic acid promotes cucumber (Cucumis sativus L.) growth under salt stress conditions

Emirates Journal of Food and Agriculture ◽

10.9755/ejfa.2021.v33.i5.2699 ◽

2021 ◽

pp. 407

Author(s):

Pakeeza Iqbal ◽

Muhammad Awais Ghani ◽

Basharat Ali ◽

Muhammad Shahid ◽

Qumer Iqbal ◽

...

Keyword(s):

Salt Stress ◽

Glutamic Acid ◽

Cucumis Sativus ◽

Defense Mechanism ◽

Foliar Application ◽

Guaiacol Peroxidase ◽

Maximum Height ◽

Unusual Behavior ◽

Cucumis Sativus L ◽

Salinity Levels

Salinity is expected to be the major destructive abiotic stress that causes ionic and oxidative damage leading to growth reduction and ultimately plant death. Glutamic acid (GA) is an α-amino acid that is used by almost all living beings in the biosynthsis of proteins. Therefore, in the present study, we tried to investigate the effect of foliar application of glutamic acid (GA) on cucumber (Cucumis sativus L.) under altered salinity levels. Cucumber seedlings were grown in plastic pots under greenhouse conditions by applying four levels of salinity (0, 3 dS/m, 6 dS/m and 12 dS/m) and two levels of foliar applied GA (0, 10 mM). Salinity was induced by mixing the salt and soil before seed sowing; however, exogenous GA was applied when the vine length was reached up to maximum height. Morphological characters showed disruptive response under saline conditions especially in indigenous cultivar (local cucumber represented as V1). Enhanced activities of superoxide dismutase (0.29 u g-1 FW), guaiacol peroxidase (3.51 u g-1 FW) and ascorbate peroxidase (0.39 µmol AsA.mg-1 Chl min-1) were observed in salt-stressed cucumber leaves. Both varieties showed unusual behavior for malondialdehyde in decreasing manner with increasing salinity levels (2.0333 µmol g-1 FW at 12dS/m in local cultivar; while, 1.98 µmol g-1 FW at 12dS/m in hybrid cultivar SSC-228). However, exogenously applied GA played a beneficial role in promoting all morphological parameters under stress with increasing scavenging abilities against reactive oxygen species. Foliar application of GA improved plant defense mechanism with minimum destruction. Remarked calculations showed that under salt stress, GA improved plant stress tolerance against salinity by maximizing the growth rate.

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Exogenously Applied Gibberellic Acid Enhances Growth and Salinity Stress Tolerance of Maize through Modulating the Morpho-Physiological, Biochemical and Molecular Attributes

Biomolecules ◽

10.3390/biom11071005 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1005

Author(s):

Kashif Shahzad ◽

Sadam Hussain ◽

Muhammad Arfan ◽

Saddam Hussain ◽

Ejaz Ahmad Waraich ◽

...

Keyword(s):

Oxidative Stress ◽

Antioxidant Enzymes ◽

Salt Stress ◽

Gibberellic Acid ◽

Growth And Development ◽

Foliar Spray ◽

Seed Priming ◽

Ion Concentration ◽

Genes Expression ◽

Antioxidant Enzymes Activities

Soil salinity is the major limiting factor restricting plant growth and development. Little is known about the comparative and combined effects of gibberellic acid (GA3) seed priming and foliar application on maize under salt stress. The current study determined the impact of different application methods of GA3 on morpho-physiological, biochemical and molecular responses of maize seedlings under three salinity stress treatments (no salinity, moderate salinity-6 dS m−1, and severe salinity-12 dS m−1). The GA3 treatments consisted of control, hydro-priming (HP), water foliar spray (WFS), HP + WFS, seed priming with GA3 (GA3P, 100 mg L−1), foliar spray with GA3 (GA3FS, 100ppm) and GA3P + GA3FS. Salt stress particularly at 12 dS m−1 reduced the length of shoots and roots, fresh and dry weights, chlorophyll, and carotenoid contents, K+ ion accumulation and activities of antioxidant enzymes, while enhanced the oxidative damage and accumulation of the Na+ ion in maize plants. Nevertheless, the application of GA3 improved maize growth, reduced oxidative stress, and increased the antioxidant enzymes activities, antioxidant genes expression, and K+ ion concentration under salt stress. Compared with control, the GA3P + GA3FS recorded the highest increase in roots and shoots length (19-37%), roots fresh and dry weights (31-43%), shoots fresh and dry weights (31-47%), chlorophyll content (21-70%), antioxidant enzymes activities (73.03-150.74%), total soluble protein (13.05%), K+ concentration (13-23%) and antioxidants genes expression levels under different salinity levels. This treatment also reduced the H2O2 content, and Na+ ion concentration. These results indicated that GA3P + GA3FS could be used as an effective tool for improving the maize growth and development, and reducing the oxidative stress in salt-contaminated soils.

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Chitosan–Selenium Nanoparticle (Cs–Se NP) Foliar Spray Alleviates Salt Stress in Bitter Melon

Nanomaterials ◽

10.3390/nano11030684 ◽

2021 ◽

Vol 11 (3) ◽

pp. 684

Author(s):

Morteza Sheikhalipour ◽

Behrooz Esmaielpour ◽

Mahdi Behnamian ◽

Gholamreza Gohari ◽

Mousa Torabi Giglou ◽

...

Keyword(s):

Salt Stress ◽

Foliar Application ◽

Foliar Spray ◽

Growth And Yield ◽

Critical Parameters ◽

Bitter Melon ◽

Negative Effects ◽

Positive Effects ◽

Relative Water ◽

Salinity Levels

Salt stress severely reduces growth and yield of plants. Considering the positive effects of selenium (Se) and chitosan (Cs) separately against abiotic stress, in these experiments, we synthesized chitosan–selenium nanoparticles (Cs–Se NPs) and investigated their ability to reduce the negative effects of salt stress on growth and some biochemical parameters of bitter melon (Momordica charantia). Bitter melon plants were grown at three NaCl salinity levels (0, 50, and 100 mM) and a foliar spray of Cs–Se NPs (0, 10, and 20 mg L−1) was applied. Some key morphological, biochemical, and physiological parameters in leaf samples and essential oil from fruit were measured at harvest. Salinity decreased growth and yield while foliar application of Cs–Se NPs increased these critical parameters. Furthermore, Cs–Se NPs enhanced bitter melon tolerance to salinity by increasing antioxidant enzyme activity, proline concentration, relative water content, and K+, and decreasing MDA and H2O2 oxidants and Na aggregation in plant tissues. Yield was also improved, as the highest amount of essential oils was produced by plants treated with Cs–Se NPs. Generally, the greatest improvement in measured parameters under saline conditions was obtained by treating plants with 20 mg L−1 Cs–Se NPs, which significantly increased salinity tolerance in bitter melon plants.

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Selenium Alleviates the Adverse Effect of Drought in Oilseed Crops Camelina (Camelina sativa L.) and Canola (Brassica napus L.)

Molecules ◽

10.3390/molecules26061699 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1699

Author(s):

Zahoor Ahmad ◽

Shazia Anjum ◽

Milan Skalicky ◽

Ejaz Ahmad Waraich ◽

Rana Muhammad Sabir Tariq ◽

...

Keyword(s):

Drought Stress ◽

Adverse Effects ◽

Yield Components ◽

Foliar Application ◽

Foliar Spray ◽

Seed Priming ◽

Brassica Napus L ◽

Yield Attributes ◽

Oilseed Crops ◽

Effects Of Drought

Drought poses a serious threat to oilseed crops by lowering yield and crop failures under prolonged spells. A multi-year field investigation was conducted to enhance the drought tolerance in four genotypes of Camelina and canola by selenium (Se) application. The principal aim of the research was to optimize the crop yield by eliciting the physio-biochemical attributes by alleviating the adverse effects of drought stress. Both crops were cultivated under control (normal irrigation) and drought stress (skipping irrigation at stages i.e., vegetative and reproductive) conditions. Four different treatments of Se viz., seed priming with Se (75 μM), foliar application of Se (7.06 μM), foliar application of Se + Seed priming with Se (7.06 μM and 75 μM, respectively) and control (without Se), were implemented at the vegetative and reproductive stages of both crops. Sodium selenite (Na2SeO3), an inorganic compound was used as Se sources for both seed priming and foliar application. Data regarding physiochemical, antioxidants, and yield components were recorded as response variables at crop maturity. Results indicated that WP, OP, TP, proline, TSS, TFAA, TPr, TS, total chlorophyll contents, osmoprotectant (GB, anthocyanin, TPC, and flavonoids), antioxidants (APX, SOD, POD, and CAT), and yield components (number of branches per plant, thousand seed weight, seed, and biological yields were significantly improved by foliar Se + priming Se in both crops under drought stress. Moreover, this treatment was also helpful in boosting yield attributes under irrigated (non-stress) conditions. Camelina genotypes responded better to Se application as seed priming and foliar spray than canola for both years. It has concluded that Se application (either foliar or priming) can potentially alleviate adverse effects of drought stress in camelina and canola by eliciting various physio-biochemicals attributes under drought stress. Furthermore, Se application was also helpful for crop health under irrigated condition.

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Silicon Improves Ion Homeostasis and Growth of Liquorice (Glycyrrhiza Uralensis Fisch. and Glycyrrhiza Inflata Bat.) Under Salt Stress by Reducing Plant Na+ Uptake

10.21203/rs.3.rs-899487/v1 ◽

2021 ◽

Author(s):

Zihui Shen ◽

Xiaozhen Pu ◽

Shaoming Wang ◽

Xiuxiu Dong ◽

Xiaojiao Cheng ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Foliar Application ◽

Photosynthetic Pigment ◽

Ion Homeostasis ◽

Foliar Spray ◽

Glycyrrhiza Uralensis ◽

Ion Balance ◽

Glycyrrhiza Uralensis Fisch ◽

Glycyrrhiza Inflata

Abstract Silicon effectively alleviates the damage caused by salt stress in plants and can improve plant salt tolerance. However, the details of the mechanism by which silicon improves salt tolerance of liquorice are limited, and the effects of foliar application of silicon on different liquorice species under salt stress are not known. Here, the effects of foliar spray of silicon on the growth, physiological and biochemical characteristics, and ion balance of Glycyrrhiza uralensis Fisch. and Glycyrrhiza inflata Bat. were investigated. High salt stress resulted in the accumulation of a large amount of Na+, decreased photosynthetic pigment content, perturbed ion homeostasis, and eventually inhibited the both liquorice species growth. These effects were more pronounced in G. uralensis, as G. inflata is more salt tolerant than G. uralensis. Foliar spraying of silicon effectively reduced the decomposition of photosynthetic pigments, improved gas exchange parameters, and promoted photosynthesis. It also effectively inhibited lipid peroxidation and electrolyte leakage and enhanced osmotic adjustment of plants. Further, silicon application increased the K+ concentration, reduced Na+ absorption, transport and accumulation in the plants. The protective effects of silicon were more pronounced in G. uralensis than those in G. inflata. In conclusion, silicon reduces Na+ absorption, improves ion balance, and alleviates the negative effects of salt stress in the two liquorice species studied, but the effect is liquorice species-dependent. These findings may inform novel strategies for protecting liquorice plants against salt stress and also provide a theoretical basis for the evaluation of salt tolerance and the scientific cultivation of liquorice.

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Responses of leaf gas exchange attributes, photosynthetic pigments and antioxidant enzymes in NaCl-stressed cotton (Gossypium hirsutum L.) seedlings to exogenous glycine betaine and salicylic acid

BMC Plant Biology ◽

10.1186/s12870-020-02624-9 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Abdoul Kader Mounkaila Hamani ◽

Guangshuai Wang ◽

Mukesh Kumar Soothar ◽

Xiaojun Shen ◽

Yang Gao ◽

...

Keyword(s):

Enzyme Activity ◽

Salt Stress ◽

Gas Exchange ◽

Antioxidant Enzyme ◽

Foliar Application ◽

Leaf Gas Exchange ◽

Foliar Spray ◽

Antioxidant Enzyme Activity ◽

Relative Water ◽

Leaf Relative Water Content

Abstract Background Application of exogenous glycine betaine (GB) and exogenous salicylic acid (SA) mitigates the adverse effects of salinity. Foliar spraying with exogenous GB or SA alleviates salt stress in plants by increasing leaf gas exchange and stimulating antioxidant enzyme activity. The effects of foliar application of exogenous GB and SA on the physiology and biochemistry of cotton seedlings subjected to salt stress remain unclear. Results Results showed that salt stress of 150 mM NaCl significantly reduced leaf gas exchange and chlorophyll fluorescence and decreased photosynthetic pigment quantities and leaf relative water content. Foliar spray concentrations of 5.0 mM exogenous GB and 1.0 mM exogenous SA promoted gas exchange and fluorescence in cotton seedlings, increased quantities of chlorophyll pigments, and stimulated the antioxidant enzyme activity. The foliar spray also increased leaf relative water content and endogenous GB and SA content in comparison with the salt-stressed only control. Despite the salt-induced increase in antioxidant enzyme content, exogenous GB and SA in experimental concentrations significantly increased the activity of glutathione reductase, ascorbate peroxidase, superoxide dismutase, catalase and peroxidase, and decreased malondialdehyde content under salt stress. Across all experimental foliar spray GB and SA concentrations, the photochemical efficiency of photosystem II (FV/FM) reached a peak at a concentration of 5.0 mM GB. The net photosynthetic rate (Pn) and FV/FM were positively correlated with chlorophyll a and chlorophyll b content in response to foliar spraying of exogenous GB and SA under salt stress. Conclusions We concluded, from our results, that concentrations of 5.0 mM GB or 1.0 mM SA are optimal choices for mitigating NaCl-induced damage in cotton seedlings because they promote leaf photosynthesis, increase quantities of photosynthetic pigments, and stimulate antioxidant enzyme activity. Among, 5.0 mM GB and 1.0 mM SA, the best performance in enhancing endogenous GB and SA concentrations was obtained with the foliar application of 1.0 mM SA under salt stress.

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