Role of exogenous-applied salicylic acid, zinc and glycine betaine to improve drought-tolerance in wheat during reproductive growth stages

Abstract Background Drought has become a dangerous threat to reduce crop productivity throughout the world. Exogenous applications of regulators, micronutrients, and/or osmoprotectants for inducing drought-tolerance in field crops have been effectively adopted. A controlled pot study was performed to investigate the relative efficacy of salicylic acid (SA), zinc (Zn), and glycine betaine (GB) as foliar applications on the growth, tissues pigments content, relative water content (RWC), leaf gas-exchange, antioxidant enzymes activity, reactive oxygen species (ROS) accumulation, osmolytes contents, and the yield parameters of wheat plants subjected to two soil water conditions (85% field capacity: well-watered, 50% field capacity: water-deficient) during reproductive growth stages. Results Water deficient conditions significantly decreased the growth, yield parameters, RWC, photosynthesis pigment, and gas-exchange attributes except for intercellular CO2 concentration. However, foliar applications remarkably improved the growth and yield parameters under water deficit conditions. Under drought condition, exogenous applications of SA, Zn, and GB increased the grain yield pot− 1 by 27.99, 15.23 and 37.36%, respectively, as compared to the control treatment. Drought stress statistically increased the contents of hydrogen peroxide (H2O2), superoxide anion radical (O2•−), and malonaldehyde (MDA), and elevated the harmful oxidation to cell lipids in plants, however, they were considerably reduced by foliar applications. Foliar applications of SA, Zn, and GB decreased MDA content by 29.09, 16.64 and 26.51% under drought stress, respectively, as compared to the control treatment. Activities of all antioxidant enzymes, proline content, and soluble sugar were increased in response to foliar applications under water deficit conditions. Conclusions Overall, foliar application of GB, SA, and Zn compounds improved the drought-tolerance in wheat by decreasing the ROS accumulation, promoting enzymatic antioxidants, and increasing osmolytes accumulation. Finally, GB treatment was most effective in thoroughly assessed parameters of wheat followed by SA and Zn applications to alleviate the adverse effects of drought stress.

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Role of Exogenous-Applied Salicylic Acid, Zinc And Glycine Betaine To Improve Drought-Tolerance In Wheat During Reproductive Growth Stages

10.21203/rs.3.rs-923487/v1 ◽

2021 ◽

Author(s):

Ramadan Shemi ◽

Rui Wang ◽

El-Sayed M.S. Gheith ◽

Hafiz Athar Hussain ◽

Linna Cholidah ◽

...

Keyword(s):

Salicylic Acid ◽

Antioxidant Enzymes ◽

Drought Stress ◽

Gas Exchange ◽

Drought Tolerance ◽

Glycine Betaine ◽

Field Capacity ◽

Growth Stages ◽

Yield Parameters ◽

Ros Accumulation

Abstract Background: Drought has become a dangerous threat to reduce crop productivity throughout the world. Exogenous application of regulators, micronutrients, or osmoprotectants for inducing drought-tolerance in field crops has been effectively adopted. A controlled pot study was performed to investigate the relative efficacy of salicylic acid (SA), zinc (Zn), and glycine betaine (GB) as foliar applications on the growth, tissues pigments content, relative water content (RWC), leaf gas exchange, antioxidant enzymes activity, reactive oxygen species (ROS) accumulation, osmolytes contents and the yield parameters of wheat plants subjected to two soil water conditions (85% field capacity: well-watered, 50% field capacity: water-deficient) during reproductive growth stages.Results: Water deficient conditions significantly decreased the growth, yield parameters, RWC, photosynthesis pigment, and gas exchange attributes except for intercellular CO2 concentration. However, foliar applications remarkably improved the growth parameters under water deficit conditions. Drought stress statistically increased the contents of hydrogen peroxide (H2O2), superoxide anion radical (O2 •−), and malonaldehyde (MDA), and elevated the harmful oxidation to cell lipids in plants, however, they were considerably reduced by foliar applications. Activities of all antioxidant enzymes, proline content, and soluble sugar were increased in response to foliar applications under water deficit conditions.Conclusions: Overall, foliar application of GB, SA, and Zn compounds improved the drought-tolerance in wheat by decreasing the ROS accumulation, promoting enzymatic antioxidants, and increasing osmolytes accumulation. Finally, GB treatment was most effective in thoroughly assessed parameters of wheat followed by SA and Zn applications to alleviate the adverse effects of drought stress.

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Effects of salicylic acid, zinc and glycine betaine on morpho-physiological growth and yield of maize under drought stress

Scientific Reports ◽

10.1038/s41598-021-82264-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ramadan Shemi ◽

Rui Wang ◽

El-Sayed M. S. Gheith ◽

Hafiz Athar Hussain ◽

Saddam Hussain ◽

...

Keyword(s):

Salicylic Acid ◽

Antioxidant Enzymes ◽

Drought Stress ◽

Gas Exchange ◽

Drought Tolerance ◽

Glycine Betaine ◽

Field Capacity ◽

Yield Attributes ◽

Chlorophyll Contents ◽

Water Conditions

AbstractDrought is one of the major environmental stresses that negatively affect the maize (Zea mays L.) growth and production throughout the world. Foliar applications of plant growth regulators, micronutrients or osmoprotectants for stimulating drought-tolerance in plants have been intensively reported. A controlled pot experiment was conducted to study the relative efficacy of salicylic acid (SA), zinc (Zn), and glycine betaine (GB) foliar applications on morphology, chlorophyll contents, relative water content (RWC), gas-exchange attributes, activities of antioxidant enzymes, accumulations of reactive oxygen species (ROS) and osmolytes, and yield attributes of maize plants exposed to two soil water conditions (85% field capacity: well-watered, 50% field capacity: drought stress) during critical growth stages. Drought stress significantly reduced the morphological parameters, yield and its components, RWC, chlorophyll contents, and gas-exchange parameters except for intercellular CO2 concentration, compared with well water conditions. However, the foliar applications considerably enhanced all the above parameters under drought. Drought stress significantly (p < 0.05) increased the hydrogen peroxide and superoxide anion contents, and enhanced the lipid peroxidation rate measured in terms of malonaldehyde (MDA) content. However, ROS and MDA contents were substantially decreased by foliar applications under drought stress. Antioxidant enzymes activity, proline content, and the soluble sugar were increased by foliar treatments under both well-watered and drought-stressed conditions. Overall, the application of GB was the most effective among all compounds to enhance the drought tolerance in maize through reduced levels of ROS, increased activities of antioxidant enzymes and higher accumulation of osmolytes contents.

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EXOGENOUS APPLICATION OF SALICYLIC ACID AT DIFFERENT PLANT GROWTH STAGES IMPROVES PHYSIOLOGICAL PROCESSES IN MARIGOLD (Tagetes erecta L.)

The Pakistan Journal of Agricultural Sciences ◽

10.21162/pakjas/19.7276 ◽

2019 ◽

Vol 56 (03) ◽

pp. 541-548

Author(s):

Syed Mohsin Abbas

Keyword(s):

Salicylic Acid ◽

Drought Stress ◽

Drought Tolerance ◽

Plant Growth ◽

Tagetes Erecta ◽

Growth Stages ◽

Reproductive Growth ◽

Exogenous Application ◽

Physiological Processes ◽

Tagetes Erecta L

Marigold (Tagetes erecta L.) is a famous flowering plant in the world which has medicinal and industrial values. In Pakistan, it is an important floricultural crop and used widely as bedding plant. Pakistan is facing water shortage, which is affecting crops growth and productivity including marigold badly. Drought stress reduces plant growth, physiological and biochemical processes and flower yield in marigold. Salicylic acid (SA) is a phytohormone and its exogenous application is an effective approach to support plant during drought stress and mitigate its harmful impacts. Present study was planned to evaluate the effect of exogenous salicylic acid application on growth response and drought tolerance potential of marigold. For this purpose, a pot experiment was conducted in rain out shelter with four treatments of SA i.e., no SA application, SA foliar @ 100 mg L-1 application at vegetative growth, reproductive growth and at vegetative plus reproductive growth stages, under normal irrigation as well as under drought stress conditions were imposed. Drought stress was applied by skipping every alternate irrigation. The results showed that SA application at reproductive growth stage of marigold improved plant growth by improving its physiological processes during drought stress. It was concluded that exogenous application of SA, not only increased bioproductivity of marigold plants but also ameliorated the negative impacts of drought stress by enhancing drought tolerance potential in plants.

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The Effects of Drought on Leaf Gas Exchange and Growth of Three Species of Herbaceous Perennials

HortScience ◽

10.21273/hortsci.33.3.540a ◽

1998 ◽

Vol 33 (3) ◽

pp. 540a-540

Author(s):

K.J. Prevete ◽

R.T. Fernandez

Keyword(s):

Drought Stress ◽

Stomatal Conductance ◽

Gas Exchange ◽

Drought Tolerance ◽

Transpiration Rate ◽

Leaf Gas Exchange ◽

Gas Analysis ◽

Herbaceous Perennials ◽

Effects Of Drought ◽

Analysis System

Three species of herbaceous perennials were tested on their ability to withstand and recover from drought stress periods of 2, 4, and 6 days. Eupatorium rugosum and Boltonia asteroides `Snowbank' were chosen because of their reported drought intolerance, while Rudbeckia triloba was chosen based on its reported drought tolerance. Drought stress began on 19 Sept. 1997. Plants were transplanted into the field the day following the end of each stress period. The effects of drought on transpiration rate, stomatal conductance, and net photosynthetic rate were measured during the stress and throughout recovery using an infrared gas analysis system. Leaf gas exchange measurements were taken through recovery until there were no differences between the stressed plants and the control plants. Transpiration, stomatal conductance, and photosynthesis of Rudbeckia and Boltonia were not affected until 4 days after the start of stress. Transpiration of Eupatorium decreased after 3 days of stress. After rewatering, leaf gas exchange of Boltonia and Rudbeckia returned to non-stressed levels quicker than Eupatorium. Growth measurements were taken every other day during stress, and then weekly following transplanting. Measurements were taken until a killing frost that occurred on 3 Nov. There were no differences in the growth between the stressed and non-stressed plants in any of the species. Plants will be monitored throughout the winter, spring, and summer to determine the effects of drought on overwintering capability and regrowth.

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Promotion of Growth and Physiological Characteristics in Water-Stressed Triticum aestivum in Relation to Foliar-Application of Salicylic Acid

Water ◽

10.3390/w13091316 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1316

Author(s):

Abida Parveen ◽

Muhammad Arslan Ashraf ◽

Iqbal Hussain ◽

Shagufta Perveen ◽

Rizwan Rasheed ◽

...

Keyword(s):

Ascorbic Acid ◽

Salicylic Acid ◽

Antioxidant Enzymes ◽

Water Stress ◽

Photosynthetic Pigments ◽

Foliar Spray ◽

Field Capacity ◽

Available Water ◽

Drought Tolerant ◽

Growth Attributes

The present work reports the assessment of the effectiveness of a foliar-spray of salicylic acid (SA) on growth attributes, biochemical characteristics, antioxidant activities and osmolytes accumulation in wheat grown under control (100% field capacity) and water stressed (60% field capacity) conditions. The total available water (TAW), calculated for a rooting depth of 1.65 m was 8.45 inches and readily available water (RAW), considering a depletion factor of 0.55, was 4.65 inches. The water contents corresponding to 100 and 60% field capacity were 5.70 and 1.66 inches, respectively. For this purpose, seeds of two wheat cultivars (Fsd-2008 and S-24) were grown in pots subjected to water stress. Water stress at 60% field capacity markedly reduced the growth attributes, photosynthetic pigments, total soluble proteins (TSP) and total phenolic contents (TPC) compared with control. However, cv. Fsd-2008 was recorded as strongly drought-tolerant and performed better compared to cv. S-24, which was moderately drought tolerant. However, water stress enhanced the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2) and membrane electrolyte leakage (EL) and modulated the activities of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), as well as accumulation of ascorbic acid (AsA), proline (Pro) and glycine betaine (GB) contents. Foliar-spray with salicylic acid (SA; 0, 3 mM and 6 mM) effectively mitigated the adverse effects of water stress on both cultivars. SA application at 6 mM enhanced the shoot and root length, as well as their fresh and dry weights, and improved photosynthetic pigments. SA foliage application further enhanced the activities of antioxidant enzymes (SOD, POD, and CAT) and nonenzymatic antioxidants such as ascorbic acid and phenolics contents. However, foliar-spray of SA reduced MDA, H2O2 and membrane permeability in both cultivars under stress conditions. The results of the present study suggest that foliar-spray of salicylic acid was effective in increasing the tolerance of wheat plants under drought stress in terms of growth attributes, antioxidant defense mechanisms, accumulation of osmolytes, and by reducing membrane lipid peroxidation.

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Evaluation of Silicon and Proline Application on the Oxidative Machinery in Drought-Stressed Sugar Beet

Antioxidants ◽

10.3390/antiox10030398 ◽

2021 ◽

Vol 10 (3) ◽

pp. 398

Author(s):

Muneera D. F. AlKahtani ◽

Yaser M. Hafez ◽

Kotb Attia ◽

Emadeldeen Rashwan ◽

Latifa Al Husnain ◽

...

Keyword(s):

Antioxidant Enzymes ◽

Drought Stress ◽

Phenolic Compounds ◽

Sugar Beet ◽

Harmful Effect ◽

Sugar Yield ◽

Total Phenolic ◽

Total Phenolic Compounds ◽

Sod Activity ◽

Yield Parameters

Drought stress deleteriously affects growth, development and productivity in plants. So, we examined the silicon effect (2 mmol) and proline (10 mmol) individually or the combination (Si + proline) in alleviating the harmful effect of drought on total phenolic compounds, reactive oxygen species (ROS), chlorophyll concentration and antioxidant enzymes as well as yield parameters of drought-stressed sugar beet plants during 2018/2019 and 2019/2020 seasons. Our findings indicated that the root diameter and length (cm), root and shoot fresh weights (g plant−1) as well as root and sugar yield significantly decreased in sugar beet plants under drought. Relative water content (RWC), nitrogen (N), phosphorus (P) and potassium (K) contents and chlorophyll (Chl) concentration considerably reduced in stressed sugar beet plants that compared with control in both seasons. Nonetheless, lipid peroxidation (MDA), electrolyte leakage (EL), hydrogen peroxide (H2O2) and superoxide (O2●−) considerably elevated as signals of drought. Drought-stressed sugar beet plants showed an increase in proline accumulation, total phenolic compounds and up-regulation of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) activity to mitigate drought effects. Si and proline individually or the combination Si + proline considerably increased root and sugar yield, sucrose%, Chl concentration and RWC, MDA and EL were remarkably reduced. The treatments led to adjust proline and total phenolic compounds as well as CAT and SOD activity in stressed sugar beet plants. We concluded that application of Si + proline under drought stress led to improve the resistance of sugar beet by regulating of proline, antioxidant enzymes, phenolic compounds and improving RWC, Chl concentration and Nitrogen, Phosphorus and Potassium (NPK) contents as well as yield parameters.

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DEHYDRIN PROFILES OF SOME IRANIAN MELON VARIETIES (Cucumis melo L. Merr) UNDER DROUGHT STRE SS CONDITIONS

Acta Scientiarum Polonorum Hortorum Cultus ◽

10.24326/asphc.2019.6.8 ◽

2019 ◽

Vol 18 (6) ◽

pp. 75-84

Author(s):

Alireza Motallebi-Azar ◽

István Papp ◽

Anita Szegő

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Water Content ◽

Water Status ◽

Field Capacity ◽

Total Protein Content ◽

Severe Drought ◽

Molecular Weights ◽

Potential Marker ◽

Relative Water

Dehydrins are proteins that play a role in the mechanism of drought tolerance. This study aimed at establishing dehydrin profile and accumulation in four local melon varieties of Iran: Mino, Dargazi, Saveii, and Semsori, as well as in a commercial variety Honeydew. Plants were treated with drought stress by adjusting the soil water content to 75, 50, 40, 30 and 20% of field capacity (FC) by withholding water. Water status of plants was monitored based on the seedling fresh weight (FW) and relative water content of leaves (RWC). Total protein content was extracted, then heat-stable protein (HSP) fraction was isolated for each variety and water stress treatment. After SDS-PAGE of HSP, Western blotting analysis was carried out with Anti-dehydrin rabbit (primary) and Goat anti rabbit (secondary) antibodies. ANOVA results showed that with decreasing FC below 75%, FW and RWC decreased, but these changes significantly varied among genotypes. On the basis of FW and RWC data under different drought stress treatments, the following drought-tolerant ranking was established: Mino > Dargazi > Saveii and Honeydew > Semsori, from tolerant to sensitive order. Results of Western blot analysis showed that expression of some proteins with molecular weights of 19–52 kDa was induced in the studied varieties under drought stress (% FC). Expression level of the dehydrin proteins in different varieties was variable and also depending on the drought stress level applied. However, dehydrin proteins (45 and 50 kDa) showed strong expression levels in all varieties under severe drought stress (20% FC). The abundance of dehydrin proteins was higher in tolerant varieties (Mino and Dargazi) than in moderate and drought sensitive genotypes. Consequently, dehydrins represent a potential marker for selection of genotypes with enhanced drought tolerance.

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Impact of Exogenous Applications of Salicylic Acid on the Tolerance to Drought Stress in Pepper (Capsicum Annuum L.) Plants

10.21203/rs.3.rs-116192/v1 ◽

2020 ◽

Author(s):

zahra khazaei ◽

Asghar Estaji

Keyword(s):

Electrical Conductivity ◽

Salicylic Acid ◽

Drought Stress ◽

Field Capacity ◽

Dry Weight ◽

Sweet Pepper ◽

Total Phenolic ◽

Pepper Plant ◽

Randomized Design ◽

Relative Water

Abstract Background: Drought is also one of the most widespread abiotic stresses that adversely effects the growth and development of plants. To investigate the effect of salicylic acid and drought stress on several physiological and chemical reactions in sweet pepper plants, the experiment was achieved as a factorial based on a completely randomized design in greenhouse. Drought stress levels were non-stress conditions (irrigation with field capacity), moderate stress (30% field capacity irrigation) and intense water stress (60% field capacity irrigation) and three concentrations of salicylic acid included 0 (as control), 0.5 and 1 mM were sprayed on the plant in three to four leaf stages. Results: The results showed that drought decreased fresh and dry weight of shoots and roots, leaf relative water content (RWC), fruit diameter and length, the index including chlorophyll and leaf area and increased electrical conductivity (EC), antioxidant activity, total phenolic content, ascorbate, polyphenol oxidase (PPO) and ascorbate peroxidase (APX) activity. After application of foliar salicylic acid, all of the above parameters, except the electrical conductivity content, increased. Conclusions: From the results of this experiment it is concluded that salicylic acid provides a better tolerance for drought stress in pepper plant through its influence on vegetative, biochemical and physiological characteristics.

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Exopolysaccharides Producing Bacteria for the Amelioration of Drought Stress in Wheat

Sustainability ◽

10.3390/su12218876 ◽

2020 ◽

Vol 12 (21) ◽

pp. 8876

Author(s):

Noshin Ilyas ◽

Komal Mumtaz ◽

Nosheen Akhtar ◽

Humaira Yasmin ◽

R. Z. Sayyed ◽

...

Keyword(s):

Antioxidant Enzymes ◽

Drought Stress ◽

Drought Tolerance ◽

Indole Acetic Acid ◽

Stress Hormones ◽

Carotenoid Content ◽

Bacterial Strains ◽

Morphological Attributes ◽

Vigor Index

This research was designed to elucidate the role of exopolysaccharides (EPS) producing bacterial strains for the amelioration of drought stress in wheat. Bacterial strains were isolated from a farmer’s field in the arid region of Pakistan. Out of 24 isolated stains, two bacterial strains, Bacillus subtilis (Accession No. MT742976) and Azospirillum brasilense (Accession No. MT742977) were selected, based on their ability to produce EPS and withstand drought stress. Both bacterial strains produced a good amount of EPS and osmolytes and exhibited drought tolerance individually, however, a combination of these strains produced higher amounts of EPS (sugar 6976 µg/g, 731.5 µg/g protein, and 1.1 mg/g uronic acid) and osmolytes (proline 4.4 µg/mg and sugar 79 µg/mg) and significantly changed the level of stress-induced phytohormones (61%, 49% and 30% decrease in Indole Acetic Acid (IAA), Gibberellic Acid (GA), and Cytokinin (CK)) respectively under stress, but an increase of 27.3% in Abscisic acid (ABA) concentration was observed. When inoculated, the combination of these strains improved seed germination, seedling vigor index, and promptness index by 18.2%, 23.7%, and 61.5% respectively under osmotic stress (20% polyethylene glycol, PEG6000). They also promoted plant growth in a pot experiment with an increase of 42.9%, 29.8%, and 33.7% in shoot length, root length, and leaf area, respectively. Physiological attributes of plants were also improved by bacterial inoculation showing an increase of 39.8%, 61.5%, and 45% in chlorophyll a, chlorophyll b, and carotenoid content respectively, as compared to control. Inoculations of bacterial strains also increased the production of osmolytes such asproline, amino acid, sugar, and protein by 30%, 23%, 68%, and 21.7% respectively. Co-inoculation of these strains enhanced the production of antioxidant enzymes such as superoxide dismutase (SOD) by 35.1%, catalase (CAT) by 77.4%, and peroxidase (POD) by 40.7%. Findings of the present research demonstrated that EPS, osmolyte, stress hormones, and antioxidant enzyme-producing bacterial strains impart drought tolerance in wheat and improve its growth, morphological attributes, physiological parameters, osmolytes production, and increase antioxidant enzymes.

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