Exogenous salicylic acid-induced drought stress tolerance in wheat (Triticum aestivum L.) grown under hydroponic culture

Abstract

Wheat is an important cereal crop, which is adversely affected by water deficit stress. The effect of induced stress can be reduced by the application of salicylic acid (SA). With the objective to combat drought stress in wheat, an experiment was conducted in greenhouse under hydroponic conditions. The treatments consisted of (a) no drought (DD0 = 0 MPa), mild drought (DD1 = -0.40 MPa) and severe drought (DD2 = -0.60 MPa) by applying PEG-8000, (b) two contrasting wheat varieties Barani-17 (drought tolerant) and Anaj-17 (drought-sensitive), and (c) foliar treatments of salicylic acid (0, 50 mM, 75 mM, and 100 mM). Evaluation of wheat plants regarding biochemical, physiological, and morphological attributes were rendered after harvesting of plants. Statistically, maximum shoot and root fresh and dry weights (18.77, 11.15 and 1.99, 1.81 g, respectively) were recorded in cultivar Barani-17 under no drought condition with the application of SA (100 mM). While, minimum shoot and root fresh and dry weights (6.65, 3.14 and 0.73, 0.61 g, respectively) were recorded in cultivar Anaj-2017 under mild drought stress without SA application. The maximum shoot length (68.0 cm) was observed in cultivar Barani-2017 under no drought condition with the application of SA (100 mM). While, maximum root length (59.67 cm) was recorded in cultivar Anaj-17 under moderate drought stress without application of SA. Further, minimum shoot length (28.67 cm) was recorded in Anaj-17 under moderate drought stress without SA application. Minimum root length (38.67 cm) was recorded in cultivar Barani-17 under no drought condition without SA application. Furthermore, maximum physio-biochemical traits, including membrane stability index (MSI), chlorophyl content, photosynthetic rates, stomatal conductance, antioxidant enzymatic activities and relative water content (RWC) were found highest in cultivar Barani-17 under no drought stress and SA application at 100 mM. However, minimum values of these traits were recorded in cultivar Anaj-17 under severe drought stress without SA application. Our results also demonstrated that under severe drought, application of SA at 100 mM significantly increased leaf nitrogen (N), phosphrus (P) and potassium (K) contents and cultivar Barani-17 demonstrated significantly higher values than Anaj-17. The obtained results also indicated that the cultivation of wheat under drought stress conditions noticeably declines the morphological, physiological, and biochemical attributes of the plants. However, the exogenous application of SA had a positive impact on wheat crop for enhancing its productivity.

Chitosan-Induced Physiological and Biochemical Regulations Confer Drought Tolerance in Pot Marigold (Calendula officinalis L.)

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Multidimensional Role of Silicon to Activate Resilient Plant Growth and to Mitigate Abiotic Stress

“…Drought markedly inhibits photosynthesis rather than respiration in crop plants ( Vanlerberghe et al, 2016 ). Several studies approved the role of Si to mitigate the adverse effects of drought stress to crop plants and, hence, to regulate normal metabolism, such as photosynthesis and alleviation of photoinhibition ( Habibi and Hajiboland, 2013 ; Zhu and Gong, 2014 ; Alamri et al, 2020 ; Ahmad et al, 2021 ; Malik et al, 2021 ). Some recent examples of Si-induced drought tolerance are presented in Table 2 .…”

Research Progress in the Field of Microbial Mitigation of Drought Stress in Plants

“…Microbes can promote plant growth both directly and indirectly ( Figure 1 ). The indirect activation of plant growth involves a series of events by which microbes prevent the inhibition of plant growth and development induced by pathogens ( Ahmad et al, 2021 ). During direct activation, microbes biosynthesize bacterial compounds that promote the uptake of nutrients from the soil and stimulate plant growth and development ( Berg, 2009 ; Choudhary et al, 2016 ).…”