Effects of 24‐epibrassinolide on plant growth, antioxidants defense system, and endogenous hormones in two wheat varieties under drought stress

Abstract

Drought stress is a major limitation in enhancing agricultural productivity to fulfill the food demand for the world's population. Fertigation of plants with a variety of biochemicals is being used to create drought resistance in wheat; however, the previous work has been limited in addressing these issues in plants at different growth stages.Therefore, a greenhouse study was conducted to ameliorate the drought stress in two wheat varieties (Chakwal-50 and Faisalabad-2008) by foliar application of 24-epibrassinolide (EBL). It was evident that drought stress had a negative effect on the growth, photosynthesis, and yield of wheat plants. EBL significantly enhanced the plant growth both under optimal and drought conditions. EBL improved the plant height, spike length, and the dry weights of roots, shoots, and grains as compared to control. Furthermore, the foliar application of EBL positively enhanced the osmolyte accumulation, increased the amounts of photosynthetic pigments, and improved the gas exchange parameters. The EBL minimized the oxidative stress by reducing electrolyte leakage, malondialdehyde, and hydrogen peroxide contents whereas it enhanced the activities of antioxidant enzymes, such as catalase, superoxide dismutase, and peroxidase under drought stress. The EBL significantly improved the level of stress hormones, such as abscisic acid, indol acetic acid, and cytokinin under drought stress. The growth response of Chakwal-50 was higher than that of Faisalabad-2008 when exposed to EBL under drought stress. Overall, the EBL plays a major role in the enhancement of growth, biomass, yield, and decrease in oxidative damage in wheat under drought conditions, however; field investigations with different doses of EBL are needed before any further recommendation. | INTRODUCTIONFood security is a global issue for the development of sustainable agriculture. In the present scenario, the shortage of freshwater required for agriculture has created serious problems for the production of crops with better nutritional quality in near future (Ali et al., 2019a).

Seed Priming with Brassinosteroids Alleviates Chromium Stress in Rice Cultivars via Improving ROS Metabolism and Antioxidant Defense Response at Biochemical and Molecular Levels

“…To scavenge the higher production of MDA and H 2 O 2 , the antioxidant defense mechanism (SOD, POD, CAT, and APX) is stimulated in plants [54,55]. In a recent study, Khan et al [56] revealed that EBL significantly increased plant growth and triggered the antioxidant defense system in wheat plants against drought stress. Similarly, Rattan et al [57] reported that EBL alleviated salt stress in maize seedlings by regulating the antioxidant enzyme activities.…”

Production of Plant Beneficial and Antioxidants Metabolites by Klebsiellavariicola under Salinity Stress

“…Various reports claim that the application of PGPR for sustainable improvements in nutrients and the health of soil and plants [ 4 , 9 , 10 , 11 ]. PGPR are known to produce a wide variety of plant growth-promoting traits that include siderophores [ 10 , 11 ], phytohormones [ 12 , 13 ], hydrolytic enzymes [ 14 ], exopolysaccharide [ 15 , 16 , 17 ], stress-tolerant metabolites [ 18 , 19 , 20 , 21 ], and phosphate solubilization [ 22 , 23 ], etc. PGPR through these metabolites promotes seed germination, root and shoot growth, the level of soil and plant nutrients [ 13 , 21 , 24 ].…”

“…PGPR are known to produce a wide variety of plant growth-promoting traits that include siderophores [ 10 , 11 ], phytohormones [ 12 , 13 ], hydrolytic enzymes [ 14 ], exopolysaccharide [ 15 , 16 , 17 ], stress-tolerant metabolites [ 18 , 19 , 20 , 21 ], and phosphate solubilization [ 22 , 23 ], etc. PGPR through these metabolites promotes seed germination, root and shoot growth, the level of soil and plant nutrients [ 13 , 21 , 24 ]. The beneficial effects of PGPR are sometimes not obtained due to various reasons such as the production of a limited number of plant growth-promoting (PGP) traits, competition with the native soil microflora, less root colonization, and sensitivity to biotic and abiotic stresses [ 2 , 3 , 20 ].…”

Effects of the Combinations of Rhizobacteria, Mycorrhizae, and Seaweed, and Supplementary Irrigation on Growth and Yield in Wheat Cultivars

“…Application of PGPR offers numerous advantages, in terms of plant growth promotion through the secretion of various plant beneficial metabolites [ 12 ], increase in soil fertility [ 13 ], improved drought tolerance in plants through the production of exopolysaccharides and osmolytes [ 1 , 14 , 15 ], protection of plants from pathogens through the production of antibiotics, hydrogen cyanide, hydrolytic enzymes, etc. [ 16 , 17 , 18 ].…”