Insights into 28-homobrassinolide (HBR)-mediated redox homeostasis, AsA–GSH cycle, and methylglyoxal detoxification in soybean under drought-induced oxidative stress

Abstract

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 (H 2 O 2) 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.

Melatonin Pretreatment Confers Heat Tolerance and Repression of Heat-Induced Senescence in Tomato Through the Modulation of ABA- and GA-Mediated Pathways

“…Two essential fluorescence attributes net photosynthetic rate ( P n ) and stomatal conductance ( G s ), were measured with a portable photosynthesis system (Li-6400; LI-COR, Inc., Lincoln, NE, United States) from 10.00 am to 11.00 am. The cuvette conditions were maintained as follows: 25°C temperature, 70% relative humidity, 800 μmol photons m –2 s –1 PPFD (photosynthetic photon flux density), and 380 ± 10 μmol mol –1 external CO 2 concentration ( Ahammed et al, 2020a ; Hasan et al, 2020 ).…”

Green Synthesized Metal Oxide Nanoparticles Mediate Growth Regulation and Physiology of Crop Plants under Drought Stress

“…Drought is a common abiotic source of stress that drastically reduces crop yield in arid environments [ 6 , 73 , 74 ]. Water is necessary for plant viability and nutrient transport.…”

Alleviation of copper phytotoxicity by acetylsalicylic acid and nitric oxide application in mung bean involves the up-regulation of antioxidants, osmolytes and glyoxalase system

“…Increased accumulation of compatible osmolytes further strengthened the alleviation of oxidative impacts of Cu toxicity due to ASA and NO. Compatible osmolytes contribute to the regulation of plant growth by maintaining tissue water content and protecting the proper function of the enzyme (Elkelish et al 2019a), providing protection to major macromolecules and helping in stress signalling (Hasan et al 2019b;Hasan et al 2020b). Phytohormones play a crucial role in regulating the metabolism of osmolytes by integrating beneficial responses to the stress factor (Sharma et al 2019;Hasan et al 2021a;Hasan et al 2021b) and it was evident in this study that exogenous application not only increased the content of osmolytes but also finely regulated their metabolism.…”

“…The functioning of enzymatic as well as non-enzymatic antioxidants and the accumulation of osmolytes, including proline, glycine betaine, sugars, etc., determine the tolerance potential of plants against stress factors by protecting the functional and structural stability of major cellular components (Ahanger et al 2017;Soliman et al 2019;Rasheed et al 2020). The glyoxalase system is another intriguing pathway involved in removing toxic methylglyoxal (MG) for efficient cellular functioning (Mudalkar et al 2017;Alharbi et al 2021;Hasan et al 2020b). Up-regulation of the antioxidant and glyoxalase systems, increased accumulation of osmolytes have been correlated with the efficient functioning of plants under various stress conditions (Nahar et al 2016;Elkelish et al 2019aElkelish et al , 2019bSoliman et al 2020;Rasheed et al 2020).…”