γ-aminobutyric acid (GABA) strengthened nutrient accumulation, defense metabolism, growth and yield traits against salt and endoplasmic reticulum stress conditions in wheat plants

Salt stress and molecular level stresses, pose unprecedented threats to global agriculture, jeopardizing the pursuit of sustainable development goals (SDGs) related to food and nutritional security for the ever-increasing world population. These circumstances underscore the need to understand how plants respond to and interact with environmental stresses. Thus, our study focused on elucidating the role of γ-aminobutyric acid (GABA) in mitigating salt and endoplasmic reticulum (ER) stress in wheat plants.

Wheat (Triticum aestivum L.) plants were exposed to salt stress [100 mM sodium chloride (NaCl)] and ER stress [5 µg mL^–1 tunicamycin] applied through nutrient solution at 15 days after sowing (DAS), while 2.0 mM GABA solution was applied to leaves using a hand sprayer at 30 DAS. Growth and physiological traits measured at 45 DAS, with yield trait measurements taken at approximately 135 DAS.

Our findings demonstrate that GABA application reduced oxidative stress indicators by activating the ascorbate–glutathione pathway and the glyoxalase system. Moreover, GABA promoted proline metabolism, mineral nutrient accumulation, photosynthetic-affiliated source–sink traits, stomatal dynamics, nitric oxide biosynthesis, and defense- metabolites production in wheat plants under salt and ER stress.

Overall, GABA application helped safeguard growth and yield responses in stressed plants, reversing the growth, physiological, and yield inhibition caused by salt and ER stresses. Thus, GABA may emerge as a pivotal strategy for mitigating the adverse impacts of salt and ER stress and developing tolerant genotypes in future studies.