Exogenous γ-aminobutyric acid (GABA) mitigated salinity-induced impairments in mungbean plants by regulating their nitrogen metabolism and antioxidant potential

• DOI: 10.3389/fpls.2022.1081188
• Publication Date: 2023-01-18T06:19:12Z
• Authors: Abd Ullah; Iftikhar Ali; Javaria Noor; Fanjiang Zeng; Sami Bawazeer; Sayed M Eldin; Muhammad Ahsan As...; Hafiz Hassan Javed; Khansa Saleem; Sami Ullah; Haider Ali
• Keywords: Osmolyte; APX; Glutathione reductase; Glutamate synthase

Background Increasing soil salinization has a detrimental effect on agricultural productivity.Therefore, strategies are needed to induce salinity-tolerance in crop species for sustainable foodproduction. γ-aminobutyric acid (GABA) plays key role regulating plant salinity stresstolerance. However, it remains largely unknown how mungbean plants (Vigna radiata L.) respondto exogenous GABA under stress. Methods Thus, we evaluated the of (1.5 mM) growth and physiobiochemicalresponse mechanism saline stress (0-, 50-, 100 mM [NaCland Na2SO4, at 1:1 molar ratio]). Results Increased adversely affected plants' metabolism. Forinstance, leaf-stem-root biomass (34- 56%, 31- 53%, 27- 56% 50- 100mM, respectively]) chlorophyll concentrations declined. The carotenoid level increased (10%)at 50 remained unaffected mM. Hydrogen peroxide (H2O2), malondialdehyde(MDA), osmolytes (soluble sugars, soluble proteins, proline), total phenolic content, andenzymatic activities superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase(POD), glutathione reductase (GTR), polyphenol oxidation (PPO) were significantlyincreased. In leaves, caused significant increase Na+ concentration but decrease inK+ concentration, resulting low K+/Na+ (51- 71% 100- mMstress). Additionally, nitrogen nitrate (NR) andglutamine synthetase (GS) decreased significantly. reduction glutamate synthase (GOGAT)activity was only (65%) Exogenous Na+, H2O2,and MDA enhanced photosynthetic pigments, K+ ratio, Nmetabolism, osmolytes, enzymatic antioxidant activities, thus reducing salinity-associatedstress damages, improved biomass. Conclusion may have tolerance by maintaining their morpho-physiological responses accumulation harmfulsubstances salinity. Future molecular studies can contribute better understanding themolecular mechanisms which regulates tolerance.