Application of GABA (γ-aminobutyric acid) to improve saline stress tolerance of chufa (Cyperus esculentus L. var. sativus Boeck) plants by regulating their antioxidant potential and nitrogen assimilation

作者：Abd Ullah, Akash Tariq, Fanjiang Zeng, Javaria Noor, Jordi Sardans, Muhammad Ahsan Asghar, Zhihao Zhang, Josep Peñuelas · 发表于：South African Journal of Botany · 年份：2023 · DOI：10.1016/j.sajb.2023.04.027 · 被引用次数：12 · 研究领域：GABA and Rice Research、Plant tissue culture and regeneration、Plant Stress Responses and Tolerance

The chufa is a perennial plant known for its almond-like underground tubers that have several health benefits for humans. GABA (γ-amino butyric acid) can regulate plants’ tolerance to stress including tolerance to salinity. However, it is unknown how chufa plants respond to GABA application and salinity. Here, we analysed the impact of GABA (2 mM) on growth features and physio-biochemical changes in chufa seedlings subjected to different saline stress levels (SS; 0, 100 and 200 mM NaCl and Na 2 SO 4 , 1:1 molar ratio). Our findings show that increasing SS levels negatively affected growth and metabolism. Increased SS reduced growth (root and shoot length, and their fresh and dry weights) and photosynthetic pigments, and significantly increased hydrogen peroxide (H 2 O 2 ), malondialdehyde (MDA) and osmolytes (i.e. soluble sugars, proline, soluble protein and superoxide dismutase (SOD). Peroxidase (POD) significantly declined at 50 mM and catalase (CAT) decreased under both stress levels. SS significantly enhanced salt ions (Na + and Cl – ) in roots and leaves but decreased root K + and increased Mg 2+ at 100 mM, levels that then declined under 200 mM SS. However, foliar K + and Mg 2+ remained unchanged. As well, NO 3 – and NH 4 + concentrations and nitrate reductase (NR) and glutamine oxoglutarate aminotransferase (GOGAT) declined significantly, while glutamine synthetase (GS) remained unaffected. However, exogenous GABA significantly reduced Na + and Cl – ions, H 2 O 2 and M...