DOI:10.1021/acs.jproteome.9b00627

Zhou Li, Bizhen Cheng, Weihang Zeng, Xinquan Zhang, and Yan Peng

发表期刊：Journal of Proteome Research

链接：https://pubs.acs.org/doi/abs/10.1021/acs.jproteome.9b00627

Abstract：

The global emergence of soil salinization poses a serious challenge to many countries

and regions. γ-Aminobutyric acid (GABA) is involved in systemic regulation of plant adaptation tosalt stress but the underlying molecular and metabolic mechanism still remains largely unknown. Theelevated endogenous GABA level by the application of exogenous GABA improved salt toleranceassociated with the enhancement of antioxidant capacity, photosynthetic characteristics, osmoticadjustment (OA), and water use efficiency in creeping bentgrass. GABA strongly upregulatedtranscript levels ofAsPPa2,AsATPaB2,AsNHX2/4/6, andAsSOS1/20in roots involved in enhancedcapacity of Na⁺compartmentalization and mitigation of Na⁺toxicity in the cytosol. Significantdownregulation ofAsHKT1/4expression could be induced by GABA in leaves in relation tomaintenance of the significantly lower Na⁺content and higher K⁺/Na⁺ratio. GABA-depressedaquaporin expression and accumulation induced declines in stomatal conductance and transpiration,thereby reducing water loss in leaves during salt stress. For metabolic regulation, GABA primarilyenhanced sugar and amino acid accumulation and metabolism, largely contributing to improved salttolerance through maintaining OA and metabolic homeostasis. Other major pathways could berelated to GABA-induced salt tolerance including increases in antioxidant defense, heat shock proteins, and myo-inositolaccumulation in leaves. Integrative analyses of molecular, protein, metabolic, and physiological changes reveal systemic functions ofGABA in regulating ionic, water, and metabolic homeostasis in nonhalophytic creeping bentgrass under salt stress.