背景回顾：The non-protein amino acid γ-aminobutyric acid (GABA) has been proposed to be an ancient messenger for cellular communication conserved across biological kingdoms. 

提出问题：GABA has well-defined signalling roles in animals; however, whilst GABA accumulates in plants under stress it has not been determined if, how, where and when GABA acts as an endogenous plant signalling molecule.

主要发现：Here, we establish endogenous GABA as a bona fide plant signal, acting via a mechanism not found in animals. 

结果1：Using Arabidopsis thaliana, we show guard cell GABA production is necessary and sufficient to reduce stomatal opening and transpirational water loss, which improves water use efficiency and drought tolerance, via negative regulation of a stomatal guard cell tonoplast-localised anion transporter. 

结果2：We find GABA modulation of stomata occurs in multiple plants, including dicot and monocot crops.

结论：This study highlights a role for GABA metabolism in fine tuning physiology and opens alternative avenues for improving plant stress resilience.

 摘 要 

非蛋白氨基酸γ-氨基丁酸（GABA）是生物界一个比较古老且保守的细胞间通讯信号。在动物的相关研究中，已经明确GABA具有信号转导的作用；植物在逆境条件下体内会积累GABA，但是GABA是否、如何、何处以及何时作为内源性植物信号分子起作用还没有确定。本文中，作者发现植物内源性GABA确实作为信号发挥作用，并且通过一个在动物中未曾发现的机制发挥作用。利用拟南芥，作者发现保卫细胞GABA的产生对于减少气孔开度和蒸腾水分丢失是必须且充分的，这能够提高植株的水分利用效率和干旱耐受性，GABA信号通过负调控气孔保卫细胞中定位于液泡膜的阴离子转运蛋白发挥功能。作者发现GABA调节气孔在多种植物中均存在，包括了双子叶植物和单子叶植物。本文的研究揭示了GABA代谢在植物精细调控生理中的作用，并为提高植物抗逆性开辟了另一条途径。