Chen Mingjia, Zhu Changhua, Zhang Hui, Chen Siheng, Wang Xi, Gan Lijun
College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Plants (Basel). 2024 Sep 30;13(19):2750. doi: 10.3390/plants13192750.
Rice is an important food crop worldwide but is usually susceptible to saline stress. When grown on soil with excessive salt, rice plants experience osmotic, ionic, and oxidative stresses that adversely affect growth performance. γ-Aminobutyric acid (GABA) is a nonproteinogenic amino acid that plays an important role in the metabolic activities of organisms. Glutamate decarboxylase (GAD) is the rate-limiting enzyme in GABA metabolism. Here, we genetically modified rice GAD by overexpression or CRISPR-mediated genome editing. These lines, named and or , were used to explore the effects of endogenous GABA accumulation on salt tolerance in rice. Both the and lines exhibited significant accumulation of the GABA content, whereas the line presented a reduced GABA content in vivo. Notably, the two overexpression lines were markedly resistant to salt stress compared with the wild-type and knockout lines. Furthermore, our results demonstrated that endogenous GABA accumulation in the and lines increased the contents of antioxidant substances and osmotic regulators, decreased the content of membrane lipid peroxidation products and the Na content, and resulted in strong tolerance to salt stress. Together, these data provide a theoretical basis for cultivating rice varieties with strong salt tolerance.
水稻是全球重要的粮食作物，但通常对盐胁迫敏感。当种植在盐分过高的土壤上时，水稻植株会遭受渗透胁迫、离子胁迫和氧化胁迫，这些胁迫会对其生长性能产生不利影响。γ-氨基丁酸（GABA）是一种非蛋白质氨基酸，在生物体的代谢活动中起重要作用。谷氨酸脱羧酶（GAD）是GABA代谢中的限速酶。在此，我们通过过表达或CRISPR介导的基因组编辑对水稻GAD进行了基因改造。这些品系分别命名为 和 或 ，用于探究内源性GABA积累对水稻耐盐性的影响。 和 品系的GABA含量均显著积累，而 品系体内的GABA含量降低。值得注意的是，与野生型和敲除品系相比，两个过表达品系对盐胁迫具有明显抗性。此外，我们的结果表明， 和 品系内源性GABA的积累增加了抗氧化物质和渗透调节物质的含量，降低了膜脂过氧化产物的含量和Na含量，并产生了较强的耐盐胁迫能力。总之，这些数据为培育耐盐性强的水稻品种提供了理论依据。
