Wang Wenlong, Chi Menghan, Liu Shupeng, Zhang Ying, Song Jiawang, Xia Guangmin, Liu Shuwei
Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education; Shandong Key Laboratory of Precision Molecular Crop Design and Breeding; School of Life Science, Shandong University, Qingdao, 266237, China.
National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Dongying, 257345, China.
J Integr Plant Biol. 2025 Feb;67(2):208-225. doi: 10.1111/jipb.13808. Epub 2024 Nov 27.
One mechanism plants use to tolerate high salinity is the deposition of cutin and suberin to form apoplastic barriers that limit the influx of ions. However, the mechanism underlying barrier formation under salt stress is unclear. Here, we characterized the glycerol-3-phosphate acyltransferase (GPAT) family gene TaGPAT6, encoding a protein involved in cutin and suberin biosynthesis for apoplastic barrier formation in wheat (Triticum aestivum). TaGPAT6 has both acyltransferase and phosphatase activities, which are responsible for the synthesis of sn-2-monoacylglycerol (sn-2 MAG), the precursor of cutin and suberin. Overexpressing TaGPAT6 promoted the deposition of cutin and suberin in the seed coat and the outside layers of root tip cells and enhanced salt tolerance by reducing sodium ion accumulation within cells. By contrast, TaGPAT6 knockout mutants showed increased sensitivity to salt stress due to reduced cutin and suberin deposition and enhanced sodium ion accumulation. Yeast-one-hybrid and electrophoretic mobility shift assays identified TaABI5 as the upstream regulator of TaGPAT6. TaABI5 knockout mutants showed suppressed expression of TaGPAT6 and decreased barrier formation in the seed coat. These results indicate that TaGPAT6 is involved in cutin and suberin biosynthesis and the resulting formation of an apoplastic barrier that enhances salt tolerance in wheat.
植物耐受高盐度的一种机制是沉积角质和木栓质以形成质外体屏障，从而限制离子的流入。然而，盐胁迫下屏障形成的潜在机制尚不清楚。在此，我们对甘油-3-磷酸酰基转移酶（GPAT）家族基因TaGPAT6进行了表征，该基因编码一种参与角质和木栓质生物合成的蛋白质，用于小麦（Triticum aestivum）质外体屏障的形成。TaGPAT6具有酰基转移酶和磷酸酶活性，负责合成角质和木栓质的前体sn-2-单酰甘油（sn-2 MAG）。过表达TaGPAT6促进了角质和木栓质在种皮和根尖细胞外层的沉积，并通过减少细胞内钠离子积累增强了耐盐性。相比之下，TaGPAT6敲除突变体由于角质和木栓质沉积减少以及钠离子积累增加，对盐胁迫表现出更高的敏感性。酵母单杂交和电泳迁移率变动分析确定TaABI5为TaGPAT6的上游调节因子。TaABI5敲除突变体表现出TaGPAT6表达受抑制以及种皮中屏障形成减少。这些结果表明，TaGPAT6参与角质和木栓质的生物合成以及由此产生的质外体屏障的形成，从而增强了小麦的耐盐性。
