Sui Na, Tian Shanshan, Wang Wenqing, Wang Mingjie, Fan Hai
Shandong Provincial Key Laboratory of Plant Stress, College of Life Science, Shandong Normal UniversityJinan, China.
Front Plant Sci. 2017 Aug 2;8:1337. doi: 10.3389/fpls.2017.01337. eCollection 2017.
Glycerol-3-phosphate acyltransferase is the first acyl esterifying enzyme in phosphatidylglycerol (PG) synthesis process. In this study, we isolated and characterized the glycerol-3-phosphate acyltransferase (GPAT) gene from () and obtained the full length of the GPAT gene from () by 5' and 3' RACE. The clone contained an open reading frame (ORF) of 1167 bp nucleotides that comprised of 388 amino acid residues. Real-time PCR revealed that the mRNA accumulation of in was induced by salt stress. The highest expression levels were observed when leaves were exposed to 300 mM NaCl treatment. At the germination stage, the germination rate and root length of overexpressed Arabidopsis strains were significantly higher than WT under different concentrations of NaCl treatments, while the inhibitory effect was significantly severe in T-DNA insertion mutant strains. In the seedling stage, chlorophyll content, the photochemical efficiency of PSII, PSI oxidoreductive activity (ΔI/Io), and the unsaturated fatty acid content of PG decreased less in overexpressed strains and more in mutant strains than that in WT under salt stress. These results suggest that the overexpression of in Arabidopsis enhances salt tolerance and alleviates the photoinhibition of PSII and PSI under salt stress by improving the unsaturated fatty acid content of PG.
3-磷酸甘油酰基转移酶是磷脂酰甘油（PG）合成过程中的首个酰基酯化酶。在本研究中，我们从（）中分离并鉴定了3-磷酸甘油酰基转移酶（GPAT）基因，并通过5'和3' RACE从（）中获得了GPAT基因的全长。该克隆包含一个1167 bp核苷酸的开放阅读框（ORF），由388个氨基酸残基组成。实时PCR显示，（）中（）的mRNA积累受盐胁迫诱导。当（）叶片接受300 mM NaCl处理时，观察到最高表达水平。在萌发阶段，在不同浓度NaCl处理下，过表达拟南芥株系的萌发率和根长显著高于野生型，而在T-DNA插入突变株系中抑制作用显著更严重。在幼苗期，盐胁迫下，过表达株系中叶绿素含量、PSII的光化学效率、PSI氧化还原活性（ΔI/Io）以及PG的不饱和脂肪酸含量下降幅度小于野生型，而突变株系中下降幅度大于野生型。这些结果表明，拟南芥中（）的过表达通过提高PG的不饱和脂肪酸含量增强了耐盐性，并减轻了盐胁迫下PSII和PSI的光抑制。
