玉米I型二酰基转移酶(DGAT1)基因的生物信息学分析及其在非生物胁迫下的表达研究
二酰甘油酰基转移酶(DGAT)作为植物油脂三酰甘油(TAG)合成途径中唯一的限速酶,参与植物油脂合成及生长发育等重要过程。本研究对玉米中的两个I型DGAT基因ZmDGAT1.1和ZmDGAT1.2进行了全面的生物信息学分析, 结果表明, 两个玉米DGAT1基因编码的蛋白均属于膜结合的酰基转移酶类MBOAT家族,均含有多个跨膜结构域,以及保守的底物结合和催化功能区。两个玉米DGAT1基因的不同组织和发育阶段表达分析显示两者在胚乳发育期表现出高水平表达,但是在种子发育期表达模式完全不同,ZmDGAT1.2在种子发育既油脂合成的早期表达水平较高,而ZmDGAT1.1在种子发育和油脂合成的后期表达水平更高。多种非生物胁迫处理条件下的qRT-PCR检测结果表明两个DGAT1基因对多种非生物胁迫的响应模式也有明显差异,说明其在参与逆境胁迫响应方面也发挥着不同的作用。本研究首次揭示了高等植物中两个DGAT1同源基因的差异表达模式及其在油脂积累和非生物胁迫响应过程中可能存在的功能差异,对实现精确调控脂类合成途径,从而提高高等植物种子油脂生成及对非生物胁迫的抗性具有重要意义。
英文摘要:
Diacylglycerol acyltransferase (DGAT) is the only rate-limiting enzyme in the synthesis of plant lipids triglyceride (TAG), and involves in the process of plant lipid synthesis and growth. In this study, the bioinformatic analysis of two maize DGAT1 genes in maize were conducted, which revealed that the proteins encoded by two ZmDGAT1 genes belonged to membrane-bound acyltransferases MBOAT family, both containing multiple transmembrane domains, as well as conserved substrate binding and catalytic functional domains. The expression patterns of ZmDGAT1 genes were different in various tissues and developmental stages of maize. Though both ZmDGAT1.1 and ZmDGAT1.2 expressed at in seed development stage, ZmDGAT1.1 was highly expressed at early stage of seed development, whereas higher expressipon level of ZmDGAT1.2 was observed in the e late stage of seed development and lipid synthesis. The differential expression profiles were also observed on the qRT-PCR analysis of two maize DGAT1 genes under different abiotic stresses, the results implied both genes might play different roles in stress responses. In this study, the differential expression patterns of two DGAT1 homologous genes in higher plants were revealed for the first time, and their possible functional differences in lipid accumulation and abiotic stress responses were analyzed, which could h to achieve precise regulation of lipid synthesis pathways, thereby enhancing seeds oil synthesis and resistance to abiotic stress of higher plant .
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