谷子MDH基因非生物逆境响应特性研究

为揭示谷子MDH基因对逆境胁迫的响应,本研究通过序列比对得到2个谷子苹果酸脱氢酶(malate dehydrogenase,MDH)基因SiMDH1、SiMDH2,并对SiMDH1和SiMDH2的编码蛋白特征、基因结构、功能、进化等性状进行了系统的分析和预测,用荧光实时定量PCR(qPCR)检测了SiMDH1和SiMDH2在苗期不同逆境及关键生育期干旱胁迫和不同光照强度下的表达。蛋白特征参数和序列分析表明,SiMDH1和SiMDH2蛋白特征参数相似度很高,序列非常保守,都含有MDH基因的特征功能域苹果酸酶NAD结合域和苹果酸酶C端功能域。亚细胞定位预测显示,SiMDH1和SiMDH2主要定位于叶绿体、细胞质和线粒体。启动子区域顺式元件分析发现,在SiMDH1和SiMDH2启动子区域含有大量光应答、激素类和其他类应答元件。苗期逆境qPCR表达谱分析发现,SiMDH1和SiMDH2受脱落酸(ABA)、聚乙二醇(PEG)、高盐和低温不同程度诱导,揭示SiMDH1和SiMDH2参与了谷子苗期非生物逆境胁迫应答。进一步分析发现,SiMDH1和SiMDH2参与了谷子在拔节、抽穗、灌浆期的干旱应答,...

Study on the Abiotic Stress Response Characteristics of MDH Gene in Foxtail Millet (Setaria italica)

In order to reveal the response of foxtail millet MDH gene to stress, two malate dehydrogenase genes (SiMDH1 and SiMDH2) were obtained from the foxtail millet by sequence alignment. The protein characteristics, gene structure, function, evolution and other traits of SiMDH1 and SiMDH2 were systematically analyzed and predicted. The expression of SiMDH1 and SiMDH2 under different stresses at seedling stage and key growth stages under drought stress and different light intensities were detectedby fluorescence real-time quantitative PCR. The characteristic parameters and sequence analysis indicated that SiMDH1 and SiMDH2 protein were very similar and the sequences were very conservative. Both of them contained the NAD binding domain and C-terminal domain of malate dehydrogenase, which are the typical characteristic domain of MDH gene. Subcellular localization showed that SiMDH1 and SiMDH2 were localized in chloroplast, cytoplasmic, and mitochondria. Promoter analysis identified a variety of light, hormonal, and other growth-related cis-elements in the SiMDH1 and SiMDH2 promoter sequences. The qPCR expression profiles showed that SiMDH1 and SiMDH2 were induced by ABA, PEG, high salt and low temperature at seedling stage, indicating that SiMDH1 and SiMDH2 were involved in abiotic signaling pathway at the seedling stage. Subsequent expression analysis showed that SiMDH1 and SiMDH2 were involved in drought stress pathway at jointing, heading and filling stages. Further analysis of light intensity showed that light intensity seriously affected the expression of SiMDH1 and SiMDH2 at different growth stages. This study provided experimental date and theoretical support for further analysis on stress responses mechanism of SiMDH and improvement of crop stress resistance and yield using genetic engineering methods.