高温胁迫下甜玉米雌穗发育基因差异表达谱分析

Gene Expression Profile of Sweet Corn Ears under Heat Stress

利用数字化基因表达谱技术,对高温胁迫下优良甜玉米杂交种粤甜13雌穗发育相关基因的表达谱进行分析。结果表明,在高温胁迫和适温下差异表达基因达949个,其中有上调表达基因705个,下调表达基因244个,上调表达10倍以上的基因108个,下调表达10倍以上的基因40个。对差异表达基因功能注释分析表明,它们主要集中在细胞内组分和膜上,主要具催化活性、结合活性、水解酶活性、氧化还原酶活性等,参与代谢、细胞结构与功能、胁迫应答、物质运输和生物调节等生物学过程,推测对雌穗发育过程中籽粒和果穗的形成具有重要作用。这些基因中有一半以上的基因功能未知,下一步将对其开展克隆和功能方面的分析。

Sweet corn is an important vegetable crop around the world. Heat stress is one of the limiting factors in the production of maize in southern China. Therefore, digitalgene expression profile was used to investigate the global gene expression profiles in ear development of maize cultivar Yuetian 13 widely planted in Guangdong under heat stress. The resultsin the distribution of total Clean Tags, high-expression tags with copy numbers larger than 100 were in absolute dominance whereas low-expression tags with copy numbers smaller than five occupy the majority of distinct tag distributions. In total, 949 differentially expressed genes were detected, including 705 and 244 of genes up- and down-regulated, respectively. Among them, 108 and 40 genes were up- and down-regulated at least 10-fold. Using maize Gene Ontology database, we categorized these genes into three main categories： cellular component, molecular function and biological process. A large proportion of differentially expressed genes distributed in cell, intracellular and membrane, related to catalytic, binding, hydrolase and oxidoreductase activities, and involved in metabolic, cellular structure and function,response to stimulusbiological regulation, were valuable for investigating kernel and ear development. Under heat stress, the genes related to cell structure maintenance, photosynthesis, signal transduction, transcription factor, and response to stress had higher expression levels in ear. And six genes were randomly selected for confirming their expression patterns by quantitative RT-PCR. The result showed these expression patterns basically consistent with the digital gene expression data. Further research should concentrate on characterizing the unknown function ones among differentially expressed genes., transport and indicated that,