PEG胁迫下玉米基因表达谱分析

为了解PEG胁迫下玉米基因表达情况,采用数字化基因表达谱（DGE）技术,检测了20%PEG胁迫下玉米植株中基因表达谱,同时利用实时荧光定量PCR技术对部分基因表达特点进行了验证。结果表明玉米植株在20%PEG胁迫下48h时,共检测到31829个基因表达量发生了改变,其中表达量差异达到2倍以上的基因共1438个,其中801个表达量呈现上调,637个表达量呈现下调。这些差异表达基因功能主要涉及到结合、催化、转录、抗氧化剂活性,参与代谢过程、细胞过程、定位、生物调节、定位建立以及刺激反应等。实时荧光定量PCR分析表明7个随机选择的基因在胁迫前后的表达特点与表达谱测序结果一致。本研究表明玉米对PEG胁迫反应是一个多基因参与、多个生物过程协同调控的过程,基因表达量的变化可能是调控的主要方式,此外候选了与玉米耐PEG胁迫相关的应答关键基因,为揭示与玉米耐旱机理以及克隆与玉米耐旱性相关关键基因奠定了基础。

Gene Expression Profile of Maize under 20% PEG Stress

The objective of this study is to dissect the variation of maize gene expression profile under 20% PEG stress and explore maize drought resistance mechanism. Digital gene expression profile technology was used to investigate the global gene expression profiles of maize under 20% PEG stress,and the real-time fluorescent qRT-PCR technique was used to verify the expression characteristic of random selected 7 genes. These results indicated that 31829 genes expressed differentially in maize under 20% PEG stress and control at 48 h, and 1438 of them express higher or lower more one fold under 20% PEG stress than control, expression of 801 among the 1438 genes were up-regulated and 637 were down-regulated. The functions of a large proportion of differentially expressed genes are involved in cellular process, metabolic process, binding, biological regulation, establishment of localization, response to stimulus and so on. And expression patterns of random selected 7 genes confirmed the results of the digital gene expression profile. The study indicated that the response of maize under PEG stress involved many genes and regulated by several collaborative biological processes, and changes of gene expression level maybe play important roles in regulation process. And the experiment found many candidate genes which were crucial for maize to endure drought stress, and will help to reveal and understand the mechanism of maize drought stress tolerance. The study also laid the foundation to clone new genes related with drought stress tolerance for maize.