水稻WRKY转录因子基因家族响应外源一氧化氮的表达谱分析

摘要

一氧化氮(nitric oxide,NO)信号分子与WRKY转录因子均参与植物抗逆、发育与代谢等许多生理过程.采用Agilent水稻全基因组cDNA芯片分析了NO处理后1、6和12 h水稻幼苗WRKY转录因子基因的表达谱,鉴定出在1个时间点有两倍或两倍以上表达变化的WRKY基因32个,主要分布在WRKY的Ⅰ和Ⅱ组,其中75%的Ⅱa和45.6%的Ⅱd亚组成员为差异表达基因;鉴定出至少在2个时间点有两倍或两倍以上表达变化的WRKY基因15个,均为早期(1 h)应答,且多数(64.2%)持续上调;基因功能预测分析表明,这些基因主要参与生物学过程中的细胞过程、代谢过程和刺激响应,以及分子功能中的转录调节活性和结合;代谢通路分析表明,WRKY24涉及植物与病原菌相互作用代谢通路.实时荧光定量PCR验证结果与芯片杂交结果基本一致,印证了芯片杂交结果的有效性.上述发现提示,NO信号可能参与了WRKY转录因子介导的生物学调控功能,并为这些基因的进一步功能分析奠定基础.%Signal molecule nitric oxide (NO)and WRKY transcription factors are involved in many physiological processes, such as defense against stresses, development and metabolism in plants.In the present study, we investigated the expression patterns of WRKY transcription factor gene family in rice seedlings at 1,6 and 12 after exogenous NO treatments using Agilent rice cDNA oligo microarray.Totally,32 differently expressed WRKY genes, whose expression levels increased or decreased by at least two-fold at one time point compared with the control (T0), were identified.These WRKY genes were mainly distributed over Groups Ⅰ and Ⅱ,among which 75% of Ⅱa and 45.6% of Ⅱ d subgroup members were differently expressed upon the NO treatments.Moreover, 15 identified NO-responsive WRKY genes,whose expression level changed by more than two-fold at least two time points among the three time points compared with the control,exhibited an earlier (1h)response to the NO treatments,and most of them (64.2%)were continually up-regulated.Prediction of gene function revealed that the NO-responsive WRKY genes were mainly involved in cellular process,metabolic process and response to stimulus of biological process,and transcription regulator activity and binding of molecular function.The analysis of metabolic pathways showed that WRKY24 was involved in plant-pathogen interaction pathway.The results of microarray hybridization were largely consistent with those of quantitative real-time PCR,verifying the validity of microarray hybridization.These findings suggest that NO signaling might be involved in the regulatory functions of WRKY transcription factors,and provide a basis for further functional research for these differentially expressed WRKY genes.