Li Na, Li Xianghua, Xiao Jinghua, Wang Shiping
National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China,
Plant Cell Rep. 2014 Sep;33(9):1493-505. doi: 10.1007/s00299-014-1633-4. Epub 2014 May 29.
Expression levels of rice VQ motif-containing genes in response to pathogen infection vary among pathogens, and some of the genes are co-expressed with defense-response WRKY genes. Recent studies have revealed that some VQ (FxxxVQxLTG) motif-containing proteins in plants partner with WRKY transcription factors to participate in their functions. Accumulating information suggests that WRKY proteins play important roles in the response of rice plants to pathogen infection. However, the functions of rice VQ motif-containing proteins are unknown. To explore whether VQ motif-containing proteins are involved in defense against pathogens in rice, we performed a comprehensive expression analysis of the genes for these proteins. The rice VQ motif-containing family consists of 40 genes, all of which encode proteins harboring a 21-amino acid VQ-containing motif, which in turn contains the known VQ motif. On the basis of their phylogenetic relationships and tissue-specific and developmental stage-specific expression characteristics, we transcriptionally analyzed 13 representative genes in rice responses to three pathogens: Xanthomonas oryzae pv. oryzae, which causes bacterial blight disease; X. oryzae pv. oryzicola, which causes bacterial streak disease; and Magnaporthe oryzae, which causes fungal blast disease. The expression of some of the genes changed markedly in response to infection by at least one of the pathogen species, and some of the genes also showed markedly different expression in resistant and susceptible reactions. In addition, some defense-responsive VQ motif-containing genes were co-expressed with defense-response WRKY genes. These results provide a new perspective on the putative roles of rice VQ motif-containing proteins and their putative WRKY partners in rice-pathogen interactions.
水稻中含VQ基序的基因在响应病原体感染时的表达水平因病原体而异，其中一些基因与防御反应相关的WRKY基因共表达。最近的研究表明，植物中一些含VQ（FxxxVQxLTG）基序的蛋白与WRKY转录因子相互作用以参与其功能。越来越多的信息表明，WRKY蛋白在水稻植株对病原体感染的反应中发挥重要作用。然而，水稻中含VQ基序蛋白的功能尚不清楚。为了探究含VQ基序的蛋白是否参与水稻对病原体的防御，我们对这些蛋白的基因进行了全面的表达分析。水稻含VQ基序的家族由40个基因组成，所有这些基因编码的蛋白都含有一个21个氨基酸的含VQ基序，该基序又包含已知的VQ基序。基于它们的系统发育关系以及组织特异性和发育阶段特异性表达特征，我们对水稻中13个代表性基因在响应三种病原体时的转录情况进行了分析：引起白叶枯病的水稻白叶枯病菌；引起细菌性条斑病的水稻条斑病菌；以及引起稻瘟病的稻瘟病菌。一些基因的表达在受到至少一种病原体感染后发生了显著变化，并且一些基因在抗性和感病反应中的表达也存在明显差异。此外，一些与防御反应相关的含VQ基序的基因与防御反应相关的WRKY基因共表达。这些结果为水稻中含VQ基序的蛋白及其假定的WRKY伙伴在水稻-病原体相互作用中的假定作用提供了新的视角。
