Zhou Jie, Wang Jian, Zheng Zuyu, Fan Baofang, Yu Jing-Quan, Chen Zhixiang
Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China Department of Botany and Plant Pathology, 915W. State Street, Purdue University, West Lafayette, IN 47907-2054, USA
Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China.
J Exp Bot. 2015 Aug;66(15):4567-83. doi: 10.1093/jxb/erv221. Epub 2015 May 11.
Arabidopsis AtWRKY33 plays a critical role in broad plant stress responses. Whether there are evolutionarily conserved homologues of AtWRKY33 in other plants and what make AtWRKY33 such an important protein in plant stress responses are largely unknown. We compared AtWRKY33 with its close homologues to identify AtWRKY33-specific regulatory and structural elements, which were then functionally analysed through complementation. We also performed phylogenetic analysis to identify structural AtWRKY33 homologues in other plants and functionally analysed two tomato homologues through complementation and gene silencing. AtWRKY33 has an extended C-terminal domain (CTD) absent in its close homologue AtWRKY25. Both its CTD and the strong pathogen/stress-responsive expression of AtWRKY33 are necessary to complement the critical phenotypes of atwrky33. Structural AtWRKY33 homologues were identified in both dicot and monocot plants including two (SlWRKY33A and SlWRKY33B) in tomato. Molecular complementation and gene silencing confirmed that the two tomato WRKY genes play a critical role similar to that of AtWRKY33 in plant stress responses. Thus, WRKY33 proteins are evolutionarily conserved with a critical role in broad plant stress responses. Both its CTD and promoter are critical for the uniquely important roles of WRKY33 in plant stress responses.
拟南芥AtWRKY33在植物广泛的应激反应中起关键作用。在其他植物中是否存在AtWRKY33的进化保守同源物，以及是什么使AtWRKY33在植物应激反应中成为如此重要的蛋白质，目前尚不清楚。我们将AtWRKY33与其紧密同源物进行比较，以鉴定AtWRKY33特异性的调控和结构元件，然后通过互补分析对其进行功能分析。我们还进行了系统发育分析，以鉴定其他植物中AtWRKY33的结构同源物，并通过互补和基因沉默对两个番茄同源物进行功能分析。AtWRKY33具有一个在其紧密同源物AtWRKY25中不存在的延伸C末端结构域（CTD）。AtWRKY33的CTD及其强烈的病原体/应激反应性表达对于补充atwrky33的关键表型都是必需的。在双子叶植物和单子叶植物中都鉴定出了AtWRKY33的结构同源物，包括番茄中的两个（SlWRKY33A和SlWRKY33B）。分子互补和基因沉默证实，这两个番茄WRKY基因在植物应激反应中发挥着与AtWRKY33类似的关键作用。因此，WRKY33蛋白在进化上是保守的，在植物广泛的应激反应中起关键作用。其CTD和启动子对于WRKY33在植物应激反应中独特的重要作用都至关重要。
