WRKY72-type transcription factors contribute to basal immunity in tomato and Arabidopsis as well as gene-for-gene resistance mediated by the tomato R gene Mi-1
WRKY72-type transcription factors contribute to basal immunity in tomato and Arabidopsis as well as gene-for-gene resistance mediated by the tomato R gene Mi-1
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DOI：
10.1111/j.1365-313x.2010.04232.x
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发表时间：
2010-07-01
期刊：
影响因子：
7.2
通讯作者：
Eulgem, Thomas
中科院分区：
文献类型：
--
作者：
Bhattarai, Kishor K.;Atamian, Hagop S.;Eulgem, Thomas
WRKY转录因子在与植物免疫应答相关的转录重编程中起着重要作用.然而，由于功能冗余，通常该家族的个体成员对免疫的贡献是微小的。利用微阵列分析，我们发现旁系同源番茄WRKY基因SlWRKY 72 a和B在抗病基因Mi-1介导的抗病过程中转录上调。在番茄中，病毒诱导的这两个基因的基因沉默导致Mi-1介导的抗性以及对根结线虫（RKN）和马铃薯蚜虫的基础防御明显降低。使用拟南芥T-DNA插入突变体，我们发现，他们的拟南芥直向同源物，AtWRKY 72，也需要对RKN以及卵菌Hyaloperonospora arabidopsidis的全面基础防御。尽管它们在两种测试的植物物种中对RKN的基础防御中具有相似的作用，但番茄中的WRKY 72型转录因子，而不是拟南芥中的WRKY 72型转录因子，显然有助于对细菌病原体假单胞菌的基础防御。在我们在番茄和拟南芥中测试的五个R基因中，只有Mi-1似乎依赖于WRKY 72型转录因子。有趣的是，AtWRKY 72靶基因，通过H.拟南芥引发的转录变化，似乎在很大程度上是不响应类似物的防御激素水杨酸（SA）。因此，类似于Mi-1，其部分独立于SA发挥作用，AtWRKY 72似乎利用SA独立的防御机制。我们建议，WRKY 72型转录因子在番茄和拟南芥的基础防御中发挥部分保守的作用，该功能已被招募为Mi-1依赖性免疫。
P>WRKY transcription factors play a central role in transcriptional reprogramming associated with plant immune responses. However, due to functional redundancy, typically the contribution of individual members of this family to immunity is only subtle. Using microarray analysis, we found that the paralogous tomato WRKY genes SlWRKY72a and b are transcriptionally up-regulated during disease resistance mediated by the R gene Mi-1. Virus-induced gene silencing of these two genes in tomato resulted in a clear reduction of Mi-1-mediated resistance as well as basal defense against root-knot nematodes (RKN) and potato aphids. Using Arabidopsis T-DNA insertion mutants, we found that their Arabidopsis ortholog, AtWRKY72, is also required for full basal defense against RKN as well as to the oomycete Hyaloperonospora arabidopsidis. Despite their similar roles in basal defense against RKN in both tested plant species, WRKY72-type transcription factors in tomato, but not in Arabidopsis, clearly contributed to basal defense against the bacterial pathogen Pseudomonas syringae. Of the five R genes that we tested in tomato and Arabidopsis, only Mi-1 appeared to be dependent on WRKY72-type transcription factors. Interestingly, AtWRKY72 target genes, identified by microarray analysis of H. arabidopsidis-triggered transcriptional changes, appear to be largely non-responsive to analogs of the defense hormone salicylic acid (SA). Thus, similarly to Mi-1, which in part acts independently of SA, AtWRKY72 appears to utilize SA-independent defense mechanisms. We propose that WRKY72-type transcription factors play a partially conserved role in basal defense in tomato and Arabidopsis, a function that has been recruited to serve Mi-1-dependent immunity.