An E3 ligase affects the NLR receptor stability and immunity to powdery mildew
An E3 ligase affects the NLR receptor stability and immunity to powdery mildew
复制标题
E3 连接酶影响 NLR 受体稳定性和对白粉病的免疫力
DOI：
10.1104/pp.16.01520
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发表时间：
2016
期刊：
影响因子：
7.4
通讯作者：
沈前华
中科院分区：
文献类型：
--
作者：
王涛;常诚;谷成;唐三元;谢旗;沈前华
Following the detection of pathogen cognate effectors, plant Nod-like receptors (NLRs) trigger isolate-specific immunity that is generally associated with cell death. The regulation of NLR stability is important to ensure effective immunity. In barley (Hordeum vulgare), the allelic Mildew locus A (MLA) receptors mediate isolate-specific disease resistance against powdery mildew fungus (Blumeria graminis f. sp. hordei). Currently, how MLA stability is controlled remains unknown. Here, we identified an MLA-interacting RING-type E3 ligase, MIR1, that interacts with several MLAs. We showed that the carboxyl-terminal TPR domain of MIR1 mediates the interaction with the coiled-coil domain-containing region of functional MLAs, such as MLA1, MLA6, and MLA10, but not with that of the nonfunctional MLA18-1. MIR1 can ubiquitinate the amino-terminal region of MLAs in vitro and promotes the proteasomal degradation of MLAs in vitro and in planta. Both proteasome inhibitor treatment and virus-induced gene silencing-mediated MIR1 silencing significantly increased MLA abundance in barley transgenic lines. Furthermore, overexpression of MIR1 specifically compromised MLA-mediated disease resistance in barley, while coexpression of MIR1 and MLA10 attenuated MLA10-induced cell death signaling in Nicotiana benthamiana. Together, our data reveal a mechanism for the control of the stability of MLA immune receptors and for the attenuation of MLA-triggered defense signaling by a RING-type E3 ligase via the ubiquitin proteasome system.
