Suppression of LjBAK1-mediated immunity by SymRK promotes rhizobial infection in Lotus japonicus
Suppression of LjBAK1-mediated immunity by SymRK promotes rhizobial infection in Lotus japonicus
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DOI：
10.1016/j.molp.2021.07.016
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发表时间：
2021-11-01
期刊：
影响因子：
27.5
通讯作者：
Cao, Yangrong
中科院分区：
文献类型：
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作者：
Feng, Yong;Wu, Ping;Cao, Yangrong
生物学中的一个重要问题是，生物体如何与不构成威胁的微生物（病原体），构成严重威胁的微生物（病原体）以及有益的微生物（共生体）相关联。根瘤共生作为一个重要的模式系统，解决这些问题的背景下，植物微生物相互作用。目前普遍认为，根瘤菌在感染过程中可以主动抑制宿主的免疫反应，类似于植物病原体逃避免疫识别的方式。然而，关于宿主将根瘤菌识别为病原体的机制以及随后这些途径如何被抑制以建立固氮共生关系，还有很多东西有待了解。在这项研究中，我们发现SymRK（共生受体样激酶）是所需的根瘤菌抑制植物天然免疫在百脉根。SymRK与LjBAK 1（油菜素甾醇不敏感1相关受体激酶1）（一种充分表征的植物先天免疫正调节因子）相关，并直接抑制LjBAK 1激酶活性。根瘤菌接种增强植物体内SymRK和LjBAK 1之间的关联。LjBAK 1是植物天然免疫调节所必需的，在根瘤菌感染L. - 是的这些数据表明，SymRK-LjBAK 1蛋白复合物作为根瘤菌共生信号传导途径和先天免疫途径之间的交叉点，并支持根瘤菌可以积极抑制宿主的能力，在豆科植物根瘤菌共生过程中安装防御反应。
An important question in biology is how organisms can associate with different microbes that pose no threat (commensals), pose a severe threat (pathogens), and those that are beneficial (symbionts). The root nodule symbiosis serves as an important model system for addressing such questions in the context of plant microbe interactions. It is now generally accepted that rhizobia can actively suppress host immune responses during the infection process, analogous to the way in which plant pathogens can evade immune recognition. However, much remains to be learned about the mechanisms by which the host recognizes the rhizobia as pathogens and how, subsequently, these pathways are suppressed to allow establishment of the nitrogen-fixing symbiosis. In this study, we found that SymRK (Symbiosis Receptor-like Kinase) is required for rhizobial suppression of plant innate immunity in Lotus japonicus. SymRK associates with LjBAK1 (BRASSINOSTEROID INSENSITIVE 1-Associated receptor Kinase 1), a well-characterized positive regulator of plant innate immunity, and directly inhibits LjBAK1 kinase activity. Rhizobial inoculation enhances the association between SymRK and LjBAK1 in planta. LjBAK1 is required for the regulation of plant innate immunity and plays a negative role in rhizobial infection in L. japonicus. The data indicate that the SymRK-LjBAK1 protein complex serves as an intersection point between rhizobial symbiotic signaling pathways and innate immunity pathways, and support that rhizobia may actively suppress the host's ability to mount a defense response during the legume-rhizobium symbiosis.