Differential regulation of the Epr3 receptor coordinates membrane-restricted rhizobial colonization of root nodule primordia.
Differential regulation of the Epr3 receptor coordinates membrane-restricted rhizobial colonization of root nodule primordia.
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DOI：
10.1038/ncomms14534
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发表时间：
2017-02-23
影响因子：
16.6
通讯作者：
Stougaard J
中科院分区：
文献类型：
--
作者：
Kawaharada Y;Nielsen MW;Kelly S;James EK;Andersen KR;Rasmussen SR;Füchtbauer W;Madsen LH;Heckmann AB;Radutoiu S;Stougaard J
在百脉根中，LysM受体激酶EPR3在表皮区分相容和不相容的根瘤菌胞外多糖。然而，这种识别系统在细菌定植的根内部的作用是未知的。在这里，我们表明，EPR3的细胞内感染机制，介导根皮层和根瘤原基的感染线程入侵。在细胞水平上，EPR3表达描绘了感染线进展为结节原基和皮质感染线形成受损的EPR3突变体。这种发育协调的遗传解剖表明，EPR3整合到共生信号转导途径。进一步的分析表明，表皮和皮层原基中的EPR3的差异表达，并确定了控制这种组织特异性的关键转录因子。这些结果表明，胞外多糖的识别过程中不断重复进行感染和EPR3感知兼容胞外多糖促进细胞内皮层感染机制，保持细菌封闭在植物膜。莲花根瘤菌LysM受体激酶EPR3感知根瘤菌胞外多糖启动根表皮的感染。在这里，作者表明，EPR3也介导根皮层中的感染线进展，并表明调节共生的关键转录因子指定了EPR3的表达。
In Lotus japonicus, a LysM receptor kinase, EPR3, distinguishes compatible and incompatible rhizobial exopolysaccharides at the epidermis. However, the role of this recognition system in bacterial colonization of the root interior is unknown. Here we show that EPR3 advances the intracellular infection mechanism that mediates infection thread invasion of the root cortex and nodule primordia. At the cellular level, Epr3 expression delineates progression of infection threads into nodule primordia and cortical infection thread formation is impaired in epr3 mutants. Genetic dissection of this developmental coordination showed that Epr3 is integrated into the symbiosis signal transduction pathways. Further analysis showed differential expression of Epr3 in the epidermis and cortical primordia and identified key transcription factors controlling this tissue specificity. These results suggest that exopolysaccharide recognition is reiterated during the progressing infection and that EPR3 perception of compatible exopolysaccharide promotes an intracellular cortical infection mechanism maintaining bacteria enclosed in plant membranes. The Lotus japonicus LysM receptor kinase EPR3 perceives rhizobial exopolysaccharides to initiate infection of the root epidermis. Here the authors show that EPR3 also mediates infection thread progression in the root cortex and show that key transcription factors that regulate symbiosis specify the expression of Epr3.