SrSymRK, a plant receptor essential for symbiosome formation
SrSymRK, a plant receptor essential for symbiosome formation
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DOI：
10.1073/pnas.0504250102
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发表时间：
2005-07-19
影响因子：
11.1
通讯作者：
Holsters, M
中科院分区：
文献类型：
--
作者：
Capoen, W;Goormachtig, S;Holsters, M
豆科植物和根瘤菌之间的共生关系对地球生命周期中氮的输入至关重要。新的根器官，即根瘤，被建立起来，在根瘤中，固氮细菌作为水平获得的细胞器，即共生体被内化到宿主细胞质中。这种相互作用是由细菌通过表皮根部的毛发卷曲和皮层的细胞分裂侵入而开始的，两者都是由细菌结瘤因子触发的。在已经确定的参与结节起始的几个基因中，一个编码富含亮氨酸的重复型受体激酶SymRK。在日本莲花及其同属植物紫花苜蓿（Medicago sp.）和向日葵（Pisum sativum）的SymRK突变体中，根毛相互作用水平的根瘤形成被阻止。由于表皮阻滞，SymRK在结节发育后期的作用仍然是谜。为了分析SymRK在表皮下游的作用，我们以耐水豆科植物田菁为研究对象，该植物已经形成了一种结瘤策略，以规避细菌入侵时的根毛反应。有证据表明，SymRK在植物细胞内共生吸收过程中起着重要作用。
The symbiosis between legumes and rhizobia is essential for the nitrogen input into the life cycle on our planet. New root organs, the nodules, are established, which house N-2-fixing bacteria internalized into the host cell cytoplasm as horizontally acquired organelles, the symbiosomes. The interaction is initiated by bacterial invasion via epidermal root hair curling and cell division in the cortex, both triggered by bacterial nodulation factors. Of the several genes involved in nodule initiation that have been identified, one encodes the leucine-rich repeat-type receptor kinase SymRK. In SymRK mutants of Lotus japonicus or its orthologs in Medicago sp. and Pisum sativum, nodule initiation is arrested at the level of the root hair interaction. Because of the epidermal block, the role of SymRK at later stages of nodule development remained enigmatic. To analyze the role of SymRK downstream of the epidermis, the water-tolerant legume Sesbania rostrata was used that has developed a nodulation strategy to circumvent root hair responses for bacterial invasion. Evidence is provided that SymRK plays an essential role during endosymbiotic uptake in plant cells.