The Small GTPase ROP6 Interacts with NFR5 and Is Involved in Nodule Formation in Lotus japonicus
The Small GTPase ROP6 Interacts with NFR5 and Is Involved in Nodule Formation in Lotus japonicus
复制标题
小 GTP 酶 ROP6 与 NFR5 相互作用并参与莲子根瘤形成
DOI：
10.1104/pp.112.197269
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发表时间：
2012-05-01
期刊：
影响因子：
7.4
通讯作者：
Zhang, Zhongming
中科院分区：
文献类型：
--
作者：
Ke, Danxia;Fang, Qing;Zhang, Zhongming
Nod Factor Receptor5 (NFR5) is an atypical receptor-like kinase, having no activation loop in the protein kinase domain. It forms a heterodimer with NFR1 and is required for the early plant responses to Rhizobium infection. A Rho-like small GTPase from Lotus japonicus was identified as an NFR5-interacting protein.该Rho样GTP酶的氨基酸序列与拟南芥(Arabidopsis thaliana)ROP6和蒺藜苜蓿ROP6最接近，被命名为LjROP6。 The interaction between Rop6 and NFR5 occurred both in vitro and in planta. No interaction between Rop6 and NFR1 was observed. Green fluorescent protein-tagged ROP6 was localized at the plasma membrane and cytoplasm. The interaction between ROP6 and NFR5 appeared to take place at the plasma membrane. The expression of the ROP6 gene could be detected in vascular tissues of Lotus roots.接种中索根瘤菌后，根毛、根尖、根维管束、根瘤原基和幼根瘤中ROP6表达水平升高。在表达 ROP6 RNA 干扰构建体的转基因毛状根中，根瘤菌进入根毛似乎没有受到影响，但穿过根皮层的感染线生长受到严重抑制，导致每株植物的根瘤发育减少。 These data demonstrate a role of ROP6 as a positive regulator of infection thread formation and nodulation in L. japonicus.
Nod Factor Receptor5 (NFR5) is an atypical receptor-like kinase, having no activation loop in the protein kinase domain. It forms a heterodimer with NFR1 and is required for the early plant responses to Rhizobium infection. A Rho-like small GTPase from Lotus japonicus was identified as an NFR5-interacting protein. The amino acid sequence of this Rho-like GTPase is closest to the Arabidopsis (Arabidopsis thaliana) ROP6 and Medicago truncatula ROP6 and was designated as LjROP6. The interaction between Rop6 and NFR5 occurred both in vitro and in planta. No interaction between Rop6 and NFR1 was observed. Green fluorescent protein-tagged ROP6 was localized at the plasma membrane and cytoplasm. The interaction between ROP6 and NFR5 appeared to take place at the plasma membrane. The expression of the ROP6 gene could be detected in vascular tissues of Lotus roots. After inoculation with Mesorhizobium loti, elevated levels of ROP6 expression were found in the root hairs, root tips, vascular bundles of roots, nodule primordia, and young nodules. In transgenic hairy roots expressing ROP6 RNA interference constructs, Rhizobium entry into the root hairs did not appear to be affected, but infection thread growth through the root cortex were severely inhibited, resulting in the development of fewer nodules per plant. These data demonstrate a role of ROP6 as a positive regulator of infection thread formation and nodulation in L. japonicus.