Mesorhizobium huakuii HtpG Interaction with nsLTP AsE246 Is Required for Symbiotic Nitrogen Fixation
Mesorhizobium huakuii HtpG Interaction with nsLTP AsE246 Is Required for Symbiotic Nitrogen Fixation
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Mesorhizobium huakuii HtpG 与 nsLTP AsE246 相互作用是共生固氮所必需的
DOI：
10.1104/pp.18.00336
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发表时间：
2019-05-01
期刊：
影响因子：
7.4
通讯作者：
Li，Youguo
中科院分区：
文献类型：
--
作者：
Zhou，Donglai;Li，Yanan;Li，Youguo
植物非特异性脂质转移蛋白（nsLTPs）参与了包括根瘤共生在内的许多生物过程。然而，人们对nsLTPs在豆科植物与根瘤菌共生中的作用仍然知之甚少，迄今为止还没有报道与nsLTPs相互作用的根瘤菌蛋白。在本研究中，我们利用细菌双杂交系统鉴定了与nsLTP AsE246相互作用的华库中根瘤菌高温蛋白G （HtpG）。HtpG与AsE246的相互作用通过远western印迹和双分子荧光互补得到证实。结果表明，HtpG的热休克蛋白90 （HSP90）结构域介导了HtpG- ase246的相互作用。免疫荧光分析显示HtpG与AsE246在感染的结节细胞和共生体膜上共定位。htpggene在年轻结节中表达较高，在感染区表达较高。进一步的研究表明，tpgp的表达影响根瘤的脂质丰度和分布，并在根瘤发育和固氮中起重要作用。我们的研究结果进一步揭示了根瘤中通过nsltp转运共生体脂质的功能机制。
Plant nonspecific lipid transfer proteins (nsLTPs) are involved in a number of biological processes including root nodule symbiosis. However, the role of nsLTPs in legume-rhizobium symbiosis remains poorly understood, and no rhizobia proteins that interact with nsLTPs have been reported to date. In this study, we used a bacteria two-hybrid system and identified the high temperature protein G (HtpG) fromMesorhizobium huakuiithat interacts with the nsLTP AsE246. The interaction between HtpG and AsE246 was confirmed by far-Western blotting and bimolecular fluorescence complementation. Our results indicated that the heat shock protein 90 (HSP90) domain of HtpG mediates the HtpG-AsE246 interaction. Immunofluorescence assay showed that HtpG was colocalized with AsE246 in infected nodule cells and symbiosome membranes. Expression of thehtpGgene was relatively higher in young nodules and was highly expressed in the infection zones. Further investigation showed thathtpGexpression affects lipid abundance and profiles in root nodules and plays an essential role in nodule development and nitrogen fixation. Our findings provide further insights into the functional mechanisms behind the transport of symbiosome lipids via nsLTPs in root nodules.