A D-pinitol transporter, LjPLT11, regulates plant growth and nodule development in Lotus japonicus
A D-pinitol transporter, LjPLT11, regulates plant growth and nodule development in Lotus japonicus
复制标题
DOI：
10.1093/jxb/erab402
复制
发表时间：
2021-08-30
影响因子：
6.9
通讯作者：
Chen, Yaping
中科院分区：
文献类型：
--
作者：
Tian, Lu;Liu, Leru;Chen, Yaping
多元醇转运蛋白在酵母和非洲爪蟾卵母细胞中作为具有广泛底物特异性的H+-协同转运蛋白被广泛研究，但对其在植物中的生理作用知之甚少。为了扩展这方面的知识，我们研究了LjPLT 11在百脉根-中慢生根瘤菌共生中的作用。LjPLT 11在酵母中的功能分析将其表征为木糖醇、两种O-甲基肌醇、木糖和半乳糖的能量非依赖性转运蛋白。我们发现LjPLT 11位于类菌体膜上，在感染的L.结节。LjPLT 11（LjPLT 11i）在L.在氮素充足的条件下，根瘤菌促进了植物的生长，但在固氮共生条件下，根瘤菌的固氮酶活性和植物的生长都相应地降低，从而导致了异常拟杆菌的产生。LjPLT 11 i根瘤在接种中慢生根瘤菌3周和4周后，细胞质中的渗透压高于野生型根瘤，而类菌体中的渗透压低于野生型根瘤。活性氧的水平和分布也受到干扰，在LjPLT 11 i植物的4周龄结节感染细胞。结果表明，LjPLT 11在调节其底物松醇的水平，从而维持受感染细胞的渗透平衡和结节发育过程中的类菌体膜稳定性方面起着关键作用。
Polyol transporters have been functionally characterized in yeast and Xenopus laevis oocytes as H+-symporters with broad substrate specificity, but little is known about their physiological roles in planta. To extend this knowledge, we investigated the role of LjPLT11 in Lotus japonicus-Mesorhizobium symbiosis. Functional analyses of LjPLT11 in yeast characterized it as an energy-independent transporter of xylitol, two O-methyl inositols, xylose, and galactose. We showed that LjPLT11 is located on peribacteroid membranes and functions as a facilitative transporter of D-pinitol within infected cells of L. japonicus nodules. Knock-down of LjPLT11 (LjPLT11i) in L. japonicus accelerated plant growth under nitrogen sufficiency, but resulted in abnormal bacteroids with corresponding reductions in nitrogenase activity in nodules and plant growth in the nitrogen-fixing symbiosis. LjPLT11i nodules had higher osmotic pressure in cytosol, and lower osmotic pressure in bacteroids, than wild-type nodules both 3 and 4 weeks after inoculation of Mesorhizobium loti. Levels and distributions of reactive oxygen species were also perturbed in infected cells of 4-week-old nodules in LjPLT11i plants. The results indicate that LjPLT11 plays a key role in adjustment of the levels of its substrate pinitol, and thus maintenance of osmotic balance in infected cells and peribacteroid membrane stability during nodule development.