期刊
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
卷 116, 期 43, 页码 21758-21768出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.1904456116
关键词
Bradyrhizobium; T3SS; symbiosis; nodulation; legume
资金
- French National Research Agency [ANR-16-CE20-0013]
- Franco-Japanese Cooperation Program (Partenariat Hubert Curien SAKURA 2017) [35920RL]
- ANR Project RADAR [ANR15-CE20-0016-01]
- French Laboratory of Excellence Project TULIP [ANR-10-LABX-41, ANR-11-IDEX-0002-02]
- French Ministry of National Education, Higher Education and Research
Several Bradyrhizobium species nodulate the leguminous plant Aeschynomene indica in a type III secretion system-dependent manner, independently of Nod factors. To date, the underlying molecular determinants involved in this symbiotic process remain unknown. To identify the rhizobial effectors involved in nodulation, we mutated 23 out of the 27 effector genes predicted in Bradyrhizobium strain ORS3257. The mutation of nopAO increased nodulation and nitrogenase activity, whereas mutation of 5 other effector genes led to various symbiotic defects. The nopM1 and nopP1 mutants induced a reduced number of nodules, some of which displayed large necrotic zones. The nopT and nopAB mutants induced uninfected nodules, and a mutant in a yet-undescribed effector gene lost the capacity for nodule formation. This effector gene, widely conserved among bradyrhizobia, was named ernA for effector required for nodulation-A. Remarkably, expressing ernA in a strain unable to nodulate A. indica conferred nodulation ability. Upon its delivery by Pseudomonas fluorescens into plant cells, ErnA was specifically targeted to the nucleus, and a fluorescence resonance energy transfer-fluorescence lifetime imaging microscopy approach supports the possibility that ErnA binds nucleic acids in the plant nuclei. Ectopic expression of ernA in A. indica roots activated organogenesis of root- and nodule-like structures. Collectively, this study unravels the symbiotic functions of rhizobial type III effectors playing distinct and complementary roles in suppression of host immune functions, infection, and nodule organogenesis, and suggests that ErnA triggers organ development in plants by a mechanism that remains to be elucidated.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据