Xiaoman You,Shanshan Zhu,Haowen Sheng, Zheng Liu, Dan Wang, Min Wang, Xiao Xu, Feng He, Hong Fang, Fan Zhang, Debao Wang, Zeyun Hao, Ruyi Wang, Yinghui Xiao, Jianmin Wan, Guo-Liang Wang, Yuese Ning.The rice peroxisomal receptor PEX5 negatively regulates resistance to rice blast fungus Magnaporthe oryzae.

https://doi.org/10.1016/j.celrep.2023.113315

Summary

The receptor protein PEX5, an important component of peroxisomes, regulates growth, development, and immunity in yeast and mammals. PEX5 also influences growth and development in plants, but whether it participates in plant immunity has remained unclear. Here, we report that knockdown of OsPEX5 enhances resistance to the rice blast fungus Magnaporthe oryzae. We demonstrate that OsPEX5 interacts with the E3 ubiquitin ligase APIP6, a positive regulator of plant immunity. APIP6 ubiquitinates OsPEX5 in vitro and promotes its degradation in vivo via the 26S proteasome pathway. In addition, OsPEX5 interacts with the aldehyde dehydrogenase OsALDH2B1, which functions in growth-defense trade-offs in rice. OsPEX5 stabilizes OsALDH2B1 to enhance its repression of the defense-related gene OsAOS2. Our study thus uncovers a previously unrecognized hierarchical regulatory mechanism in which an E3 ubiquitin ligase targets a peroxisome receptor protein that negatively regulates immunity in rice by stabilizing an aldehyde dehydrogenase that suppresses defense gene expression.

Cell Reports，IF=8.8

https://doi.org/10.1016/j.celrep.2023.113315