Ubiquitin-mediated degradation restricts spatiotemporal accumulation of the cytoplasmic male sterility protein WA352 to anthers in rice
Abstract
Cytoplasmic male sterility (CMS) is caused by mitochondrial genes that are constitutively expressed in plant tissues, although the encoded proteins preferentially accumulate in anthers. The mechanisms regulating CMS protein accumulation remain unclear. Here, we explored this process using wild-abortive CMS (CMS-WA) rice ( Oryza sativa ). We show that WA352, the causal protein of CMS-WA, is degraded by the ubiquitin–proteasome system (UPS). Structural analysis and protein truncation assays revealed that the N terminus of WA352 is critical for its anchoring to the inner mitochondrial membrane and its UPS-mediated degradation. Functional complementation confirmed that WA352 151–352 , lacking the N-terminal domain, accumulates constitutively in vegetative tissues, causing a reactive oxygen species burst and retarding rice growth. We further identified three mitochondrion-localized F-box proteins that participate in WA352 ubiquitination and degradation. Our findings demonstrate that UPS-mediated regulation restricts WA352 accumulation to anthers, allowing it to specifically disrupt anther development, thus helping to explain the male-specific effects of CMS genes in plants.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (11)
Zixu Zhang
Guangdong Basic Research Center of Excellence for Precise Breeding of Future Crops, Guangdong Laboratory for Lingnan Modern Agriculture, College of Agriculture, South China Agricultural University
Zhi Ding
Guangdong Basic Research Center of Excellence for Precise Breeding of Future Crops, Guangdong Laboratory for Lingnan Modern Agriculture, College of Agriculture, South China Agricultural University
Xueye Feng
College of Life Sciences, South China Agricultural University
Jingjing Huang
College of Life Sciences, South China Agricultural University
Xu Peng
Yubin Xiao
College of Life Sciences, South China Agricultural University
Wubei Zong
Guangdong Basic Research Center of Excellence for Precise Breeding of Future Crops, Guangdong Laboratory for Lingnan Modern Agriculture, College of Agriculture, South China Agricultural University
Zhe Zhao
Guangdong Basic Research Center of Excellence for Precise Breeding of Future Crops, Guangdong Laboratory for Lingnan Modern Agriculture, College of Agriculture, South China Agricultural University
Yao-Guang Liu
Guangdong Basic Research Center of Excellence for Precise Breeding of Future Crops, Guangdong Laboratory for Lingnan Modern Agriculture, College of Agriculture, South China Agricultural University
Yongyao Xie
Guangdong Basic Research Center of Excellence for Precise Breeding of Future Crops, Guangdong Laboratory for Lingnan Modern Agriculture, College of Agriculture, South China Agricultural University
Letian Chen
Guangdong Basic Research Center of Excellence for Precise Breeding of Future Crops, Guangdong Laboratory for Lingnan Modern Agriculture, College of Agriculture, South China Agricultural University