Mitochondrial mutation impairs cytoplasmic male sterility rice in response to H₂O₂ stress.

摘要

Cytoplasmic male sterility (CMS) is a phenomenon widely observed in various plant species characterized with disrupted anther development caused by mitochondrial mutation. CMS is becoming a model system for the investigations of nucleus-cytoplasmic interaction. To reveal the possible effects of CMS genes on plant growth in adverse environment, plant development and biochemical characters of mitochondria from Honglian (HL)-CMS line Yuetai A and maintainer Yuetai B treated with H₂O₂ were analyzed. Results showed that 40-60 mM H₂O₂ significantly inhibits rice seedling development and growth. When treated with H₂O₂, ATP content and mitochondrial membrane potential in Yuetai A decreased significantly faster than those of Yuetai B. These biochemical changes were accompanied by the severe nuclear DNA fragmentation and the release of mitochondrial cytochrome c in the leaf cells of Yuetai A. In addition, the antioxidative enzyme activities and mitochondrial electron transfer chain complexes were significantly down-regulated. Disturbance of the biochemical indexes indicate that HL-CMS line is more susceptible to H₂O₂ stress than the maintainer line, the deleterious effects caused by the CMS-related ORFH79 peptide compromises the adaptability of HL-CMS line to the adverse environment.CAS Registry Numbers 56-65-5 7722-84-1