Perturbation of Auxin Homeostasis Caused by Mitochondrial FtSH4 Gene-Mediated Peroxidase Accumulation Regulates Arabidopsis Architecture

作     者：Shengchun Zhang Juelin Wu Dongke Yuan Daowei Zhang Zhigang Huang Langtao Xiao Chengwei Yang 

作者机构：Guangdong Key Lab of Biotechnology for Plant Development College of Life Sciences South China Normal University Guangzhou 510631 China Hunan Provincial Key Laboratory of-Phytohormones and Growth Development Hunan Agricultural University Changsha 410128 China 

出 版 物：《Molecular Plant》 (分子植物（英文版）)

年 卷 期：2014年第7卷第5期

页      面：856-873页

核心收录：

学科分类：0710[理学-生物学] 090403[农学-农药学(可授农学、理学学位）] 071010[理学-生物化学与分子生物学] 081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 09[农学] 0904[农学-植物保护] 

基　　金：国家自然科学基金 the Guangzhou Pearl River new star project for science and technology the Education Department of Guangdong Province the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (2010) 

主　　题：Arabidopsis thaliana auxin development FtSH4 hydrogen peroxide IAA oxidation peroxidase. 

摘      要：Reactive oxygen species and auxin play important roles in the networks that regulate plant development and morphogenetic changes, However, the molecular mechanisms underlying the interactions between them are poorly understood. This study isolated a mas （More Axillary Shoots） mutant, which was identified as an allele of the mitochondrial AAA-protease AtFtSH4, and characterized the function of the FtSH4 gene in regulating plant development by medi- ating the peroxidase-dependent interplay between hydrogen peroxide （H2Oz） and auxin homeostasis. The phenotypes of dwarfism and increased axillary branches observed in the mas （renamed as ftsh4-4） mutant result from a decrease in the IAA concentration. The expression levels of several auxin signaling genes, including IAA1, IAA2, and IAA3, as well as several auxin binding and transport genes, decreased significantly in ftsh4-4 plants. However, the H202 and peroxidases levels, which also have IAA oxidase activity, were significantly elevated in ftsh4-4 plants. The ftsh4-4 phenotypes could be reversed by expressing the iaaM gene or by knocking down the peroxidase genes PRX34 and PRX33. Both approaches can increase auxin levels in the ftsh4-4 mutant. Taken together, these results provided direct molecular and genetic evidence for the interaction between mitochondrial ATP-dependent protease, H2O2, and auxin homeostasis to regulate plant growth and development.