Perturbation of auxin homeostasis caused by mitochondrial FtSH4 gene-mediated peroxidase accumulation regulates arabidopsis architecture.
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 mediating the peroxidase-dependent interplay between hydrogen peroxide (H2O2) 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 H2O2 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.
Guangdong Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631, China.
Shengchun
S
Zhang
Juelin
J
Wu
Dongke
D
Yuan
Daowei
D
Zhang
Zhigang
Z
Huang
Langtao
L
Xiao
Chengwei
C
Yang
D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001692:Biological Transport; D055785:Gene Knockdown Techniques; D006706:Homeostasis; D006861:Hydrogen Peroxide / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D045726:Metalloproteases / Q000235:genetics*; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D010544:Peroxidases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype
D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D006861:Hydrogen Peroxide; D010544:Peroxidases; C574008:PRX33 protein, Arabidopsis; C553803:PRX34 protein, Arabidopsis; C506771:FtsH4 protein, Arabidopsis; D045726:Metalloproteases
Arabidopsis thaliana; FtSH4; IAA oxidation; auxin; development; hydrogen peroxide; peroxidase.