摘要
Peroxisomes compartmentalize a dynamic suite of biochemical reactions and play a central role in plant metabolism, such as the degradation of hydrogen peroxide, metabolism of fatty acids, photorespiration, and the biosyn- thesis of plant hormones. Plant peroxisomes have been traditionally classified into three major subtypes, and in-depth mass spectrometry （MS）-based proteomics has been per- formed to explore the proteome of the two major subtypes present in green leaves and etiolated seedlings. Here, we carried out a comprehensive proteome analysis of perox- isomes from Arabidopsis leaves given a 48-h dark treatment. Our goal was to determine the proteome of the third major subtype of plant peroxisomes from senescent leaves, and further catalog the plant peroxisomal proteome. We identified a total of 111 peroxisomal proteins and verified the peroxisomal localization for six new proteins with potential roles in fatty acid metabolism and stress response by in vivo targeting analysis. Metabolic pathways compartmentalized in the three major subtypes of peroxisomes were also compared, which revealed a higher number of proteins involved in the detoxification of reactive oxygen species in peroxisomes from senescent leaves. Our study takes an important step towards mapping the full function of plant peroxisomes.
Peroxisomes compartmentalize a dynamic suite of biochemical reactions and play a central role in plant metabolism, such as the degradation of hydrogen peroxide, metabolism of fatty acids, photorespiration, and the biosyn- thesis of plant hormones. Plant peroxisomes have been traditionally classified into three major subtypes, and in-depth mass spectrometry （MS）-based proteomics has been per- formed to explore the proteome of the two major subtypes present in green leaves and etiolated seedlings. Here, we carried out a comprehensive proteome analysis of perox- isomes from Arabidopsis leaves given a 48-h dark treatment. Our goal was to determine the proteome of the third major subtype of plant peroxisomes from senescent leaves, and further catalog the plant peroxisomal proteome. We identified a total of 111 peroxisomal proteins and verified the peroxisomal localization for six new proteins with potential roles in fatty acid metabolism and stress response by in vivo targeting analysis. Metabolic pathways compartmentalized in the three major subtypes of peroxisomes were also compared, which revealed a higher number of proteins involved in the detoxification of reactive oxygen species in peroxisomes from senescent leaves. Our study takes an important step towards mapping the full function of plant peroxisomes.
基金
supported by grants from the National Science Foundation to J.H.(MCB 0618335
MCB 1330441)and L.J.O.(MCB 0618279)
