Abstract
Peroxisomes in higher plant have been known to differentiate into at least three different classes, namely glyoxysomes, leaf peroxisomes and unspecialized peroxisomes. The peroxisomes are known to directly transform each other, which have been well observed in greening cotyledons. We extensively surveyed gene expression profile of proxisomal proteins in various organs of Arabidopsis. In seedlings, genes of glyoxysomal proteins were expressed. In green cotyledons, a group of genes that encoded peroxisomal proteins with unknown function were expressed in addition to genes of leaf peroxisomal proteins. We isolated peroxisomes from etiolated- and green-cotyledons to proteomic analysis. We identified 19 glyoxysomal proteins and 29 cotyledonary peroxisomal proteins in each organ by MALDI-TOF MS. However, only two proteins were commonly identified in both peroxisomes, and other proteins were exclusively localized in one of each peroxisome. We discuss detailed characterization of peroxisomes before and after the transformation by both of proteomic- and transcriptomic analyses.
