Abstract
We have been screening for the mutants of altered peroxisomal motility, subcellular localization, and morphology as peup (peroxisome unusual positioning) mutants, using Arabidopsis thaliana in which peroxisomes are visualized with GFP. In this presentation, we will introduce peup1 mutant in which peroxisomes are found as an aggregated form. The aggregated peroxisomes are observed in photosynthetic cells such as mesophyll cells whereas they are not observed in non-photosynthetic cells such as the cells of root and trichomes. The functions of peroxisomes in A. thaliana are photorespiration, degradation of fatty-acids, synthesis of plant hormone, and synthesis of polyamine. In these functions, photorespiration is dominant in photosynthetic cells, and the peroxisomes in photosynthetic cells are especially called leaf peroxisomes. We found that the aggregated peroxisomes in the peup1 mutant accumulate the catalase with low-activity. We will discuss the roles of PEUP1 on the functional maintenance of leaf peroxisomes.
