Abstract
Peroxisome is an organelle that exists universally in eukaryotic cells, however the function of it differs among species and type of tissues. In higher plants, peroxisomes are directly transformed from glyoxysomes to leaf peroxisomes in greening cotyledons of fatty seedlings. Glyoxisomes contain enzymes for the fatty acid β-oxidation cycle and the glyoxylate cycle, while leaf peroxisomes contain enzymes for photorespiration pathway. Reverse transformation of leaf peroxisomes to glyoxysomes is observed in the senescing cotyledons. Almost of peroxisomal enzymes bear an element that works as a peroxisomal targeting signal (PTS). We detected a PTS1-like element in malate synthase and glycolate oxidase genes ofChlamydomonas reinhardtii. To know these enzymes are actually located in the peroxisomes and if higher plant's PTS acts normally in this unicellular green alga, we expressed a fusion gene of GFP with PTS. We also analyzed expression patterns of these enzymes in photoautotrophic and heterotrophic growth conditions.
