FUNCTIONAL TRANSFORMATION OF MICROBODIES IN HIGHER-PLANT CELLS

In germinating fatty seedlings, microbodies are functionally transform ed to leaf peroxisomes from glyoxysomes during greening, and then conv erted to glyoxysomes from leaf peroxisomes during senescence. Immunocy tochemical studies revealed that glyoxysomes can exchange directly int o leaf peroxisomes during greening and leaf peroxisomes are once again directly converted to glyoxysomes during senescence. The reversible t ransformations of microbodies are regulated at various levels, such as gene expression, splicing of the mRNA and degradation of microbody pr oteins. The regulatory mechanisms underlying this organelle differenti ation are described.