Molecular basis of peroxisome division and proliferation in plants

Peroxisomes are multifunctional organelles whose abundance varies depending on the cell type, organism, developmental stage, and environmental and metabolic conditions in which the organism lives. Plant peroxisomes are essential to embryo viability and are involved in numerous biochemical processes in development and in plant interaction with the environment. In the past few years, several classes of peroxisomal proteins required for various steps in peroxisome division and proliferation and a signaling pathway underlying the light induction of peroxisome proliferation have been identified from the model plant species Arabidopsis thaliana. Some of the major components of the peroxisome division apparatus have been conserved from plants to yeasts and animals, whereas plant-specific components are also being revealed. Environmental factors and nuclear events that control the process appear to be highly unique in different evolutionary lineages. Future research needs to identify additional members of the peroxisome division/proliferation pathways and to dissect signaling pathways by which various environmental and metabolic cues regulate the abundance of peroxisomes in plants.