Recent data from studies of peroxisome assembly and the subcellular sorting
of peroxisomal matrix and membrane proteins have led to an expansion of th
e 'growth and division' and 'endoplasmic reticulum-vesiculation' models of
peroxisome biogenesis into a more flexible, unified model. Within this cont
ext, we discuss the proposed role for the endoplasmic reticulum in the form
ation of preperoxisomes and the potential for 15 Arabidopsis peroxin homolo
gs to function in the biogenesis of peroxisomes in plant cells.