Plant proteases, protein degradation, and oxidative stress:: role of peroxisomes

Growth and development in all organisms occur as a result of an overall balance between synthesis and proteolysis. In plants, protein degradation is a crucial mechanism in some developmental stages such as germination, morphogenesis and cell biogenesis, senescence, and programmed cell death. In this work, the main proteases that take part in these processes are reviewed. Proteolysis is also an important component together with protein oxidation in oxidative stress situations induced by senescence and heavy metals. The presence of exo- and endoproteolytic activity in plant peroxisomes is analyzed, and the role of peroxisomal proteases in different physiological events that take place under oxidative stress situations is discussed. (C) 2002 Editions scientitiques et medicales Elsevier SAS. All rights reserved.