Plastid Protein Degradation During Leaf Development and Senescence: Role of Proteases and Chaperones

摘要: During leaf development, plastids undergo dynamic changes in morphology. Chloroplasts develop from proplastids during growth: this process includes synthesis, import, and maturation of numerous chloroplast proteins. senescence, chloroplasts change gradually into a senescing form termed gerontoplast, with the breakdown thylakoid membranes degradation photosynthetic In these developmental processes, it is apparent that proteolytic activity within key to control such remarkable morphological/functional changes. Processing proteins are very important since development requires imported cytosol. Various efforts elucidate functions proteases have revealed existence signal peptidases (SPP, PreP, TPP, PlsP1) involved processing steps. addition, quality ­necessary for proper development. Recent studies using Arabidopsis mutants identified several chloroplastic (Clp, FtsH, Deg, some intramembrane-proteases), which originated bacterial homologs, contrast, on senescence implied multiple pathways, not limited proteases, protein process. addition inside chloroplasts, engulfed whole-chloroplasts vacuole, small spherical bodies like senescence-associated vacuoles (SAV), Rubisco-containing (RCB) include stromal known occur senescence. The latter implicates autophagy plays an role delivering vacuole. This chapter provides integrated summary roles current view