title: Responses of proteolytic enzymes in embryonic axes of germinating bean seeds under copper stress.
abstract: The changes in protease activities in embryonic axes during the first days of bean (Phaseolus vulgaris L.) seed germination were investigated in response to copper stress. Synthetic substrates and specific protease inhibitors have been used to define qualitatively and quantitatively different catalytic classes, particularly endoproteases (EP), carboxypeptidases (CP) and aminopeptidases (AP), then identify which ones were affected in the presence of copper. In fact, a failure in storage proteins mobilization and a disorder of nitrogen supply at enzymatic level occurred in Cu. In fact, Cu inhibited azocaseinolytic activity (ACA) and cysteine-, aspartic-, serine-, and metallo-endopeptidases activities (Cys-EP, Asp-EP, Ser-Ep, and Met-EP, respectively). Besides, Cu affected leucine- and proline-aminopeptidases (LAP and PAP, respectively) and glycine-carboxypeptidases (Gly-CP). The proteolytic responses might also be associated with the decrease in defense capacity in the Cu-treated embryos.
authors.affiliation: Plant Toxicology and Molecular Biology of Microorganisms, Faculty of Sciences of Bizerta, 7021, Zarzouna, Tunisia, ines.karmous@yahoo.fr.
authors.forename: Inès
authors.initials: I
authors.lastname: Karmous
authors.forename: Khadija
authors.initials: K
authors.lastname: Jaouani
authors.forename: Ezzedine
authors.initials: E
authors.lastname: El Ferjani
authors.forename: Abdelilah
authors.initials: A
authors.lastname: Chaoui
mesh_terms: D000626:Aminopeptidases / Q000032:analysis / Q000378:metabolism; D002268:Carboxypeptidases / Q000032:analysis / Q000378:metabolism; D003300:Copper / Q000633:toxicity*; D018548:Cotyledon / Q000378:metabolism; D018525:Germination / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D010447:Peptide Hydrolases / Q000032:analysis / Q000378:metabolism*; D027805:Phaseolus / Q000187:drug effects* / Q000201:enzymology*; D011480:Protease Inhibitors / Q000032:analysis; D012639:Seeds / Q000187:drug effects / Q000201:enzymology; D014361:Trypsin Inhibitors / Q000032:analysis
chemical_list: D011480:Protease Inhibitors; D014361:Trypsin Inhibitors; D003300:Copper; D002268:Carboxypeptidases; D010447:Peptide Hydrolases; D000626:Aminopeptidases