title: Redox regulation of peroxiredoxin and proteinases by ascorbate and thiols during pea root nodule senescence.
abstract: Redox factors contributing to nodule senescence were studied in pea. The abundance of the nodule cytosolic peroxiredoxin but not the mitochondrial peroxiredoxin protein was modulated by ascorbate. In contrast to redox-active antioxidants such as ascorbate and cytosolic peroxiredoxin that decreased during nodule development, maximal extractable nodule proteinase activity increased progressively as the nodules aged. Cathepsin-like activities were constant throughout development but serine and cysteine proteinase activities increased during senescence. Senescence-induced cysteine proteinase activity was inhibited by cysteine, dithiotreitol, or E-64. Senescence-dependent decreases in redox-active factors, particularly ascorbate and peroxiredoxin favour decreased redox-mediated inactivation of cysteine proteinases.
authors.affiliation: Crop Performance and Improvement Division, Rothamsted Research, West Common, Harpenden, Hertfordshire AL5 2JQ, UK.
authors.forename: Karin
authors.initials: K
authors.lastname: Groten
authors.forename: Christelle
authors.initials: C
authors.lastname: Dutilleul
authors.forename: Philippus D R
authors.initials: PD
authors.lastname: van Heerden
authors.forename: Hélène
authors.initials: H
authors.lastname: Vanacker
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Bernard
authors.forename: Iris
authors.initials: I
authors.lastname: Finkemeier
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Dietz
authors.forename: Christine H
authors.initials: CH
authors.lastname: Foyer
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D002403:Cathepsins / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000378:metabolism; D010084:Oxidation-Reduction; D018532:Pisum sativum / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism*; D010544:Peroxidases / Q000378:metabolism*; D054464:Peroxiredoxins; D018517:Plant Roots / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013997:Time Factors
chemical_list: D000975:Antioxidants; D013438:Sulfhydryl Compounds; D010544:Peroxidases; D054464:Peroxiredoxins; D002403:Cathepsins; D010447:Peptide Hydrolases; D003546:Cysteine Endopeptidases; D001205:Ascorbic Acid