title: Leaf senescence in Brassica napus: expression of genes encoding pathogenesis-related proteins.
abstract: Genes that are expressed during leaf senescence in Brassica napus were identified by the isolation of representative cDNA clones. DNA sequence and deduced protein sequence from two senescence-related cDNAs, LSC94 and LSC222, representing genes that are expressed early in leaf senescence before any yellowing of the leaves is visible, showed similarities to genes for pathogenesis-related (PR) proteins: a PR-1a-like protein and a class IV chitinase, respectively. The LSC94 and LSC222 genes showed differential regulation with respect to each other; an increase in expression was detected at different times during development of healthy leaves. Expression of both genes was induced by salicylic acid treatment. These findings suggest that some PR genes, as well as being induced by pathogen infection, may have alternative functions during plant development, for example in the process of leaf senescence.
authors.affiliation: Plant Molecular Biology Laboratory, Department of Biological Sciences, Wye College, University of London, Ashford, Kent, UK.
authors.forename: C
authors.initials: C
authors.lastname: Hanfrey
authors.forename: M
authors.initials: M
authors.lastname: Fife
authors.forename: V
authors.initials: V
authors.lastname: Buchanan-Wollaston
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001937:Brassica / Q000235:genetics* / Q000254:growth & development; D002688:Chitinases / Q000235:genetics / Q000502:physiology; D018076:DNA, Complementary; D018744:DNA, Plant; D015870:Gene Expression / Q000187:drug effects; D017343:Genes, Plant; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000502:physiology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D012459:Salicylates / Q000494:pharmacology; D020156:Salicylic Acid; D013997:Time Factors
chemical_list: D018076:DNA, Complementary; D018744:DNA, Plant; C099004:LSC222 protein, Brassica napus; D010940:Plant Proteins; D012459:Salicylates; C099003:YPR1 protein, Brassica napus; C053376:pathogenesis-related proteins, plant; D002688:Chitinases; D020156:Salicylic Acid