title: Prunus domestica pathogenesis-related protein-5 activates the defense response pathway and enhances the resistance to fungal infection.
abstract: Pathogenesis-related protein-5 (PR-5) has been implicated in plant disease resistance and its antifungal activity has been demonstrated in some fruit species. However, their roles, especially their interactions with the other defense responses in plant cells, are still not fully understood. In this study, we have cloned and characterized a new PR-5 cDNA named PdPR5-1 from the European plum (Prunus domestica). Expression of PdPR5-1 was studied in different cultivars varying in resistance to the brown rot disease caused by the necrotrophic fungus Monilinia fructicola. In addition transgenic Arabidopsis, ectopically expressing PdPR5-1 was used to study its role in other plant defense responses after fungal infection. We show that the resistant cultivars exhibited much higher levels of transcripts than the susceptible cultivars during fruit ripening. However, significant rise in the transcript levels after infection with M. fructicola was observed in the susceptible cultivars too. Transgenic Arabidopsis plants exhibited more resistance to Alternaria brassicicola. Further, there was a significant increase in the transcripts of genes involved in the phenylpropanoid biosynthesis pathway such as phenylalanine ammonia-lyase (PAL) and phytoalexin (camalexin) pathway leading to an increase in camalexin content after fungal infection. Our results show that PdPR5-1 gene, in addition to its anti-fungal properties, has a possible role in activating other defense pathways, including phytoalexin production.
authors: Department of Plant Agriculture, University of Guelph, Vineland, Ontario, Canada.
authors: Ashraf
authors: A
authors: El-kereamy
authors: Islam
authors: I
authors: El-sharkawy
authors: Rengasamy
authors: R
authors: Ramamoorthy
authors: Ali
authors: A
authors: Taheri
authors: Deena
authors: D
authors: Errampalli
authors: Prakash
authors: P
authors: Kumar
authors: Subramanian
authors: S
authors: Jayasankar
mesh_terms: D000528:Alternaria / Q000502:physiology*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D001483:Base Sequence; D019295:Computational Biology; D018506:Gene Expression Regulation, Plant; D007113:Immunity, Innate / Q000276:immunology*; D007211:Indoles / Q000378:metabolism; D020407:Internet; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D027861:Prunus / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction / Q000276:immunology*; D013844:Thiazoles / Q000378:metabolism; D000094162:Phytoalexins
chemical_list: D007211:Indoles; D010940:Plant Proteins; D012333:RNA, Messenger; D013844:Thiazoles; C102405:camalexin; D000094162:Phytoalexins