title: Long-term induction of defense gene expression in potato by pseudomonas sp. LBUM223 and streptomyces scabies.
abstract: Streptomyces scabies is a causal agent of common scab of potato, which generates necrotic tuber lesions. We have previously demonstrated that inoculation of potato plants with phenazine-1-carboxylic acid (PCA)- producing Pseudomonas sp. LBUM223 could significantly reduce common scab symptoms. In the present study, we investigated whether LBUM223 or an isogenic phzC- mutant not producing PCA could elicit an induced systemic resistance response in potato. The expression of eight defense-related genes (salicylic acid [SA]-related ChtA, PR-1b, PR-2, and PR-5; and jasmonic acid and ethylene-related LOX, PIN2, PAL-2, and ERF3) was quantified using newly developed TaqMan reverse-transcription quantitative polymerase chain reaction assays in 5- and 10-week-old potted potato plants. Although only wild-type LBUM223 was capable of significantly reducing common scab symptoms, the presence of both LBUM223 and its PCA-deficient mutant were equally able to upregulate the expression of LOX and PR-5. The presence of S. scabies overexpressed all SA-related genes. This indicates that (i) upregulation of potato defense-related genes by LBUM223 is unlikely to contribute to common scab's control and (ii) LBUM223's capacity to produce PCA is not involved in this upregulation. These results suggest that a direct interaction occurring between S. scabies and PCA-producing LBUM223 is more likely involved in controlling common scab development.
authors.forename: Tanya
authors.initials: T
authors.lastname: Arseneault
authors.forename: Corné M J
authors.initials: CM
authors.lastname: Pieterse
authors.forename: Maxime
authors.initials: M
authors.lastname: Gérin-Ouellet
authors.forename: Claudia
authors.initials: C
authors.lastname: Goyer
authors.forename: Martin
authors.initials: M
authors.lastname: Filion
mesh_terms: D003517:Cyclopentanes / Q000378:metabolism; D060467:Disease Resistance; D015536:Down-Regulation; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D054883:Oxylipins / Q000378:metabolism; D010572:Pest Control, Biological; D010619:Phenazines / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology* / Q000517:prevention & control; D010937:Plant Growth Regulators / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics; D011549:Pseudomonas / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020156:Salicylic Acid / Q000378:metabolism; D011198:Solanum tuberosum / Q000235:genetics / Q000276:immunology / Q000382:microbiology*; D013302:Streptomyces / Q000235:genetics / Q000502:physiology*; D015854:Up-Regulation
chemical_list: D003517:Cyclopentanes; D005030:Ethylenes; D054883:Oxylipins; D010619:Phenazines; D010937:Plant Growth Regulators; D010940:Plant Proteins; C053376:pathogenesis-related proteins, plant; C037165:1-phenazinecarboxylic acid; C011006:jasmonic acid; C036216:ethylene; D020156:Salicylic Acid