Induction of resistance to Verticillium dahliae in Arabidopsis thaliana by the biocontrol agent K-165 and pathogenesis-related proteins gene expression.
The biocontrol bacterium Paenibacillus alvei K165 has the ability to protect Arabidopsis thaliana against Verticillium dahliae. A direct antagonistic action of strain K165 against V. dahliae was ruled out, making it likely that K165-mediated protection results from induced systemic resistance (ISR) in the host. K165-mediated protection was tested in various Arabidopsis mutants and transgenic plants impaired in defense signaling pathways, including NahG (transgenic line degrading salicylic acid [SA]), etr1-1 (insensitive to ethylene), jar1-1 (insensitive to jasmonate), npr1-1 (nonexpressing NPR1 protein), pad3-1 (phytoalexin deficient), pad4-1 (phytoalexin deficient), eds5/sid1 (enhanced disease susceptibility), and sid2 (SA-induction deficient). ISR was blocked in Arabidopsis mutants npr1-1, eds5/sid1, and sid2, indicating that components of the pathway from isochorismate and a functional NPR1 play a crucial role in the K165-mediated ISR. Furthermore, the concomitant activation and increased transient accumulation of the PR-1, PR-2, and PR-5 genes were observed in the treatment in which both the inducing bacterial strain and the challenging pathogen were present in the rhizosphere of the A. thaliana plants.
Tjamos
Sotirios E
SE
Agricultural University of Athens, Laboratory of Plant Pathology, Athens, Greece. stjamos@yahoo.com
Flemetakis
Emmanouil
E
Paplomatas
Epaminondas J
EJ
Katinakis
Panagiotis
P
D017360:Arabidopsis / Q000235:genetics / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000235:genetics; D001407:Bacillus / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D007113:Immunity, Innate; D010572:Pest Control, Biological / Q000379:methods*; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D018517:Plant Roots / Q000235:genetics / Q000382:microbiology; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D020172:Verticillium / Q000254:growth & development*
D029681:Arabidopsis Proteins; D018749:RNA, Plant; C077262:PR-1 protein, Arabidopsis; C077263:BG2 protein, Arabidopsis; C077264:PR-5 protein, Arabidopsis