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.
Agricultural University of Athens, Laboratory of Plant Pathology, Athens, Greece. stjamos@yahoo.com
Sotirios E
SE
Tjamos
Emmanouil
E
Flemetakis
Epaminondas J
EJ
Paplomatas
Panagiotis
P
Katinakis
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