Heteroconium chaetospira Induces Resistance to Clubroot via Upregulation of Host Genes Involved in Jasmonic Acid, Ethylene, and Auxin Biosynthesis

摘要: An endophytic fungus, Heteroconium chaetospira isolate BC2HB1 (Hc), suppressed clubroot (Plasmodiophora brassicae -Pb) on canola in growth-cabinet trials. Confocal microscopy demonstrated that Hc penetrated roots and colonized cortical tissues. Based qPCR analysis, the amount of DNA found at 14 days after treatment was negatively correlated (r = 0.92, P<0.001) with severity 5 weeks a low (2×10(5) spores pot(-1)) but not high dose pathogen inoculum. Transcript levels nine B. napus (Bn) genes treated plus Pb, Pb alone nontreated control were analyzed using supplemented biochemical analysis for activity phenylalanine ammonia lyases (PAL). These encode enzymes involved several biosynthetic pathways related potentially to plant defence. increased PAL other two (BnCCR BnOPCL) also phenylpropanoid biosynthesis, relative inoculation alone. In contrast, expression jasmonic acid (BnOPR2), ethylene (BnACO), auxin (BnAAO1), PR-2 protein (BnPR-2) biosynthesis upregulated by 63, 48, 3, 3 fold, respectively, over This indicates these may be inducing resistance against clubroot. The upregulation BnAAO1 appears both pathogenesis induced defence mechanisms roots. is first report regulation specific host non-mycorrhizal endophyte.