Methyl jasmonate induced tolerance effect of Pinus koraiensis to Bursaphelenchus xylophilus

BACKGROUND: Methyl jasmonate (MeJA) can affect the balance of hormones and regulate the disease resistance of plants.Exploring the application and mechanism of MeJA in inducing the tolerance ofPinus koraiensisto pine wood nematode(PWN) infection is of great significance for developing new strategies for pine wilt disease control. RESULTS: Different concentrations (0.1, 1, 5 and 10 mM) of MeJA treatment groups showed differences in relative toleranceindex and relative anti-nematode index ofP. koraiensisseedlings to PWN infection. The treatment of 5 mMMeJA solutioninduced the best tolerance effect, followed by the 1 mMMeJA solution. Transcriptome analysis indicated that many plantdefense-related genes upregulated after treatment with 1, 5 and 10 mMMeJA solutions. Among them, genes such asjasmonateZIM domain-containing protein,phenylalanine ammonia-lyaseandperoxidasealso continuously upregulated after PWN infec-tion. Metabolome analysis indicated that jasmonic acid (JA) was significantly increased at 7 days postinoculation with PWN,and after treatment with both 1 and 5 mMMeJA solutions. Integrated analysis of transcriptome and metabolome indicated thatdifferences in JA accumulation might lead to ubiquitin-mediated proteolysis, and expression changes in trans-caffeic acid andtrans-cinnamic acid-related genes, leading to the abundance differences of these two metabolisms and the formation of mul-tiple lignin and glucosides. CONCLUSIONS: MeJA treatment could activate the expression of defense-related genes that correlated with JA, regulate theabundance of defense-related secondary metabolites, and improve the tolerance ofP. koraiensisseedlings to PWN infection.(c) 2024 Society of Chemical Industry.