Chitosan is involved in elicitation of vestitol production in Lotus japonicus

Leaves of Lotus japonicus infected by powdery mildew accumulate isoflavonoids, especially vestitol and sativan as protective compounds, whereas their flavonol-glycosides or phenylpropanoic acids content were rather decreased. For a better understanding the induction phytoalexin production in L. japonicus, influence important signalling molecules, namely methyl jasmonate salicylic acid, was tested leaf application, up to 15 d. No effects after spraying leaves with 0.5 mM acid observed regarding plant isoflavonoid content, showed moderate effect on accumulation. Chitosan application led strong increase derivative also increased. In similar way infection, ferulic kaempferol glycosides decreased, except for one compound, identified kaempferol-6-deoxyhexose, that is result acetylation glycosides. The chitosan an approximately 2.5- 3.5-fold hydrogen peroxide indicating involvement H2O2 pathway. activity key enzyme phenolic biosynthesis, phenylalanine amonia lyase (PAL), stimulated well expression 3 PAL-isogenes (LjPAL4, LjPAL6, LjPAL9), LjPAL8 Moreover, two enzymes biosythesis: pterocarpan reductase isoflavone synthase strongly induced. data suggest acts elicitor fungal attack do not lead general stimulation metabolism phenols, but specific isoflavonoid-phytoalexine production, vestitol.