Endo- and exopolygalacturonases of Ralstonia solanacearum are inhibited by polygalacturonase-inhibiting protein (PGIP) activity in tomato stem extracts

摘要: Polygalacturonases (PGs) of wild-type and non-virulent phenotype conversion mutant (PC) strains Ralstonia solanacearum were compared by investigating their activities inhibition polygalacturonase-inhibiting proteins (PGIPs) from tomato stems. In cultures strain ToUdk2, slimy (s), retarded (rs) non-slimy (ns) colonies appeared. The the 's' into 'rs' colony form coincided with beginning PG production. activity PC increased about 5 h earlier (at 6 hpi), was up to 35 times higher in media supplemented two different stem extracts or polygalacturonic acid, at hpi, generally 4-8 across test time. By hydrophobic interaction chromatography (HIC), fluorophor-assisted carbohydrate-polyacrylamid-gel electrophoresis (FACE-PAGE) mass spectrometry analyses, endo-PG PehA, exo-PGs PehB PehC identified. PGs consisted mainly endo-PG. production after supplementing medium cell wall extract reflected a for both strains. Total (endo-PG exo-PGs) inhibited PGIPs extracts. PGIP concentration dependent, constitutively present, not related resistance nor susceptibility recombinant inbred lines R. solanacearum. proteinaceous character inhibiting component inferred ammonium sulphate precipitation. For first time plant against bacterial pathogen is reported. Observations support that endo- exo-PG synthesis governed sensitive regulatory network, which, degradation products, leads generation avoidance elicitor-active oligomers, and, thus, may contribute development compatible incompatible interaction.