The PR10 gene family is highly expressed in Lilium regale Wilson during Fusarium oxysporum f. sp. lilii infection

Abstract

Pathogenesis-related (PR) proteins play key roles in plant responses to pathogens and abiotic stresses. In this study, nine novel PR genes were isolated from Lilium regale Wilson, which is a wild lily species of China with high-level resistance to the soilborne fungal pathogen Fusarium oxysporum f. sp. lilii, and homology analysis classified them into the PR10 family. These novel LrPR10s were clustered together with PR10s from monocotyledons in a phylogenetic tree, moreover, phylogenetic analysis divided the nine LrPR10s into two groups. The main-chain conformation and folding patterns of the LrPR10s were highly conserved with other plant PR10s. The expression patterns of the nine LrPR10s in L. regale during normal development were examined by QRT-PCR, and the transcription levels of the LrPR10s were relatively high in roots. Furthermore, QRT-PCR analysis indicated that the expression levels of LrPR10-1, LrPR10-2, LrPR10-5, LrPR10-6, and LrPR10-7 in L. regale roots were up-regulated by two or more stress-related signaling molecules including salicylic acid, jasmonic acid, ethylene, and H2O2, while the other four LrPR10s were repressed by these four signaling molecules. In addition, five members of the LrPR10 gene family including LrPR10-2, LrPR10-4, LrPR10-5, LrPR10-6, LrPR10-7, and LrPR10-9 were strongly induced by F. oxysporum in resistant L. regale compared with the susceptible Lilium Oriental hybrid ‘Siberia’. The other four LrPR10s were down-regulated by F. oxysporum infection. In summary, our results indicate that the members of PR10 gene family are involved in L. regale defense responses against F. oxysporum f. sp. lilii.