Cloning And Expression Analysis Of LrPR10Gene And LrNAC Transcription Factor Gene From Lilium Regale

This study aimed to clone PR10gene and NAC transcription factor gene which wereup-regulated in the leaves of Lilium regale infected by cucumber mosaic virus (CMV) andexamine the role of these two genes in defense response against CMV. The full lengths ofLrPR10and LrNAC transcription factor gene were amplified by RACE and analyzed withbioinformatics tools. Real-time PCR was performed to check the transcript levels of thesetwo genes in different organs of L. regale, CMV-inoculated and salicylic acid (SA)-treatedleaves. The results showed:1. The full cDNA of LrPR10gene was756bp and encoded a157-amino acid peptidewith a Bet_v1_like conserved domain of pathogenesis-related proteins.2. The transcript level of LrPR10gene was highest in bulbs, whereas lowest in tenderleaves. LrPR10was significantly induced by CMV inoculation and SA treatment. Transcriptlevel of LrPR10reached a peak at4d,4d and1d in the CMV-inoculated leaves of L. regale, L.lancifolium and L. leucanthum respectively, while the maximum relatively expression valuesin CMV-inoculated samples were about58,27and292times larger than the un-inoculatedones in these three species. After SA treatment, LrPR10peaked at8h in L. regale, L.lancifolium and L. leucanthum and the maximum relatively expression values in treatedsamples were about34,8and38times larger than the untreated ones in three species. Wehypothesize that LrPR10from L. regale probably plays an essential role in plant defenseagainst CMV.3. The full cDNA of LrNAC transcription factor gene was827bp and encoded a208-amino acid peptide with a conserved domain of NAC transcription factor family.4. Therelative expression level of LrNAC transcription factor gene was the highest in tender leaves,but the lowest in tender stems. LrNAC transcription factor gene was up-regulated by CMV.After being inoculated by CMV, this gene peaked on4d,3d and4d in L. regale, L.lancifolium and L. leucanthum respectively and the maximum expression values of treatedsamples were38,3and13times larger than the untreated ones in these three species. AfterSA treatment, LrNAC transcription factor gene peaked at8h,6h and8h in L. regale, L.lancifolium and L. leucanthum respectively and the maximum relatively expression values in treated samples were about33,4and8times larger than the untreated ones in threespecies.These results suggested that LrNAC transcription factor gene played a role in L.regale against CMV.