Abstract: This study aimed to clone PR10 gene which was up-regulated in the leaves of Lilium regale infected by Cucumber mosaic virus（CMV）and examine the role of PR10 gene in defense response against CMV.The full length of LrPR10 was amplified by RACE and analyzed with bioinformatics tools. Real-time PCR was performed to check the transcript levels of LrPR10 in different organs of L. regale，CMV-inoculated and salicylic acid（SA）–treated leaves. The results showed that the length of complete cDNA of LrPR10 was 756 bp，which encoded 157 amino acids consisting of a Bet_v1_like conserved domain of pathogenesis-related proteins. The transcript level of LrPR10 was the highest in bulbs，whereas the lowest in tender leaves. LrPR10 was significantly induced by CMV inoculation and SA treatment. Transcript level of LrPR10 reached a peak at 4 d，4 d and 1d in the CMV-inoculated leaves of L. regale， L. lancifolium and L. leucanthum respectively，while the maximum relatively expression values in CMV-inoculated samples were about 58，27 and 292 times higher than the uninoculated ones in these three species. After SA treatment，LrPR10 peaked at 8 h in L. regale，L. lancifolium and L. leucanthum and the maximum relatively expression values in treated samples were about 34，8 and 38 times higher than the untreated ones in three species. We hypothesize that LrPR10 from L. regale probably plays an essential role in plant defenseagainst CMV.

Key words: Lilium regale, Cucumber mosaic virus, LrPR10, RACE, expression analysis