Studies On Volatile Substances And Fragrance-related Gene Expression During Flowering Period In Jasminum Sambac

Jasminum sambac (L.) planted in fujian agriculture and forestry university for 8 years was used as the experimental material to detect floral composition of Five different periods by GC-MS, to filtrate differential genes associated with fragrance metabolic pathways in Jasminum sambac by cDNA-AFLP, and to give quantitative expression of fragrance-related genes. These results mainly provided the basis to further study the jasmine flowers Volatile substances metabolic pathways. The results of the study were as follows:1) By GC-MS, volatile substances released intensively in anthesis stage, and decreased sharply in trockne blumen period, only a few of which existed in early and mature bud. These findings were consistent with jasmine characteristics of little frangrance in non-blossoming. Terpenes and esters were main volatile substances in Jasminum sambac, terpenoids released largely in flowering, and esters reached maximum volatilization in 12 hours flowering period.43 volatile substances were identified from 5 different times, the kinds and content of which reached maximum in blooming, and the main volatile substances included linalyl acetate, α-farnesene, methyl phenylacetate, benzyl alcohol, γ-muurolene, Acetic acid methyl ester, trans-Farnesol and β-Ocimene.2) By cDNA-AFLP analysis of the flower bud I period and flowering Ⅲ period,100 fragments were obtained, including 78 up-regulated genes,22 down-regulated genes.85 fragments were involved in the terpenoids biosynthesis pathway, benzene/phenylpropanoid chemical synthesis and fatty acid synthesis pathway. There were 23 significant up-regulated genes and 5 down-regulated genes in terpenoid smetabolism, accounted for 28% of all the different genes; 35 up-regulation and 12 down-regulated genes were associated with benzene/phenylpropanoid metabolism, accounted for 47%, and 8 up-regulated and 2 down-regulated genes in fatty acid metabolism, accounted for 10%;3) To validate expression levels,6 fragrance-related genes, phosphomevalonate kinase(PMK), 3-ketoacyl CoA thiolase 2, phenylalanine ammonia-lyase(PAL), Ferulic acid 5-hydroxylase (F5H), Lipoxygenase(LOX) and Jasmonate induced protein, were selected for qRT-PCR analysis. The quantitative expression of six genes matched well with cDNA-AFLP analysis.