Diversity Distributions and the Anthocyanin Associations of Fungal Endophytes in Different Colored Grapevine Leaves

摘要

Anthocyanins composed the major pigments which conferred sensory and chemical values to red grapes and wines. Multiple factors involved in grape anthocyanin biosynthesis have been greatly covered to date. However, the endophytes which closely associate with plants, their possible roles in plant coloration are still under clear. Our present research firstly investigated the diversity distributions of culturable fungal endophytes (CFE) in different colored grapevine leaves which harvested from same vineyard and cultivar, and then proposed method to analyze the possible effects of these fungal endophytes on anthocyanin concentrations of grape cells. In totally 532 endophytic fungal isolates, 19 OTUs belong to 13 genera were isolated from five color different grapevine leaves. Obvious leaf color specificity of CFE communities were observed distribution in different colored grapevine leaves in this experiment. Assessing the influences of those isolated CFEs on anthocyanin concentrations of a teinturier grape pulp cells via dual culture system revealed that anthocyanin promotion fungal strains were more possibly isolated from red and purple colored grape leaves. And elite CFE strains such as DQ53 and DQ55, both belong to the fungal genus Epicoccum, which conferred significant promotion effects on grape cellular anthocyanin contents were selected out. And the transcriptions of anthocyanin biosynthesis association genes MYBA1, UFGT and F3 ' 5 ' H in grape cells, were significantly influenced by these endophytic fungi, furtherly implicated the involvements of these genes in fungal endophytes-mediated grape cell anthocyanin promotion process. Additionally, endophytic fungi triggered anthocyanin promotion in grape cells seem independently to that of the light mediated anthocyanin synthesis pathway. This work demonstrated that beside other environmental factors, endophytes may also involve in grape anthocyanin metabolisms. And the study provided methods and clues to explore fungal endophytes in colored grape leaves which possibly applied in grape pigmentation processing.