Interfamily Graft Hybrids Vitis vinifera / Schisandra chinensis resulted in changes among phenotype, genetic information and metabolite

Background: Grafting is an efficient method in producing the grafted hybrids of fruit tree.For the formation mechanism of the grafted hybrids, long-distance transfer of genetic material and metabolites between rootstock and scions is well documented in homo-grafted hybrid, but it has rarely been reported in distant-grafted cases in which the rootstock and scion belong to different families. Results: : In current study, we grafted common grape vine, Vitis vinifera (Vv)scions onto Schisandra chinensis (Sc) stocks, and obtained 20 grafted hybrids, Vitis vinifera / Schisandra chinensis (Vs), that grew normally for 25 years, and showed the variation in phenotypic traits, including leaf, internode, and fruit with a tendency toward rootstock-like traits. We further analysed the genetic material and metabolites between Vv plants and Vs hybrids using high-throughput sequencing, and found that a total of 2113 differentially expressed genes (DEGs) were identified in Vs hybrids. which mainly involved in the oxidation-reduction process, and the metabolic process. Meanwhile seventy-nine differentially expressed miRNAs (DEMs) containing 27 known miRNAs and 52 novel miRNAs were identified in Vs hybrids, and the degradation further detected 840 target genes corresponding to 252 miRNAs, of which 12 DEMs and the corresponding target gene expression levels were mostly negatively correlated. Furthermore, 1188 differential metabolic compounds were also identified in Vs hybrids. In particular, the abundance of metabolites schizandrin and gomisin that were the main medicinal ingredients in S. chinensis , were down-regulated and up-regulated in Vs hybrids, respectively. Conclusion: The results of this study provide first insights into the effects of interfamily grafts on the transcript profile and metabolites of the scion, and contribute to explore new mechanisms of interfamily grafts for fruit tree in the future.