Endophytes proved to exert multiple effects on host plants, including growth promotion, stress resistance. However, whether endophytes have a role in metabolites shaping of grape has not been fully understood. Eight endophytic fungal strains which originally isolated from grapevines were re-inoculated to field-grown grapevines in this study, and their effects on both leaves and berries of grapevines at maturity stage were assessed, with special focused on secondary metabolites and antioxidant activities. High-density inoculation of all these endophytic fungal strains modified the physio-chemical status of grapevine to different degrees. Fungal inoculations promoted the content of reducing sugar (RS), total flavonoids (TF), total phenols (TPh), trans-resveratrol (Res) and activities of phenylalanine ammonia-lyase (PAL), in both leaves and berries of grapevine. Inoculation of endophytic fungal strains, CXB-11 (Nigrospora sp.) and CXC-13 (Fusarium sp.) conferred greater promotion effects in grape metabolic re-shaping, compared to other used fungal strains. Additionally, inoculation of different strains of fungal endophytes led to establish different metabolites patterns of wine grape. The work implies the possibility of using endophytic fungi as fine-tuning regulator to shape the quality and character of wine grape.

The quality and characteristics of grape are fundamentally determined by its biochemical components. Quantitative detection of these components in berries is a classic method to evaluate grapevine resources. However, fruits are not always available for the new generated grape plantlets due to their long juvenile stage (3 to 4 years), as well as for many other potential valuable germplasm resources, such as wild grapes. Therefore, an effective berry-independent method for grapevine evaluation should have great significance. Data were provided from both leaves and berries for 2 groups of grapevine: one group is 12 genotype different varieties or species from environmental similar collections; the other group is one variety of wine grape with 18 different treatments. After quantitative correlation tests, 9 in total 11 detected parameters in genotype different (GD) group and 5 in 9 detected parameters in treatment different (TD) group, respectively, were significantly correlated between leaf and berry, respectively were found. Higher correlation coefficients were found in GD group than in TD group. Parameters of leaf reducing sugar, total flavonoids and superoxide anion scavenging capacity were found significantly correlated to berry, in both groups. These parameters with significant correlation may potentially be used as metabolite markers to estimate the qualities and characters of some new grapevine germplasm, by using the obtained data from leaves. The prospects of this leave-dependent evaluation method have also been discussed in this report.