Ya-li Zhou’s research while affiliated with Northwest A & F University and other places

Cabernet Sauvignon and Cabernet Gernischt (Vitis vinifera L.) berries were sampled at seven stages from pre-veraison to harvest. According to seed weight to berry weight (SB) of berries, the sampled berries were divided into two groups as Low-SB and High-SB grapes. The results showed 0074hat most of colored grapes were Low-SB grapes while under-ripe green berries belonged to High-SB group at mid-veraison. What's more, compared with that of High-SB, there were more accumulation of sugar and anthocyanin and faster decreased total phenols in Low-SB berries. These were indicated that grapes with Low-SB ripened quicker. Abscisic acid (ABA) and auxin (IAA) were two main hormones in regulating berry ripening. Higher ABA and lower IAA concentration were observed in Low-SB grapes during maturation. To further illustrate the relationship of seed content with berry ripening, Cabernet Gernischt clusters were sprayed with 50 mg/L IAA. The results of this study suggested that IAA treatment delayed sugar and anthocyanin accumulation and retarded berry ripening, but increased the synchronicity of maturity by depressing the difference in sugar and anthocyanin contents between Low-SB and High-SB grapes. The delayed grapes had lower ABA and higher IAA content by reducing the expression of VvBG1, VvNCED, VvYUC1 and enhancing the expression of VvGH3-1. When the same amount of the control and IAA treatment grapes were mixed together, there were more grapes of IAA treatment belonged to the High-SB category and more berries of the control were Low-SB, further suggesting that seed content negatively correlated with berry ripening.

Copper (Cu) stress is the most common abiotic stress experienced in vineyards owing to the copper-based fungicides application. Plant hormones, including 24-Epibrassinolide (EBR), may alleviate the adverse impacts of heavy metal stress on plants. We investigated the effects of EBR pretreatment on root morphological parameters, active oxygen metabolism, osmolytes contents, antioxidant enzyme activity, endogenous phytohormone contents, and ascorbate-glutathione (AsA-GSH) cycle activity of one-year-old grape (Vitis vinifera L.) cuttings under Cu stress. Pretreatment with EBR significantly enhanced root morphological parameters (total root length, root surface area, root diameter, root volume, and tip number), increased soluble protein and proline contents, and significantly decreased the contents of H2O2, O2⋅−, and malondialdehyde (MDA) in roots and leaves. EBR pretreatment increased the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase oxidase (POD), and the contents of the endogenous phytohormones abscisic acid, jasmonic acid, and salicylic acid in the leaves. In addition, EBR regulated the balance of the AsA-GSH cycle by increasing the activities of monodehydroascorbate reductase (MDHAR), glutathione peroxidase (GR), ascorbate peroxidase (APX), and dehydroascorbate reductase (DHAR), and the contents of the antioxidant ascorbate (AsA) and dehydroascorbic acid (DHA), but the contents of glutathione (GSH) and oxidized glutathione (GSSG) decreased. Among the treatments tested, pretreatment with 0.10 mg/L EBR showed the optimal performance for alleviation of Cu toxicity. The results show that exogenous brassinosteroids reduce oxidative damage and improve the tolerance of Cu stress of grapevine cuttings.