The Accumulation Of Catechin And Epicatechin, Expression Of Anthocyanidin Reductase Induced By UV-C Irradiation In Grape Berry

Flavanols, are one subclass of the polyphenols and widely distributed in plants,which have an effect on plant growth and development, product quality and human health. Especially, flavanols have a important role in deciding the sensory quality of the wine, such as color, flavor, clarity, convergence, storage life and stability. Anthocyanidin reductase (ANR) is (-)-epicatechin synthetic precursor enzyme, is a key enzyme flavanols polyphenol biosynthesis process. In this study, the plants of the 7-years old grape (Vitis vinifera L. cv. Cabernet Sauvignon) were treated with UV-C irradiation regularly at the development stages. The experiment studied ANR expression pattern on the level of transcriptional and translational and catechin and epicatechin accumulation law in order to clarify the impact of UV-C irradiation on catechin and epicatechin accumulation and the effect of VvANR, VvMYBPA1, VvMYBPA2 expression in the development of grape fruit. The main results are as follows:1. UV-C irradiation does not change the laws of catechin and epicatechin accumulation law during the development of the grapes. But UV-C induces accumulation of catechin and epicatechin in young fruit significantly, and 5 min s UV-C irradiation is stronger than 10 min s UV-C irradiation.2. UV-C irradiation does not change ANR activity variation law during the development of grape berry, but it increases the ANR activity significantly, and 5 min s UV-C irradiation is stronger than 10 min s UV-C irradiation.3. The expression of ANR gene at transcriptional and translational levels during grape berry development was investigated by the technique of Real-time PCR and Western blotting.The results showed that a higher expression of ANR gene at both transcriptional and translational levels was present at the early stage of berry development.4. At the transcriptional level, different dose of UV-C irradiation could activate the transcription of two regulatory genes(VvMYBPA1、VvMYBPA2), but depending on the developmental stage of grape berries and the ultraviolet dose. In addition, VvANR expression law is similar to that of VvMYBPA2 after UV-C irradiation, which indicated that the activation of VvANR by UV-C was closely related by VvMYBPA2.5. The expression of VvANR was positively correlated with the expression of VvMYBPA2, significantly. And the expression of VvANR was positively correlated with the contents of catechin, epicatechin in grape berry.