Effects Of Pruning Of Floral Cluster And Bagging On Grape Anthocyanins And Biosynthetic Genes Expression

The study used’Houman’ and ’Manicure finger’ grape as the materials that were treated respectively by pruning of floral cluster and bagging. The anthocyanin compositions during berry development were examined through HPLC/MSD-ESI-MS method. Meanwhile, the expression patterns of fourteen structural genes and four regulatory genes in anthocyanin biosynthesis pathway were analyzed through RT-PCR. The results showed that:1. Pruning of floral cluster improved ’Houman’ fruit quality significantly by increasing the berry size, the every berry weight and the total soluble solids content and decreasing the titratable acid content. The effect of berry size、every berry weight and the total soluble solids content in’Manicure finger’were not significant. Black bag processing reduced the content of fruit soluble solids and TSS/TA, but not significantly compared with the white bag in the mature period.2. The onset of anthocyanin biosynthesis in ’Houman’ grape under pruning of floral cluster was earlier than the control.Besides, the total content and the amount of five anthocyanins derivatives were also increased in the mature period. Meanwhile, there were more anthocyanins detected in fruits with pruning of floral cluster treatment. There were 16 anthocyanins detected in ’Houman’ grape under pruning of floral cluster,one more than the control.The transcriptional expression of structural genes PAL,4CL,CHS1, CHS2,CHI1, F3’H,F3’5’H, F3H, DFR, LDOX, OMT,3GT,5GTand regulatory genes MYB5a, MYB5b, VvmybAl, VlmybA 1-1 in anthocyanin biosynthesis pathway were up-regulated by pruning of floral cluster (during the whole or part of berry development stages).The up-regulation of these genes by pruning of floral cluster was related to the increase of anthocyanin biosynthesis.3. Anthocyanin content of ’Manicure finger’ grape berries with the black bag was less than white bag before bags removal. However, after bags were removed, anthocyanins synthesis of grape berries with the black bag accelerated rapidly. At last, total anthocyanins content is significantly higher than the white bag in the mature period.Black bag processing increased the content of Dp derivatives、Pt derivatives、Pn derivatives, but reduced the content of Cy derivatives,and had no effect on the content of Mv derivatives. The transcriptional level of anthocyanin biosynthetic genes in grapes with the black bag was lower than white bag before bags removal. Then, after bags were removed, black bag processing up-regulated structural genes PAL,4CL,CHS,CHI, F3’5’H, F3H, DFR, LDOX, OMT,3GT,5GTand regulatory genes MYB5a, VvmybAl, VlmybA 1-1 during the whole or part of berry development stages. The up-regulation of these genes by black bag processing was consistent with the higher level of anthocyanin biosynthesis than white bag. Black bag processing up-regulated the expression of F3’5’H, but reduced the expression of F3’H, corresponding to the higher content of Dp derivatives and the lower content of Cy derivatives than white bag.