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ATP-binding cassette (ABC) transporters are a large class of superfamily involved in a variety of biological processes with multiple functions, including phytohormone transport, heavy metal ion detoxification, and so on. Anthocyanin pigmentation in grapes is a commercially important feature of this superfamily. To elucidate the mechanisms of the VvABC gene at different stages in grape berries, we analyzed and characterized the ABC family in 'ZhongShan-HongYu' (ZS-HY) berries using RNA-seq analysis. In this study, a total of 146 VvABC genes were identified by comprehensive bioinformatics analysis, which outlined their gene structure, chromosomal location, conserved domains, phylogenetic relationships, and collinearity analysis. The VvABC family could be divided into eight subfamilies based on the phylogenetic analysis. Fifty-eight VvABC genes were identified from the RNA-seq data, of which 31 belong to the ABCG subfamily, 15 belong to the ABCC subfamily, 8 belong to the ABCB subfamily, 2 belong to the ABCF subfamily, and only 1 belongs to each of the ABCA and ABCD subfamilies. We used qRT-PCR to detect the expression of VvABC genes in different organs and found that it changed significantly in different organs. Phylogenetic analysis showed that genes involved in anthocyanin transport in other species were closely related to members of the ABCC subfamily. Subsequently, analysis of the promoter elements and the protein interactions of the VvABCC genes using RNA-seq was performed. This study has improved our understanding of the functions of the ABC gene family and provided a basis for the role of ABC genes in grape anthocyanin transport. [ABSTRACT FROM AUTHOR]

Anthocyanins are synthesized in the endoplasmic reticulum and then transported to the vacuole in plants. Glutathione S-transferases (GSTs) are thought to play a key role in anthocyanin transport. To clarify the mechanism of GST genes in the accumulation and transport of anthocyanin in the early fruit stage, we analyzed and characterized the GST family in the flesh of 'Zhongshan-HongYu' (ZS-HY) based on the transcriptome. In this study, the 92 GST genes identified through a comprehensive bioinformatics analysis were unevenly present in all chromosomes of grapes, except chromosomes 3, 9 and 10. Through the analysis of the chromosomal location, gene structure, conserved domains, phylogenetic relationships and cis-acting elements of GST family genes, the phylogenetic tree divided the GST genes into 9 subfamilies. Eighteen GST genes were screened and identified from grape berries via a transcriptome sequencing analysis, of which 4 belonged to the phi subfamily and 14 to the tau subfamily, and the expression levels of these GST genes were not tissue-specific. The phylogenetic analysis indicated that VvGST4 was closely related to PhAN9 and AtTT19. This study provides a foundation for the analysis of the GST gene family and insight into the roles of GSTs in grape anthocyanin transport. [ABSTRACT FROM AUTHOR]

• Transcriptome sequencing of a new germplasm, 'ZhongShan-HongYu' (ZS-HY), was carried out for bagging treatment and bag removal treatment. • Differentially expressed genes (DEGs) and pathways associated with anthocyanin in young fruits were identified. • It was found that light plays a positive role in anthocyanin biosynthesis in the teinturier grape 'ZS-HY'. Teinturier grapevine cultivars of grapevine (Vitis vinifera L.) are characterized by red pulp berries. A new teinturier germplasm 'ZS-HY', accumulates pigments in its pulp and peel. We observed that bagging treatment (without light) caused an obvious inhibition of anthocyanin accumulation in 'ZS-HY' berries. Under bag removal treatment (with light), the malvidin, cyanidin and delphinidin derivatives accumulated rapidly after the berries exposed to light. To further determine the transcriptional mechanism of light-regulated anthocyanin accumulation in 'ZS-HY', we performed RNA-sequencing (RNA-seq) on the berries under bagging treatment and bag removal treatment. Correlation between anthocyanin content, concentration and 741 up-regulated differentially expressed genes (DEGs) in transcriptomic data were analyzed by using weighted gene co-expression network analysis (WGCNA), which indicated that the up-regulated genes had a similar expression pattern to the change in anthocyanin. The expression of the VvHY5-like, VvUVR3 and VvBBX25 light-responsive factors; the VvMYBA1, VvMYB30 and VvbHLH61-like transcription factors (TFs); and the VvUDP86A1, VvGT5, VvGT1 and VvUFGT4-like structural genes was significantly increased, under bag removal treatment as compared with the expression levels observed in bagging treatment. The results showed that light plays a critical role in the anthocyanin accumulation of dyer's grapes and in other biological changes. Here, we provide a theoretical basis for the transcriptional regulatory network that operates during light response, which will further strengthen our understanding of the molecular mechanism of light-induced anthocyanin biosynthesis in teinturier grapes. [ABSTRACT FROM AUTHOR]

Anthocyanins are flavonoids that contribute to the color of grape berries and are an essential component of grape berry and wine quality. Anthocyanin accumulation in grape berries is dependent on the coordinated expression of genes encoding enzymes in the anthocyanin pathway that are principally regulated at the transcriptional level, with VvMYBA1 as the main transcriptional regulator in grapes. Alternative splicing (AS) events in VvMYBA1, however, have not been examined. In the present study, VvMYBA1-L, an AS variant of VvMYBA1, was identified in 'ZhongShan-Hong' (ZS-H) and its offspring. The AS variant is characterized by a deletion in the third exon of the open reading frame (ORF) of VvMYBA1-L , resulting in the early termination of the encoded protein. Overexpression of VvMYBA1-L in grape berries resulted in delayed flesh coloration and ectopic overexpression of VvMYBA1-L in tobacco inhibited the coloration of petals. Yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays revealed that VvMYBA1-L interacts with VvMYBA1. Dual luciferase assays indicated that co-infiltration of VvMYC1 and VvMYBA1 significantly activated the promoter regulated expression of VvCHS3 , VvDFR , VvUFGT, and VvF3H. In the presence of VvMYBA1-L, however, the induction effect of VvMYBA1 on the indicated promoters was significantly inhibited. Our findings provide insight into the essential role of VvMYBA1 and its variant, VvMYBA1-L, in regulating anthocyanin accumulation in grape berry flesh. • We identified an alternative splicing variant of VvMYBA1, VvMYBA1-L. • Overexpression of VvMYBA1-L in grape berry flesh inhibits the flesh coloration. • Ectopic overexpression of VvMYBA1-L in tobacco depresses the petals coloration. • VvMYBA1-L depresses the expression of VvMYBA1. • VvMYBA1-L disrupts the transcriptional activation of downstream genes by VvMYBA1. [ABSTRACT FROM AUTHOR]