Anthocyanin Accumulation in Muscadine Berry Skins Is Influenced by the Expression of the MYB Transcription Factors, MybA1, and MYBCS1

Abstract

The skin color of grape berry is very important in the wine industry. The red color results from the synthesis and accumulation of anthocyanins, which is regulated by transcription factors belonging to the MYB family. The transcription factors that activate the anthocyanin biosynthetic genes have been isolated in model plants. However, the genetic basis of color variation is species-specific and its understanding is relevant in many crop species. This study reports the isolation of MybA1, and MYBCS-1 genes from muscadine grapes for the first time. They are designated as VrMybA1 (GenBank Accession No. KJ513437), and VrMYBCS1 (VrMYB5a) (GenBank Accession No. KJ513438). The findings in this study indicate that, the deduced VrMybA1 and VrMYBCS1 protein structures share extensive sequence similarity with previously characterized plant MYBs, while phylogenetic analysis confirms that they are members of the plant MYB super-family. The expressions of MybA1, and MYBCS1 (VrMYB5a) gene sequences were investigated by quantitative real-time PCR using in vitro cell cultures, and berry skin samples at different developmental stages. Results showed that MybA1, and MYBCS1 genes were up-regulated in the veràison and physiologically mature red berry skins during fruit development, as well as in in vitro red cell cultures. This study also found that in ripening berries, the transcription of VrMybA1, and VrMYBCS1 in the berry skin was positively correlated with anthocyanin accumulation. Therefore, the upregulation of VrMybA1, and VrMYBCS1 results in the accumulation and regulation of anthocyanin biosynthesis in berry development of muscadine grapes. This work greatly enhances the understanding of anthocyanin biosynthesis in muscadine grapes and will facilitate future genetic modification of the antioxidants in V. rotundifolia.

Exogenous Abscisic Acid Promotes Anthocyanin Biosynthesis and Increased Expression of Flavonoid Synthesis Genes in Vitis vinifera × Vitis labrusca Table Grapes in a Subtropical Region

“…Anthocyanins are produced through multiple pathways that are controlled by MYB transcription factors. These transcription factors are responsive to ABA and are associated with the regulation of the biosynthetic genes CHI , F3H , DFR , LDOX , and UFGT ( Yu et al, 2012 ; Oglesby et al, 2016 ; Olivares et al, 2017 ). The transcription factors VvMYBA1 and VvMYBA2 activate anthocyanin biosynthesis in grapevines and are not functional in white grape cultivars ( Rinaldo et al, 2015 ).…”

ABA mediates development-dependent anthocyanin biosynthesis and fruit coloration in Lycium plants

“…The structural genes involved in anthocyanin biosynthesis, which belongs to the classical flavonoid synthesis pathway [5], in the fruits of many plant species, such as tomatoes, cherries, strawberries and apples, have been identified and cloned [6–8]. In addition, previous studies have shown that anthocyanin biosynthesis is regulated mainly by the transcription factor MYB-bHLH-WD40 complex at both the transcriptional and posttranslational levels [9–11]. However, the link between developmental and environmental cues and these transcription factors remains unknown.…”

Flavonoid Accumulation Plays an Important Role in the Rust Resistance of Malus Plant Leaves

“…Anthocyanins are an important subgroup of flavonoids and have been shown to act as a ‘sunscreen’ and protect cells from high-light damage by absorbing blue-green and ultraviolet light in photosynthetic tissues, thereby protecting the tissues from photoinhibition or high stress. This protective effect has been shown to occur in red juvenile leaves, autumn leaves, and broad-leaf evergreen leaves that turn red during winter ( Jaakola, 2013 ; Zhu et al, 2013 ; Oglesby et al, 2016 ). Flavonols and proanthocyanidins have been suggested to play a role in suppressing the growth of E. coli bacteria and greatly reducing the ability of these bacteria to initiate an infection ( Ge et al, 2013 ; Nguyen et al, 2016 ; Shang et al, 2017 ).…”