Dataset Information

DcMYB113, a root-specific R2R3-MYB, conditions anthocyanin biosynthesis and modification in carrot.

ABSTRACT: Purple carrots, the original domesticated carrots, accumulate highly glycosylated and acylated anthocyanins in root and/or petiole. Previously, a quantitative trait locus (QTL) for root-specific anthocyanin pigmentation was genetically mapped to chromosome 3 of carrot. In this study, an R2R3-MYB gene, namely DcMYB113, was identified within this QTL region. DcMYB113 expressed in the root of 'Purple haze', a carrot cultivar with purple root and nonpurple petiole, but not in the roots of two carrot cultivars with a purple root and petiole (Deep purple and Cosmic purple) and orange carrot 'Kurodagosun', which appeared to be caused by variation in the promoter region. The function of DcMYB113 from 'Purple haze' was verified by transformation in 'Cosmic purple' and 'Kurodagosun', resulting in anthocyanin biosynthesis. Transgenic 'Kurodagosun' carrying DcMYB113 driven by the CaMV 35S promoter had a purple root and petiole, while transgenic 'Kurodagosun' expressing DcMYB113 driven by its own promoter had a purple root and nonpurple petiole, suggesting that root-specific expression of DcMYB113 was determined by its promoter. DcMYB113 could activate the expression of DcbHLH3 and structural genes related to anthocyanin biosynthesis. DcUCGXT1 and DcSAT1, which were confirmed to be responsible for anthocyanins glycosylation and acylation, respectively, were also activated by DcMYB113. The WGCNA identified several genes co-expressed with anthocyanin biosynthesis and the results indicated that DcMYB113 may regulate anthocyanin transport. Our findings provide insight into the molecular mechanism underlying root-specific anthocyanin biosynthesis and further modification in carrot and even other root crops.

SUBMITTER: Xu ZS

PROVIDER: S-EPMC7292547 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Purple carrots can accumulate large quantities of anthocyanins in their roots and -in some genetic backgrounds- petioles, and therefore they represent an excellent dietary source of antioxidant phytonutrients. In a previous study, using linkage analysis in a carrot F2 mapping population segregating for root and petiole anthocyanin pigmentation, we identified a region in chromosome 3 with co-localized QTL for all anthocyanin pigments of the carrot root, whereas petiole pigmentation segregated as a single dominant gene and mapped to one of these "root pigmentation" regions conditioning anthocyanin biosynthesis. In the present study, we performed fine mapping combined with gene expression analyses (RNA-Seq and RT-qPCR) to identify candidate genes controlling anthocyanin pigmentation in the carrot root and petiole. Fine mapping was performed in four carrot populations with different genetic backgrounds and patterns of pigmentation. The regions controlling root and petiole pigmentation in chromosome 3 were delimited to 541 and 535 kb, respectively. Genome wide prediction of transcription factor families known to regulate the anthocyanin biosynthetic pathway coupled with orthologous and phylogenetic analyses enabled the identification of a cluster of six MYB transcription factors, denominated DcMYB6 to DcMYB11, associated with the regulation of anthocyanin biosynthesis. No anthocyanin biosynthetic genes were present in this region. Comparative transcriptome analysis indicated that upregulation of DcMYB7 was always associated with anthocyanin pigmentation in both root and petiole tissues, whereas DcMYB11 was only upregulated with pigmentation in petioles. In the petiole, the level of expression of DcMYB11 was higher than DcMYB7. DcMYB6, a gene previously suggested as a key regulator of carrot anthocyanin biosynthesis, was not consistently associated with pigmentation in either tissue. These results strongly suggest that DcMYB7 is a candidate gene for root anthocyanin pigmentation in all the genetic backgrounds included in this study. DcMYB11 is a candidate gene for petiole pigmentation in all the purple carrot sources in this study. Since DcMYB7 is co-expressed with DcMYB11 in purple petioles, the latter gene may act also as a co-regulator of anthocyanin pigmentation in the petioles. This study provides linkage-mapping and functional evidence for the candidacy of these genes for the regulation of carrot anthocyanin biosynthesis.

Dataset Information

DcMYB113, a root-specific R2R3-MYB, conditions anthocyanin biosynthesis and modification in carrot.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets