Metabolomic and Transcriptomic Analyses of the Flavonoid Biosynthetic Pathway for the Accumulation of Anthocyanins and Other Flavonoids in Sweetpotato Root Skin and Leaf Vein Base

Abstract

Sweetpotato [Ipomoea batatas (L.) Lam.] is a major tuberous root crop that is rich in flavonoids. Here, we discovered a spontaneous mutation in the color of the leaf vein base (LVB) and root skin (RS) in the Zheshu 81 cultivar. The flavonoid and anthocyanin metabolites and molecular mechanism were analyzed using metabolome and transcriptome data. Compared to the wild type, 13 differentially accumulated metabolites (DAMs) in the LVB and 59 DAMs in the RS were all significantly downregulated. Moreover, all the anthocyanin metabolites decreased significantly. The differentially expressed genes (DEGs) encoding the key enzymes in the later enzymatic reaction of anthocyanin and flavonoid were significantly downregulated in the mutant. The expression trends of the transcription factor MYB were evidently related to the anthocyanin content. These results offer insights into the coloration in the LVB and RS and a theoretical basis for determining the regulation of flavonoid and anthocyanin synthesis in sweetpotato.

Regulatory network characterization of anthocyanin metabolites in purple sweetpotato via joint transcriptomics and metabolomics

“…Colorful sweet potato is rich in secondary metabolites, which are the dominant factors leading to the pigmentation in root flesh (Zhao et al, 2022). Anthocyanin belongs to the flavonoid compound that can present a purple or red color in plant tissue, whereas the high accumulation of b-carotene results in an orange color (Hu et al, 2011;Liu et al, 2017).…”

“…The crucial transcription factors (TF) controlling anthocyanin biosynthesis have been identified to be the MYB, bHLH, and WD40 (Xie et al, 2012;Dixon et al, 2013). These TFs usually form a protein complex (MBW complex) to induce the expressions of the downstream structural genes (Xu et al, 2015;Bulgakov et al, 2017), of which the IbMYB1 was found to be the key regulator in the storage roots of purple sweet potato, and that it either functions individually or can bound to the bHLH and WD40 (Mano et al, 2007;Hichri et al, 2010;Li et al, 2016;Zhao et al, 2022). Hence, the elucidation of the plant anthocyanin biosynthesis as well as the relevant tissue-specific pigmentation is mostly concerned with the gene expressions and interactions in this respect (Li et al, 2019).…”

“…To support that, the given molecular mechanisms underlying the anthocyanin anabolism in the purple sweet potato root flesh, which is the primary economic organ for harvesting, should be investigated in-depth, particularly in the regional germplasms that have had more genetic variations relative to the existing cultivars (Mano et al, 2007;Liu et al, 2017). The known knowledge of other plants, such as Arabidopsis (Arabidopsis thaliana) (He et al, 2020), apple (Malus domestica) (Zhang et al, 2019), tomato (Solanum lycopersicum) (Sun et al, 2020), as well as the recently reported studies in purple sweet potato (Zhang et al, 2022;Zhao et al, 2022), would provide a solid reference foundation for relevant research.…”

Integrative Analysis of the Metabolome and Transcriptome Provides Insights into the Mechanisms of Flavonoid Biosynthesis in Quinoa Seeds at Different Developmental Stages

“…Moreover, various transcription factors (TFs), such as myeloblastosis (MYB), basic helix–loop–helix (bHLH), and WD40 proteins, have important regulatory effects on flavonoid synthesis [ 14 ]. The biosynthetic pathways of flavonoids are well studied in many plant species [ 15 , 16 , 17 , 18 , 19 ]. Flavonoids have antioxidant properties and have the potential to counter some diseases [ 20 , 21 ].…”

DhMYB2 and DhbHLH1 regulates anthocyanin accumulation via activation of late biosynthesis genes in Phalaenopsis-type Dendrobium

“…The anthocyanin biosynthesis pathway (ABP) has been extensively studied in various plants and found to be generally conserved ( Tohge et al., 2017 ; Zhao et al., 2022 ). The biosynthesis and accumulation of anthocyanins are controlled by various transcription factors (TFs) and ABP structural genes.…”