A WD40-repeat protein from persimmon interacts with the regulators of proanthocyanidin biosynthesis DkMYB2 and DkMYB4

MBW complexes impinge on anthocyanidin reductase gene regulation for proanthocyanidin biosynthesis in persimmon fruit

“…Other PA biosynthetic regulators, such as DkMYB4 and DkMYC1, reproduce well this low expression profile in 'Hana Fuyu' and other non-astringent cultivars, as shown in previous studies 26,27,29 . However, DkMYB2 relative expression decays in a similar way in both astringent and non-astringent cultivars ( Fig.…”

“…As DkMYB4 and DkMYC1 genes are similarly down-regulated during fruit development concomitantly with PA reduction, and are differentially expressed in a non-astringent cultivar 26,27,29 , their promoters have been also cloned and tested by dual luciferase assays in N. benthamiana. MBW factors assayed in the experiment do not increase the activity of DkMYB4 nor DkMYC1 promoters, however DkWDR1 transient expression associates with a significant decrease in LUC expression driven by DkMYB4 promoter (Fig.…”

“…On the other hand, a persimmon bHLH gene named DkMYC1 is underexpressed in non-astringent cultivars, following an expression pattern in fruit similar to DkMYB4 29 . DkMYC1 protein interacts with DkMYB2 and DkMYB4, and these, in turn, interact with the WD40-repeat protein DkWDR1 by two-hybrid analysis, suggesting the conserved participation of MBW complexes in PA synthesis regulation in persimmon fruit 26 . In this study, we go further on the cytological and molecular characterization of MBW complex in persimmon by approaching the subcellular localization, protein interaction and transcriptional regulation effects of these MYB (DkMYB2 and DkMYB4), bHLH (DkMYC1) and WD40 (DkWDR1) components.…”

“…These regulatory factors form a ternary complex named MYB-bHLH-WD40 (MBW) that may invoke the participation of alternative MYB and bHLH components for the regulation of particular steps of PA and anthocyanin biosynthetic pathways 21,22 . MBW complexes also contribute to PAs production in edible fruits of crop plants such as grapevine 23 , strawberry 24 , apple 25 and persimmon 26 .…”

miRNA858b Inhibits Proanthocyanidin Accumulation by Repression ofDkMYB19andDkMYB20in Persimmon

“…In persimmon, two MYB transcription factors, DkMYB2 and DkMYB4 , have been reported to involve in PA regulation in persimmon by activating the DkF3’5’H / DkANR and DkANR / DkLAR transcription, respectively (Akagi et al ., 2009b, 2010a). Subsequently, a DkbZIP5 could directly regulate DkMYB4 in an ABA-dependent manner through recognizing ABA-responsive elements in the promoter region of DkMYB4 (Akagi et al ., 2012) and a DkMYC1 might be an important bHLH transcription factor for the regulating of PA biosynthesis (Su et al ., 2012; Naval et al ., 2016; Nishiyama et al ., 2018) have been verificated. Meanwhile, DkMYB2 or DkMYB4 could interact with DkMYC1 and DkWDR1 to compose a MBW ternary complexes which involved in regulating PA accumulation in fruit (Naval et al ., 2016).…”