A single amino acid mutant in the EAR motif of IbMYB44.2 reduced the inhibition of anthocyanin accumulation in the purple-fleshed sweetpotato.
Plant Physiol Biochem
; 167: 410-419, 2021 Oct.
Article
em En
| MEDLINE
| ID: mdl-34411780
ABSTRACT
Purple-fleshed sweetpotato (Ipomoea batatasï¼L.ï¼Lam.) is rich in anthocyanins. R2R3-type MYB transcription factorsï¼TFsï¼with EAR motifs inhibiting anthocyanin biosynthesis have been reported, and there is still a lack of information on how mutations in the EAR motifs of MYBs affect anthocyanin accumulation. In this study, we obtained three IbMYB44 TFs by bioinformatics. Among these TFs, IbMYB44.1, IbMYB44.3 with a complete EAR motif and IbMYB44.2 with a single amino acid mutant in the EAR motif caused an amino acid substitution from leucine to valine. RT-qPCR analysis showed that IbMYB44s was expressed at lower levels in the purple-fleshed sweetpotato than in nonpurple-fleshed sweetpotato (P < 0.01). Transient expression assays showed that the inhibitory effect of IbMYB44.1/3 was stronger than IbMYB44.2 in tobacco leaves and red-skinned pears. RT-qPCR analysis further proved that IbMYB44.1/3 significantly inhibited the expression of anthocyanin biosynthesis-related genes compared with IbMYB44.2 in tobacco leaves and red-skinned pears. A dual luciferase reporter assay showed that IbMYB44s cannot directly activate the IbANS promoter, and the result was also verified by yeast one-hybrid (Y1H) experiments. Moreover, we identified the interaction of IbMYB340 with IbMYB44.1, IbMYB44.2 and IbMYB44.3 via yeast two-hybrid (Y2H) assays. Thus, IbMYB44.1/3 could interact with IbMYB340 to negatively regulate anthocyanin biosynthesis. This study enriched the regulatory network of anthocyanins and also provided a theoretical basis for a single amino acid mutant from leucine to valine in the EAR motif of IbMYB44.2 affecting anthocyanin biosynthesis in the purple-fleshed sweetpotato.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ipomoea batatas
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Plant Physiol Biochem
Ano de publicação:
2021
Tipo de documento:
Article