The R2R3-MYB transcription factor MdMYB73 is involved in malate accumulation and vacuolar acidification in apple.
Plant J
; 91(3): 443-454, 2017 Aug.
Article
em En
| MEDLINE
| ID: mdl-28423209
ABSTRACT
Malate, the predominant organic acid in many fruits, is a crucial component of the organoleptic quality of fruit, including taste and flavor. The genetic and environmental mechanisms affecting malate metabolism in fruit cells have been studied extensively. However, the transcriptional regulation of malate-metabolizing enzymes and vacuolar transporters remains poorly understood. Our previous studies demonstrated that MdMYB1 modulates anthocyanin accumulation and vacuolar acidification by directly activating vacuolar transporters, including MdVHA-B1, MdVHA-E, MdVHP1 and MdtDT. Interestingly, we isolated and identified a MYB transcription factor, MdMYB73, a distant relative of MdMYB1 in this study. It was subsequently found that MdMYB73 protein bound directly to the promoters of MdALMT9 (aluminum-activated malate transporter 9), MdVHA-A (vacuolar ATPase subunit A) and MdVHP1 (vacuolar pyrophosphatase 1), transcriptionally activating their expression and thereby enhancing their activities. Analyses of transgenic apple calli demonstrated that MdMYB73 influenced malate accumulation and vacuolar pH. Furthermore, MdCIbHLH1 interacted with MdMYB73 and enhanced its activity upon downstream target genes. These findings help to elucidate how MdMYB73 directly modulates the vacuolar transport system to affect malate accumulation and vacuolar pH in apple.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
/
Fatores de Transcrição
/
Vacúolos
/
Malus
/
Malatos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Plant J
Assunto da revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
China