Two B-box proteins, PpBBX18 and PpBBX21, antagonistically regulate anthocyanin biosynthesis via competitive association with Pyrus pyrifolia ELONGATED HYPOCOTYL 5 in the peel of pear fruit.
Plant J
; 100(6): 1208-1223, 2019 12.
Article
em En
| MEDLINE
| ID: mdl-31444818
ABSTRACT
Light is indispensable for the accumulation of anthocyanin in the peel of red pear fruit (Pyrus pyrifolia Nakai). ELONGATED HYPOCOTYL 5 (HY5) is considered to be a critical regulator for induction of anthocyanin biosynthesis, but detailed characterization of its regulatory mechanism is needed. In this study, multiple genetic and biochemical approaches were applied to identify the roles of P. pyrifolia HY5 (PpHY5) and two B-box (BBX) proteins, PpBBX18 and PpBBX21, in the transcriptional regulation of PpMYB10. The functions of the two BBX proteins were analyzed in overexpression lines using pear calli-based approaches. On its own PpHY5 was unable to activate downstream genes. The two BBX proteins, PpBBX18 and PpBBX21, physically interacted with PpHY5 and antagonistically regulated anthocyanin biosynthesis in Arabidopsis and pear. PpBBX18 formed a heterodimer with PpHY5 via two B-box domains, in which PpHY5 bound to the G-box motif of PpMYB10 and PpBBX18 provided the trans-acting activity, thus inducing transcription of PpMYB10. PpBBX21 interacted with PpHY5 and PpBBX18 and hampered formation of the PpHY5-PpBBX18 active transcription activator complex, and subsequently repressed anthocyanin biosynthesis. The present results demonstrate the fine-tuned regulation of anthocyanin biosynthesis via transcriptional regulation of PpMYB10 by PpHY5-associated proteins and provide insights into light-induced anthocyanin biosynthesis.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
/
Fatores de Transcrição
/
Proteínas de Ligação a DNA
/
Fatores de Transcrição de Zíper de Leucina Básica
/
Frutas
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Antocianinas
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Idioma:
En
Revista:
Plant J
Assunto da revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
China