AcHZP45 is a repressor of chlorophyll biosynthesis and activator of chlorophyll degradation in kiwifruit.
J Exp Bot
; 75(1): 204-218, 2024 Jan 01.
Article
em En
| MEDLINE
| ID: mdl-37712824
ABSTRACT
The degradation of chlorophyll during fruit development is essential to reveal a more 'ripe' color that signals readiness to wild dispersers of seeds and the human consumer. Here, comparative biochemical analysis of developing fruit of Actinidia deliciosa cv. Xuxiang ('XX', green-fleshed) and Actinidia chinensis cv. Jinshi No.1 ('JS', yellow-fleshed) indicated that variation in chlorophyll content is the major contributor to differences in flesh color. Four differentially expressed candidate genes were identified the down-regulated genes AcCRD1 and AcPOR1 involved in chlorophyll biosynthesis, and the up-regulated genes AcSGR1 and AcSGR2 driving chlorophyll degradation. Prochlorophyllide and chlorophyllide, the metabolites produced by AcCRD1 and AcPOR1, progressively reduced in 'JS', but not in 'XX', indicating that chlorophyll biosynthesis was less active in yellow-fleshed fruit. AcSGR1 and AcSGR2 were verified to be involved in chlorophyll degradation, using both transient expression in tobacco and stable overexpression in kiwifruit. Furthermore, a homeobox-leucine zipper (HD-Zip II), AcHZP45, showed significantly increased expression during 'JS' fruit ripening, which led to both repressed expression of AcCRD1 and AcPOR1 and activated expression of AcSGR1 and AcSGR2. Collectively, the present study indicated that different dynamics of chlorophyll biosynthesis and degradation coordinate the changes in chlorophyll content in kiwifruit flesh, which are orchestrated by the key transcription factor AcHZP45.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Actinidia
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
J Exp Bot
Assunto da revista:
BOTANICA
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
China