Location: Plant, Soil and Nutrition ResearchTitle: Involvement of an ethylene response factor in chlorophyll degradation during citrus fruit degreening Author
|Yin, Xueren - Zhejiang University|
|Xie, Xiu-ian - Zhejiang University|
|Xia, Xiao-jian - Zhejiang University|
|Furgeson, Ian - New Zealand Institute Of Plant & Food Research|
|Chen, Kunsong - Zhejiang University|
Submitted to: Plant Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/11/2016
Publication Date: 8/13/2016
Citation: Yin, X., Xie, X., Xia, X., Furgeson, I., Giovannoni, J.J., Chen, K. 2016. Involvement of an ethylene response factor in chlorophyll degradation during citrus fruit degreening. Plant Journal. 86:403-412.
Interpretive Summary: Chlorophyll degradation naturally occurs during plant senescence, and can be triggered by environmental stimuli such as excessive light, low temperature and plant hormones such as ethylene. Degradation is also an important component of the degreening necessary for marketability of most citrus fruit, and thus there is wide interest in characterizing the underlying regulatory mechanisms involved. Here we provide evidence to demonstrate that the orange gene CitERF13 plays an important regulatory role in both developmental and postharvest degreening. As such, this gene is both a component of fruit quality and a potential target for manipulating citrus fruit quality and color.
Technical Abstract: Chlorophyll degradation naturally occurs during plant senescence. However, in fruit such as citrus, it is a positive characteristic, as degreening is an important colour development contributing to fruit quality. In the present work, Citrus sinensis Osbeck, cv. Newhall fruit was used as a model for chlorophyll degradation. An ethylene response factor, CitERF13, was isolated and its transcriptional changes were closely correlated with fruit peel degreening during development or in response to ethylene. Dual-luciferase and yeast one-hybrid assays, as well as motif mutation, indicated that CitERF13 directly binds to the CitPPH promoter and enhances its activity. Transient and stable over-expression of CitERF13 resulted in rapid chlorophyll degradation in Nicotiana tabacum leaves and led to accumulation of pheophorbide (Pheide) a, a metabolite of pheophorbide hydrolase (PPH). Similar results were observed from transient transformation of CitERF13 in citrus fruit peel. Moreover, this function of CitERF13 was conserved within Arabidopsis and tomato, as the homologs AtERF17 and SlERF16 similarly acted as activators of PPH genes and accelerators of chlorophyll degradation.