Differential regulation of red light- and ethephon-induced degreening in postharvest kumquat fruit

• Published in: Postharvest biology and technology 2023-04, Vol.198, p.112264, Article 112264
• Main Authors: Gong, Jinli, Yang, Hongbin, Xu, Yanna, Zeng, Yunliu, Liu, Ping, Chen, Chuanwu, Wang, Pengwei, Sun, Xuepeng
• Format: Article
• Language: English
• Subjects: Chloroplast; Degreening; Ethephon; Kumquat fruit; Postharvest; Red LED light
• ISSN: 0925-5214; 1873-2356
• DOI: 10.1016/j.postharvbio.2023.112264

Peel color is closely associated with the commercial value of citrus fruit. In early market or tropical regions, citrus fruit often show non-uniform coloration, which requires degreening practice at post-harvest stage. Here, we studied the degreening effect of red LED light, ethephon, and their combination treatment on kumquat fruit. Both red LED light and ethephon promoted fruit degreening, causing ultrastructural changes of chloroplasts accompanied by chlorophyll degradation. Transcriptome analysis revealed metabolic reprogramming in chloroplasts but the way how genes responded to red LED light and ethephon were remarkably different. Transient expression in Nicotiana benthamiana suggested that FcrCLH, FcrPPH and FcrSGR genes were potentially key factors in regulation of fruit degreening. Furthermore, red LED light promoted the catabolism of chloroplast components in vitro. This study provides novel insights into the molecular mechanism of fruit degreening and unravels an efficient practice for future post-harvest management of citrus fruit. •Degreening induced by red light is superior to ethephon.•Red light promotes the degradation of chloroplast in vitro.•Red light and ethephon show distinct pattern of transcription reprogramming.•FcrCLH, FcrPPH and FcrSGR genes are key factors in regulation of degreening.