SlCHYR1, a RING and CHY zinc finger domain-containing protein, promotes tomato fruit ripening by reprograming abscisic acid and ethylene signaling

During storage, transportation and sales, the deterioration of the tomato ripening fruit mainly caused by mechanical damage and microbial infection results in great economic losses. There is growing interest in fruit ripening studies and postharvest quality improvement to further enhance its already high economic value. Fruit ripening are coordinated by a complex network of endogenous and exogenous factors, including the phytohormone ethylene and abscisic acid, transcription factors, non-coding RNA, epigenetic modification, and environmental factors. However, the studies on RING-finger proteins involved in fruit development and ripening have not been reported. In this study, SlCHYR1, encoding a RING and CHY zinc finger domain-containing protein, which shows high expression levels in fruit was isolated and studied in tomato. Overexpression of SlCHYR1 with a fruit-specific promoter originating from pineapple leads to accelerated fruit ripening, reduced shelf life and repressed chlorophyll accumulation in tomato fruit. Further investigation indicate that SlCHYR1 promotes tomato fruit ripening through abscisic acid and ethylene production and signaling. This work provides novel insights into the regulation of fruit development and ripening by ZFPs (Zinc finger proteins), and would contribute to the improvement of quality and shelf life of tomato.