Functional analysis of the transcription factor CcUNE10 in red and blue LED light‐induced coloration of mandarin fruit

Abstract BACKGROUND The peel and flesh of early maturing mandarin fruit in the Chongqing region do not reach maturity at the same time. RESULTS It was found that red and blue LED light could promote color change in these fruit by inducing the degradation of chlorophyll and the synthesis of carotenoids. Blue LED light was more effective in inducing the synthesis of carotenoids. Analysis of transcriptome data revealed that the transcription factor CcUNE10 (Ciclev10020053mg) may participate in the regulation of mandarin fruit peel coloration under both red and blue LED light. Analysis of the CcUNE10 biological information showed that CcUNE10 is highly homologous to Arabidopsi s AtUNE10, and has transcriptionally active elements that are localized in the nucleus and responsive to light, abscisic acid, and growth factors. On the second day following infection, tobacco leaves with heterologous transient overexpression of CcUNE10 showed a significant reduction in chlorophyll b and chlorophyllide b ( P < 0.05). Mandarin fruit with transient overexpression of CcUNE10 also showed a significant yellow phenotype on the third day, with a significantly accelerated reduction of chlorophyll and its metabolites ( P < 0.05). Significant up‐regulation was observed in the genes CcCHlH , CcChlase2 , CcNYC1 , and CcPAO , which are related to chlorophyll degradation ( P < 0.05). CONCLUSION In summary, red and blue LED light led to color change in mandarin fruit by inducing chlorophyll degradation and carotenoid synthesis. CcUNE10 may play an important role in red and blue LED irradiation‐induced degradation of chlorophyll. © 2025 Society of Chemical Industry.