Insight into ripening-associated transcription factors in tomato: A review

Abstract

The regulation of ripening in fleshy fruits has been the subject of considerable scientific study, mainly due to that it directly affects the shelf life and quality of such fruits. Fruit ripening is controlled by many factors, including hormones, environmental signals and transcription factors. Tomato (Solanum lycopersicum) has long served as an excellent model for fleshy fruit ripening. Here, we present a comprehensive overview of the recent developments of the mechanisms that regulate fruit ripening in tomato by transcription factors, including NAC, MADS-box and bHLH transcription factors, ZFPs, SRs/CAMTA and HD-zip homeobox proteins. The involvement of ethylene- and auxin-related transcription factors in controlling ripening has been highlighted in this review. Interestingly, some transcription factors regulate fruit ripening in tomato via directly targeting ripening-related genes. Protein-protein interaction also plays a vital role in modulating tomato fruit ripening. Moreover, we also review the advances in the application of RNAi and CRISPR/Cas technology for crop improvement, which may help develop many mutant crop varieties in the future. The identification of the key transcription factors in tomato ripening has opened new horizons in our understanding of fruit ripening. This review will be useful for researchers engaged in fruit ripening and crop improvement around the globe.