The tomato HIGHPIGMENT1/DAMAGED DNA BINDING PROTEIN1 gene contributes to regulation of fruit ripening

Authors: WANG, ANQUAN - Boyce Thompson Institute; CHEN, DANYANG - Hefei University Of Technology; MA, QIYUE - Hefei University Of Technology; ROSE, JOCELYN - Cornell University; FEI, ZHANGJUN - Boyce Thompson Institute; LIU, YOUNGSHENG - Hefei University Of Technology; Giovannoni, James

Submitted to: Horticulture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/23/2018
Publication Date: 9/26/2018
Citation: Wang, A., Chen, D., Ma, Q., Rose, J., Fei, Z., Liu, Y., Giovannoni, J.J. 2018. The tomato HIGHPIGMENT1/DAMAGED DNA BINDING PROTEIN1 gene contributes to regulation of fruit ripening. Horticulture Research. 6:15. https://doi.org/10.1038/s41438-018-0093-3.
DOI: https://doi.org/10.1038/s41438-018-0093-3

Interpretive Summary: As sessile organisms, plants have evolved fleshy fruits to disperse seeds by attracting animals, which consume them and release their seeds. Tomato is a model system for fleshy fruit ripening that, like many fruits, undergoes changes in color, aroma, texture, nutrient composition and additional quality traits. These changes are coordinated by multiple internal and external factors, including the gaseous hormone ethylene, key transcription factors, epigenetic changes and environmental stimuli, such as light and temperature. One of these regulators is the light signaling gene HP1/DDB1. Here we further characterize the influence of DDB1 on fruit ripening. We show that in addition to previously reported effects on fruit coloration, this gene influences additional ripening activities including texture and shelf-life suggesting a re-examination of its utility in modifying agriculturally important fleshy fruit traits.

Technical Abstract: Fleshy fruit ripening is governed by multiple external and internal cues and accompanied by changes in color, texture, volatiles and nutritional quality traits. While extended shelf-life and increased phytonutrients are desired, delaying ripening via genetic or postharvest means can be accompanied by reduced nutritional value. Here, we report that the high pigment1 (hp1) mutation at the UV-DAMAGED DNA BINDING PROTEIN 1 (DDB1) locus, previously shown to influence carotenoid and additional phytonutrient accumulation via altered light signal transduction, also results in delayed ripening and firmer texture, resulting at least in part from decreased ethylene evolution. Transcriptome analysis revealed multiple ethylene biosynthesis and signaling-associated genes downregulated in hp1. Furthermore, the hp1 mutation impedes softening of the pericarp, placenta, columella as well as the whole fruit, in addition to reduced expression of the FRUITFUL2 (FUL2) MADS-box transcription factor and xyloglucan endotransglucosylase/hydrolase 5 (XTH5). These results indicate that DDB1 influences a broader range of fruit development and ripening processes than previously thought and present an additional genetic target for increasing fruit quality and shelf-life.