Fruit ripening and post-harvest changes in very early ripening fruit.

Authors: CHEN, YAO - Boyce Thompson Institute; TABG, XUEMEI - Boyce Thompson Institute; FEI, ZHANGJUN - Boyce Thompson Institute; Giovannoni, James

Submitted to: Horticulture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/18/2024
Publication Date: 7/22/2024
Citation: Chen, Y., Tabg, X., Fei, Z., Giovannoni, J.J. 2024. Fruit ripening and post-harvest changes in very early ripening fruit.. Horticulture Research. Volume 11, Issue 9. https://doi.org/10.1093/hr/uhae199.
DOI: https://doi.org/10.1093/hr/uhae199

Interpretive Summary: Development and ripening of fleshy fruits are complex and tightly controlled programs that involve a range of changes in chemistry and physiology with ripening often typified by accumulation of nutritional compounds, synthesis and accrual of pigments, reduction in photosynthesis and photosynthetic pigments, texture changes, and alterations in aroma volatile profiles in carpel or adjacent floral tissues that house the mature seeds. Better understanding of early harvest fruit development and maturation could help address crop losses and provide alternatives for successfully securing seed during breeding and for biological inquiries. Here we show that very early harvested fruits displayed modest effects on fruit ripening in terms of color and water loss, especially at the earliest harvest times, while transcriptome analysis indicated that molecular alterations on ripening related factors are minimal and consistent with the observed phenotypic differences. Our analysis makes clear that tomato fruits can be harvested early in order to limit economic loss. Very early harvested fruits have substantial changes in fruit texture and water loss during the storage due to impaired fruit cuticle integrity, yet produce viable seed which has important implications to the seed industry, plant breeding and breeding strategies. Through gene editing of the CER1-2 gene we demonstrate that impaired cuticle integrity and increased water loss after harvesting in very early harvested fruits are due at least in part to reduced expression of CER1-2. While this analysis provides insights into the mechanisms of altered fruit development in very early harvested fruits it also suggests that identification and selection of CER1-2 alleles with higher expression and/or targeted engineering of this gene may prove useful in developing more climate and postharvest resilient crops.

Technical Abstract: It is well known that if a fruit is harvested extremely early its development and function are interrupted, and it may never attain full maturity and optimal quality. Reports revealing insights regarding the alterations of maturation, ripening and postharvest quality in very early picked fruits are rare. We examined the effects of early harvesting on tomatoes by characterizing different accessions at the molecular, physiological, and biochemical levels. We found that even very early harvested fruits could achieve postharvest maturation and ripening though with some defects in pigment and cuticle formation, and seeds from very early harvested fruits could still germinate and develop as normal and healthy plants. One critical regulator of tomato cuticle integrity, SlCER1–2, was shown to contribute to cuticle defects in very early harvested fruits. Very early fruit harvest still allowing ripening and seed development indicates that the genetic and physiological programs of later maturation and ripening are set into motion early in fruit development and are not dependent on complete fruit expansion nor attachment to the plant.