Phytohormones in fruit development and maturation

Authors: FENN, MATTHEW - Cornell University; Giovannoni, James

Submitted to: The Plant Journal
Publication Type: Literature Review
Publication Acceptance Date: 11/23/2020
Publication Date: 12/4/2020
Citation: Fenn, M., Giovannoni, J.J. 2020. Phytohormones in fruit development and maturation. The Plant Journal. 105:446-458. https://doi.org/10.1111/tpj.15112.
DOI: https://doi.org/10.1111/tpj.15112

Interpretive Summary: Fruit development is an elegant evolutionary strategy unique to flowering plants, serving the dual purpose of protecting developing seeds and facilitating their dispersal. Following fertilization, fruits arise from growth and enlargement of the ovary and, occasionally, from accessory tissues in cases such as apple or strawberry. Given the critical role of 'eshy fruit in the human diet and the need for a deeper understanding of fruit biology in the face of evolving pest populations and a changing climate, the content of this review aims to present and highlight recent insights and open questions relevant to plant hormone fruit set, growth, and ripening.

Technical Abstract: Phytohormones are integral to the regulation of fruit development and maturation. This review expands upon current understanding of the relationship between hormone signaling and fruit development, emphasizing 'eshy fruit and highlighting recent work in the model crop tomato and additional species. Fruit development comprises fruit set initiation, growth, and maturation and ripening. Fruit set transpires after fertilization and is associated with auxin and gibberellic acid (GA) signaling. Fruit growth consists of cell division and expansion, the former shown to be in'uenced by auxin While regulation of cell expansion is less thoroughly understood, evidence indicates synergistic regulation via both auxin and GAs, with input from additional hormones. Fruit maturation, a transitional phase that precipitates ripening, occurs when auxin and GA levels subside with a concurrent rise in abscisic acid (ABA) and ethylene. During fruit ripening, ethylene plays a clear role in climacteric fruits, whereas non-climacteric ripening is generally associated with ABA. Recent evidence indicates varying requirements for both hormones within both ripening physiologies, suggesting re-balancing and speci'cation of roles for common regulators rather than reliance upon one. Numerous recent discoveries pertaining to the molecular basis of hormonal activity and crosstalk are discussed, while we also note that many questions remain such as the molecular basis of additional hormonal activities, the role of epigenome changes, and how prior discoveries translate to other crop species.