Molecular Biology of ethylene during tomato fruit development and maturation

Authors: BEATRIZ, CARA - BTI; Giovannoni, James

Submitted to: Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/23/2008
Publication Date: 6/11/2008
Citation: Beatriz, C., Giovannoni, J.J. 2008. Molecular Biology of ethylene during tomato fruit development and maturation. Plant Science. 175:106-113.

Interpretive Summary: Important traits for complete ripening and consumer fruit quality preferences include development of aroma, flavor color, texture, and nutritional quality. These attributes are influenced by the endogenously produced hormone ethylene in many fleshy fruits such as apple, avocado, banana, mango, pear and tomato. Even in species where endogenous ethylene seems to play little if any role as an endogenous regulator, exogenous ethylene will often promote ripening characteristics and can be the target of post harvest strategies designed to accelerate, synchronize or delay ripening. The genetic regulation that controls ethylene production at different developmental stages of fruits has only recently begun to be studied. Tomato has emerged as the primary model plant to further understand the molecular biology that controls ethylene synthesis and additional ripening regulators during fruit development. Here we summarize data pertaining to ethylene biology specifically as related to fruit maturation and including recent insights into genetic control of the ripening process prior to and controlling ethylene.

Technical Abstract: The phytohormone ethylene plays critical roles in many developmental events and environmental responses of plants. Climacteric fruits such as tomato, apple or pears, are characterized by a ripening-related increase in respiration and elevated ethylene synthesis to rapidly coordinate and synchronize ripening. Recent discoveries have led to identification of transcription factors regulating ethylene synthesis and additional ripening activities. The rin locus encodes a MADS-box transcription factor which is a member of the SEPALATA subfamily of MADS genes, while the Cnr mutation resulted from a dominant epigenetic alteration in the promoter of a SQUAMOSA promoter binding protein (SBP). It is known that MADS-box genes act together in multimeric complexes and SBP proteins have been shown to directly regulate the expression of MADS-box genes. It is plausible to anticipate that other MADS-box genes may interact with RIN in the control of fruit ripening and CNR may act to directly influence RIN expression or the expression of other participating in ripening.