Abstract
Climacteric and non-climacteric fruits are differentiated by the ripening process, in particular by the involvement of ethylene, high respiration rates and the nature of the process, being autocatalytic or not, respectively. Here, we focus on the biosynthesis, metabolism and function of three compounds (auxin, salicylic acid and melatonin) sharing not only a common precursor (chorismate), but also regulatory functions in plants, and therefore in fruits. Aside from describing their biosynthesis in plants, with a particular emphasis on common precursors and points of metabolic diversion, we will discuss recent advances on their role in fruit ripening and the regulation of bioactive compounds accumulation, both in climacteric and non-climacteric fruits.
Highlights
Correct progression of fruit ripening is essential to achieve both optimal fruit quality and long shelf life, important traits that determine price markets and final profits
Multiple Roles of Salicylic Acid During Fruit Development and Ripening. Salicylic acid is another chorismate-derived phytohormone that has been mostly related to its protective effect under biotic stress to control preharvest and post-harvest losses derived from pathogen fruit infection (Babalar et al, 2007; Cao et al, 2013)
Post-harvest treatment with salicylic acid (SA), acetylsalicylic acid (ASA), or metyl salicylate (MeSA) maintained total phenolic contents as well as anthocyanin contents during cold storage in pomegranate (Sayyari et al, 2011), sweet cherry (Valero et al, 2011), cornelian cherry (Dokhanieh et al, 2013), and apricot (Wang et al, 2015). These results suggest that salicylates may be involved in the activation of phenylalanine ammonia lyase, which is the main enzyme involved in the biosynthesic pathway of phenolic compounds (Martínez-Esplá et al, 2017)
Summary
Correct progression of fruit ripening is essential to achieve both optimal fruit quality and long shelf life, important traits that determine price markets and final profits. Grape berries showed enhanced GH3−1 expression after ABA and ethephon application, which could explain the involvement of ethylene in the control of IAA contents after the onset of ripening, even in non-climacteric fruits (Böttcher et al, 2010). IAA contents decrease before ripening onset in some non-climacteric fruits to de-repress 9-cis-epoxycarotenoid dioxygenase (NCED) and start ABA synthesis (Figure 2C; Jia et al, 2016) This process is mediated by IAA conjugation through enhanced GH3−1 activity (Böttcher et al, 2010). Auxin treatments after harvest delay over-ripening in some fruits (Chen et al, 2016; Moro et al, 2017) and increase the contents of some organic acids, maintaining fruit acidity (Li et al, 2017), suggesting auxin plays a significant role in the control of fruit ripening during post-harvest
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
