Brassinosteroids: An Innovative Compound Family That Could Affect the Growth, Ripening, Quality, and Postharvest Storage of Fleshy Fruits.

Brassinosteroids (BRs), a new family of plant hormones, have been used in a range of food staples, oil crops, and cereals. However, the scientific literature pertaining to their use in fleshy fruits remains scarce. This review presents, for the first time, the knowledge developed over the last decade on the role of BR preharvest treatments in crop yield and fruit quality properties at harvest and during storage, although information about the effects of BR postharvest treatments is also addressed. This review revealed that 24-epibrassinolide is the most used BR analogue in research experiments, either as a pre- or postharvest treatment, with doses ranging from 0.1 to 15 μM. Additionally, most of the research has been conducted on non-climacteric fruit species. In most of these preharvest treatments, an increase in crop yield has been reported, as well as enhanced anthocyanin concentration in red-coloured fruit. In addition, increases in firmness, total soluble solids, and phenolic content have also been observed. On the other hand, BR postharvest treatments led to the maintenance of these fruit quality properties during storage due to increased antioxidant systems, either enzymatic or non-enzymatic ones. Finally, as future perspectives, it is proposed to extend the research about BR treatments to other climacteric fruits and to deepen the knowledge of how BRs regulate physiological aspects from preharvest to postharvest. Furthermore, it is essential to investigate the role of BRs in the prevention of rot and biotic stress.