Different regulatory mechanisms of plant hormones in the ripening of climacteric and non-climacteric fruits: a review.

KEY MESSAGE: This review contains the regulatory mechanisms of plant hormones in the ripening process of climacteric and non-climacteric fruits, interactions between plant hormones and future research directions. The fruit ripening process involves physiological and biochemical changes such as pigment accumulation, softening, aroma and flavor formation. There is a great difference in the ripening process between climacteric fruits and non-climacteric fruits. The ripening of these two types of fruits is affected by endogenous signals and exogenous environments. Endogenous signaling plant hormones play an important regulatory role in fruit ripening. This paper systematically reviews recent progress in the regulation of plant hormones in fruit ripening, including ethylene, abscisic acid, auxin, jasmonic acid (JA), gibberellin, brassinosteroid (BR), salicylic acid (SA) and melatonin. The role of plant hormones in both climacteric and non-climacteric fruits is discussed, with emphasis on the interaction between ethylene and other adjustment factors. Specifically, the research progress and future research directions of JA, SA and BR in fruit ripening are discussed, and the regulatory network between JA and other signaling molecules remains to be further revealed. This study is meant to expand the understanding of the importance of plant hormones, clarify the hormonal regulation network and provide a basis for targeted manipulation of fruit ripening.