Abstract:

As an important plant hormone, abscisic acid (ABA) plays a series of significant physiological roles
in higher plants including but not limited to bud dormancy, leaf fall, stoma closure, growth inhibition and plant
resistance. Recently, it has been revealed that ABA also has an important regulatory role in the growth, development
and ripening of fruits. In higher plants, the sesquiterpenoid ABA is produced via an indirect pathway from the cleavage
products of C40 carotenoids. The accumulation of endogenous ABA levels in plants is a dynamic balance controlled by
the processes of biosynthesis and catabolism, through transcriptional regulation of key ABA biosynthetic genes and
enzymes activities. Levels of endogenous ABA gradually increase during the late stage of fruit development, and fruit
ripening and softening are promoted by ABA accumulation. It has been hypothesized that the ABA level could be part
of the signal that triggers fruit ripening, and that ABA biosynthesis and accumulation may play an important role in the
regulation of ripening and senescence of both non-climacteric and climacteric fruits. These findings have demonstrated
that ABA has varieties of important roles in the regulation of growth and development, quality formation, coloring
and softening, ripening and senescence of fruits, which has great realistic significance in food science and postharvest
biology of horticultural products. In this review, we summarize recent progress in the study of the role of ABA in fruit
ripening and transcriptional regulation. In addition, we prospecte possible commercial applications of ABA signal
regulation to improve fruit quality and shelf life.

Key words: abscisic acid (ABA), biosynthesis, fruit, ripening, regulation