Synthesis and biological activity of photostable and persistent abscisic acid analogs.

The plant hormone abscisic acid (ABA) plays a critical role in various environmental stress responses and has long been expected to be used in agriculture. However, the practical use of ABA has been limited, mainly because of its photoinstability and rapid biodegradation. We previously developed photostable ABA agonists, BP2A and Me 1',4'--diol BP2A, in which the dienoic acid side chain of ABA was replaced with phenylacetic acid.