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Abscisic acid physiology and biosynthesis in higher plants
Author(s) -
Creelman Robert A.
Publication year - 1989
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1989.tb02074.x
Subject(s) - abscisic acid , biology , mutant , biosynthesis , farnesyl pyrophosphate , gravitropism , biochemistry , plant physiology , dormancy , microbiology and biotechnology , botany , enzyme , arabidopsis , gene , germination
Abscisic acid (ABA) has been postulated to modulate several aspects of plant growth and development. While it is tempting to attribute changes in growth and development to a specific hormone such as ABA, the reality is that these processes are complex and poorly understood. Since there is so little known about basic biochemical events that occur during growth and development, it is difficult ot unambiguously assign a role for ABA in any process. Becuse of this, many of the cited effects of ABA on growth and development have not been conclusively demonstrated. Howver, it is clear that ABA has a function in ameliorating water‐stress and preventing vivipary. The roles of ABA in bud dormancy and growth still remain unclear. With the use of biosynthesis inhibitors and mutants which block ABA accumulation, it has been shown that ABA does not play a role in gravitropism. Knowledge of how the levels of any particular growth regulator are modulated is essential for the understanding of its physiology. The use of mutants, inhibitors and heavy isotopes suggests that ABA may be derived from a carotenoid rather than directly from farnesyl pyrophosphate (FPP), and that the cleavage of a carotenoid is the rate limiting step. However, the relative contribution of each pathway (and the role of xanthoxin) in ABA biosynthesis remain unknown.