European Journal of Biotechnology and Bioscience

Authors
Ting Lu, Gang-gang Wang

Abstract
ABA (Abscisic acid) is a central hormone in plants, which plays a key role in the regulation of several important processes. The pathways for ABA biosynthesis contains three main steps: Phase I. Biosynthesis of Isopentenyl pyrophosphate (IPP) from precursors. Phase II. Biosynthesis of Zeaxanthin (XAN) from IPP. Phase III. Biosynthesis of ABA. ABA level responses rapidly to a number of in vitro stresses including heat, drought, cold, salinity and chemical herbicide. ABA plays a lot of vital functions in plants in embryo development, seeds germination, fruit ripening. etc. This review elaborates the biosynthesis of ABA and its physiological functions in plants.