The role of ABF family bZIP class transcription factors in stress response

Adverse environmental conditions, such as drought, high salinity and chilling/freezing, are major limiting factors of crop productivity worldwide. According to Boyer [Science 1982;218:443-448], approximately 70% of the genetic potential yield of major crops is lost by these environmental factors. Thus, understanding how plants respond to the 'abiotic stresses' is of agronomic importance. Being sessile, plants have the capability to perceive and respond adaptively to various abiotic stresses. The adaptive capability of plants is largely dependent on the plant hormone abscisic acid (ABA), which regulates, among others, the expression of numerous genes involved in stress adaptation. Extensive genetic and molecular studies have been carried out during the last decade or so, and, as a result, a large body of information is available on the regulatory components of ABA-responsive gene expression under stress conditions. In this article, recent advances in the area are summarized, focusing on the regulatory components of ABA-dependent stress-responsive gene expression.