Perception and transduction of abscisic acid signals: keys to the function of the versatile plant hormone ABA.
During the past decade, much progress has been made toward understanding the mechanisms underlying plant hormone activity, from perception to nuclear events. However, the signaling mechanisms for abscisic acid (ABA) have remained largely obscure. Recent breakthroughs identifying FCA, which is an RNA-binding protein, the Mg-chelatase H subunit, and a G protein-coupled receptor as receptors for ABA provide a major leap forward in understanding the initial steps of ABA signaling mechanisms. Recent studies have also revealed the molecular mechanisms of second messenger production, protein modifications such as phosphorylation, and regulatory mechanisms of gene expression in the ABA response. Therefore, the connections between these events are also beginning to be determined. Here, we review recent progress and discuss the overall scheme of the ABA response mechanisms.
Hirayama
Takashi
T
Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan.
Shinozaki
Kazuo
K
D000040:Abscisic Acid / Q000494:pharmacology / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D010937:Plant Growth Regulators / Q000502:physiology*; D010944:Plants / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000235:genetics*; D015398:Signal Transduction / Q000502:physiology*; D014161:Transduction, Genetic
D010937:Plant Growth Regulators; D011956:Receptors, Cell Surface; D000040:Abscisic Acid