title: The role of abscisic acid in fruit ripening and responses to abiotic stress.
abstract: The phytohormone abscisic acid (ABA) plays a crucial role not only in fruit development and ripening, but also in adaptive responses to biotic and abiotic stresses. In these processes, the actions of ABA are under the control of complex regulatory mechanisms involving ABA metabolism, signal transduction, and transport. The endogenous ABA content is determined by the dynamic balance between biosynthesis and catabolism, processes which are regulated by 9-cis-epoxycarotenoid dioxygenase (NCED) and ABA 8'-hydroxylase (CYP707A), respectively. ABA conjugation by cytosolic UDP-glucosyltransferases, or release by β-glucosidases, is also important for maintaining ABA homeostasis. Recently, multiple putative ABA receptors localized at different subcellular sites have been reported. Among these is a major breakthrough in the field of ABA signalling-the identification of a signalling cascade involving the PYR/PYL/RCAR protein family, the type 2C protein phosphatases (PP2Cs), and subfamily 2 of the SNF1-related kinases (SnRK2s). With regard to transport, two ATP-binding cassette (ABC) proteins and two ABA transporters in the nitrate transporter 1/peptide transporter (NRT1/PTR) family have been identified. In this review, we summarize recent research progress on the role of ABA in fruit ripening, stress response, and transcriptional regulation, and also the functional verification of both ABA-responsive and ripening-related genes. In addition, we suggest possible commercial applications of genetic manipulation of ABA signalling to improve fruit quality and yields.
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, PR China pleng@cau.edu.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Leng
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, 1306 East University BouleVard, Tucson, AZ, USA.
authors.forename: Bing
authors.initials: B
authors.lastname: Yuan
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, PR China.
authors.forename: Yangdong
authors.initials: Y
authors.lastname: Guo
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D001692:Biological Transport; D005638:Fruit / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D015398:Signal Transduction; D013312:Stress, Physiological
chemical_list: D000040:Abscisic Acid
keywords: ABA; ABA metabolism; ABA signalling; ABA transporter; fruit ripening; stress response; transcriptional regulation.