title: Function of ABA in Stomatal Defense against Biotic and Drought Stresses.
abstract: The plant hormone abscisic acid (ABA) regulates many key processes involved in plant development and adaptation to biotic and abiotic stresses. Under stress conditions, plants synthesize ABA in various organs and initiate defense mechanisms, such as the regulation of stomatal aperture and expression of defense-related genes conferring resistance to environmental stresses. The regulation of stomatal opening and closure is important to pathogen defense and control of transpirational water loss. Recent studies using a combination of approaches, including genetics, physiology, and molecular biology, have contributed considerably to our understanding of ABA signal transduction. A number of proteins associated with ABA signaling and responses--especially ABA receptors--have been identified. ABA signal transduction initiates signal perception by ABA receptors and transfer via downstream proteins, including protein kinases and phosphatases. In the present review, we focus on the function of ABA in stomatal defense against biotic and abiotic stresses, through analysis of each ABA signal component and the relationships of these components in the complex network of interactions. In particular, two ABA signal pathway models in response to biotic and abiotic stress were proposed, from stress signaling to stomatal closure, involving the pyrabactin resistance (PYR)/PYR-like (PYL) or regulatory component of ABA receptor (RCAR) family proteins, 2C-type protein phosphatases, and SnRK2-type protein kinases.
authors.affiliation: Department of Life Science (BK21 program), Chung-Ang University, Seoul 156-756, Korea. gelslim@hanmail.net.
authors.forename: Chae Woo
authors.initials: CW
authors.lastname: Lim
authors.affiliation: Department of Life Science (BK21 program), Chung-Ang University, Seoul 156-756, Korea. caly1006@gmail.com.
authors.forename: Woonhee
authors.initials: W
authors.lastname: Baek
authors.affiliation: Department of Life Science (BK21 program), Chung-Ang University, Seoul 156-756, Korea. jangho12345@naver.com.
authors.forename: Jangho
authors.initials: J
authors.lastname: Jung
authors.affiliation: Department of Home Economics Education, Chung-Ang University, Seoul 156-756, Korea. jjhkim@cau.ac.kr.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Life Science (BK21 program), Chung-Ang University, Seoul 156-756, Korea. sclee1972@cau.ac.kr.
authors.forename: Sung Chul
authors.initials: SC
authors.lastname: Lee
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D055864:Droughts; D019684:Magnoliopsida / Q000276:immunology / Q000378:metabolism* / Q000502:physiology; D054046:Plant Stomata / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction; D013312:Stress, Physiological
chemical_list: D000040:Abscisic Acid
keywords: ABA receptor; PP2C; SnRK2; abscisic acid (ABA); biotic and abiotic stresses; stomatal immunity