title: Overexpression of Arabidopsis ZEP enhances tolerance to osmotic stress.
abstract: Zeaxanthin epoxidase (ZEP) is an enzyme important in ABA biosynthesis and in the xanthophyll cycle. ABA, a plant hormone, is a key molecule that regulates plant responses to abiotic stress, such as drought and salinity, and is required for stress tolerance. To investigate the biological roles of the Arabidopsis thaliana ZEP gene (AtZEP) in stress response, we generated transgenic plants overexpressing the AtZEP gene and analyzed their responses to salt and drought stresses. AtZEP-overexpressing plants exhibited more vigorous growth under high salt and drought treatments than wild-type plants. In addition to enhanced de novo ABA biosynthesis, AtZEP-overexpressing plants also exhibited much higher expression of the endogenous stress-responsive genes RD29A and Rab18 than wild-type plants under salt stress. Moreover, the stomatal aperture of the AtZEP-overexpressing plants was smaller than wild-type plants after exposure to light. Our results therefore indicated that AtZEP plays important roles in response to osmotic stress.
authors.affiliation: Department of Biological Sciences, Pusan National University, San 30, Jangjeon-dong, Geumjeong-gu, Busan 609-735, Republic of Korea.
authors.forename: Hee-Yeon
authors.initials: HY
authors.lastname: Park
authors.forename: Hye-Yeon
authors.initials: HY
authors.lastname: Seok
authors.forename: Bo-Kyung
authors.initials: BK
authors.lastname: Park
authors.forename: Sun-Ho
authors.initials: SH
authors.lastname: Kim
authors.forename: Chang-Hyo
authors.initials: CH
authors.lastname: Goh
authors.forename: Byeong-ha
authors.initials: BH
authors.lastname: Lee
authors.forename: Choon-Hwan
authors.initials: CH
authors.lastname: Lee
authors.forename: Yong-Hwan
authors.initials: YH
authors.lastname: Moon
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D009997:Osmotic Pressure; D010088:Oxidoreductases / Q000235:genetics / Q000502:physiology*; D054046:Plant Stomata / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics; D012965:Sodium Chloride / Q000378:metabolism*; D014867:Water / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D014867:Water; D012965:Sodium Chloride; D010088:Oxidoreductases; C097153:zeaxanthin epoxidase