title: A late embryogenesis abundant protein HVA1 regulated by an inducible promoter enhances root growth and abiotic stress tolerance in rice without yield penalty.
abstract: Regulation of root architecture is essential for maintaining plant growth under adverse environment. A synthetic abscisic acid (ABA)/stress-inducible promoter was designed to control the expression of a late embryogenesis abundant protein (HVA1) in transgenic rice. The background of HVA1 is low but highly inducible by ABA, salt, dehydration and cold. HVA1 was highly accumulated in root apical meristem (RAM) and lateral root primordia (LRP) after ABA/stress treatments, leading to enhanced root system expansion. Water-use efficiency (WUE) and biomass also increased in transgenic rice, likely due to the maintenance of normal cell functions and metabolic activities conferred by HVA1 which is capable of stabilizing proteins, under osmotic stress. HVA1 promotes lateral root (LR) initiation, elongation and emergence and primary root (PR) elongation via an auxin-dependent process, particularly by intensifying asymmetrical accumulation of auxin in LRP founder cells and RAM, even under ABA/stress-suppressive conditions. We demonstrate a successful application of an inducible promoter in regulating the spatial and temporal expression of HVA1 for improving root architecture and multiple stress tolerance without yield penalty.
authors.affiliation: Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan; Department of Life Sciences, National Central University, Jhongli City, Taiwan.
authors.forename: Yi-Shih
authors.initials: YS
authors.lastname: Chen
authors.forename: Shuen-Fang
authors.initials: SF
authors.lastname: Lo
authors.forename: Peng-Kai
authors.initials: PK
authors.lastname: Sun
authors.forename: Chung-An
authors.initials: CA
authors.lastname: Lu
authors.forename: Tuan-Hua D
authors.initials: TH
authors.lastname: Ho
authors.forename: Su-May
authors.initials: SM
authors.lastname: Yu
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics; D001483:Base Sequence; D001692:Biological Transport / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007210:Indoleacetic Acids / Q000494:pharmacology; D018519:Meristem / Q000187:drug effects / Q000378:metabolism; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D012275:Oryza / Q000187:drug effects / Q000196:embryology* / Q000235:genetics*; D009997:Osmotic Pressure; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D011401:Promoter Regions, Genetic; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D014867:Water
chemical_list: D007210:Indoleacetic Acids; D010940:Plant Proteins; D014867:Water; D000040:Abscisic Acid
keywords: ABA; abiotic stress tolerance; barley HVA1; lateral and primary root growth; rice; stress-inducible composite promoter