title: Maize ABP9 enhances tolerance to multiple stresses in transgenic Arabidopsis by modulating ABA signaling and cellular levels of reactive oxygen species.
abstract: The phytohormone abscisic acid (ABA) and reactive oxygen species (ROS) play critical roles in mediating abiotic stress responses in plants. It is well known that ABA is involved in the modulation of ROS levels by regulating ROS-producing and ROS-scavenging genes, but the molecular mechanisms underlying this regulation are poorly understood. Here we show that the expression of maize ABP9 gene, which encodes a bZIP transcription factor capable of binding to the ABRE2 motif in the maize Cat1 promoter, is induced by ABA, H(2)O(2), drought and salt. Constitutive expression of ABP9 in transgenic Arabidopsis leads to remarkably enhanced tolerance to multiple stresses including drought, high salt, freezing temperature and oxidative stresses. ABP9 expressing Arabidopsis plants also exhibit increased sensitivity to exogenously applied ABA during seed germination, root growth and stomatal closure and improved water-conserving capacity. Moreover, constitutive expression of ABP9 causes reduced cellular levels of ROS, alleviated oxidative damage and reduced cell death, accompanied by elevated expression of many stress/ABA responsive genes including those for scavenging and regulating ROS. Taken together, these results suggest that ABP9 may play a pivotal role in plant tolerance to abiotic stresses by fine tuning ABA signaling and control of ROS accumulation.
authors.affiliation: Maize Gene Research and Genetic Improvement Center, Biotechnology Research Institute, National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, 100081, Beijing, People's Republic of China.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhang
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Meng
authors.forename: Hongtao
authors.initials: H
authors.lastname: Wen
authors.forename: Yunliu
authors.initials: Y
authors.lastname: Fan
authors.forename: Jun
authors.initials: J
authors.lastname: Zhao
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology / Q000502:physiology; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D001483:Base Sequence; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000502:physiology; D018744:DNA, Plant / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D017343:Genes, Plant; D010937:Plant Growth Regulators / Q000494:pharmacology / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics* / Q000502:physiology*; D030821:Plants, Genetically Modified; D017382:Reactive Oxygen Species / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D013312:Stress, Physiological; D015534:Trans-Activators / Q000235:genetics / Q000502:physiology; D003313:Zea mays / Q000235:genetics* / Q000502:physiology*
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D018744:DNA, Plant; D010937:Plant Growth Regulators; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; D015534:Trans-Activators; D000040:Abscisic Acid