title: The Miscanthus NAC transcription factor MlNAC9 enhances abiotic stress tolerance in transgenic Arabidopsis.
abstract: NAC (NAM, ATAF1/2, and CUC2) transcription factors are known to play important roles in responses to abiotic stresses in plants. Currently, little information regarding the functional roles of NAC genes in stress tolerance is available in Miscanthus lutarioriparius, a promising bioenergy plant for cellulosic ethanol production. In this study, we carried out the functional characterization of MlNAC9 in abiotic stresses. MlNAC9 was shown to act as a nuclear localized transcription activator with the activation domain in its C-terminus. The overexpression of MlNAC9 in Arabidopsis conferred hypersensitivity to abscisic acid (ABA) at seed germination and root elongation stages. In addition, the overexpression of MlNAC9 led to increased seed germination rate and root growth under salt (NaCl) treatment. Meanwhile, the transgenic Arabidopsis overexpressing MlNAC9 showed enhanced tolerance to drought and cold stresses. The expression of stress-responsive marker genes was significantly increased in MlNAC9 overexpression lines compared to that of WT under ABA, drought, salt, and cold stresses. Correspondingly, the activities of antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were significantly increased and the malondialdehyde (MDA) content was lower accumulated in MlNAC9 overexpression lines under drought and salt treatments. These results indicated that the overexpression of MlNAC9 improved the tolerance to abiotic stresses via an ABA-dependent pathway, and the enhanced tolerance of transgenic plants was mainly attributed to the increased expression of stress-responsive genes and the enhanced scavenging capability of reactive oxygen species (ROS).
authors.affiliation: Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Xun
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China.
authors.forename: Xuanwen
authors.initials: X
authors.lastname: Yang
authors.affiliation: Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Shengqiang
authors.initials: S
authors.lastname: Pei
authors.affiliation: Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China.
authors.forename: Guo
authors.initials: G
authors.lastname: He
authors.affiliation: Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Tang
authors.affiliation: Shandong Institute of Agricultural Sustainable Development, Jinan 250100, PR China.
authors.forename: Chunlin
authors.initials: C
authors.lastname: Jia
authors.affiliation: National Center for Gene Research, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200233, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China. Electronic address: hurb@qibebt.ac.cn.
authors.forename: Ruibo
authors.initials: R
authors.lastname: Hu
authors.affiliation: Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China. Electronic address: zhougk@qibebt.ac.cn.
authors.forename: Gongke
authors.initials: G
authors.lastname: Zhou
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000737:chemistry / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics; D002467:Cell Nucleus / Q000737:chemistry; D003080:Cold Temperature; D004268:DNA-Binding Proteins / Q000235:genetics; D055864:Droughts; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000502:physiology*; D006109:Poaceae / Q000145:classification / Q000235:genetics*; D055049:Salt Tolerance; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014170:Transformation, Genetic
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C527342:LOV1 protein, Arabidopsis; D010940:Plant Proteins; D014157:Transcription Factors; D000040:Abscisic Acid
keywords: Abiotic stress; Miscanthus lutarioriparius; NAC transcription factor; Stress tolerance