title: TaNAC29, a NAC transcription factor from wheat, enhances salt and drought tolerance in transgenic Arabidopsis.
abstract: BACKGROUND
  NAC (NAM, ATAF, and CUC) transcription factors play important roles in plant biological processes, including phytohormone homeostasis, plant development, and in responses to various environmental stresses.
  
  
  METHODS
  TaNAC29 was introduced into Arabidopsis using the Agrobacterium tumefaciens-mediated floral dipping method. TaNAC29-overexpression plants were subjected to salt and drought stresses for examining gene functions. To investigate tolerant mechanisms involved in the salt and drought responses, expression of related marker genes analyses were conducted, and related physiological indices were also measured. Expressions of genes were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR).
  
  
  RESULTS
  A novel NAC transcription factor gene, designated TaNAC29, was isolated from bread wheat (Triticum aestivum). Sequence alignment suggested that TaNAC29 might be located on chromosome 2BS. TaNAC29 was localized to the nucleus in wheat protoplasts, and proved to have transcriptional activation activities in yeast. TaNAC29 was expressed at a higher level in the leaves, and expression levels were much higher in senescent leaves, indicating that TaNAC29 might be involved in the senescence process. TaNAC29 transcripts were increased following treatments with salt, PEG6000, H2O2, and abscisic acid (ABA). To examine TaNAC29 function, transgenic Arabidopsis plants overexpressing TaNAC29 were generated. Germination and root length assays of transgenic plants demonstrated that TaNAC29 overexpression plants had enhanced tolerances to high salinity and dehydration, and exhibited an ABA-hypersensitive response. When grown in the greenhouse, TaNAC29-overexpression plants showed the same tolerance response to salt and drought stresses at both the vegetative and reproductive period, and had delayed bolting and flowering in the reproductive period. Moreover, TaNAC29 overexpression plants accumulated lesser malondialdehyde (MDA), H2O2, while had higher superoxide dismutase (SOD) and catalase (CAT) activities under high salinity and/or dehydration stress.
  
  
  CONCLUSIONS
  Our results demonstrate that TaNAC29 plays important roles in the senescence process and response to salt and drought stresses. ABA signal pathway and antioxidant enzyme systems are involved in TaNAC29-mediated stress tolerance mechanisms.
authors.affiliation: The Genetic Engineering International Cooperation Base of Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science & Technology (HUST), Wuhan, 430074, China. 405478393@qq.com.
authors.forename: Quanjun
authors.initials: Q
authors.lastname: Huang
authors.affiliation: The Genetic Engineering International Cooperation Base of Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science & Technology (HUST), Wuhan, 430074, China. 875643001@qq.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: The Genetic Engineering International Cooperation Base of Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science & Technology (HUST), Wuhan, 430074, China. 398309982@qq.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.affiliation: The Genetic Engineering International Cooperation Base of Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science & Technology (HUST), Wuhan, 430074, China. cjl@hust.edu.cn.
authors.forename: Junli
authors.initials: J
authors.lastname: Chang
authors.affiliation: The Genetic Engineering International Cooperation Base of Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science & Technology (HUST), Wuhan, 430074, China. cmj@hust.edu.cn.
authors.forename: Mingjie
authors.initials: M
authors.lastname: Chen
authors.affiliation: The Genetic Engineering International Cooperation Base of Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science & Technology (HUST), Wuhan, 430074, China. 651380086@qq.com.
authors.forename: Kexiu
authors.initials: K
authors.lastname: Li
authors.affiliation: The Genetic Engineering International Cooperation Base of Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science & Technology (HUST), Wuhan, 430074, China. ygx@hust.edu.cn.
authors.forename: Guangxiao
authors.initials: G
authors.lastname: Yang
authors.affiliation: The Genetic Engineering International Cooperation Base of Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science & Technology (HUST), Wuhan, 430074, China. hegy@hust.edu.cn.
authors.forename: Guangyuan
authors.initials: G
authors.lastname: He
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D055049:Salt Tolerance; D012965:Sodium Chloride / Q000378:metabolism; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014908:Triticum / Q000235:genetics / Q000254:growth & development / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D012965:Sodium Chloride