title: Overexpression of a novel chrysanthemum NAC transcription factor gene enhances salt tolerance in tobacco.
abstract: The plant-specific NAC (for NAM, ATAF1, 2 and CUC2) transcription factors (TFs) have been implicated in different cellular processes involved in stress responses such as cold, high salinity or drought as well as abscisic acid (ABA) signalling. However, the roles of the chrysanthemum NAC TF genes in plant stress responses are still unclear. A full-length cDNA designated DgNAC1, containing a highly conserved N-terminal DNA-binding NAC domain, has been isolated from chrysanthemum by RACE (rapid amplification of cDNA ends). It encodes a protein of 284 amino acids residues (=~32.9 kDa) and theoretical pI of 7.13. The transcript of DgNAC1 was enriched in roots and flowers than in stems and leaves of the adult chrysanthemum plants. The gene expression was strongly induced by ABA, NaCl, drought and cold treatment in the seedlings. Subcellular localization revealed that DgNAC1:GFP fusion protein was preferentially distributed to nucleus. To assess whether DgNAC1 is a practically useful target gene for improving the stress tolerance of chrysanthemum, we ectopically over-expressed the full-length DgNAC1 cDNA in tobacco and found that the 35S:DgNAC1 transgenic tobacco exhibited a markedly increased tolerance to salt. Despite this increased salt stress tolerance, the transgenic tobacco showed no detectable phenotype defects under normal growth conditions. These results proposed that DgNAC1 is appropriate for application in genetic engineering strategies aimed at improving salt stress tolerance in chrysanthemum.
authors.affiliation: Department of Ornamental Horticulture, Sichuan Agricultural University, 555 Northeast Road, Wenjiang District, Chengdu, Sichuan 611130, People's Republic of China. qinglinliu@126.com
authors.forename: Qing-Lin
authors.initials: QL
authors.lastname: Liu
authors.forename: Ke-Dong
authors.initials: KD
authors.lastname: Xu
authors.forename: Liang-Jun
authors.initials: LJ
authors.lastname: Zhao
authors.forename: Yuan-Zhi
authors.initials: YZ
authors.lastname: Pan
authors.forename: Bei-Bei
authors.initials: BB
authors.lastname: Jiang
authors.forename: Hai-Qing
authors.initials: HQ
authors.lastname: Zhang
authors.forename: Guang-Li
authors.initials: GL
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D031202:Chrysanthemum / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000096:biosynthesis* / Q000235:genetics; D030821:Plants, Genetically Modified; D055049:Salt Tolerance / Q000235:genetics / Q000502:physiology*; D016415:Sequence Alignment; D015398:Signal Transduction; D012965:Sodium Chloride; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D012965:Sodium Chloride