title: Characterization of two highly similar CBF/DREB1-like genes, PhCBF4a and PhCBF4b, in Populus hopeiensis.
abstract: The C-repeat binding factors (CBFs)/dehydration-responsive element-binding protein (DREBs) are a group of conserved transcription factors that play an important role in the response and adaptation to environmental stress in many plants. Two highly similar CBF/DREB1-like genes, PhCBF4a and PhCBF4b, were previously identified in Populus hopeiensis. In this paper, we describe the function of these proteins in detail in terms of abiotic stress tolerance. Phylogenic analysis suggests that PhCBF4a and PhCBF4b are expressed as two distinct alleles. Expression of both genes is induced mainly by dehydration, low-temperature, and high-salinity. Agroinfiltration experiments in tobacco leaves revealed differential transcriptional activation of the genes, likely driven by differences in their C-terminal regions. When constitutively expressed in Arabidopsis, PhCBF4a and PhCBF4b induced elevated expression of the CBF/DREB1 regulons without prior stimulus, resulting in dwarfism, delayed flowering, and greater drought tolerance compared with vector controls. These results demonstrate that PhCBF4a and PhCBF4b are functional transcriptional regulators involved in the response of P. hopeiensis to abiotic stresses.
authors.affiliation: Sichuan Academy of Forestry, Chengdu, Sichuan 610081, PR China; National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, PR China.
authors.forename: Zeliang
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Forestry Station of Haidian District, Beijing 100194, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Sichuan Academy of Forestry, Chengdu, Sichuan 610081, PR China; National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, PR China.
authors.forename: Hongying
authors.initials: H
authors.lastname: Guo
authors.affiliation: Sichuan Academy of Forestry, Chengdu, Sichuan 610081, PR China.
authors.forename: Xiang
authors.initials: X
authors.lastname: He
authors.affiliation: Sichuan Academy of Forestry, Chengdu, Sichuan 610081, PR China.
authors.forename: Wanbo
authors.initials: W
authors.lastname: Wu
authors.affiliation: Sichuan Academy of Forestry, Chengdu, Sichuan 610081, PR China.
authors.forename: Jincheng
authors.initials: J
authors.lastname: Du
authors.affiliation: National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, PR China.
authors.forename: Zhiyi
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, PR China. Electronic address: anxinmin@bjfu.edu.cn.
authors.forename: Xinmin
authors.initials: X
authors.lastname: An
mesh_terms: D000595:Amino Acid Sequence; D017343:Genes, Plant; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D032107:Populus / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
chemical_list: D010940:Plant Proteins
keywords: Abiotic stress; CBF; DREB; Populus hopeiensis