A novel bZIP gene from Tamarix hispida mediates physiological responses to salt stress in tobacco plants.
Basic leucine zipper proteins (bZIPs) are transcription factors that bind abscisic acid (ABA)-responsive elements (ABREs) and enable plants to withstand adverse environmental conditions. In the present study, a novel bZIP gene, ThbZIP1 was cloned from Tamarix hispida. Expression studies in T. hispida showed differential regulation of ThbZIP1 in response to treatment with NaCl, polyethylene glycol (PEG) 6000, NaHCO(3), and CdCl(2), suggesting that ThbZIP1 is involved in abiotic stress responses. To identify the physiological responses mediated by ThbZIP1, transgenic tobacco plants overexpressing exogenous ThbZIP1 were generated. Various physiological parameters related to salt stress were measured and compared between transgenic and wild type (WT) plants. Our results indicate that overexpression of ThbZIP1 can enhance the activity of both peroxidase (POD) and superoxide dismutase (SOD), and increase the content of soluble sugars and soluble proteins under salt stress conditions. These results suggest that ThbZIP1 contributes to salt tolerance by mediating signaling through multiple physiological pathways. Furthermore, ThbZIP1 confers stress tolerance to plants by enhancing reactive oxygen species (ROS) scavenging, facilitating the accumulation of compatible osmolytes, and inducing and/or enhancing the biosynthesis of soluble proteins.
Key Laboratory of Forest Tree Genetic Improvement and Biotechnology (Northeast Forestry University), Ministry of Education, 26 Hexing Road, Harbin 150040, PR China.
Yucheng
Y
Wang
Caiqiu
C
Gao
Yenan
Y
Liang
Chao
C
Wang
Chuanping
C
Yang
Guifeng
G
Liu
D000595:Amino Acid Sequence; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D019256:Cadmium Chloride; D050260:Carbohydrate Metabolism; D002254:Carbonates; D003001:Cloning, Molecular; D008315:Malondialdehyde / Q000378:metabolism; D008969:Molecular Sequence Data; D010544:Peroxidases / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018514:Plant Structures / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000201:enzymology; D011092:Polyethylene Glycols; D054712:Salinity; D036226:Seedlings / Q000378:metabolism; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000378:metabolism; D032363:Tamaricaceae / Q000235:genetics* / Q000378:metabolism; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics
D050976:Basic-Leucine Zipper Transcription Factors; D002254:Carbonates; D010940:Plant Proteins; D011092:Polyethylene Glycols; C005686:sodium carbonate; D008315:Malondialdehyde; D010544:Peroxidases; D013482:Superoxide Dismutase; D019256:Cadmium Chloride