Cotton GhDREB1 increases plant tolerance to low temperature and is negatively regulated by gibberellic acid

• Published in: The New phytologist 2007-01, Vol.176 (1), p.70-81
• Main Authors: Shan, Da-Peng, Huang, Jin-Guang, Yang, Yu-Tao, Guo, Ying-Hui, Wu, Chang-Ai, Yang, Guo-Dong, Gao, Zheng, Zheng, Cheng-Chao
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Cell Nucleus - metabolism; chilling tolerance; Cold Temperature; Complementary DNA; Cotton; Flowers - genetics; Flowers - growth & development; Gene Expression Regulation, Plant - drug effects; Gene Library; Genes; GhDREB1; gibberellic acid (GA3); gibberellic acid (GA₃); Gibberellins - pharmacology; Gossypium - drug effects; Gossypium - genetics; Gossypium - metabolism; Gossypium hirsutum; Low temperature; Molecular Sequence Data; Nicotiana - genetics; Nicotiana - growth & development; Nicotiana tabacum; Plant growth; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - physiology; Plants; Plants, Genetically Modified - growth & development; Plants, Genetically Modified - physiology; promoter; Promoter Regions, Genetic; RNA; Seedlings; Sequence Alignment; transcription factor; Transcription factors; Transcription Factors - chemistry; Transcription Factors - genetics; Transcription Factors - physiology; Transgenic plants; transgenic tobacco
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2007.02160.x

The transcription factors C-repeat binding factors/dehydration-responsive element binding proteins (CBFs/DREBs) control the expression of many stress-inducible genes in Arabidopsis. A cDNA clone, designated GhDREB1, was isolated from cotton (Gossypium hirsutum) by cDNA library screening. Northern blot analysis indicated that mRNA accumulation of GhDREB1 was induced by low temperatures and salt stress, but was not induced by abscisic acid (ABA) or drought stress in cotton seedlings. Transgenic tobacco (Nicotiana tabacum) plants overexpressing GhDREB1 displayed stronger chilling tolerance than wild-type plants. Their leaf chlorophyll fluorescence, net photosynthetic rate and proline concentrations were higher than those of control plants during low-temperature treatment. However, under normal growth conditions, the transgenic tobacco plants exhibited retarded growth and delayed flowering. Interestingly, GhDREB1 transcripts in cotton seedlings were negatively regulated by gibberellic acid (GA₃) treatment. Analysis of the promoter of the GhDREB1 gene revealed the presence of one low-temperature and four gibberellin-responsive elements. Green fluorescent protein (GFP) signal intensity or β-glucuronidase (GUS) activity driven by the GhDREB1 promoter was clearly enhanced by low temperature but repressed by GA₃. These results suggest that GhDREB1 functions as a transcription factor and plays an important role in improving cold tolerance, and also affects plant growth and development via GA₃.