Abstract: [Objective] TATA box-binding protein associated factor TAF10, as one of the basic transcription factors, plays an extensive and important biological role in the regulation of growth, development and stress response. Cloning and functional analysis of TAF10 homologous gene CpTAF10 in wintersweet (Chimonanthus praecox) may help to enrich the understanding of plant TAFs gene, and provide theoretical basis for the analysis of the mechanism of transcriptional regulation of the resistant formation of wintersweet.[Method] Based on the cDNA sequence of TAF family gene in wintersweet transcription database, we obtained the CpTAF10 gene and analyzed the sequence characteristics and evolutionary tree. The expressions of CpTAF10 in different tissues and flowering stages, and the changes of CpTAF10 gene expression under heat, cold, NaCl stress and ABA treatments were analyzed using real-time quantitative PCR. Meanwhile, the overexpression vector of CpTAF10 was constructed, and transformed into Arabidopsis thaliana via floral dipping method, phenotypes and stress tolerance of the homozygous transgenic lines were analyzed.[Result] The cDNA sequence of CpTAF10 is 712 bp, including 405 bp of ORF (open reading frame). The open reading frame of CpTAF10 encoded a protein composed of 134 amino acids. The theoretical molecular weight of this protein was 15.21 kDa, and the predicted isoelectric point pI value was 5.19. The CpTAF10 protein has high homology with other plant homologous proteins. The multiple sequence alignment shows that CpTAF10 protein belongs to the TAF10 homologous protein and contains the histone folding domain. The results showed that the CpTAF10 gene expressed in the roots, stems, cotyledon, young leaves, mature leaves and flowers of wintersweet, and the mature leaves had the highest expression level. CpTAF10 showed a fluctuating expression pattern in different flowering stages, and showed the highest expression in the senescence stage. The expression of CpTAF10 was induced in cold, salt stress and ABA treatment in wintersweet. The overexpression of CpTAF10 gene increased the germination rate of transgenic Arabidopsis seeds under salt stress. Compared with the wild type, the main root and lateral roots of the transgenic plants showed growth advantage to some extent under salt stress.[Conclusion] The expression of CpTAF10 gene can be induced under cold, salt stress and ABA treatment, and CpTAF10 gene may be involved in molecular regulation of stress tolerance in wintersweet. The overexpression of CpTAF10 gene in Arabidopsis significantly enhanced the germination rate and the growth advantages of root under salt stress, enhanced the salt stress tolerance in transgenic Arabidopsis to some extent.

Key words: Chimonanthus praecox, TBP associated factors, gene expression, salt stress