【目的】通过研究白桦BpTCP8基因的序列特征及其在不同组织部位、激素处理与胁迫应答中的表达特性,为揭示BpTCP8在白桦生长发育中的功能提供依据。【方法】利用生物信息学方法对BpTCP8基因进行分析,采用实时荧光定量 PCR 技术分析BpTCP8基因在不同组织部位、激素处理与胁迫应答中的表达特性。【结果】生物信息学分析发现,BpTCP8含有TCP家族高度保守的bHLH结构域;qRT-PCR分析结果表明,白桦BpTCP8在发育和衰老初期的叶片中表达量高,并在深裂型叶片、顶芽、木质部、韧皮部中都上调表达。在激素(GA₃、ME-JA、ABA)与非生物胁迫(PEG、NaCl、CdCl₂、NaHCO₃)处理下,BpTCP8都对其产生了相应的应答。【结论】BpTCP8基因可能参与到了白桦叶片成熟、叶型、顶芽、木质部和韧皮部的生长过程中;该基因在GA₃、JA处理中呈现正调控的应答模式,并且可能通过ABA信号途径影响植物抗旱,耐盐、碱、重金属胁迫等。

【Objective】 To reveal the function of BpTCP8 in the growth and development ofBetula platyphylla Suk., we analyzed the sequence characteristics, expression pattern in different tissues and the BpTCP8 gene response to hormones and stress.【Method】 The sequence characteristics of BpTCP8 gene were analyzed using bioinformatic methods. Besides, the expression characteristics of the BpTCP8 gene in different tissues as well as its response to hormones and stress were analyzed by real-time fluorescent quantitative PCR.【Result】 Using bioinformatic tools, it was found that the predicted amino acid sequence for the BpTCP8 gene contained a highly conserved bHLH domain, similar to that of the TCP family of transcriptional regulators. Results from qRT-PCR analyses indicated that BpTCP8 was highly expressed during the early developmental stages and during leaf senescence; BpTCP8 was also found to be upregulated in leaves with deep-splitting, apical buds, the xylem and the phloem. Different expression patterns of BpTCP8 were exhibited under different hormone treatments (GA₃, ME-JA and ABA) and abiotic stresses (high PEG, NaCl, CdCl₂ and NaHCO₃concentrations).【Conclusion】 Therefore, the BpTCP8 gene may be involved in leaf maturation and leaf shape, and in the growth of apical buds, the xylem, and the phloem of B. platyphylla Suk.. The gene is positively regulated by GA₃ and JA. BpTCP8 expression may also affect plant resistance to drought, salt, alkali and heavy metals through the ABA signaling pathway.