白桦BpTCP2基因的克隆及表达特性分析

目的通过克隆白桦BpTCP2基因，分析其序列特征，并检测该基因在不同组织部位、激素处理及非生物胁迫下的基因表达特性，为揭示BpTCP2在植物生长发育及逆境应答中的作用提供理论依据。方法通过PCR技术克隆BpTCP2基因的全长，并对得到的cDNA序列进行生物信息学分析；采用实时荧光定量PCR技术分析该基因的组织表达特性，以及在外源植物激素（ABA、IAA、BR、JA、SA）处理和非生物胁迫（CdCl₂、NaCl、NaHCO₃、PEG）下的响应模式。结果成功克隆了BpTCP2基因的cDNA序列；生物信息学分析发现BpTCP2含有高度保守的bHLH结构域，属于PCF亚类。qRT-PCR结果显示，BpTCP2基因在木质部、幼嫩的叶片和茎节中表达量较高；在CdCl₂、NaCl、NaHCO₃处理下，该基因持续上调表达；且5种外源激素均能诱导该基因表达。结论BpTCP2基因参与白桦木质部的形成，影响叶片及初期茎节的发育，并能在各激素、重金属、盐、碱的诱导下表达。 

Cloning and expression characteristics analysis of BpTCP2 gene in Betula platyphylla

ObjectiveThe BpTCP2 gene was cloned, sequence characteristics were analyzed, and the gene expression characteristics of the gene under different tissues, hormone treatments and abiotic stress were detected, which provided a reference for revealing the function of BpTCP2 in plant growth and development and stress response.MethodThe full-length cDNA sequence of BpTCP2 gene was cloned by PCR technology and its cDNA sequence characteristics were analyzed by bioinformatics. Real-time quantitative PCR was used to analyze expression level of the gene in different tissues and the responses of exogenous phytohormones (ABA, IAA, BR, JA, SA) and abiotic stress (CdCl₂, NaCl, NaHCO₃, PEG).ResultThe full-length cDNA sequence of BpTCP2 gene was successfully cloned. Bioinformatics analysis found that BpTCP2 contained a highly conserved bHLH domain and BpTCP2 belongs to TCP-P subclass; qRT-PCR analysis showed that the expression of BpTCP2 gene was higher in xylem, young leaves and stem segments. Under the treatment of CdCl₂, NaCl and NaHCO₃, the gene was up-regulated. Five exogenous phytohormones could induce the expression of the gene.ConclusionThe BpTCP2 gene was involved in the development of stems of Betula platyphylla, and affects the development of leaves and early stem segments and responds to various hormones and heavy metals, salts and alkalis.