目的 克隆三七Panax notoginseng（Burk）F.H.Chen多聚半乳糖醛酸酶抑制蛋白（polygalacturonase-inhibiting protein，PGIP）基因（PnPGIP）的全长cDNA序列，分析该基因的表达特性。方法 根据三七中编码PGIP的EST（expressed sequence tag）序列设计引物，采用cDNA末端快速扩增技术克隆PnPGIP基因的全长cDNA序列；用qRT-PCR分析PnPGIP基因的表达水平。结果 PnPGIP基因的cDNA全长为1 171 bp，含有981 bp的开放阅读框，13 bp的5’-非翻译区以及177 bp的3’-非翻译区，编码含326个氨基酸的蛋白质，PnPGIP蛋白的相对分子质量约为36 770，等电点约为5.83；qRT-PCR分析结果显示，PnPGIP基因的表达量分别在三七接种茄腐镰刀菌和人参链格孢后4 h和2 h内迅速上升；此外，信号分子茉莉酸甲酯（methyl jasmonate，MeJA）、乙烯利（ethylene，ETH）、H₂O₂、水杨酸（salicylic acid，SA）处理均能不同程度地诱导PnPGIP基因的表达水平。结论 PnPGIP基因在转录水平响应茄腐镰刀菌和人参链格孢的侵染，并受几种逆境胁迫相关信号分子的诱导，PnPGIP基因可能参与三七对茄腐镰刀菌和人参链格孢的防卫反应。

Objective To clone the full-length cDNA sequence of PnPGIP gene encoding polygalacturonase-inhibiting protein (PGIP) from Panax notoginseng and analyze the expression levels of PnPGIP. Methods Based on P. notoginseng expressed sequence tag (EST) encoding PGIP, specific primers were designed and the full-length cDNA of EST was cloned with the method of rapid amplification of cDNA ends (RACE). The expression levels of PnPGIP were analyzed by qRT-PCR. Results The full-length cDNA of PnPGIP was 1 171 bp and contained an intact open reading frame (ORF) of 981 bp, a 13 bp 5'-untranslated region (UTR), and a 177 bp 3'-UTR. The deduced amino acid sequence of PnPGIP has 326 amino acid residues which form a 36 770 polypeptide with a calculated pI of 5.83. qRT-PCR analysis indicated that the expression of PnPGIP was quickly induced after inoculation with Fusarium solani and Alternaria panax, and the highest transcription level was achieved at 4 h and 2 h post inoculation, respectively. Moreover, the expression of PnPGIP was induced in different degrees by methyl jasmonate (MeJA), ethylene (ETH), H₂O₂, and salicylic acid (SA). Conclusion PnPGIP responds to F. solani and A. panax infection in the transcription level, and it is induced by several kinds of adversity stresses related signaling molecules. Therefore, PnPGIP may be involved in defense response of P. notoginseng against F. solani and A. panax.

国家自然科学基金项目（81560610）；云南省应用基础研究计划项目（2014FA003）