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研究桑树抗病关键蛋白基因的启动子及其活性,对阐明基因的功能与表达调控机制十分重要.利用Tail-PCR技术成功地从桑树叶片基因组DNA模板中扩增得到病程相关蛋白基因MuPR1-2的启动子,将之命名为MuPR1-2.利用PlantCARE软件分析pMuPR1-2的核苷酸序列,发现其具有多个转录起始所必需的顺式作用元件以及多种转录因子结合位点,另外还包含多种环境因子响应元件.构建由pMuPR1-2启动GUS基因表达的植物表达载体,通过农杆菌介导的烟草瞬时表达及GUS组织化学染色分析pMuPR1-2具有启动子的功能,证实烟草叶片接种Pst DC3000菌液后能驱动下游报告基因GUS表达,pMuPR1-2具有病原菌诱导表达活性.进一步构建pMuPR1-2稳定表达的转基因拟南芥植株,通过GUS组织化学染色与GUS荧光定量分析发现pMuPR1-2不仅具有病原真菌和细菌诱导表达活性,同时具有可被多种激素诱导表达的特性和组织表达特异性.“,”Studying the promoter of key genes related to mulberry disease resistance and its activity plays a critical role in clarifing the gene function and expressional regulatory mechanism.In present study,the promoter of pathogenesis-reiated protein gene MuPR1-2 was successfully cloned from genomic DNA of mulberry leaf by TaiI-PCR and designated as pMuPR1-2.Sequence analysis of pMuPR1-2 was performed using software PlantCARE and the results showed that it contains several cis-acting elements necessary for transcriptional initiation,multiple transcription factor binding sites,and a variety of environmental factor responsive elements.The plant expression vector containing GUS gene drived by pMuPR1-2 promoter was constructed.The activity of pMuPR1-2 was investigated by the method of Agrobacterium-mediated transient expression in tobacco leaves,and the result indicated that pMuPR1-2 could initiate the transcription of downstream GUS gene which was used as a reporter gene after tobacco leaves were inoculated by Pst DC3000 bacterial solution and could be induced upon pathogen attack.The transgenic Arabidopsis plants stably expressing pMuPR1-2 were further constructed.GUS histochemical staining and fluorescent quantitative analysis of GUS showed that pMuPR1-2 could be induced by pathogenic fungi and bacteria,and it was expressed in special tissues after induced by some hormones.