中文摘要：

选择适宜的转录调控序列以提高启动子的转录效率，增强外源基因在转基因植株中的表达，对改良作物的抗病虫性具有重要意义。将甘露碱合成酶基因（mgs）启动子和章鱼碱合成酶基因（ocs）增强子杂合而成的嵌合启动子ocs／mas与GUS报告基因连接，构建了植物表达载体pOMS-GUS。对照载体pMAS—GUS仅携带mas启动子驱动的GUS基因。利用根癌农杆菌介导法，将以上植物表达载体分别转化烟草。应用半定量RT-PCR和GUS荧光定量分析法分别检测不同胁迫条件下启动子驱动的GUS基因表达量的变化。结果显示，未诱导处理的转基因植株GUS基因仅有微弱表达。伤害处理1h后，mas启动子驱动的GUS活性是未诱导处理的1．8倍，而嵌合启动子ocs／mas的诱导表达活性是未处理的5．7倍。植物激素水杨酸（SA）和茉莉酸甲酯（MJ）处理也诱导了较高水平的ocs／mas嵌合启动子活性；而且SA和MJ联合作用时呈现叠加效应，转基因烟草的GUS活性明显高于伤害处理后的GUS表达水平。以上结果表明，ocs／mas嵌合启动子是一种强诱导型启动子，可以接受多种刺激因子的诱导，从而为更有效地改良作物抗病虫的能力提供新的候选高效启动子元件。

英文摘要：

The use of optimal regulatory sequences for simultaneous expression of the transgenes might play a significant role in engineering plants with increased disease and insect resistance. The plant expression vector pOMS-GUS, which contained the GUS gene under the control of a chimeric promoter based upon the mannopine synthase （mas） promoter and the octopine synthase （ocs） enhancer, was constructed. Used as control, another vector pMAS-GUS, carried the GUS gene driven by only the mas promoter. The two vectors were introduced into tobacco plants by Agrobacterium-mediated transformation. Fluorometric assays for GUS activity and reverse transcription - polymerase chain reaction （RT-PCR） analysis revealed that GUS gene expressed weakly with untreated transgenic tobacco while the level of GUS activity increased steadily after 1 h subjected to wounding. The expression of the mas and ocs/mas promoters was induced a further 1.8-fold and 5.7 -fold, respectively. SA （1 mmol/L） or MJ（250 μmol/L） treatment also caused a large induction of the ocs/mas chimeric promoter;And the application of SA in combination with MJ（ 1 mmol/LSA ＆ 250μmol/L MJ） produced an additive effect that exceeded the wounding response. The results showed that the ocs/mas chimeric promoter is a strong inducible promoter that can be activated by various stresses. The chimeric promoter should have utility in development of disease and insect resistant transgenic crops.