应用双向凝胶电泳技术，分析了抗病毛白杨和感病北京杨接种溃疡病菌Botryosphaeria dothidea前后的蛋白质表达差异。通过比较两个树种接菌前后的双向凝胶电泳图谱，结果得到在两树种之间共有35个3倍蛋白质差异点，其中接种前毛白杨与北京杨相比上调蛋白4个，下调15个；接种后相比则上调蛋白7个，下调9个。同一树种内，毛白杨接种后与对照相比检测到8个上调蛋白，6个下调蛋白；北京杨接种后与对照相比有8个上调蛋白、10个下调蛋白。对这些差异蛋白产生条件及含量进行分析，笔者认为接菌前抗病毛白杨与感病北京杨相比上调蛋白可能与杨树抗溃疡病的组成型抗病机制有关，接菌后抗病毛白杨与感病北京杨相比上调蛋白可能与杨树对溃疡病的诱导型抗病机制密切相关。最后利用质谱技术鉴定出其中的4个差异蛋白分别是核酮糖二磷酸羧化酶小链、预测蛋白、过氧化物歧化酶、异戊烯二磷酸-异构酶，这些差异蛋白可能与杨树对溃疡病的抗性有一定关系。

By twodimension gel electrophoresis, differential proteomic analysis was conducted on Populus beijingensis(sensitive to Botryosphaeria dothidea) and P. tomentosa(resist to B. dothidea) before and after inoculated with B. dothidea（2DE）. Comparison of the 2DE maps of proteins from the two inoculated and control species. The results showed that 35 3fold different proteins were detected between the two species.Among which there were 4 upregulated proteins, 15 downregulated proteins before inoculation, and 7 upregulated proteins, 9 downregulated proteins after inoculation. For P. tomentosa, there were 8 upregulated proteins and 6 downregulated proteins detected after inoculation, and for P. beijingensis, 8 upregulated proteins and 10 downregulated proteins were identified after inoculation The analysis was taken on the produce conditions and contents of these proteins.It could be deduced that the upregulated proteins expressed in P. tomentosa before and after inoculation may be associated with consistutive resistance mechanisms and induced resistance mechanisms respectively. Four of them were detected by mass spectrometry, which were ribulose bisphosphate carboxylase small clain, predicted protein, superoxide dismutase, isopentenyldiphosphate deltaisomerase respectively. These proteins may be associated with the resistance of poplar to canken.