中文摘要：

【目的】研究从土壤中分离出来的具有广谱抗菌活性的枯草芽孢杆菌（Bacillus subtilis）菌株NJ-18与作物互作关系，并观察外源导入绿色荧光蛋白（green fluorescent protein，GFP）基因的NJ-18菌株在小麦根部的定殖能力。【方法l首先使用十二烷基硫酸钠（SDS）消解NJ-18的质粒，然后采用化学法导入gfp分子标记，并采用激光共聚焦显微镜检测该标记菌株在小麦根部的定殖能力。[结果】获得了NJ-18的质粒消解菌株c136，并采用化学方法成功将外源基因导入野生型菌株NJ-18及其质粒消解菌株C136，C136的转化效率可达到3．42×10^5cfu／μg质粒DNA，是NJ-18转化效率的10倍左右。对比NJ-18与c136的生物活性发现，C136能够保持原有的抑菌活性；但是C136的生长曲线第一峰值出现的时间滞后12h，第一峰值被抑制了29．4％；NJ-18-GFP能够附着在病原菌菌体上，导致其菌丝呈现膨大、畸形等；接种7d后能够在小麦根部表皮和中柱稳定定殖。【结论】枯草芽孢杆菌NJ-18菌株的转化方法宜选用化学法；该菌株能够在小麦根部定殖。

英文摘要：

[Objective] Bacillus subtilis strain NJ-18, isolated from the soil of oilseed rape field, has a broad spectrum antibacterial activity and a great potential for biocontrol. In order to study the interaction between NJ-18 and plants, NJ-18 was marked with a green fluorescent protein （gfp） gene and its colonization ability on wheat roots was observed with a laser scanning confocal microscope. [ Method ] The plasmids of N J-18 were cured by sodium dodecyl sulfate （SDS） and gyp was transformed into the strain with a chemical method. Colonization ability of NJ-18 on wheat roots was observed with a laser scanning confocal microscope. [Result] By a chemical method, gfp was sucessfuUy transformed into wild strain NJ-18 and C136, a plasmid cured strain from N J-1 8. The transformation efficiency of C 136 could be up to 3.42 ×10^5cfu/μg of plasmid DNA and was about 10-fold of that of N J-18. Compared with N J-18, C 136 had the same antibacterial activity, but its growth was inhibited in a certain extent. N J-18 could attach on the pathogen microbial cells, resulting in mycelium enlargement and malformations. NJ-18 was able to colonize in the phloem and xylem of wheat roots on 7 days after inoculation. [Conclusion] The chemical transformation method is suitalbe for strain NJ-18. NJ-18 can colonize on wheat roots.