芽孢杆菌绿色荧光蛋白标记及其在小麦体表定殖的初探

Colonization study of GFP-tagged Bacillus strains on wheat surface

将来自质粒 pAD4 4 12的启动子和绿色荧光蛋白基因 gfpmut3a插入大肠杆菌 枯草芽孢杆菌穿梭载体pBE2 ,构建成芽孢杆菌表达载体 pGFP4 4 12 ,用其转化野生型生防芽孢杆菌 83 6和A 4 7等 8个菌株 ,均得到良好的发光表型。质粒稳定性实验表明重组质粒 pGFP4 4 12稳定性为 92 %。借助荧光显微镜对GFP标记的菌株A 4 7 gfp在小麦体表的定殖进行初步的研究。结果表明 :A 4 7 gfp能够在小麦根际及小麦体表定殖 (包括根表和茎叶表面 ) ;相对于在茎叶表面定殖的A 4 7 gfp在根表定殖的菌体与根的结合更为牢固 ;从根基到根尖A 4 7

The green fluorescent protein (GFP) acts as a vital dye upon the absorption of blue light in the living bacterial cell. A gfp gene was inserted into an E.coli-Bacillus shuttle vector to obtain a new vector pGFP4412, in which the gfp gene was expressed under the control of 4412 promoter. Plasmid pGFP4412 was introduced into several Bacillus strains by electroporation and the transformants appeared bright green under blue light. The gfp-labeled Bacillus cereus A-47 was used in the colonization study. The results indicated that the gfp-tagged A-47-gfp could colonize on the surface of wheat and it adhered more tightly to the rhizoplane than to the phylloplane. In the direction from root base to tip, the bacterial distribution showed a clear decreasing tendency in wheat root.