烟草内生细菌YN201448的定殖能力研究

The Colonization of Endophytic Bacterium YN201448 in Tobacco

为测定烟草内生细菌YN201448的定殖能力,通过自然转化法将携带绿色荧光蛋白基因的质粒p GFP4412成功导入YN201448细胞中,获得了GFP标记菌株48-p GFP。48-p GFP能稳定表达GFP蛋白,且对5种病原真菌的拮抗能力与野生型YN201448的相同。用48-p GFP菌液浸泡烟草种子和浇灌烟草苗后,在烟草的根、茎、叶等组织中都能检测到标记菌,其定殖数量分布为根﹥茎﹥叶;同时标记菌也能在根际土中稳定地定殖。激光共聚焦显微镜观察发现标记菌株主要聚集在烟草茎组织的表皮、皮层部位及维管组织。因此,YN201448可以在烟草体内外较长期定殖。

In order to determine the colonization of endophytic bacterium YN201448 in tobacco,we successfully obtained a stable GFP tagged strain 48-p GFP by transferring the p GFP4412 plasmid into YN201448 via natural transformation.48-p GFP showed the same antagonistic effect against 5 pathogenic fungi as the wild strain YN201448.48-p GFP was observed to be distributed in root,stem and leaf tissues of tobacco after its seeds soaked and seedling roots drenched with 48-p GFP.The colonizing bacterium decreased with the trend of root stem leaf,and 48-p GFP could colonize in rhizospheric soil stably.Fluorescence microscope observation indicated that 48-p GFP mainly appeared in tobacco stem epidermis,cortex and vascular tissue cells.Therefore,YN201448 could colonize inside and around tobacco plant stably for a relatively long period of time.