The Microvirga zambiensis strain WSM 3693 is an endophytic strain isolated from saline area of kutch, Gujarat. The green fluorescent protein (GFP) was used to mark this endophyte in order to visualize and analyze the colonization processes in vivo. After inoculation for 2 to 15 d, it was visualized in cotton tissue using fluorescence microscopy. Thus, the objectives of this study were to construct gfp-marked derivatives of Microvirga zambiensis strain WSM 3693and to determine the endophytic patterns of colonization of cotton under gnotobiotic conditions by using genetically marked derivatives of this strain. | Microscopic colonization of salt tolerant plant–bacterium Microvirga Zambiensis strain WSM 3693 in cotton tissue using auto fluorescent proteins GFP