Abstract :
Acetobacter diazotrophicus was isolated from roots of two commercial varieties of sugar cane in Tucumلn, Argentina and inoculated into stem cuttings of sugar cane. The bacterial colonization stimulated the production and development of root hairs, and changes in root hair morphology with infection-thread-like formation. The study was correlated with nitrogen fixation. The bacterized root hair cells were the site of nitrogen fixation.