Enhancement of cell division in wheat root tips and growth of root elongation zone induced by Azospirillum brasilense Cd

Abstract

Inoculation by bacterial infiltration of germinating wheat seeds with 10⁶–10⁸ colony-forming units of the beneficial rhizosphere bacteria, Azospirillum brasilense Cd, significantly increased cell division in root tips during germination. The phenomenon occurred mainly in the second wave, i.e., 24 h after inoculation, of cell division in the meristem. Seed inoculation significantly enlarged the elongation zone of their roots. These inoculation effects suggest that the larger root system, which is usually observed in inoculated plants, may originate in part from the enhancement of cell division and the intensive growth of the elongation zone of seminal roots. Key words: Azospirillium, beneficial bacteria, bacteria–root interaction, cell division, rhizosphere bacteria, root growth.