Migration of Azospirillum brasilense Yu62 from Root to Stem and Leaves Inside Rice and Tobacco Plants

摘要

Azospirillum brasilense Tarrand, Krieg et Doebereiner is one of the important plant growth-promotion endophytes. A. brasilense Yu62 tagged with gfp gene was inoculated into roots of rice and tobacco seedlings, which were then, cultured in gnotobiotic condition. At a certain days after inoculation the different portions of the seedling were observed under laser confocal microscope, resulting in that A. brasilense Yu62 bacteria were colonized in epidermal and cortical cells, intercellular spaces and vascular system of stem and leaf tissue interiors besides in roots. Higher populations of the bacteria isolated from roots, stems and leaves indicated that A. brasilense Yu62 bacteria could ascend themselves from roots to stems and leaves of rice and tobacco. This observation lays down the foundation for ecology and cell morphology of bacterial migration inside plants, interaction between A. brasilense Yu62 bacteria and host cells as well as the plant-growth promotion, provides scientific basis for further application, and is of importance in science and practice.