44] N2-Fixing plant-bacterial symbiosis in tissue culture

Abstract

This chapter discusses the nitrogen-fixing (N 2 ) plant-bacterial symbiosis in tissue culture. The infection of specific plants of the family Leguminosae by selective bacteria of the genus Rhizobium results in the formation of the vital N 2 -fixing plant-bacterial symbiosis. The chemistry and biology of the development of this symbiosis are only poorly defined, largely because of the complexity and diversity of experimental systems utilizing whole plants or more recently root organ cultures. The tissue culture symbiotic system combining plant tissue and bacterial culture techniques provides the system available for the study of the symbiotic process. The cytology of the callus symbiosis at the light and electron microscope level shows similarities to the nodule system formed by bacteria interacting with the whole plants. Soybean seeds, surface sterilized by a 15-minute immersion in a commercial hypochlorite solution and thoroughly rinsed with sterile distilled water, are germinated on the surface of 1% (w/v) agar-solidified medium.