pubmed-article:755154 | pubmed:abstractText | The ability of extracellular polysaccharides of different strains of Rhizobium meliloti to induce the production of polygalacturonase by roots of Medicago sativa seedlings has been studied. Some strains showed a high inducing activity while those derived from them, after treatment with acridine orange and in which extrachromosomal DNA was absent, did not show this character. A comparative study of polysaccharide production and preliminary studies on the chemical composition of the active fractions obtained after Sephadex G-25 filtration indicated that the monomers which form the active fractions are qualitatively and quantitatively different according to their origin. | lld:pubmed |