COMPOUNDS EXUDED BY PHASEOLUS-VULGARIS THAT INDUCE A MODIFICATION OF RHIZOBIUM-ETLI LIPOPOLYSACCHARIDE

Exudates released from germinating seeds and roots of a black-seeded b ean (Phaseolus vulgaris cv, Midnight Black Turtle Soup) induce an anti genic change in the lipopolysaccharide (LPS) of Rhizobium etli CE3, By spectroscopic analyses and chromatographic comparisons with derived s tandards, the chemical structures of the aglycone portions of the majo r inducing molecules from seed exudate were deduced, and they were ide ntified as delphinidin, cyanidin, petunidin, and malvidin, These antho cyanidins were present in seed exudate mainly as glycosides, the chief inducer being delphinidin 3-glucoside. Also present were 3-glucosides of petunidin and malvidin and glycosides of cyanidin and delphinidin, Seed exudate from a bean variety deficient in anthocyanins did not in duce the LPS conversion, The ability of root exudate to induce an anti genic change in the LPS was due to compounds other than anthocyanins.