02186naa a2200229 a 450000100080000000500110000800800410001910000160006024501100007626000090018652015390019565000150173465000120174965000160176165000160177765000230179365000280181665300090184465300140185370000200186777300690188714577712019-05-27       1993    bl ---       0--  u    #d1 aHUNGRIA, M.  aEffects of a seed color mutation on rhizobial nod-gene-inducing flavonoids and nodulation in common bean.  c1993  aA white-seeded mutant of common bean (Phaseolus vulgaris L. PI 165426WS) differed from its isogenic black-seeded parent, PI 165426CS, in the amounts and types of flavonoid nod-gene inducers released from the seed and in the pattern of root nodules formed by Rhizobium tropici CIAT 899 and by R. leguminosarum bv. phaseoli CNPAF 512. Comparisons of 14-day-old plants developing from black (CS) and white (WS) seeds showed that although there were no differences in any plant growth parameter measured, CS plants had at least 80% more nodules on the primary root. Rinsing seeds before planting decreased nodulation at the top of the primary root in CS, but not WS, seedlings. A direct role for seed compounds in the nodulation differences was supported by the fact thatrinses from CS seeds induced 10-fold higher beta-galactosidase activity from a nodA::lacZ fusion in R. leguminosarum bc. phaseoli than WS seed rinses. Analytical chemistry techniques showed that WS seeds lacked five nod-gene-inducing anthocyanins previously identified on CS seeds. WS seed rinses contained five nod-inducing flavonol glycosides released by CS seeds, but only 45% as much of those compounds was present. The nod-gene-inducing activity of WS root wxudates, however, was much more similar to that from CS roots both quantitatively and qualitatively. Adding 20 micromoles of malvidin-3-O-glucoside or quercetin-3-O-glucoside to WS seeds inoculated either with CIAT 899 or with CNPAF 512 increased nodulation by at least 40%, but malvidin and quercetin...  anodulation  aFeijão  aFlavonóide  aNodulação  aPhaseolus Vulgaris  aRhizobium Leguminosarum  aBean  aFlavanoid1 aPHILLIPS, D. A.  tMolecular Plant-Microbe Interactionsgv.6, n.4, p.418-422, 1993.