Presence of gibberellin-like substances and their possible role in auxin bioproduction in root nodules and roots of Lupinus luteus L.

Studies based on bioassay techniques showed that root nodules of Lupinus luteus L. contain substantially more methanol-extractable gibberellin-like substances than the roots do. Experiments done in vitro with sterile, cell-free enzyme preparations of nodule tissue revealed that the bioproduction of IAA from L-tryptophan is promoted by GA3. These results are discussed in the light of current theories about action of gibberellins as related to auxin in plants.