Lectins are involved in the recognition between anabaena and azolla

The presence of a lectin in extracts of the endosymbiotic Anabaena azottae was demonstrated using the haemagglutination assay. This activity was sensitive to D(-) fucose and L(-) rhamnose but was not affected by other saccharides tested. Furthermore, an endogenous inhibitor was extracted from isolated leaf cavity envelopes of Azolla, suggesting the possibility of a recognition site for the lectin in the host.