Studies on the distribution of theDolichos biflorus lectin during the life cycle of the plant have shown that the seed lectin appears at about 27 days after flowering and is localized in the cotyledons. Although this lectin disappears during the absorption of the cotyledons, a related molecule that cross reacts with antibodies to the seed lectin, appears in the stems and leaves of the plant. Structural studies on this cross reactive material show that it appears to have one subunit in common with the active subunit of the seed lectin and another subunit that has a higher molecular weight than the seed lectin subunits. The subunits of the seed lectin and cross reactive material may all represent different degrees of completion or modification of a common gene product.
The cross reactive material has been found to have carbohydrate binding activity at low ionic strength and a significant amount of this “lectin-like” glycoprotein appears to be associated with the cell wall. Further studies on the distribution and properties of lectins during the life-cycle of the plant may be valuable in obtaining a better insight into the physiological role(s) of these molecules in the plants.