LECTIN ACTIVITY IN WINTER-WHEAT CROWNS DURING HARDENING

The activity and carbohydrate specificity of lectins were studied in t he fractions of cell walls and total cell organelles from the crowns o f winter wheat, cv. Mironovskaya 808, during plant cold acclimation fo r one to seven days at 2 degrees C. Using the technique of hemagglutin ation of trypsinized erythrocytes, lectin activity in the fraction of cell organelles from unhardened plants was shown to exceed threefold t hat of the fraction of cell walls. The carbohydrate specificity of lec tins from two fractions differed. The cell wall lectins showed high af finity for uridine diphosphoglucose, whereas the organellar lectins di d not interact with this carbohydrate. The cell wall lectins also show ed higher affinity for N-acetylglucosamine, D-galactosamine, and gluco se 6-phosphate, as compared to the organellar lectins. The temporal pa ttern of the lectin activity during hardening could be described by a single-peak curve. In the cell wall fraction, the highest activity man ifested after one-day hardening, and in the fraction of organelles it peaked after five-day hardening. The carbohydrate specificity of lecti ns also changed during hardening: The cell wall lectins completely los t their capacity for interaction with uridine diphosphoglucose, glucos e 6-phosphate, D-galactosamine, and N-acetylglucosamine and the lectin s of organelles retained some affinity only for aminosugars. Lectin in volvement in the frost resistance of winter cereal crops is discussed.