Change in the activity of lectins in cell structure of winter wheat crown under the action of low-temperature hardening and fusicoccin.
Haemagglutinating activity was determined in cell walls and total cell organelles of crown cells of Winter wheat (Triticum aestivum L. ) plants. The effect of fusicoccin (FC) was investigated using fractions obtained from plants hardened for 7 days at 2 degrees C and from untreated plants. FC concentration (5x10(-7) m) increased the frost resistance of the plants. The temporal pattern of lectin activity during hardening could be described by a single-peak curve. In the cell wall fraction, the highest activity manifested itself after one-day hardening, and in the fraction of organelles it peaked after five-days hardening. The carbohydrate specificity of lectins also changed during hardening; cell wall lectins completely lost their capacity for interaction with uridine diphosphoglucose, glucose 6-phosphate, D-galactosamine, and N-acetylglucosamine and the lectins of organelles retained some affinity only for amino sugars. After hardening the test plants, the activity of the lectins increased substantially in the cell walls and plastids, decreased in the nuclei, and was practically flat in mitochondria and microsomes. Consequently, low temperature and FC with their antistress effect improved frost resistance and stimulated the activity of the lectins of some cell structures of the tillering node of winter wheat. A similar action of low temperature and FC in increasing the activity of lectins of plastids was found. Further information was obtained on the subcellular localization of lectins providing additional information on their possible participation in the development of frost resistance of winter wheat.