Effect of cytoskeleton modifiers on the lectin activity during plant acclimation to low temperatures and under ABA treatment

Effects of inhibitors of microtubule polymerization, 1 mM colchicine and 15 mu M oryzalin, and a microtubule stabilizer, 7% dimethyl sulfoxide, on the activities of soluble and cell-wall lectins were studied in unhardened (23 degrees C) and cold acclimated (3-7 days at 2-3 degrees C) winter wheat (T riticum aestivum L,.) 7-day-old seedlings. Three wheat cultivars differing in their frost tolerance were compared. Seedlings were grown in the presenc e of 30 mu M ABA or without hormone in the medium. Cell-wall lectins were m ore sensitive to the cytoskeleton modifiers than soluble lectins. Colchicin e and oryzalin enhanced lectin activity, whereas dimethyl sulfoxide suppres sed it. Plant hardening and ABA treatment reduced the sensitivity of cell-w all lectins to the cytoskeleton inhibitors, probably due to appearance of t he subpopulation of cold-stable microtubules. An increase in the activity o f cell-wall lectins under the conditions resulting in the cytoskeleton degr adation could be a compensatory mechanism directed to cytoskeleton stabiliz ation, with genotype-dependent manifestation of this mechanism.