Lectin activity in cell walls of winter wheat apical meristems during the first day of hardening

The patterns of lectin activity and their carbohydrate-binding specificity were studied in the cell walls of the apical meristems of shoots grown from the crowns of winter wheat (Triticum aestivum L.) plants during the first day of their cold acclimation at 2 degrees C. The content and composition o f cell-wall polypeptides were also estimated. The protein content did not c hange during the first 6 h of chilling, then increased sharply, and, by the end of experiment, it was 1.5-2 times higher than its initial level. The c omposition of cell-wall polypeptides changed as well. A protein with a mol wt of 109 kD appeared within 2 h of chilling, and three other proteins with mol wts of 34, 44, and 125 kD were detected after 24-h cold acclimation. L ectin activity was constant during the first 4 h and then increased for 20 h, so that, by the end of experiment, it was 5 times higher than its initia l level. Alteration in the carbohydrate-binding specificity of lectins was detected within 2 h of chilling, i.e., earlier than in lectin activity. It is suggested that all changes observed were related to metabolic preparatio ns for the development of plant resistance to low temperature.