The state of membranes in seeds of Triticum aestivum L. under different humidity conditions and in the course of wetting

We used NMR to study characteristic features of the state of water in wheat seeds at different relative humidity. We have also examined kinetics of wa ter uptake and its state in cells of such seeds using the technique of NMR with a paramagnetic dope. Mobility of water bound with seed starch appears to remain unchanged at relative humidity below 50%, suggesting that cell me mbranes have low permeability. Recovery of membrane permeability for water during seed swelling proceeds significantly slower as compared with seeds h aving higher initial relative humidity. We have also noted differences in t he rate of seed germination. We discuss various aspects of water action on the structure of membranes at different relative humidity values. We also d iscuss biological significance of these phenomena during seed ripening and swelling, as well as their importance for the retention of seed viability d uring storage.