CHANGES IN THE COMPOSITION OF CONA-BINDING GLYCOPEPTIDES FROM LUPINUS-ALBUS ROOT MEMBRANES INDUCED BY NODULATION AND SCALLUS FORMATION

Concanavalin A (ConA)-binding glycopeptides (GP) from crude membrane f ractions of Lupinus albus were analysed by SDS PAGE and detected on bl ots by the ConA/peroxidase affinity method. Changes in the GP pattern of the root membrane fraction were studied when nodulation and callus formation occurred and were compared with the patterns obtained for ot her organs. Nodulation markedly increased the detection of a set of th ree GPs with apparent molecular masses in the range of 45-65 kDa. Anot her GP, of 23.5 kDa (GP 23), which was also increased by nodulation, w as apparently absent from cotyledons and leaves and was faintly detect ed in stems. Callus formation increased the detection of GP 23 as well as several other GPs; two of them, with apparent molecular masses aro und 24 and 42 kDa, seemed particularly specific to calli. Treatment of the membranes of roots, calli and nodules with several agents (low an d high ionic strength, NaClO4, urea, Triton X100, Triton X114, Tween 2 0, DDAP, SDS, sodium cholate and sodium deoxycholate) showed that only stronger detergents were efficient in extracting GP 23, suggesting th at GP 23 is an integral membrane protein. The data obtained in this wo rk are a good base for subsequent studies on the role of membrane GPs in plant development. GP 23 and other GPs found here to be intensively detected in specific organs or tissues seem of great interest in this respect.