CHANGES IN THE COMPOSITION OF EXOCELLULAR PROTEINS OF SUSPENSION-CULTURED LUPINUS-ALBUS CELLS IN RESPONSE TO FUNGAL ELICITORS OR CUCL2

Among many aspects of plant defence responses to pathogenic infection are changes in the composition of the exocellular matrix, To study pot ential defences in white lupin (Lupinus albus L.), suspension-cultured cells were treated for 24 h with one of three different elicitors: Cu Cl2, and two fungal elicitor preparations from purified cell walls of yeast and Colletotrichum lindemuthianum, Two subsets of exocellular pr oteins: ionically-bound wall proteins and proteins secreted into cultu re medium, were isolated, and their patterns compared following electr ophoretic separation, Only a few proteins were observed in culture fil trates with dominating bands at 27, 33, and 42 kDa, About 30 proteins were observed in cell wall extracts. Changes in protein intensities ev oked by elicitor treatments depended on the type of elicitor used, the age and composition of lupin cell culture, and concentration of appli ed fungal elicitor. Based on these observations, ten proteins were cho sen for N-terminal sequencing, and sequences 5-30 amino acids long for nine proteins were obtained, Three of the major proteins sequenced we re identified as acidic exocellular chitinase, polygalacturonase-inhib iting protein, and germin/oxalate oxidase.