The extensibility of isolated cell walls of young expanding leaves and root apices from Ceratonia siliqua L. (carob tree) has been investigated when: a) subjected to acidic buffers, b) treated with enzymes degrading specific cell wall components and c) applied crude protein extract from growing walls of cucumber and carob. The extension was generally restricted and smaller than that reported for rapidly growing tissues; while, specimens treated with pectolyase and pectinase rapidly extend
