MICRO-PENETRATION TECHNIQUE FOR MECHANICAL TESTING OF PLANT-CELL WALLS

A close examination of mechanical ''noise'' produced during the cuttin g of potato tuber parenchyma tissue suggested that the signals reflect ed the summation of the stretching and breaking of individual cell wal ls. Replacement of the cutting blade by a thin parallel-sides glass pr obe, together with the use of very sensitive load- and deflection-tran sducers, produced a micro-penetration test capable of resolving indivi dual cell-wall stretching and breaking events. The use of such data to provide information about mean cell diameters, cell wall fracture ene rgies and cell wall stiffens, together with associated limitations, is discussed.