Electron Microscopy as a Method to Evaluate Structure and Degradation of Plant Cell Walls

Abstract

The structure and degradation of plant cell walls can be evaluated by chemical methods, but such methods measure only the contents of cell wall components. Physical methods, such as electron microscopy, provide information on the distribution of such constituents both within and between cell walls. The ease of breakdown of different plant tissues and their selective attack by microorganisms in the rumen have been visualised by electron microscopy, which provides an understanding of the differences in digestibility that have been observed. The relationship between rumen microorganisms and plant tissues, and in particular, the adhesion of bacteria to cell walls have been demonstrated by this technique, which also made possible the relatively recent discovery of anaerobic fungi in the rumen. The limitations of electron microscopy reside in the necessity to select appropriate samples that are representative of the plant studied, and the present impossibility of obtaining quantitative results. Its future development is likely to be linked to that of immunocytochemistry which should permit the study of cell walls constituents and microbial enzyme secretion in far greater detail than is possible at present.