Histochemical & Biochemical Differences Between Lignin-Like Materials in Phleum pratense L.

Abstract

Although differences in lignins among major plant groups are known (23), the extent of variations found within one plant is not well understood (3). Histochemical tests for lignin with phloroglucinol and with Maule reagents do not always give identical patterns of lignification (3, 10, 24). Since similar discrepancies were observed in Phleum pratense L., the lignin in different parts of the timothy plant at various developmental stages was compared by histochemical and biochemical tests. Differences can be detected among the lignins of the elongated first internode, the upper internodes or sheaths, and the blade. These are related in part to the type of lignified cells. The results indicate that a satisfactory definition of lignin is still needed, that the detection of the extent of lignification may depend on the analytical method used, and the factors controlling lignification may vary in different tissues or even in the same tissue at various stages of development.