OBSERVATIONS ON THE DEVELOPMENT OF CERTAIN CELL-WALL CONSTITUENTS OF FORAGE PLANTS

Emmett Bennett

$FIGURES) Introduction In the conventional methods of "proximate analysis," pectic substances, hemicelluloses, and lignin, for the most part, appear in the "nitrogen-free extract" fraction. It is now generally recognized that this method of differentiation gives very little information as to the nature of the substances composing these fractions; hence attempts are being made to ascertain their chemical constitution, nutritional value, precursors, and relationships in the plant. In this way a better understanding of the metabolism and economic value of plants will be obtained. The changes which the cell-wall constituents undergo during the development of the plant are not definitely known. True chemical relationships cannot be established as yet because the chemical constitution of lignin is not known. Transformation studies have been made, however, and a number of theories have been evolved. The principal theories as summarized by NORMAN (14) are: 1. That pectin undergoes transformation to lignin. 2. That the hemicelluloses or certain groups thereof may be converted to lignin. 3. That the polyuronide hemicelluloses are formed from pectin. 4. That all three substances are connected, lignin being formed from pectin through the intermediate stage of polyuronide hemicelluloses. Most investigations of this kind have dealt with woody tissues,$

OBSERVATIONS ON THE DEVELOPMENT OF CERTAIN CELL-WALL CONSTITUENTS OF FORAGE PLANTS

Emmett Bennett

Follow Plant Physiology , Volume 15 (2): 327 American Society of Plant Biologist – Apr 19, 1940