Improving Forage Quality of Tall Fescue (\u3ci\u3eFestuca Arundinacea\u3c/i\u3e) by Genetic Manipulation of Lignin Biosynthesis

Lignification of plant cell walls is a major factor limiting forage digestibility and concomitantly animal productivity. Improvement in forage grass cell wall digestibility has become an important goal of many plant-ruminant animal research programs. Lignins are complex phenolic heteropolymers associated with the polysaccharidic components of the wall in specific plant cells. Lignin in forage grasses comprises guaiacyl (G) units derived from coniferyl alcohol, syringyl (S) units derived from sinapyl alcohol, and p-hydroxyphenyl (H) units derived from p-coumaryl alcohol. Cinnamyl alcohol dehydrogenase (CAD) and caffeic acid O- methyltransferase (COMT) are key enzymes involved in lignin biosynthesis. Tall fescue is the predominant cool-season forage grass in the United States