Institute for Advanced Learning and Research 1 article published in JoVE Bioengineering Lignin Down-regulation of Zea mays via dsRNAi and Klason Lignin Analysis Sang-Hyuck Park1, Rebecca Garlock Ong2, Chuansheng Mei3, Mariam Sticklen4 1The School of Plant Sciences, University of Arizona, 2Department of Chemical Engineering and Materials Science, DOE Great Lakes Bioenergy Research Center, Michigan State University, 3The Institute for Sustainable and Renewable Resources, The Institute for Advanced Learning and Research, 4Department of Plant, Soil and Microbial Sciences, Michigan State University A double stranded RNA interference (dsRNAi) technique is employed to down-regulate the maize cinnamoyl coenzyme A reductase (ZmCCR1) gene to lower plant lignin content. Lignin down-regulation from the cell wall is visualized by microscopic analyses and quantified by the Klason method. Compositional changes in hemicellulose and crystalline cellulose are analyzed.