Histochemical analysis of lignin in stem. Cross sections of stems at the first internode of developmentally equivalent plants were dissected when the flag leaf was 4 cm below the spike. (A) to (C) Wiesner staining of empty vector control (A), amiR-cad1-1 (B), amiR-comt4-5 (C). Wiesner reagents stain lignified tissue in a concentration-indicative manner; heavily lignified tissue stains dark red, while areas with less lignin stain orange-yellow. (D) to (F) Maule reagent staining of empty vector control (D), amiR-cad1-1 (E), and amiR-comt4-5. The Maule reagent stains S lignin; a shift from red to brown-yellow is representative of a decrease in S lignin.