The composition of tissue lignin determines host resistance. A and B, S. hermonthica infection phenotypes of wild-type Nipponbare. OsC3′H-kd, OsF5H-kd, and OsF5H-OX rice plants. C and D, Effects of inhibiting OsC3′H and OsF5H or overexpression of OsF5H on host resistance against S. hermonthica. Values represent means ± SE of the percentage of matured S. hermonthica and their leaf numbers determined as described in “Materials and Methods.” Data are from two independent experiments containing 13 wild-type and 14 mutant plants. Observations were made at 50 dpi. *Statistically significant difference (Student’s t test, P < 0.05) from wild type. **Statistically significant difference (Student’s t test, P < 0.01) from wild type. Bars = 2 mm. WT, wild type.