Overexpression or mutation of OsIAA1/9/21/31 affects ethylene-induced OsTAR2 expression in root tips. A, Ethylene-induced OsTAR2 expression in root tips of Osiaa1 Osiaa9 and Osiaa21 Osiaa31 double mutants. One-DAG etiolated seedlings were treated with 10 ppm ethylene for 0, 4, or 8 h, and root tips were used for analyzing OsTAR2 expression. Three independent biological replicates were performed. Data are means ± sd. B–E, Ethylene-induced OsTAR2 expression in root tips of OsIAA1/9/21/31-OE seedlings. Data are means ± sd (n = 3). F–I, Effects of OsIAA1/9/21/31 overexpression on OsTAR2 expression in root tips of OsEIL1-OE seedlings. The data of OsTAR2 expression in WT and OsIAAs overexpression in WT background are from (B–E). Data are means ± sd (n = 3). *P < 0.05; **P < 0.01; ***P < 0.001, as determined by a two-tailed Student’s t test compared to WT or OsEIL1-OE seedlings.