Influence of KAN1 on shade-induced auxin production. A, Hypocotyl lengths of 35S::FLAG::GR-KAN1 and wild-type Col-0 without 50 μm
DEX in white light and simulated canopy shade (far-red light-enriched white light) are significantly shorter in the DEX-induced transgenic line. Box plots show the observed experimental data; white boxes represent hypocotyls grown in white light, and gray boxes represent shade-grown hypocotyls. B, Determination of free auxin levels in Col-0 and in 35S::FLAG-GR-KAN1 transgenic plants using gas chromatography-mass spectrometry. Plants were grown on petri dishes for 10 d and treated with either mock solution or a 5 μm
DEX solution for 45 min. One-half of the plants were then transferred to simulated canopy shade conditions for another 45 min (gray background). Plotted are levels of free IAA per gram fresh weight (FW). C, Hypocotyl lengths of kan1 kan2 double mutant and wild-type Col-0 seedlings in white light (WL) and far-red light (FR)-supplemented white light. Box plots show the observed experimental data; white boxes represent hypocotyls grown in white light, and gray boxes represent WL+FR hypocotyls. *, P < 0.001. D, Ratio of the lengths of hypocotyls grown in far-red light-enriched white-light conditions compared with white light. Plotted is the average of three biological experiments with sd. *, P < 0.05.