Fig. 4. α-hydroxylated h24:0 rescues the metazachlor-induced PI4P distribution defect at TGN.

a, b GC-MS analysis of Arabidopsis roots in control condition (pink), metazaclor (Mz)-treated roots (green), and metazachlor-treated roots implemented with h24:0 (blue) (n = 4 biological replicates, the dots show the dispersion of data). a Quantification of non-α-hydroxylated fatty acids and b α-hydroxylated fatty acids. External application of h24:0 in Mz-treated seedlings restores the level of h24:0 of control seedlings. c Confocal micrographs of Arabidopsis root epidermal cells expressing the PI4P biosensor mCIT-3xPH^FAPP1 upon 0, 50 nM Mz treatment or 50 nM Mz treatment + h24:0 add-back. Scale bar, 10 µm. d Quantification of the fluorescence intensity at intracellular dots. While Mz treatment induces PI4P accumulation in intracellular dots, external application of h24:0 rescues this defect. n = 75 cells from 25 roots for each condition. Statistics were done by two-sided Dwass-Steel-Critchlow-Flinger multiple comparison test with Monte Carlo method (10000 iterations). *P < 0.01, ***P < 0.0001. Each element of the boxplot indicates the following value: center line, median; box limits, the first and third quartiles; whiskers, 1.5× interquartile range; points above or below the whiskers, outliers.