Extended Data Fig. 4. pH, salt and redox sensitivity of AuxSen.

a, The FRET ratio is slightly affected by changes in the pH, but fully functional in the range of pH values within the plant cell. Red, pH 6.0; blue, pH 6.5; green, pH 7.0; violet, pH 7.5; cyan, pH 8.0. b, The FRET ratio is not strongly affected by salts and changes in the redox potential. Black, control; red, 1 mM (NH₄)₂SO₄; blue, 1 mM CaCl₂; green, 10 mM NH₄NO₃; violet, 10 mM DTT; cyan, 10 mM H₂O₂; yellow, 10 mM KCl; orange squares, 10 mM KNO₃; orange diamonds, 10 mM NaCl. c, ITC data of AuxSen binding to IAA, measured at different pH values. Data are mean ± s.d., derived from 3 technical replicates.