Rhizosphere pH measurement
For rhizosphere pH measurement, seedlings were hydroponics with 0.5 mM
KNO3 + 50 µM Fe, 15 mM KNO3 + 50 µM Fe,
0.5 mM KNO3-Fe
(-Fe solution supplemented with 200 µM ferrozine), 15 mM
KNO3-Fe (-Fe solution supplemented with 200 µM
ferrozine) treatments. The pH was measured daily with a pH electrode
(PHS-3C, INESA Scientific Instrument Co., Ltd, Shanghai, China). Each
treatment contained 10 biological replicates.