Fig. 4

Effect of twenty different growth conditions on GFP-intensity in the root tip of P_{Ertip1+35Smini}:GFP-expressing plants. Plants were pre-cultured vertically on medium agar-plates for 7 d and then transferred to the medium plates with 20 different treatments for 24 h growth (see “Methods” section). The treatments are shown below: IAA (60 nM), ABA (200 nM), GA (500 nM), ACC (500 nM), 6-BA (100 nM), l-Glu (0.5 mM), l-Leu (0.5 mM), l-Lys (0.5 mM), l-Met (0.5 mM), pH (4.5 and 8), P (phosphorus, high-2.5 mM, low-50 μM), NH₄⁺ (high-10 mM, low-10 µM; in the form of (NH₄)₂SO₄), NO₃⁻ (high-10 mM, low-10 µM; in the form of KNO₃), AlCl₃ (50 μM), NaCl (80 mM), cold (4 °C). Control plants (CK) were grown on a half-strength of MS medium, which was also used as basic nutrients in the different treatment experiments (except for N- or P-treatment). All plants were cultivated under normal growth conditions, except for those treated with 4 °C. The intensity of green fluorescence photographed by using a fluorescence microscope-camera device was quantified using ImageJ (see “Methods” section). GA, gibberelin. 6-BA, 6-Benzylaminopurine (a type of cytokinins). ACC, 1-Aminocyclopropanecarboxylic acid (a precursor for ethylene biosynthesis). Mean values SE (n = 8) were potted. “*” or “**” indicates statistically significance calculated by using one-sided paired t test at P < 0.05 or P < 0.01