Bas ip ms

Radiolabeled Pi was used for determining Pi uptake under different soil water conditions in Arabidopsis. Arabidopsis (Col-0, CS60000) was grown under the same conditions as described in Fig. 6. Before drought treatment, all pots were removed from the nutrient solution and kept on paper towels to remove excess water for 10 min. Pots were soaked in 20 kBq/ml ³²Pi solution (H₃PO₄, PerkinElmer, Inc., Japan) in filtrated water for 1 h. After ³²Pi treatment, pots were divided into two groups as described in Fig. 6. The aboveground parts of three seedlings were collected from each pot at 1 and 4 days after drought treatment, and ³²Pi radioactivity was measured using an imaging plate (BAS-IP MS, FUJIFILM, Tokyo Japan) and a Typhoon FLA-7000 image reader (Cytiva, Tokyo, Japan). Signal intensities detected in the region of interest (ROI) were measured using ImageJ software.

Wide-angle X-ray diffraction was performed using a small/wide-angle diffractometer (Molecular Metrology SAXS system), equipped with a sealed microfocus tube (MicroMax-002 + S) emitting Cu Kα radiation (λ = 1.542 Å), two Göbel mirrors, and three pinhole slits. The generator is powered at 45 kV and 0.8 mA. The scattering patterns were recorded by a 15 × 15 cm two-dimensional imaging plate (BAS-IP-MS, FUJIFILM), positioned about 6 cm behind the sample. Exposition time was about 18 h. The single fiber sample was fixed on a two-dimensional holder perpendicular to the beam, and measured under vacuum at ambient temperature. The imaging plate was scanned by a Fluorescent Image Analyzing System (FLA-7000), and analyzed by FLA-7000 ImageReader software with 100 μm resolution.