Potassium ferricyanide 3

Graphite powder (average particle size of 50 μm) was received from Merck Millipore (Darmstadt, Germany) and the epoxy resin EpoTek H77 with the corresponding hardener was supplied by Epoxy Technologies (Billerica, MA, USA). Nanodiamonds (>87%) were obtained from PlasmaChem (Berlin, Germany). Potassium chloride (99.5%), potassium ferrocyanide trihydrate (>99%), potassium ferricyanide (III) (99%), nitric acid (99.5%), potassium nitrate (99%), potassium hydrogenphosphate (99.5%), potassium dihidrogenpohsphate (99.5%), silver nitrate (≥99%), gold chloride trihydrate (≥99.9%), sodium chloride (99.5%), sodium borohydride, chloroauric acid (≤99.9%), hydrogen peroxide (30%), glucose oxidase VII from Aspergillus niger (174,400 units/g), D-(+)-Glucose (≥99.5%), and bovine serum albumin, all of them were supplied by Sigma-Aldrich (St. Louis, MO, USA). Phosphate buffers were prepared from the potassium hydrogenphosphate (K₂HPO₄) and dihydrogenphosphate (KH₂PO₄) salts in Milli-Q water (Millipore, Billerica, MA, USA). All the dissolutions were prepared using deionized water from the Milli-Q system (Millipore, Billerica, MA, USA) with a resistivity value of 18.2 MΩ·cm.

We measured the following chemicals without dilution in a custom-built Raman spectrometer (Chemistry Department of Goethe University Frankfurt) with a range of 0–4,400-cm⁻¹ wavelength: (1) 0.15 M sodium cacodylate buffer; (2) 1% potassium osmate(VI) in 0.15 M cacodylate buffer; (3) 0.3% potassium osmate(VI) and 1.3% potassium ferrocyanide(II) (Sigma-Aldrich) in 0.15 M cacodylate buffer; (4) 2.5% potassium ferrocyanide(II) in 0.15 M cacodylate buffer; (5) 1.9% potassium ferricyanide(III) (Sigma-Aldrich) in 0.15 M cacodylate buffer; (6) staining solution of 2-mm samples in 2-ml Eppendorf tubes, after 24 h of 2% OsO₄ (Serva) in 0.15 M cacodylate buffer, 1 h of 0.15 M cacodylate buffer wash and 17 h of 2.5% potassium ferrocyanide(II) in 0.15 M cacodylate buffer.

Mucin (from porcine stomach, Type III), 11-mercapto-1-undecanol, epichlorohydrin, diethylene glycol dimethyl ether, potassium chloride, potassium hexacyanoferrate (II) trihydrate, potassium ferricyanide (III), sodium phosphate, and d-mannose were purchased from Sigma-Aldrich (St. Louis, MO, USA). Absolute ethyl alcohol, sodium hydroxide, acetone, sulfuric acid, sodium acetate, acetic acid, and hydrogen peroxide were from DaeJung Chemicals & Metals Co., Ltd. (Gyeonggi-do, Korea). Carboxyfluorescein diacetate (CFDA) was obtained from Dojindo Molecular Technologies, Inc. (Rockville, MD, USA), and potassium phosphate from Pure Chemicals Co., Ltd. (Kyoto, Japan). Lysogeny broth (LB) broth and agar powder were purchased from BD (BD Difco, Lawrence, KS, USA).

Sodium chloride was purchased
from Fisher Scientific (Hampton, New Hampshire, USA) and sucrose from
Bio Basic (Markham ON, Canada). Sodium nitrite, sodium dithionite,
potassium ferricyanide(III), and potassium cyanide were purchased
from Sigma-Aldrich (St. Louis, Missouri, USA), whereas the isotopic
derivatives of the latter—KC¹³N, KC¹⁵N and K¹³C¹⁵N—were purchased from Cambridge
Isotope Laboratories (Tewksbury, Massachusetts, USA).
RBCs were
washed and stored in 0.9% Sodium chloride solution supplemented with
0.2% sucrose, and the pH was adjusted to 7.4 using 1 M hydrochloric
acid in order to keep the cells in functional conditions, as previously
published.^{21 (link)}The Ringer-Tris buffer
solution used to wash RBCs was prepared ex tempore, as described previously,^{22 (link),23 (link)} with the following
composition: 140.5 mM NaCl, 2 mM CaCl₂, 4.7 mM KCl, 1.2
mM MgSO₄, 21 mM Tris base, 5.5 mM glucose,
and 76 μM bovine albumin. All reagents were dissolved in distilled
water and filtered through a 0.22 μm pleated filter; the pH
was adjusted to 7.40 using 1 M hydrochloric acid. All the above-mentioned
chemicals were purchased from Sigma-Aldrich.

pKdTOR::GUS leaf margins and mature plantlets were incubated in GUS staining solution (100-mM sodium phosphate buffer, pH 7.2 [BDH Chemicals, UK], 10-mM EDTA, pH 8 [Promega, USA], 0.1% [v/v] Triton X-100 [Fisher Scientific, UK], 1-mM potassium ferricyanide (III) [Sigma-Aldrich, UK], 1-mM potassium ferrocyanide [Sigma-Aldrich, UK], 2-mM X-GlcA [Melford, UK]). Tissues were incubated in the dark for 24 h, and then cleared in 100% (v/v) ethanol.