Materials and Reagents

1. 4-weak old A. thaliana leaves and roots
   
2. Ultrapure water (MilliQ) (EMD Millipore)
   
3. Ice
   
4. Liquid N₂
   
5. 4 mm diameter glass beads (Glaswarenfabrik Karl Hecht) (VWR International, catalog number: 201-0278 )
   
6. EVA Capband for capping 8 tubes (Micronic, catalog number: MP227B1 )
   
7. Flat bottom spectrophotometer microplates (Deltalab, catalog number: 900011.1 )
   
8. 1.2 ml 96-well storage plate (Thermo Fisher Scientific, catalog number: AB-0564 )
   
9. Sodium phenolate or sodium phenoxide trihydrate (Sigma-Aldrich, catalog number: 318191 )
   
10. Sodium nitroprusside dihydrate (Sigma-Aldrich, catalog number: s0501 )
    
11. Commercial bleach or Sodium Hypochlorite solution 10% (Panreac Applichem, catalog number: 211921 )
    
12. Solution A (see Recipes)
    
13. Solution B (see Recipes)
    
14. Solution C (see Recipes)
    
15. 10 mM NH₄⁺ stock (for standard curve) (see Recipes)
    

Equipment

1. TissueLyser (Retsch, model: MM400 )
   
2. TissueLyser Adapter Set 2 x 96 (QIAGEN, catalog number: 69984 )
   
3. Plate centrifuge (Sigma, model: 2-16K )
   
4. Drying oven
   
5. Absorbance microplate reader (Biotek PowerWave X 340 Microplate Spectrophometer)
   

Procedure