Materials and Reagents

1. Arabidopsis thaliana seeds of reporter lines IU.GUS-8 and DGU.US-1 (Figure 1) (Orel et al., 2003) [introgressed into various genetic backgrounds and genotyped for homozygosity of reporters and mutations (Rosa et al., 2013). As an example, we use wild type Columbia-0, and mutants arp6-3 and swc6-1. Both mutants lack subunits of the Arabidopsis homolog of the SWR1 complex and, additional to being sensitive to DNA damaging agents (Rosa et al., 2013), have pleiotropic developmental defects (for more information see Schuermann et al., 2005)]
   
2. Sodium hypochlorite (Sigma-Aldrich, catalog number: 425044 )
   
3. Tween-80 (Sigma-Aldrich, catalog number: 4780 )
   
4. Sterile H₂O
   
5. Solid growth medium
   
6. Liquid plant growth medium (same as solid growth medium but without agar)
   
7. Hydroxyurea
   
8. 70% ethanol
   
9. Seed sterilization solution (see Recipes)
   
10. Bleocin (commercial name for bleomycin) (EMD Millipore, catalog number: 203408 ) (see Recipes)
    
11. Mitomycin C (Duchefa Biochemie BV, catalog number: M0133 ) (see Recipes)
    
12. GUS staining solution (see Recipes)
    
13. 1 M Sodium Phosphate Buffer (see Recipes)
    

Equipment

1. Plastic petri dishes for plant culture (see Notes) (round 200 x 15 mm, with 20 ml of solid growth medium)
   
2. Sterile hood, preferably a biological safety cabinet to avoid exposure to the genotoxins
   
3. Bench top block shaker (e.g. Eppendorf, Thermomixer^®)
   
4. UV crosslinker (254-nm UV light bulbs, 15 watts each) (Stratagene, model: Stratalinker 2400 )
   
5. Forceps
   
6. Box or aluminum foil
   
7. Parafilm
   
8. 1.5 ml Eppendorf tubes
   
9. 50 and 15 ml Falcon tubes
   
10. Vacuum applicator (e.g. desiccator)
    
11. Plant growth facilities with 16-h-light/8-h-dark cycles, at 21 °C
    
12. Incubator at 37 °C
    
13. Stereomicroscope
    

Procedure