Silwet l 77

The plasmid pCambia1305-3flag-NOS was transformed into Agrobacterium tumefaciens strain GV3101 (Van Larebeke et al., 1974) (link) by mixing the plasmid DNA with the bacterial cells in a 1mm gap cuvette (BTX, #45-0124) followed by electroporation for 5 millisecond at 1,500 volts using the ECM 399 Electroporation System (BTX, #45-0000) (Gao et al., 2009) (link). The resulting strain was used in the plant transformation experiments. Bacteria were grown overnight in sterilized 4 ml LB media (Bio Basic Inc., #SD7002) with kanamycin, gentamicin and rifampicin antibiotics (50 μg/ml each, Bio Basic Inc. #KB0286, #GB0217, #RB0808) in a 28°C shaker (New Brunswick Scientific Co G25 Controlled Environment Incubator Shaker). Then the overnight culture was diluted into 100 ml LB media with kanamycin (50 μg/ml) and allowed to grow further for 8 h (OD 600 =1.5~1.8) in the same shaker. The bacteria were collected by centrifugation (Thermo Scientific, Sorvall Legend X1R) at 6000 g for 10 min at room temperature and then resuspended in 100 ml floral dip medium to final OD 600 of 1, 0.1, 0.01, and 0.002 (measured by BioSpec-1601 UVvisible spectrophotometer from SHIMADZU) prior to use. The floral dip medium contained 5.0% (w/v) sucrose (Bio Basic Inc. #SB0498) and 0.01% (v/v) Silwet L-77 (PhytoTechnology Laboratories #S7777) in distilled water.