FIG 5.

A. tumefaciens GV3103 ΔmltB3 can be used to transform plants efficiently, and bacteria can be removed using low concentrations of ampicillin. (A) An ampicillin susceptibility assay was performed by spotting dilutions. Briefly, exponentially grown cultures were serially diluted, spotted on solid medium containing no ampicillin (No AMP), ampicillin at 25 μg/mL (AMP 25), or carbenicillin at 15 μg/mL (CARB 15), and incubated at 28°C for ~40 h before imaging. (B) Determination of β-lactamase production was performed by a nitrocefin assay using cell lysates. Data shown represent one of two biological replicates. No AMP or AMP 25 indicates cells untreated or treated with ampicillin at 25 μg/mL, respectively, for 2 h before the generation of cell lysates. (C and D) Transformation efficiency (C) and bacterial loads (D) of seeds transformed with WT A. tumefaciens GV3101 and GV3101 ΔmltB3 using the floral dip assay technique (83).