The GABA transaminase GabT is required for full virulence of in tomato.

The utilization of plant gamma-aminobutyric acid (GABA) is essential for the pathogenicity of the bacterial plant pathogen . A knockout mutant in the GABA transaminase-encoding gene is unable to utilize GABA as a nutrient and its ability to cause disease in plants is strongly compromised. However, the proximity of the gene (encoding a succinate semialdehyde dehydrogenase) in the same operon raises the question of whether an impact on the gene underlies or contributes to the virulence attenuation of the mutant. In this work, we use genetic complementation to show that the expression of the gene is able to rescue the impaired virulence of the knockout mutant in tomato plants, confirming that the -encoded GABA transaminase is indeed required for full virulence of in a natural host plant.