Fig. 6.

Involvement of GABA-regulated genes in virulence. (A) Aggressiveness of A. tumefaciens C58 and its derivatives attM, atu1049, atu3178, and atu3181 derivatives on tobacco plants. (B) aggressiveness of A. tumefaciens C58 and attM mutant on wild-type and GS1 line of tobacco plants supplied with NH₄. Categories of symptom severity are the same as in Fig. 5. Bacterial genotypes showing statistical differences (Kruskal-wallis test; P < 0.01) in their aggressiveness categories are noted by different letters (a–c, A–C). In A and B, asterisks indicate a statistical difference in the severity of symptoms caused by A. tumefaciens C58 on wild-type tobacco plants supplied with water or NH₄ solution; diamonds indicate no statistical difference when symptoms were caused by the attM mutant on wild-type and GS1 tobacco plants supplied with water or NH₄ solution. All data were collected from two independent replicates. (C) level of GABA and Pro in wild type and GS1 line of tobacco plants under NH₄ supply.