Y. Gafni et al., STIMULATION OF AGROBACTERIUM-TUMEFACIENS VIRULENCE WITH INDOLE-3-ACETIC-ACID, Letters in applied microbiology, 20(2), 1995, pp. 98-101
The phytopathogen Agrobacterium tumefaciens incites the production of
crown-gall on a wide range of dicotyledonous plants. Gall formation is
dependent upon indole-3-acetic acid (IAA) and cytokinin production by
the transformed plant cells. Upon incubation of Agrobacterium tumefac
iens C58 with the plant hormone indole-3-acetic acid (IAA), bacterial
virulence on cucumber plants was stimulated up to tenfold. Stimulation
was maximized after exposure of bacteria to 50 or 100 mu g ml(-1) IAA
for 3 h. This was shown to be at the early log phase of bacterial gro
wth. The authors suggest that the excretion of IAA by the transformed
plant cells stimulates bacterial virulence mechanism(s) encoded by the
Ti plasmid, the chromosome, or both.