Tobacco root exudates contains which chemical substances during induction of chemtotaxis against A. tumefaciens?

Tobacco root exudates contain Acetosyringone chemical substances during induction of chemotaxis against A. tumefaciens.
Agrobacterium tumefaciens is a soil phytopathogen that naturally infects plant wound sites and causes crown gall disease via delivery of transferred (T)-DNA from bacterial cells into host plant cells through a bacterial type IV secretion system.
Acetosyringone is known to improve transformation efficiency by up-regulating the virulence of Agrobacterium. In previous studies using Eustoma, the effect of this compound has only been tested during inoculation.