Answer:
The _VirA_ protein is embedded in the membrane of Agrobacterium and senses the presence of acetosyringone from the wounded plant cell.
Explanation:
VirA is a protein histidine kinase which detects certain phenolic compounds and sugars. Wounded plants areas are typically contains these compounds. This site is a potential infection site for Agrobacterium tumefaciens as a result VirA is used by Agrobacterium tumefaciens to locate it and cause damage.