A possible mechanism of how stress controller bacteria
reduce ethylene levels in the plant root using bacterial ACC
deaminase. ACC synthesized in plant tissues by ACC synthase is
thought be exuded from plant roots and be taken up by
neighboring bacteria. Subsequently, the bacteria hydrolyze ACC
to ammonia and 2-oxobutanoate. This ACC hydrolysis maintains
ACC concentrations low in bacteria and permits continuous ACC
transfer from plant roots to bacteria. Otherwise, ethylene can be
produced from ACC and then cause stress responses including
growth inhibition. S-AdoMet: S-adenosyl-L-methionine; ACC: 1-
aminocyclopropane-1-carboxylate (Adapted from Kang et al.
(2010)).