Here we describe conditions under which two reporter genes, encoding β-glucuronidase (gusA) and β-galactosidase (lacZ), can be used to simultaneously distinguish between the sites of expression of... Show moreHere we describe conditions under which two reporter genes, encoding β-glucuronidase (gusA) and β-galactosidase (lacZ), can be used to simultaneously distinguish between the sites of expression of plant and bacterial genes, respectively, in symbiotic tissues. These conditions involve the fixation of cytoplasmic proteins with cold methanol before detecting gusA expression, and the addition of detergents to the incubation solution in order to inactivate endogenous plant β-galactosidases. Show less
