Hi,

there is no generic response to this question, as this will depend on the specific promoter and also the used fragment. E.g. the Ubiquitin1 promoter from maize was reported to function in tobacco (I am quite sure), although I don't remember the precise reference. But others might not, or they might lose their specific properties, as expression domain, strength, whatsoever. So if the promoter you are thinking of (you do not specify) was not previously tested, you simply can't know.

Anyways, is there any reason that prevents you from using a previously characterized promoter fragment, besides the effort of making the construct? Since it takes several months to make and characterize the transgenic tobacco, I would rather go for such a chimeric construct.

Bests,

Johannes