When I was growing up on a farm, we grew tomatoes in our garden and deadly nightshade was a fairly common weed in a nearby field. I was concerned at the time that bees might cross the two and produce tomatoes whose hybrid seeds might be toxic. None of us died from eating our tomatoes, but I certainly wouldn't deliberately cross the two.

Ironically, there was a time over a hundred years ago when tomatoes themselves were thought to be poisonous. If memory serves, tomatoes were referred to as "love apples."

MM

"... I think it would only affect the plant of the tomato, not the tomatoes themselves."

I wouldn't be so sure of that. The black berries of the Deadly Nightshade are themselves poisonous, so the F1 hybrids would very possibly have poisonous berry-tomatoes. After all, a tomato is botanically a berry. Incidentally, that's the answer to the old question of whether a tomato is a fruit or a vegetable. It's neither. It's a berry.

MM

So tomatoes are a fruit.

TBH the definition of a vegetable is hazy, and certainly not scientific, any edible part of a plant can be considered a vegetable, so logically a tomato is a fruit, vegetable and a berry.

Under US tax law a tomato is a vegetable.