In terms of reactions to finding the new world generally, I honestly haven't seen any. I'm not certain there weren't any, but if there were they're not any I have seen. Individual Jews may have, but there's no body of Jewish awareness of it that I've seen.

However, I can answer the part about new plants and animals. First, plants. Generally speaking, all plants are kosher. So there wasn't much of an issue with tobacco^1 which was something you mentioned. However, not all plants are kosher for passover. While there are 5 prohibited grains (I'm massively simplifying^2 ), many Jews abtain from a group of other foods, called Kitniyot, which are not the prohibited grains but are grain-like--things like legumes and rice. The status of a few American crops, such as quinoa and coffee, have been discussed about whether or not they fall into this categorization. Because there's no real methodology (it's an ad hoc list made by tradition), it can be dodgy, though coffee is relatively uncontroversial because it's not a bean at all. Corn is held to be prohibited if you don't eat kitniyot, because it's made into flour (I think). This particular bit of kashrut laws is somewhat famously vague and hard to determine consistent rules besides "do what tradition says".

For animals, there are consistent rules for determining if they're kosher. Land animals that have cloven hooves and chew their cud are kosher, otherwise they're not. I'm not aware of any animals from the Americas which were borderline on this^3 . Buffalo are new-world, and are kosher. For fish, they must have fins and scales, excluding shellfish, eels, catfish, etc^4 . Defining what this means can be difficult--some fish, such as swordfish, change as they grow, and may meet the criteria at some times and not at others. Whether that permits or forbids them for the entirety of their lifespan is also a point of modern debate.

Birds are the most interesting. There are no biblically-given guidelines, just lists of birds. The issue is that with thousands of years passing, which birds are which is unclear in many cases. The only observable pattern is that birds of prey are forbidden. The status of birds is dependent on tradition--birds for which there's a tradition of eating them as kosher are kosher. A borderline case is the turkey. When it was first brought to Europe, it was sometimes thought to be a sort of chicken. By the time it was known to be its own animal, it was permitted because there was a tradition of it being kosher by then. This article discusses the specifics.

So the big picture is that there are usually relatively consistent rules were applied in most cases. For borderline things, such as turkey, a community consensus developed and was maintained on an ad hoc basis.

1. However, whether or not smoking is permissible is an actual debate in Jewish law. But it applies to smoking pretty much anything, and has little to do directly with the fact that it's tobacco.

• To elaborate, the 5 grains are mixed with water and cooked within 18 minutes to prevent leavening to make matzah. Other foods with them are not allowed, except for the borderline case of egg matzah (flour from a grain mixed with stuff other than water, still cooked within 18 minutes), which is its own subject
• And more generally controversy around this set of rules is rather minimal, though the definitions of these things per Jewish law can be somewhat different from either colloquial or modern scientific ones
• Though again here, fins and scales have specific definitions, which is why sharks aren't kosher.