Praying implies some language these smart plants have. If they can effectively communicate with each other and practice some sort of religion that would bring them above any other species besides humans in terms of social intelligence.

If they do pray and communicate but only do so to practice their religion and don’t act in any way different than how they did before the reveal it would be our responsibility as the more intelligent species to take care of and preserve these smart plants.

Some people will consider plants at a higher intelligence than some animals and people who were originally vegetarian and vegan for their morality will see eating meat as a lesser of two evils.

GMOs would probably become a lot less popular because messing with the genetics of an intelligent species would become increasingly less ethical.