How did the introduction of artificial light changed the life cycle of a plant?
According to this study, artificial lighting similar to that provided by streetlights in the UK can reduce flowering in at least one plant, which also affects the aphids that feed on it.

This article discusses it in more general terms - night lighting doesn't affect photosynthesis, but can affect the length of day/night perceived by plants and alter growth accordingly. There are two examples given of how it is harmful:


Young trees grow longer and don't enter dormancy, making them increasingly susceptible to cold temperatures.
The stomatal pores of leaves remain open longer, making some trees more susceptible to pollution and water stress.