Plant responses to their environment are underpinned by myriad molecular events. This course examines the molecular and cellular biology of plant responses to environmental cues, with an emphasis on signalling and regulation of gene expression mediating physiological responses. Topics such as plant cell walls, phytohormone action, photoreceptors, and programmed cell death will be covered. Lectures are the same as for BOT 445, but with additional assignments and evaluation appropriate to graduate studies. Prerequisite: Consent of the instructor. Credit cannot be obtained for both BOT 445 and 545. Offered in alternate years.