This course explores how plants function. Topics include water transport and the soil-plant-atmosphere continuum, photosynthesis and carbon resource utilization, nitrogen nutrition and symbioses, photosensing, and responses to environmental stresses such as attack by pests and pathogens. Lectures, assignments and exams are the same as BOT 340 with additional assignments and evaluation appropriate to graduate studies. Normally, BOT 540 students will also participate in the BOT 340 laboratory component. Prerequisite: consent of the instructor. Credit cannot be obtained for both BOT 340 and 540.