Plant Form and Physiology
Plant Sensory Systems and Responses
Plant Responses to Light
Plants respond to light stimuli by growing, differentiating, tracking the time of day and seasons, and moving toward or away from the light.
The Phytochrome System and Red Light Response
Plants use a phytochrome system to sense the level, intensity, duration, and color of environmental light to adjust their physiology.
Blue Light Response
The protein-based receptors, phototropins and cryptochromes, sense blue light to alter plant physiology accordingly.
Plant Responses to Gravity
Plant shoots grow away from gravity, toward sunlight, while plant roots grow into the soil in the direction of gravity.
Auxins, Cytokinins, and Gibberellins
All physiological aspects of plants are affected by plant hormones (chemical messengers), including auxins, cytokinins, and gibberellins.
Abscisic Acid, Ethylene, and Nontraditional Hormones
All physiological aspects of plants are affected by plant hormones, including abscisic acid, ethylene, and nontraditional hormones.
Plant Responses to Wind and Touch
Plants respond to wind and touch by changing their direction of growth, movement, and shape.