page_title: Plant physiology
section_title: Signals and regulators
hierarchical_section_title: Plant physiology / Signals and regulators
caption_attribution_description: Wild type Arabidopsis thaliana (left), auxin signal-transduction mutant (axr2, right)
context_page_description: Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology, plant ecology, phytochemistry, cell biology, genetics, biophysics and molecular biology.
  Fundamental processes such as photosynthesis, respiration, plant nutrition, plant hormone functions, tropisms, nastic movements, photoperiodism, photomorphogenesis, circadian rhythms, environmental stress physiology, seed germination, dormancy and stomata function and transpiration, both parts of plant water relations, are studied by plant physiologists.
context_section_description: Plants produce hormones and other growth regulators which act to signal a physiological response in their tissues.  They also produce compounds such as phytochrome that are sensitive to light and which serve to trigger growth or development in response to environmental signals.
caption: A mutation that stops Arabidopsis thaliana responding to auxin causes abnormal growth (right)
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