AI overview
Plant hormones are chemical compounds that plants produce to control their growth, development, and responses to their environment. They matter because they regulate important processes like how plants grow toward light, develop roots and shoots, and respond to stress or seasonal changes.
AI-generated from the Wikipedia summary — may contain errors.
Article
Lack of the plant hormone auxin can cause abnormal growth (right)
Plant hormones (or phytohormones) are signal molecules, produced within plants, that occur in extremely low concentrations. Plant hormones control all aspects of plant growth and development, including embryogenesis, the regulation of organ size, pathogen defense, stress tolerance and reproductive development. Unlike in animals (in which hormone production is restricted to specialized glands) each plant cell is capable of producing hormones. Went and Thimann coined the term "phytohormone" and used it in the title of their 1937 book.