Give information about the plant endocrine system, incl. mechanisms of action, types of cellular responses, and major hormone categories.
- Hormones (chemical messengers) function to coordinate growth & development and mediate response to external cues (affect division, elongation, gene expression, and differentiation of cells)
- Hormones are produced in a variety of locations, and are active even in small amounts (not used in their mechanisms, so they can continue to affect another cell)
- Hormones work by signal transduction pathways: ligand (substance that binds to a receptor), target tissue (tissue equipped with receptors specific to a particular ligand)
- Hormone sequence of action: reception, signal transduction, cellular response
- Examples of cellular responses: Altering gene expression (protein synthesis regulation), activating or deactivating enzymes (protein kinase enzymes), changing the properties of membranes (permeability to ions)
- Cellular response may differ based on hormone concentration, developmental state of tissue, interplay of two or more hormones, tissue type
- Major hormone categories: Auxins, Cytokinins, Gibberellins, Ethylene, Abscisic Acid