BI111 Lecture Notes - Pericycle, Apical Dominance, Terpene
Document Summary
Plant growth and development: to understand diversity of plant structures and life histories, need to understand role that signal response pathways play in their growth and development. Hormones and environmental stimuli alter behavior of target cells. Signal molecules bind to receptors in target cells. Elicit cellular response (different response in different tissues) By means of a response pathway, signal can: Induce changes in cell"s shape or internal structure. Alter gene activation and rate of protein synthesis. Set in motion events that modify existing cell proteins. Some hormones and growth factors bind to receptors at target cell"s plasma membrane, on er, or in cytoplasm. Binding triggers release of internal second messengers that diffuse through cytoplasm and provide main chemical signal that alters cell functioning. Gibberellins stimulate growth, including the elongation of stems. Ethylene regulates a range of responses, including senescence. Abscisic acid suppresses growth and influences responses to environmental stress. Jasmonates and oligosaccharins regulate growth and have roles in plant defense.