GENERAL BOTANY Lecture 26 - Plant Growth Regulation I. Terminology and classification A. Plant growth regulator - broad category of organic substances that, in minute amounts, promote, inhibit, or otherwise modify physiological processes. B. Other terms - plant hormones, phytohormones, plant growth substances, and plant growth regulators 1. PGRs - usually a broad term encompassing plant hormones C. Classes of PGRs (more specifically, plant hormones) 1. Auxins (IAA, NAA) - cell enlargement (with cell-wall modification) 2. Gibberellins (GA) - cell enlargement (less cell-wall modification) 3. Cytokinins (Kinetin, BA) - cell division 4. 5. II. Actions of the five plant hormones A. Auxins (found in meristematic tissue) 1. Mechanism: IAA - cell-wall softening - extension - membrane RNA synthesis - cell-wall enzymes - new wall material - elongation 2. Auxin moves to the cells on the lower side of a horizontal organ, stimulating cell
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This note was uploaded on 01/30/2012 for the course BSC BSC1085 taught by Professor Sharonsimpson during the Fall '10 term at Broward College.