{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}


GENERAL BOTANY Lecture 26 - GENERAL BOTANY Lecture 26 Plant...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
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. Growth inhibitors (ABA) - leaf abscision & fruit drop 5. Ethylene (ethylene) - senescence & ripening 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 elongation and curvature 3.
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Ask a homework question - tutors are online