Agronomy and Horticulture Department
Cellular Absorption of Herbicides
Date of this Version
2010
Document Type
Article
Citation
Plant and Soil Sciences eLibrary (PASSeL) Lesson
Abstract
Before a herbicide can kill a plant, it must be absorbed by the plant’s leaves or roots and enter a cell which possesses the metabolic pathway the herbicide targets. This lesson follows the fate of the herbicide after it has entered the plant via leaf or root tissue and explains the factors controlling transport of a herbicide into plant cells. This lesson describes (1) the barriers to herbicide entry, such as the plant cell membrane, (2) the role that the herbicide’s chemical properties have on the rate of cellular absorption, and (3) experimental approaches to understanding herbicide absorption at the cellular level.
Overview
Herbicides are effective because they each target a specific metabolic pathway in plants. In order for an herbicide to kill a plant, it must first be absorbed by the plant’s leaves or roots. Once the herbicide is absorbed, it will enter a cell which possesses the metabolic pathway the herbicide was designed to target. This lesson follows the fate of the herbicide after it has entered the plant via leaf or root tissue and explains the factors controlling transport of a herbicide into plant cells. This lesson describes (1) the barriers to herbicide entry, such as the plant cell membrane, (2) the role that the herbicide’s chemical properties have on the rate of cellular absorption, and (3) experimental approaches to understanding herbicide absorption at the cellular level.
Objectives
At the completion of this lesson, students will be able to:
- Define lipophilicity and hydrophilicity;
- Compare and contrast passive and active transport across membranes;
- Identify the factors controlling herbicide transport across membranes;
- Explain ion trapping of weak acids; and
- Identify experimental approaches to characterizing modes of herbicide transport across membranes.
Modules:
- Lesson home
- Overview and Objectives
- Introduction
- Membrane Review
- Passive Absorption — Some General Concepts
- Passive Absorption — Looking at Effects of Charge
- Passive Absorption — Ion Trapping and Accumulation
- Benefits of Accumulation via Ion Trapping
- Passive Absorption — Additional Accumulation Mechanisms
- Passive Absorption Summary
- Active Absorption — General Concepts
- Active Absorption — Three Herbicide Examples
- Active Absorption Summary
- Lesson Summary
- Glossary
- Videos
Comments
Copyright © 2010 Tracy M. Sterling and Deana Namuth-Covert. Used by permission.
This project was supported in part by the National Research Initiative Competitive Grants CAP project 2011-68002-30029 from the USDA National Institute of Food and Agriculture, administered by the University of California-Davis and by the National Science Foundation (NSF), Division of Undergraduate Education, National SMETE Digital Library Program, Award #0938034, administered by the University of Nebraska. Any opinions, findings, conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the USDA or NSF.
Development of this lesson was supported in part by the Cooperative State Research, Education, & Extension Service, U.S. Dept of Agriculture under Agreement Number PX2003-06237 administered by Cornell University, Virginia Tech and the American Distance Education Consortium (ADEC), and in part by the New Mexico and Nebraska Agricultural Experiment Stations. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the view of the U.S. Department of Agriculture.