Metabolism of Herbicides or Xenobiotics in Plants Glossary

A thin, mechanically strong structure surrounding all plant cells consisting of a complex mixture of polysaccharides and other polymers that are secreted by the cell and are assembled into an organized network linked together by a mixture of covalent and noncovalent bonds. Cell walls regulate cell volume and determine cell shape.

The organelle in plant cells that contains chlorophyll and is the site of photosynthesis.

To join together, as in a xenobiotic molecule binding with a sugar or glutathione molecule.

Also known as cytochrome P-450 monooxygenases or CytP450s; multifunctional enzymes widely distributed among living organisms. They function as monooxygenases by binding and activating molecular oxygen, incorporating one of its atoms into an organic substrate, and reducing the second atom to form water.

Altered so the compound is less toxic.

A pesticide used to kill plants.

The reaction of a substance with water.

The reaction of a substance with water.

Alteration in the herbicide chemical structure usually detoxifies the herbicide. Metabolism is the most important mechanism of herbicide selectivity among weed and crop plants.

Alteration in the herbicide chemical structure usually detoxifies the herbicide. Metabolism is the most important mechanism of herbicide selectivity among weed and crop plants.

Seeks positive charge; may be negatively charged or neutral.

The part of a redox reaction in which there is a loss of electrons.

The conversion of light energy into chemical energy by plants using low-energy inorganic compounds (carbon dioxide) to produce high-energy organic compounds (sugars)

A substance which is toxic to plants.

The part of a redox reaction in which there is a gain of electrons.

Relative humidity.

Herbicides which cause one species of plants to die, but another species will survive the same treatment. Selectivity allows for acceptable weed control without injury to crop plants.

Differential effect of a herbicide when applied to a mixed population of plants; sensitive plants die, tolerant plants are unharmed. Implies that different plant species do not respond in the same way to a particular herbicide. Herbicides which cause one species of plants to die, but not another, are selective. Selectivity allows for acceptable weed control without injury to crop plants.

The inability to survive a herbicide at its use rate.

The vacuolar membrane in plant cells.

The transport of herbicide short or long distances. Herbicides movement from site of application to site of action might involve cell to cell transport or long distance transport in the xylem or phloem.

A membrane-bound (tonoplast) space larger than a vesicle which stores material, either dissolved in water or as a crystalline or flocculent mass. Vacuoles are key organelles for storage of compounds and osmoregulation in plants.

Foreign chemicals; natural or synthetic substances that cannot be utilized by plants for energy-yielding processes.