Chlormequat is an organic compound with the formula that is used as a plant growth regulator. It is typically sold as the chloride salt, chlormequat chloride (C₅H₁₃Cl₂N), a colorless hygroscopic crystalline substance that is soluble in water and ethanol.Wilhelm Rademacher, Lutz Brahm "Plant Growth Regulators" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim, 2010. It is an alkylating agent and a quaternary ammonium salt. Chlormequat is one of the onium-type growth regulators. Chlormequat has been called the "most important inhibitor of gibberellin

biosynthesis Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. ...

." As such, it inhibits cell elongation, resulting in thicker stalks, which are sturdier, facilitating harvesting of

cereal A cereal is any Poaceae, grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, Cereal germ, germ, and bran. Cereal Grain, grain crops are grown in greater quantit ...

crops. It can also be used as an adjuvant for

herbicide Herbicides (, ), also commonly known as weedkillers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page fo ...

s by retarding their oxidative disposal by plants. This is due to

cytochrome P450 Cytochromes P450 (CYPs) are a Protein superfamily, superfamily of enzymes containing heme as a cofactor (biochemistry), cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are ...

-inhibition.

Regulation and toxicity

In the United States, chlormequat is classified as a low risk plant growth regulator and it is registered for use on ornamental plants grown in greenhouses, nurseries, and shadehouses.Chlormequat Chloride Reregistration Eligibility Decision for Low Risk Pesticide
/ref> It is not approved for use on crops intended for animal or human consumption. The (rat, oral) is low, approximately 670 mg/kg. Exposure to high levels of chlormequat has been linked to developmental toxicity in animal models. It also affects reproduction in mammals. It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.

References

External links

*{{Commons category-inline Quaternary ammonium compounds Organochlorides Plant growth regulators Cations