Photodegradation product of sulcotrione and the physiological response of maize ( Zea mays) and white mustard ( Sinapis alba)

• Published in: Chemosphere (Oxford) 2009-03, Vol.74 (9), p.1224-1230
• Main Authors: Wiszniowski, Jaroslaw, Halle, Alexandra Ter, Richard, Claire, Hitmi, Adnane, Ledoigt, Gérard
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biodegradation, Environmental; Biodiversity and Ecology; Biological and medical sciences; Chlorophyll - metabolism; Chromone; Chromones - metabolism; Chromones - toxicity; corn; Cyclohexanones - metabolism; Cyclohexanones - toxicity; Dose-Response Relationship, Drug; Ecotoxicology; Ecotoxicology, biological effects of pollution; Environmental Sciences; Fluorescence; Fundamental and applied biological sciences. Psychology; General aspects; Global Changes; herbicidal properties; Herbicide; Herbicides - metabolism; Herbicides - toxicity; Mesylates - metabolism; Mesylates - toxicity; nontarget organisms; Photochemistry; photolysis; photoproducts; photosynthesis; phytotoxicity; Plant stress; Sinapis - drug effects; Sinapis alba; Statistics, Nonparametric; sulcotrione; Sulcotrione photodegradation; Zea mays; Zea mays - drug effects
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2008.11.017

One of the strategies for decreasing the consumption of herbicides consists in improving their uptake and efficiency. It was suggested that the photodegradation of herbicides due to sunlight results in a greater demand of herbicides to be introduced into the environment in order to ensure the plant protection activity. Moreover, an ecotoxicological effect of the photoproducts needs to be clarified. The physiological response of Zea mays and Sinapis alba (weed) to sulcotrione and its main photoproduct, called chromone (xanthene-1,9-dione-3,4-dihydro-6-methylsulfonyl), was evaluated under controlled conditions in a growth chamber. The dose-response effects were determined on Z. mays and S. alba. Using the sulcotrione (doses ranging from 1 to 9 mg per plant), the physiological parameters indicated a decrease of photosynthesis for the S. alba species while the Z. mays species were only slightly affected. On the contrary, the chromone had no herbicide activity on both species. The sulcotrione is known to block 4-hydroxyphenyl pyruvate dioxygenase (HPPD) enzyme. The differences between the parent herbicide and the photoproduct could be ascribed to drastic structural modifications. We have shown that the chromone probably do not block the HPPD active site.