Increase in nutritionally important sweet corn kernel carotenoids following Mesotrione and atrazine applications.
The herbicide mesotrione inhibits a critical enzyme, phytoene desaturase, in plant carotenoid biosynthesis. Mesotrione is currently labeled for selective weed control in sweet corn ( Zea mays var. rugosa). Mesotrione applied alone, or in mixtures with the photosystem II inhibitor atrazine, acted to increase concentrations of kernel antheraxanthin, lutein, and zeaxanthin carotenoids in several sweet corn genotypes. Kernel lutein and zeaxanthin levels significantly increased 15.6% after mesotrione + atrazine early postemergence applications, as compared to the control treatment. It appears that mesotrione applications resulted in greater pools of kernel carotenoids once the sweet corn genotypes expressing moderate injury overcame the initial herbicidal photo-oxidative stress. This is the first report of herbicides directly up-regulating the carotenoid biosynthetic pathway in corn kernels, which is associated with the nutritional quality of sweet corn. Enhanced accumulation of lutein and zeaxanthin is important because dietary carotenoids function in suppressing aging eye diseases such as macular degeneration, now affecting 1.75 million older Americans.
Kopsell
Dean A
DA
Plant Sciences Department, The University of Tennessee, Knoxville, Tennessee 37996, USA. dkopsell@utk.edu
Armel
Gregory R
GR
Mueller
Thomas C
TC
Sams
Carl E
CE
Deyton
Dennis E
DE
McElroy
J Scott
JS
Kopsell
David E
DE
D001280:Atrazine / Q000008:administration & dosage*; D002338:Carotenoids / Q000032:analysis* / Q000096:biosynthesis; D003512:Cyclohexanones / Q000008:administration & dosage* / Q000032:analysis; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000008:administration & dosage; D005838:Genotype; D006540:Herbicides / Q000008:administration & dosage*; D010088:Oxidoreductases / Q000037:antagonists & inhibitors; D012639:Seeds / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development
D003512:Cyclohexanones; D004791:Enzyme Inhibitors; D006540:Herbicides; D002338:Carotenoids; C432907:mesotrione; D010088:Oxidoreductases; C022398:phytoene dehydrogenase; D001280:Atrazine