Metabolism and Residues of 2,4-Dichlorophenoxyacetic Acid in DAS-40278-9 Maize (Zea mays) Transformed with Aryloxyalkanoate Dioxygenase-1 Gene.
DAS-40278-9 maize, which is developed by Dow AgroSciences, has been genetically modified to express the aryloxyalkanoate dioxygenase-1 (AAD-1) protein and is tolerant to phenoxy auxin herbicides, such as 2,4-dichlorophenoxyacetic acid (2,4-D). To understand the metabolic route and residue distribution of 2,4-D in DAS-40278-9 maize, a metabolism study was conducted with14C-radiolabeled 2,4-D applied at the maximum seasonal rate. Plants were grown in boxes outdoors. Forage and mature grain, cobs, and stover were collected for analysis. The metabolism study showed that 2,4-D was metabolized to 2,4-dichlorophenol (2,4-DCP), which was then rapidly conjugated with glucose. Field-scale residue studies with 2,4-D applied at the maximum seasonal rate were conducted at 25 sites in the U.S. and Canada to measure the residues of 2,4-D and free and conjugated 2,4-DCP in mature forage, grain, and stover. Residues of 2,4-D were not detectable in the majority of the grain samples and averaged <1.0 and <1.5 μg/g in forage and stover, respectively. Free plus conjugated 2,4-DCP was not observed in grain and averaged <1.0 μg/g in forage and stover.
Dow AgroSciences, LLC , 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
Xiao
X
Zhou
Dow AgroSciences, LLC , 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
Sandra L
SL
Rotondaro
Dow AgroSciences, LLC , 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
Mingming
M
Ma
Dow AgroSciences, LLC , 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
Steve W
SW
Rosser
Dow AgroSciences, LLC , 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
Ed L
EL
Olberding
Dow AgroSciences, LLC , 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
Brian M
BM
Wendelburg
Dow AgroSciences, LLC , 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
Yelena A
YA
Adelfinskaya
Dow AgroSciences, LLC , 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
Jesse L
JL
Balcer
Dow AgroSciences, LLC , 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
T Craig
TC
Blewett
Dow AgroSciences, LLC , 9330 Zionsville Road, Indianapolis, Indiana 46268, United States.
Bruce
B
Clements
D015084:2,4-Dichlorophenoxyacetic Acid / Q000378:metabolism / Q000493:pharmacokinetics*; D002170:Canada; D002733:Chlorophenols / Q000378:metabolism / Q000493:pharmacokinetics; D049308:Dioxygenases / Q000235:genetics*; D006540:Herbicides / Q000378:metabolism / Q000493:pharmacokinetics*; D057230:Limit of Detection; D010573:Pesticide Residues / Q000378:metabolism / Q000493:pharmacokinetics; D030821:Plants, Genetically Modified / Q000378:metabolism; D012621:Seasons; D014481:United States; D003313:Zea mays / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism
D002733:Chlorophenols; D006540:Herbicides; D010573:Pesticide Residues; D015084:2,4-Dichlorophenoxyacetic Acid; D049308:Dioxygenases; C004762:2,4-dichlorophenol
2,4-D; AAD-1; DAS-40278-9; Zea mays; corn; metabolism; residues; transgenic