Enhanced detoxification and degradation of herbicide atrazine by a group of O-methyltransferases in rice.
Atrazine (ATR) as a toxic herbicide has become one of the seriously environmental contaminants worldwide due to its long-term intensive use in crop production. This study identified novel methyltransferases (MTs) involved in detoxification and degradation of ATR residues in rice plants. From a subset of MTs differentially expressed in ATR-exposed rice, forty-four O-methyltransferase genes were investigated. Total activities were significantly enhanced by ATR in rice tissues. To prove detoxifying capacity of the MTs in rice plants, two rice O-MTs (LOC_Os04g09604 and LOC_Os11g15040) were selected and transformed into yeast cells (Pichia pastoris X-33). The positive transformants accumulated less ATR and showed less toxicity. Using UPLC-TOF-MS/MS, ATR-degraded products in rice and yeast cells were characterized. A novel O-methylated-modified metabolite (atraton) and six other ATR-derivatives were detected. The topological interaction between LOC_Os04g09604 enzyme and its substrate was specially analyzed by homology modeling programs, which was well confirmed by the molecular docking analysis. The significance of the study is to provide a better understanding of mechanisms for the specific detoxification and degradation of ATR residues in rice growing in environmentally relevant ATR-contaminated soils and may hold a potential engineering perspective for generating ATR-resistant rice that helps to minimize ATR residues in crops.
Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing, 210095, China; College of Food Science and Light Industry, Nanjing Tech University, Nanjing, 211800, China.
Yi Chen
YC
Lu
Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
Fang
F
Luo
School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116024, China.
Zhong Ji
ZJ
Pu
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.
Shuang
S
Zhang
Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
Meng Tian
MT
Huang
Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing, 210095, China; State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China. Electronic address: hongyang@njau.edu.cn.
Hong
H
Yang
D001280:Atrazine / Q000378:metabolism*; D006540:Herbicides / Q000378:metabolism*; D008658:Inactivation, Metabolic; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D062105:Molecular Docking Simulation; D012275:Oryza / Q000201:enzymology* / Q000235:genetics; D010843:Pichia / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism*; D053719:Tandem Mass Spectrometry
D006540:Herbicides; D010940:Plant Proteins; D012989:Soil Pollutants; D008780:Methyltransferases; D001280:Atrazine
Atrazine; Methyltransferase; Rice (Oryza sativa); UPLC-LTQ-MS(2)