Influention of p-Hydroxyphenylpyruvate Dioxygenase from Oryza sativa (OsHPPD) Gene on Activity of OsHPPD and Resistance of Mesotrione
This study aimed to clarify influence of p-hydroxyphenylpyruvate dioxygenase from Oryza sativa (OsHPPD) gene on activity of OsHPPD and resistance of mesotrione.OsHPPD was cloned from O.sativa 'Nipponbar',and then OsHPPD was compared with HPPD of Zea mays,Arabidopsis thaliana,Pseudomonas fluorescein and Avena sativa by BLAST.We analyzed HPPD protein sequences from different species to determine the amino acid sites to be mutated.Using overlapping PCR,12 amino acids in OsHPPD were subjected to site directed mutagenesis,resulting in 14 OsHPPD mutants.OsHPPD and its mutants were expressed in prokaryotic cells in vitro.Then relative activity of HPPD enzyme and relative resistance to mesotrione were determined by colorimetry.The results showed that relative resistance was enhanced 14 percentage points after V224I site mutation.The site mutation changed the catalytic site of OsHPPD,which resulted in the enhanced relative activity of OsHPPD and relative resistance to mesotrione.This site mutation is of great significance for the development of HPPD-tolerant germplasm resources and new herbicide-resistant rice variety.
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维普
