MECHANISM OF FENOXAPROP-p-ETHYL RESISTANCE IN Avena fatua L. POPULATIONS FROM CHINA

To explore resistant mechanism of wild oat to fenoxaprop-p-ethyl, the susceptibility ofAcetyl-CoA Carboxylase (ACCase) from 24 wild oat populations to fenoxaprop-p-ethyl, the level of gene expression and mutation site of ACCase were conducted, In vitro ACCase activities were solated and measured by enzyme -linked immunosorbent assay kit (ELISA) assays, the results indicated that the IC50 value of the ACCase of the most unsusceptible to fenoxaprop-p-ethyl in the wild oat population from Yexian2017 (W24) was 7206.557 -fold compared to that of the ACCase of the most susceptible to fenoxaprop-p-ethyl in the wild oat population from Queshan (W11). The level of gene expression of AC Case was significantly higher in the resistant populations than in the relative susceptible populations, and was significantly more suppressed in the relative susceptible populations than in the resistant populations by quantitative Real-time PCR (qPCR). The mutations point of ACCase, Ile-1781-Leu, Trp-1999Cys, Tip-2027-Cys, Ile-2041-Asn, Asp-2078-G1y, Cys-2088-Arg to have been published were not found in the populations tested by multiple sequence alignment with a model complete ACCase sequence of Alopecunis myosuroides. These findings suggest that ACCase plays a critical role in the development of wild oat resistant mechanism to fenoxaprop-pethyl.