title: Physiological, biochemical and molecular characterization of an induced mutation conferring imidazolinone resistance in wheat.
abstract: The Clearfield(®) wheat cultivars possessing imidazolinone (IMI)-resistant traits provide an efficient option for controlling weeds. The imazamox-resistant cultivar Pantera (Clearfield(®) ) was compared with a susceptible cultivar (Gazul). Target and non-target mechanisms of resistance were studied to characterize the resistance of Pantera and to identify the importance of each mechanism involved in this resistance. Pantera is resistant to imazamox as was determined in previous experiments. The molecular study confirmed that it carries a mutation Ser-Asn627 conferring resistance to imazamox in two out of three acetolactate synthase (ALS) genes (imi1 and imi2), located in wheat on chromosomes 6B and 6D, respectively. However, the last gene (imi3) located on chromosome 6A does not carry any mutation conferring resistance. As a result, photosynthetic activity and chlorophyll content were reduced after imazamox treatment. Detoxification was higher in the resistant biotype as shown by metabolomic study while imazamox translocation was higher in the susceptible cultivar. Interestingly, imazamox metabolism was higher at higher doses of herbicide, which suggests that the detoxification process is an inducible mechanism in which the upregulation of key gene coding for detoxification enzymes could play an important role. Thus, the identification of cultivars with a higher detoxification potential would allow the development of more resistant varieties.
authors.affiliation: Dominican Research Institute for Agriculture and Forestry (IDIAF) Rafael Augusto Sánchez, Santo Domingo, 10147, Dominican Republic.
authors.forename: Francisco
authors.initials: F
authors.lastname: Jimenez
authors.affiliation: Department of Agricultural Chemistry, Campus of Rabanales, and Agroalimentary Excellence Campus, ceiA3, University of Córdoba, Córdoba, Spain.
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Rojano-Delgado
authors.affiliation: Department of Agricultural Chemistry, Campus of Rabanales, and Agroalimentary Excellence Campus, ceiA3, University of Córdoba, Córdoba, Spain.
authors.forename: Pablo Tomas
authors.initials: PT
authors.lastname: Fernández
authors.affiliation: Institute for Sustainable Agriculture, CSIC, Córdoba, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Rodríguez-Suárez
authors.affiliation: Institute for Sustainable Agriculture, CSIC, Córdoba, Spain.
authors.forename: Sergio G
authors.initials: SG
authors.lastname: Atienza
authors.affiliation: Department of Agricultural Chemistry, Campus of Rabanales, and Agroalimentary Excellence Campus, ceiA3, University of Córdoba, Córdoba, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: De Prado
mesh_terms: D000095:Acetolactate Synthase / Q000235:genetics*; D001483:Base Sequence; D053209:Herbicide Resistance / Q000235:genetics*; D006540:Herbicides / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology*; D009154:Mutation; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014908:Triticum / Q000235:genetics / Q000502:physiology*
chemical_list: D006540:Herbicides; D007093:Imidazoles; D000095:Acetolactate Synthase; C494197:imazamox