Analysis of acetohydroxyacid synthase1 gene in chickpea conferring resistance to imazamox herbicide

• Published in: Genome Vol. 57; no. 11/12; pp. 593 - 600
• Main Authors: Jain, Parul, Tar’an, Bunyamin
• Format: Journal Article
• Language: English
• Published: Canada NRC Research Press 01.11.2014; Canadian Science Publishing NRC Research Press
• Subjects: acetohydroxyacid synthase; Acetolactate Synthase - chemistry; Acetolactate Synthase - genetics; Acetolactate Synthase - metabolism; activité enzymatique; acétohydroxyacide-synthétase; Amino acids; Chickpea; Cicer - drug effects; Cicer - enzymology; Cicer - genetics; colorimetric assay; Cultivars; Enzymatic activity; enzyme activity; Enzymes; Gene expression; Genes, Plant; Genetic aspects; Genotypes; Health aspects; Herbicide Resistance; Herbicides; Herbicides - toxicity; Identification and classification; imazamox; Imidazoles - toxicity; Legumes; mesure colorimétrique; Mutation; Pesticide resistance; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Plant resistance; Plant species; pois chiche; Polymerase chain reaction; Prairies; resistance; résistance; Weed control; Canada; mesure colorimétrique; pois chiche; colorimetric assay; enzyme activity; acetohydroxyacid synthase; acétohydroxyacide-synthétase; résistance; activité enzymatique; chickpea; resistance; imazamox
• ISSN: 1480-3321; 0831-2796; 1480-3321
• DOI: 10.1139/gen-2014-0145

Chickpea (Cicer arietinum L.) production in the Canadian prairies is challenging due to a lack of effective weed management mainly because of poor competition ability of the crop and limited registered herbicide options. Chickpea genotype with resistance to imidazolinone (IMI) herbicides has been identified. A point mutation in the acetohydroxyacid synthase1 (AHAS1) gene at C581 to T581, resulting in an amino acid substitution from Ala194 to Val194 (position 205, standardized to arabidopsis), confers the resistance to imazamox in chickpea. However, the molecular mechanism leading to the resistance is not fully understood. In many plant species, contrasting transcription levels of AHAS gene has been implicated in the resistant and susceptible genotypes in response to IMI. The objectives of this research were to compare the AHAS gene expression and AHAS enzyme activity in resistant and susceptible chickpea cultivars in response to imazamox herbicide treatment. Results from RT–qPCR indicated that there is no significant change in the transcript levels of AHAS1 between the susceptible and the resistant genotypes in response to imazamox treatment. Protein hydrophobic cluster analysis, protein-ligand docking analysis, and AHAS enzyme activity assay all indicated that the resistance to imazamox in chickpea is due to the alteration of interaction of the AHAS1 enzyme with the imazamox herbicide.