Properties of the enzyme acetolactate synthase in herbicide resistant canola

• Autor(a) principal: Durigon,Miria Rosa
• Data de Publicação: 2018
• Outros Autores: Mariani,Franciele, Santos,Fernando Machado dos, Vargas,Leandro, Chavarria,Geraldo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Bragantia
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052018000300485
• topic: Brassica napus L.; enzyme functionality; metsulfuron-methyl; imazapic

ABSTRACT Mutations in the gene that encodes the enzyme acetolactate synthase (ALS), conferring plant resistance to ALS inhibitor herbicides, can reduce or inhibit enzymatic function. The objective of this work was to determine the functionality and kinetic characteristics of the enzyme ALS and evaluate the action of the herbicides imazapic (imidazolinone) and metsulfuron-methyl (sulfonylurea) on the activity of the enzyme ALS in canola hybrid Hyola 571CL (imidazolinone resistant), compared to hybrids Hyola 555TT (triazine resistant) and Hyola 61 (conventional). The plants were grown in a greenhouse, and leaves were collected to perform ALS activity analysis. The concentration of pyruvate to provide initial velocity equal to half the maximum reaction rate (Km) and the maximum reaction rate (Vmax) was determined, as well as the enzyme’s activity in the presence of imazapic and metsulfuron-methyl inhibitors. There was no change in the Km and Vmax in the hybrid Hyola 571CL in relation to Hyola 61. The hybrid Hyola 555TT presented Vmax higher than the other hybrids. In the hybrid Hyola 571CL, the activity of ALS was reduced only by the application of metsulfuron-methyl, and the functionality of the enzyme did not change in relation to the other hybrids. The hybrid Hyola 571CL is resistant only to the imidazolinone group herbicide and this resistance does not cause adaptive cost in relation to the other hybrids.