Work

Variation of Protoporphyrinogen-IX Oxidase Sensitivity to Peroxidizing Herbicides among Corn Varieties.

Year: 2000

Type: article

Abstract: Peroxidizing herbicides have a common mode of action, i. e. inhibition of chlorophyll biosynthesis. A molecular target of these herbicides is protoporphyrinogen-IX oxidase (Protox). Corn is widely used for Protox inhibitory assays by peroxidizing herbicides because the plant enzyme has high and stable activity. The Protox isolated from one corn variety, Anjou, has been used for the assay in our laboratory and several others. This variety can no longer be used however, because of its reduced tolerance against corn diseases. Therefore, we collected twelve corn varieties and compared their Protox activities and sensitivities against peroxidizing herbicides. Among the tested varieties, DK212MF exhibited the highest activity. This variety has approximately two times higher activity than Anjou. Tolerance of Anjou and DK212MF to peroxidizing herbicides was evaluated by a pot test, because the varieties have quite different Protox activities. DK212MF was less sensitive to the peroxidizing herbicides oxyfluorfen and chlorophthalim than Anjou. Furthermore, DK212MF accumulated less Proto-IX than Anjou, which was believed to be one of the causes of its lower sensitivity in vivo to the peroxidizing herbicides.

Source: Journal of Weed Science and Technology

DOI: 10.3719/weed.45.7