Imidazolinone herbicides are widely used in agriculture. In some cases, they may be very persistent in soils, generating risks for the next crop in crop rotation. In several plant species, glutathione S-transferases (GSTs) take part in the detoxification of imazamox, but there exist no reports about their activity in wheat. Our study evaluated the effects of the imbibition of wheat seeds in imazamox containing solutions (10, 25 and 50 µM) on seedling growth, protein content as well as on the activity of GSTs. Growth of the young wheat seedlings was significantly inhibited after imbibition of the seeds in imazamox containing solutions. The protein content of both roots and shoots was lower compared to controls. This was partially due to a lower acetohydroxy acid synthase (AHAS) activity, leading to slowed protein turnover. The GSTs activity, determined using two different substrates 1-Chloro-2,4-dinitrobenzene (CDNB) and p-nitrophenyl acetate (pNPA), was enhanced, indicating their possible participation in cellular defence mechanisms against imazamox. The obtained new information about GSTs will be further verified in our subsequent studies.
Key words: imazamox, wheat, glutathione S-transferases (GSTs), acetohydroxy acid synthase (AHAS)