Activity of three oxidases and total dehydrogenases during the recovery from methyl methanesulphonate-induced mutagenic damage in barley

Methyl methanesulphonate (MMS), applied on barley seeds, inhibits the seed respiration and thein vitro activity of cytochrome-oxidase and catalase, whereas doubles the activity of total dehydrogenases and has no influence on the activity of peroxidase. Storage of MMS-treated seeds for 10 days at 30% seed water content, thus under conditions favouring the recovery from the MMS-induced toxic and genetic effects, resulted in an enhancement of the cytochrome oxidase and catalase activity, which reached or exceeded the activity of the control. The activity of peroxidase, although increasing during storage, did not attain the value of the control and the activity of total dehydrogenases remained two times higher as compared to the control.