Activities of amine oxidase, peroxidase and catalase in seedlings of Pisum sativum L. under different light conditions

The activities of amine oxidase, peroxidase and catalase were studied in 12 cultivars of field pea (Pisum sativum L.) and one accession of wild pea (Pisum sativum subsp. transcaucasicum). The influence of different light conditions on the enzyme activities was studied in extracts of 8-d-old seedlings. Substantially higher amine oxidase activity was detected in etiolated pea seedlings than in plants growing under controlled light conditions (12h photoperiod). Higher peroxidase and catalase activities indicate more intensive production of toxic hydrogen peroxide evolved by reactions of different type in green plants in comparison with etiolated ones. Significantly lower activity of peroxidases in etiolated plants could be related to a lower degree of lignification. Marked differences in enzyme activities between etiolated field pea and P. sativum subsp. transcaucasicum were observed for all studied enzymes. A very interesting result was the exceptionally low activity of amine oxidase in etiolated plants that was hardly detectable in green plants of Malton cultivar. Two bands with amine oxidase activity were found by the method of native PAGE in extracts of 8-d-old plants. A different relationship of these isoenzymes was detected in field pea and wild pea. Two isoenzymes were present in pea shoots but only one isoenzyme was detected in pea roots. Amine oxidase isoenzymes were studied in the roots and shoots of cv. Smaragd for three weeks. The profile of isoenzymes was opposite in 8- and 36-d-old stems of pea.