LIGHT-INDUCED-CHANGES IN EXPRESSION OF PATHOGENESIS-RELATED ANIONIC PEROXIDASE IN CUCUMBER SEEDLINGS

The effect of irradiance on the expression of the Cucumis sativus path ogenesis-related (srPRX) anionic peroxidase was studied in germinating seeds at the period when seedlings start to be photosynthetically act ive. The diversity in the expression patterns of srPRX was observed in both dark- and light-grown seedlings using activity staining and immu noblotting: beside the three srPRX isoenzymes also other three, serolo gically unrelated, peroxidase isoforms were accumulated in dark-grown seedlings and one in light-grown seedlings. Furthermore, in light-grow n seedlings, it was observed a marked difference in the expression of particular srPRX isoenzymes at higher irradiance (up to 260 W m(-2), 4 00 - 700 nm) in comparison to low irradiance. By tissue printing on ni trocellulose paper it was demonstrated that irradiance during germinat ion induced changes in the temporal and spatial distribution of the sr PRX.