Effects of different irradiance levels on peroxidase activities in Quercus castaneifolia C.A. Mey. seedlings from different provenances

Abstract

ABSTRACT:To understand the function of peroxidase (POD) in relation to a light gradient, changes in POD activity were studied in five different provenances of chestnut oak seedlings. An experiment was conducted in controlled conditions and six different irradiances (10, 20, 30, 50, 60, and 70% of full light) were considered. According to the results, POD activity was strongly related to irradiance and showed a decreasing response to light, with the largest changes at low light (10 to 30%) and a levelling-off at high light (50-70%). Five provenances were also significantly distinguished at 10-30% of full light. The gel analysis showed that there were several different bands between irradiances from 10 to 70% regardless of provenances. One isoenzyme with the highest electrophoretic mobility was significantly increased in response to reduced light and slightly decreased at high irradiance. Other isoenzymes were significantly increased at high irradiance, suggesting that these isoenzymes are most likely involved in response to light stress and leaf adaptation to high irradiance.