Np. Mishra et al., DEVELOPMENT OF ANTIOXIDATIVE DEFENSE SYSTEM OF WHEAT SEEDLINGS IN RESPONSE TO HIGH LIGHT, Physiologia Plantarum, 95(1), 1995, pp. 77-82
Changes in the activities of enzymes involved in the detoxification of
reactive oxygen species in wheat seedlings (Triticum aestivum L.) in
response to variations in the light environment were studied. Activiti
es of ascorbate peroxidase, superoxide dismutase, monodehydroascorbate
reductase, dehydroascorbate reductase, glutathione reductase and cata
lase were much lower in seedlings grown under low-light conditions tha
n in those grown under high-light conditions. Activities of all these
enzymes significantly increased within 24 h of transfer of the low-lig
ht-grown seedlings to the high-light regime. The results suggest that
the increase in enzyme activities was an adaptive response of the plan
ts to higher amounts of active oxygen species generated at higher ligh
t intensities. An accumulation of glutathione was also observed which
could also be a part of the defense strategy to meet the increased gen
eration of active oxygen species upon transfer of low-light-grown plan
ts to high-light conditions.