Interaction of lycorine with UV-B and kinetin in cucumber (Cucumis sativus L.) Cotyledons

Abstract

Interaction of lycorine, a strong inhibitor of ascorbic acid biosynthesis with kinetin and UV-B radiation has been studied in cucumber (Cucumis sativus L.) cotyledons. Lycorine inhibited hypocotyl growth of seedlings as well as kinetin induced expansion growth of cotyledons in darkness. Exposure to UV-B radiation has similar inhibitory effect on growth. Inhibition of growth by lycorine was accompanied by inhibition of ascorbic acid biosynthesis but UV-B radiation promoted ascorbic acid synthesis while inhibiting growth. The inhibitory effect of lycorine on ascorbic acid synthesis could be completely recovered by kinetin. The role of ascorbic acid as a growth promoter and as an antioxidant is discussed in the light of lycorine effect.