Uniconazole-induced changes of stress responses of <em>Vicia faba</em>: polyphenole oxidase activation pattern serves as an indicator for membrane stability


  • M. A. G. A. Bekheta
  • R. Sahbaz
  • R. Lieberei


Influence of uniconazole and different salt concentrations on growth and development of broad bean (Vicia faba L.) were investigated. Addition of salt to the irrigation water caused significant reduction of plant growth but uniconazole treated plants revealed better biomass. The number of phenolic compounds in V. faba leaf extracts changed with the age of the leaves, and the antioxidative potentials of uniconazole treated plants were slightly lower. The activity of polyphenoloxidase and its activation after plastid membrane desintegration by SDS were lower in uniconazole treated plants. Further studies with varying SDS-concentrations revealed a remarkable difference in membrane disintegration by SDS in uniconazole pretreated plants. This finding supports the hypothesis that uniconazole enhanced stress tolerance after uniconazole treatment is based on physiological change in thylakoid membrane stability.