Fig 7. Proposed role of Ca²⁺ balance in BQ regulated root recognition in parasitic and non-parasitic plants.

DMBQ reduction by plant’s NADPH- oxidase is needed to maintain the production of hydrogen peroxide via redox cycling. Ca²⁺ assisted NADPH down-regulation of NADPH oxidase in Sriga leads to decrease the rate of hydrogen production while up-regulation of the enzyme in A. thaliana leads to rise in ROS concentration along the root surface that ultimately is perceived as a signal to shut down the root growth.