Mechanisms of iron plaque formation on root surface of rice plants and their ecological and environmental effects: A review

Many aquatic plants can form iron plaque on their root surface and rhizosphere. Formation of iron plaque on root surface is an important mechanism for aquatic plants to adapt aquatic environmental stress. In this study, the conditions for iron plaque formation, their chemical components and spatial distribution are reviewed, and the molecular and physiological mechanisms of formation of iron plaque are elucidated. The roles of oxidase, oxidative substances, oxygen-excreted capacity of rice roots, oxidative microbes in the rhizosphere and process-related gene regulation in the formation of iron plaque on the surface of rice roots are discussed. Based on the above, the ecological and environmental effects of iron plaque including enhancement of nutrient uptake and avoiding heavy metal toxicity are analysed. Finally, analytical method for iron plaque measurement and their regulatory mechanisms are prospected for future study.