Research progress on bioavailability and influencing factors of selenium in soil-plant systems
Bioavailability of selenium is a key factor in determining the transport and accumulation of selenium in soil-plant system.However,systematic summary data and discussion of research progress are scant.Based on the results of our previous investigation of selenium-rich navel orange in Gannan,this study systematically summarizes and discusses the oxidation-reduction,absorption,and transport processes of selenium in soil-plant system.Furthermore,this study discussed the effects of soil physical and chemical properties,microorganisms,fertilization,agronomic management,and plant growth stages on the bioavailability and transport of selenium.Future hot spots of selenium research are proposed and discussed.These include:the coupled relationship between soil microbial activity and selenium in biogeochemical cycles;molecular mechanisms related to plant growth,fruit quality,and selenium metabolism;combined isotope tracing technique and thin film diffusion gradient technique in situ to explore the attribution of selenium in biogeochemistry.This study provides a theoretical reference for investigating the regulations of soil selenium bioavailability,effective accumulation of selenium in plant systems,and agronomic bio-enrichment measures for selenium enrichment.