Effect of phosphorus supply and signal inhibitors on oxalate efflux in ectomycorrhizal fungi

Abstract:

Abstract:［Objective］Phosphorous (P) is one of the essential elements for tree growth in forests．It is beneficial to characterize oxalate secretion by ectomycorrhizal fungi in response to P supply for understanding the mechanism of P mobilization in soils.［Method］In the present experiment，the influence of P supplies and inhibitors of Ca2 + signal/anion channel on oxalate efflux in ectomycorrhizal fungi was studied in the pure liquid culture with various P concentrations.［Results］ Ectomycorrhizal fungi released a large amount of H + and organic acids such as oxalate，acetate，malate，citrate and succinate，which are important for mobilization of insoluble P in the soils. Oxalate accounted for 15. 14% to 36. 01% of the total organic acids released by the fungi and was accelerated in culture solution under the condition of low P supply，but inhibited under normal and high P.［Conclusion］Ectomycorrhizal fungi released a large amount of H + and organic acids，particularly oxalate，which might be beneficial to inorganic P mobilization in the soils and improvement of P nutrition for their host plants.