Phosphorus(P)is an indispensable macronutrient required for plant growth and development.Natural phosphate(Pi)reserves are finite,and a better understanding of Pi utilization by crops is therefore vital for worldwide ...Phosphorus(P)is an indispensable macronutrient required for plant growth and development.Natural phosphate(Pi)reserves are finite,and a better understanding of Pi utilization by crops is therefore vital for worldwide food security.Ammonium has long been known to enhance Pi acquisition efficiency in agriculture;however,the molecular mechanisms coordinating Pi nutrition and ammonium remains unclear.Here,we reveal that ammonium is a novel initiator that stimulates the accumulation of a key regulatory protein,STOP1,in the nuclei of Arabidopsis root cells under Pi deficiency.We show that Pi deficiency promotes ammonium uptake mediated by AMT1 transporters and causes rapid acidification of the root surface.Rhizosphere acidification-triggered STOP1 accumulation activates the excretion of organic acids,which help to solubilize Pi from insoluble iron or calcium phosphates.Ammonium uptake by AMT1 transporters is downregulated by a CIPK23 protein kinase whose expression is directly modulated by STOP1 when ammonium reaches toxic levels.Taken together,we have identified a STOP1-centered regulatory network that links external ammonium with efficient Pi acquisition from insoluble phosphate sources.These findings provide a framework for developing possible strategies to improve crop production by enhancing the utilization of non-bioavailable nutrients in soil.展开更多
基金This work was supported by the Ministry of Science and Tech no logy of the People's Republic of China(2015CB942903,2016YFD0100700)the Ministry of Education and Bureau of Foreign Experts of China(B14027)the Fundamental Research Funds for the Central Universities.
文摘Phosphorus(P)is an indispensable macronutrient required for plant growth and development.Natural phosphate(Pi)reserves are finite,and a better understanding of Pi utilization by crops is therefore vital for worldwide food security.Ammonium has long been known to enhance Pi acquisition efficiency in agriculture;however,the molecular mechanisms coordinating Pi nutrition and ammonium remains unclear.Here,we reveal that ammonium is a novel initiator that stimulates the accumulation of a key regulatory protein,STOP1,in the nuclei of Arabidopsis root cells under Pi deficiency.We show that Pi deficiency promotes ammonium uptake mediated by AMT1 transporters and causes rapid acidification of the root surface.Rhizosphere acidification-triggered STOP1 accumulation activates the excretion of organic acids,which help to solubilize Pi from insoluble iron or calcium phosphates.Ammonium uptake by AMT1 transporters is downregulated by a CIPK23 protein kinase whose expression is directly modulated by STOP1 when ammonium reaches toxic levels.Taken together,we have identified a STOP1-centered regulatory network that links external ammonium with efficient Pi acquisition from insoluble phosphate sources.These findings provide a framework for developing possible strategies to improve crop production by enhancing the utilization of non-bioavailable nutrients in soil.
