Plasticity in root system architecture(RSA)allows plants to adapt to changing nutritional status in the soil.Phosphorus availability is a major determinant of crop yield,and RSA remodeling is critical to increasing th...Plasticity in root system architecture(RSA)allows plants to adapt to changing nutritional status in the soil.Phosphorus availability is a major determinant of crop yield,and RSA remodeling is critical to increasing the efficiency of phosphorus acquisition.Although substantial progress has been made in understanding the signaling mechanism driving phosphate starvation responses in plants,whether and how epigenetic regulatory mechanisms contribute is poorly understood.Here,we report that the Switch defective/sucrose non-fermentable(SWI/SNF)ATPase BRAHMA(BRM)is involved in the local response to phosphate(Pi)starvation.The loss of BRM function induces iron(Fe)accumulation through increased LOW PHOSPHATE ROOT1(LPR1)and LPR2 expression,reducing primary root length under Pi deficiency.We also demonstrate that BRM recruits the histone deacetylase(HDA)complex HDA6-HDC1 to facilitate histone H3 deacetylation at LPR loci,thereby negatively regulating local Pi deficiency responses.BRM is degraded under Pi deficiency conditions through the 26 S proteasome pathway,leading to increased histone H3 acetylation at the LPR loci.Collectively,our data suggest that the chromatin remodeler BRM,in concert with HDA6,negatively regulates Fe-dependent local Pi starvation responses by transcriptionally repressing the RSA-related genes LPR1 and LPR2 in Arabidopsis thaliana.展开更多
The maintenance of cellular phosphate(Pi)homeostasis is of great importance in living organisms.The SPX domain-containing protein 1(SPX1)proteins from both Arabidopsis and rice have been proposed to act as sensors of ...The maintenance of cellular phosphate(Pi)homeostasis is of great importance in living organisms.The SPX domain-containing protein 1(SPX1)proteins from both Arabidopsis and rice have been proposed to act as sensors of Pi status.The molecular signal indicating the cellular Pi status and regulating Pi homeostasis in plants,however,remains to be identified,as Pi itself does not bind to the SPX domain.Here,we report the identification of the inositol pyrophosphate lnsP8 as a signaling molecule that regulates Pi homeostasis in Arabidopsis.Polyacrylamide gel electrophoresis profiling of InsPs revealed that lnsP8 level positively correlates with cellular Pi concentration.We demonstrated that the homologs of diphosphoinositol pentaki-sphosphate kinase(PPIP5K),VIH1 and VIH2,function redundantly to synthesize lnsP8,and that the vih1 vih2 double mutant overaccumulates Pi.SPX1 directly interacts with PHR1,the central regulator of Pi starvation responses,to inhibit its function under Pi-replete conditions.However,this interaction is compromised in the vih1 vih2 double mutant,resulting in the constitutive induction of Pi starvation-induced genes,indicating that plant cells cannot sense cellular Pi status without lnsP8.Furthermore,we showed that lnsP8 could directly bind to the SPX domain of SPX1 and is essential for the interaction between SPX1 and PHR1.Collectively,our study suggests that lnsP8 is the intracellular Pi signaling molecule serving as the ligand of SPX1 for controlling Pi homeostasis in plants.展开更多
Phosphorus is a building block in various biomolecules such as nucleic acids,proteins,and phospholipids.It also plays pivotal roles in many metabolic pathways,including photosynthesis and respiration(Bowler et al.,201...Phosphorus is a building block in various biomolecules such as nucleic acids,proteins,and phospholipids.It also plays pivotal roles in many metabolic pathways,including photosynthesis and respiration(Bowler et al.,2010).Plants take up phosphorus as inorganic phosphate(Pi),which is limited in most soils,and Pi constraints affect plant growth and development and hence agricultural productivity.To cope with low Pi availability in soil,plants have evolved complex mechanisms to maintain Pi homeostasis at the whole-plant and cellular level,which includes Pi uptake,storage,and redistribution.展开更多
基金the Shanghai Natural Science Foundation(22ZR1469200)the National Natural Science Foundation of China(31970580)。
文摘Plasticity in root system architecture(RSA)allows plants to adapt to changing nutritional status in the soil.Phosphorus availability is a major determinant of crop yield,and RSA remodeling is critical to increasing the efficiency of phosphorus acquisition.Although substantial progress has been made in understanding the signaling mechanism driving phosphate starvation responses in plants,whether and how epigenetic regulatory mechanisms contribute is poorly understood.Here,we report that the Switch defective/sucrose non-fermentable(SWI/SNF)ATPase BRAHMA(BRM)is involved in the local response to phosphate(Pi)starvation.The loss of BRM function induces iron(Fe)accumulation through increased LOW PHOSPHATE ROOT1(LPR1)and LPR2 expression,reducing primary root length under Pi deficiency.We also demonstrate that BRM recruits the histone deacetylase(HDA)complex HDA6-HDC1 to facilitate histone H3 deacetylation at LPR loci,thereby negatively regulating local Pi deficiency responses.BRM is degraded under Pi deficiency conditions through the 26 S proteasome pathway,leading to increased histone H3 acetylation at the LPR loci.Collectively,our data suggest that the chromatin remodeler BRM,in concert with HDA6,negatively regulates Fe-dependent local Pi starvation responses by transcriptionally repressing the RSA-related genes LPR1 and LPR2 in Arabidopsis thaliana.
文摘The maintenance of cellular phosphate(Pi)homeostasis is of great importance in living organisms.The SPX domain-containing protein 1(SPX1)proteins from both Arabidopsis and rice have been proposed to act as sensors of Pi status.The molecular signal indicating the cellular Pi status and regulating Pi homeostasis in plants,however,remains to be identified,as Pi itself does not bind to the SPX domain.Here,we report the identification of the inositol pyrophosphate lnsP8 as a signaling molecule that regulates Pi homeostasis in Arabidopsis.Polyacrylamide gel electrophoresis profiling of InsPs revealed that lnsP8 level positively correlates with cellular Pi concentration.We demonstrated that the homologs of diphosphoinositol pentaki-sphosphate kinase(PPIP5K),VIH1 and VIH2,function redundantly to synthesize lnsP8,and that the vih1 vih2 double mutant overaccumulates Pi.SPX1 directly interacts with PHR1,the central regulator of Pi starvation responses,to inhibit its function under Pi-replete conditions.However,this interaction is compromised in the vih1 vih2 double mutant,resulting in the constitutive induction of Pi starvation-induced genes,indicating that plant cells cannot sense cellular Pi status without lnsP8.Furthermore,we showed that lnsP8 could directly bind to the SPX domain of SPX1 and is essential for the interaction between SPX1 and PHR1.Collectively,our study suggests that lnsP8 is the intracellular Pi signaling molecule serving as the ligand of SPX1 for controlling Pi homeostasis in plants.
基金This work was supported by the Chinese Academy of Sciences(CAS)and the Shanghai Natural Science Foundation(22ZR1469200).
文摘Phosphorus is a building block in various biomolecules such as nucleic acids,proteins,and phospholipids.It also plays pivotal roles in many metabolic pathways,including photosynthesis and respiration(Bowler et al.,2010).Plants take up phosphorus as inorganic phosphate(Pi),which is limited in most soils,and Pi constraints affect plant growth and development and hence agricultural productivity.To cope with low Pi availability in soil,plants have evolved complex mechanisms to maintain Pi homeostasis at the whole-plant and cellular level,which includes Pi uptake,storage,and redistribution.
