Low-affinity nitrate transporter genes have been identified in subfamilies 4-8 of the rice nitrate transporter 1(NRT1)/peptide transporter family(NPF),but the OsNPF3 subfamily responsible for nitrate and phytohormone ...Low-affinity nitrate transporter genes have been identified in subfamilies 4-8 of the rice nitrate transporter 1(NRT1)/peptide transporter family(NPF),but the OsNPF3 subfamily responsible for nitrate and phytohormone transport and rice growth and development remains unknown.In this study,we described OsNPF3.1 as an essential nitrate and phytohormone transporter gene for rice tillering and nitrogen utilization efficiency(NUtE).OsNPF3.1 possesses four major haplotypes of its promoter sequence in 517 cultivars,and its expression is positively associated with tiller number.Its expression was higher in the basal part,culm,and leaf blade than in other parts of the plant,and was strongly induced by nitrate,abscisic acid(ABA)and gibberellin 3(GA_3)in the root and shoot of rice.Electrophysiological experiments demonstrated that OsNPF3.1 is a pH-dependent low-affinity nitrate transporter,with rice protoplast uptake assays showing it to be an ABA and GA_3 transporter.OsNPF3.1 overexpression significantly promoted ABA accumulation in the roots and GA accumulation in the basal part of the plant which inhibited axillary bud outgrowth and rice tillering,especially at high nitrate concentrations.The NUtE of OsNPF3.1-overexpressing plants was enhanced under low and medium nitrate concentrations,whereas the NUtE of OsNPF3.1 clustered regularly interspaced short palindromic repeats(CRISPR)plants was increased under high nitrate concentrations.The results indicate that OsNPF3.1 transports nitrate and phytohormones in different rice tissues under different nitrate concentrations.The altered OsNPF3.1 expression improves NUtE in the OsNPF3.1-overexpressing and CRISPR lines at low and high nitrate concentrations,respectively.展开更多
Amino acids are essential plant compounds serving as the building blocks of proteins,the predominant forms of nitrogen(N)distribution,and signaling molecules.Plant amino acids derive from root acquisition,nitrate redu...Amino acids are essential plant compounds serving as the building blocks of proteins,the predominant forms of nitrogen(N)distribution,and signaling molecules.Plant amino acids derive from root acquisition,nitrate reduction,and ammonium assimilation.Many amino acid transporters(AATs)mediating transfer processes of amino acids have been functionally characterized in Arabidopsis,whereas the function and regulation of the vast majority of AATs in rice(Oryza sativa L.)and other crops remain unknown.In this review,we summarize the current understanding of amino acids in the rhizosphere and in metabolism.We describe their function as signal molecules and in regulating plant architecture,flowering time,and defense against abiotic stress and pathogen attack.AATs not only function in root acquisition and translocation of amino acids from source to sink organs,regulating N uptake and use efficiency,but also as transporters of non-amino acid substrates or as amino acid sensors.Several AAT genes show natural variations in their promoter and coding regions that are associated with altered uptake rate of amino acids,grain N content,and tiller number.Development of an amino acid transfer model in plants will advance the manipulation of AATs for improving rice architecture,grain yield and quality,and N-use efficiency.展开更多
Understanding the physiological processes associated with leaf photosynthetic characteristics and nitrogen(N)assimilation during grain-filling stage are helpful for enhancing nitrogen utilization efficiency(NUtE)of ma...Understanding the physiological processes associated with leaf photosynthetic characteristics and nitrogen(N)assimilation during grain-filling stage are helpful for enhancing nitrogen utilization efficiency(NUtE)of maize.In this study,the leaf photosynthetic and N assimilation parameters in maize,including Zhengdan 958(ZD958),a low-N tolerance cultivar and Huanong 138(HN138),a low-N sensitive cultivar under different N rates were examined.Results showed that ZD958 displayed significant increases on grain yield and NUtE than that in HN138.Analyses on the leaf photosynthetic and N assimilation-associated processes indicated that ZD958 had higher leaf N remobilization(Rem N),net photosynthetic rate(Pn)and photosynthetic N use efficiency(PNUE)with respect to those of HN138 during grain-filling stage.In addition,ZD958 was also shown to be higher activities of leaf nitrate reductase(NR),glutamine synthetase(GS),nitrate reductase(GDH)and glutamine synthetase(GAGOT)than those of HN138.The leaf PNUE was significantly positively correlated with NR,GS,GDH,GOGAT suggesting that leaf PNUE and NR,GS,GDH,GOGAT jointly determined the N remobilization efficiency and the leaf N remobilization during post-silking.These results suggested that ZD958 possessed improved PNUE,NR and GS activities in leaves during grain-filling stage that contributes improve grain weights and yield formation capacities upon under low-N conditions.展开更多
基金supported by the the Guizhou Provincial Excellent Young Talents Project of Science and Technology,China(YQK(2023)002)the Guizhou Provincial Science and Technology Projects,China((2022)Key 008)+2 种基金the Guizhou Provincial Science and Technology Support Plan,China((2022)Key 026)the Key Laboratory of Molecular Breeding for Grain and Oil Crops in Guizhou Province,China((2023)008)the Key Laboratory of Functional Agriculture of Guizhou Provincial Higher Education Institutions,China((2023)007)。
文摘Low-affinity nitrate transporter genes have been identified in subfamilies 4-8 of the rice nitrate transporter 1(NRT1)/peptide transporter family(NPF),but the OsNPF3 subfamily responsible for nitrate and phytohormone transport and rice growth and development remains unknown.In this study,we described OsNPF3.1 as an essential nitrate and phytohormone transporter gene for rice tillering and nitrogen utilization efficiency(NUtE).OsNPF3.1 possesses four major haplotypes of its promoter sequence in 517 cultivars,and its expression is positively associated with tiller number.Its expression was higher in the basal part,culm,and leaf blade than in other parts of the plant,and was strongly induced by nitrate,abscisic acid(ABA)and gibberellin 3(GA_3)in the root and shoot of rice.Electrophysiological experiments demonstrated that OsNPF3.1 is a pH-dependent low-affinity nitrate transporter,with rice protoplast uptake assays showing it to be an ABA and GA_3 transporter.OsNPF3.1 overexpression significantly promoted ABA accumulation in the roots and GA accumulation in the basal part of the plant which inhibited axillary bud outgrowth and rice tillering,especially at high nitrate concentrations.The NUtE of OsNPF3.1-overexpressing plants was enhanced under low and medium nitrate concentrations,whereas the NUtE of OsNPF3.1 clustered regularly interspaced short palindromic repeats(CRISPR)plants was increased under high nitrate concentrations.The results indicate that OsNPF3.1 transports nitrate and phytohormones in different rice tissues under different nitrate concentrations.The altered OsNPF3.1 expression improves NUtE in the OsNPF3.1-overexpressing and CRISPR lines at low and high nitrate concentrations,respectively.
基金supported by the National Natural Science Foundation of China(31930101)National Key Research and Development Program of China(2016YFD0100700)+1 种基金Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization and the Innovative Research Team Development Plan of the Ministry of Education of China(IRT17R56 and KYT201802)the Priority Academic Program Development from Jiangsu Government。
文摘Amino acids are essential plant compounds serving as the building blocks of proteins,the predominant forms of nitrogen(N)distribution,and signaling molecules.Plant amino acids derive from root acquisition,nitrate reduction,and ammonium assimilation.Many amino acid transporters(AATs)mediating transfer processes of amino acids have been functionally characterized in Arabidopsis,whereas the function and regulation of the vast majority of AATs in rice(Oryza sativa L.)and other crops remain unknown.In this review,we summarize the current understanding of amino acids in the rhizosphere and in metabolism.We describe their function as signal molecules and in regulating plant architecture,flowering time,and defense against abiotic stress and pathogen attack.AATs not only function in root acquisition and translocation of amino acids from source to sink organs,regulating N uptake and use efficiency,but also as transporters of non-amino acid substrates or as amino acid sensors.Several AAT genes show natural variations in their promoter and coding regions that are associated with altered uptake rate of amino acids,grain N content,and tiller number.Development of an amino acid transfer model in plants will advance the manipulation of AATs for improving rice architecture,grain yield and quality,and N-use efficiency.
基金This work was supported by the National Key Research and Development Program of China(No.2018YFD0300503)We gratefully acknowledge Jianhang Jia and Wei Ma for revising the manuscript.We also sincerely thank the reviewers for the critical comments on our original manuscript.
文摘Understanding the physiological processes associated with leaf photosynthetic characteristics and nitrogen(N)assimilation during grain-filling stage are helpful for enhancing nitrogen utilization efficiency(NUtE)of maize.In this study,the leaf photosynthetic and N assimilation parameters in maize,including Zhengdan 958(ZD958),a low-N tolerance cultivar and Huanong 138(HN138),a low-N sensitive cultivar under different N rates were examined.Results showed that ZD958 displayed significant increases on grain yield and NUtE than that in HN138.Analyses on the leaf photosynthetic and N assimilation-associated processes indicated that ZD958 had higher leaf N remobilization(Rem N),net photosynthetic rate(Pn)and photosynthetic N use efficiency(PNUE)with respect to those of HN138 during grain-filling stage.In addition,ZD958 was also shown to be higher activities of leaf nitrate reductase(NR),glutamine synthetase(GS),nitrate reductase(GDH)and glutamine synthetase(GAGOT)than those of HN138.The leaf PNUE was significantly positively correlated with NR,GS,GDH,GOGAT suggesting that leaf PNUE and NR,GS,GDH,GOGAT jointly determined the N remobilization efficiency and the leaf N remobilization during post-silking.These results suggested that ZD958 possessed improved PNUE,NR and GS activities in leaves during grain-filling stage that contributes improve grain weights and yield formation capacities upon under low-N conditions.
