Multiple nitrate transporter(NRT)genes exist in the genome of bread wheat,and it is of great importance to identify the elite NRT genes for N-efficient wheat cultivar breeding.A candidate gene association study(CGAS)o...Multiple nitrate transporter(NRT)genes exist in the genome of bread wheat,and it is of great importance to identify the elite NRT genes for N-efficient wheat cultivar breeding.A candidate gene association study(CGAS)of six N use efficiency(NUE)related traits(grain N concentration(GNC),straw N concentration(SNC),grain yield(GY),grain N accumulation(GNA),shoot total N accumulation(STN)and N harvest index(NHI))was performed based on SNPs in 46 NRT2 genes using a panel composed of 286 wheat cultivars.CGAS identified TaNRT2.1-6B as an elite NRT gene that is significantly associated with four(NHI,SNC,GNA and GY)of the six NUE-related traits simultaneously.TaNRT2.1-6B is located on the plasma membrane and acts as a dual-affinity NRT.The overexpression of TaNRT2.1-6B increased the N influx and root growth of wheat,whereas gene silence lines resulted in the opposite effects.The overexpression of TaNRT2.1-6B also improved GY and N accumulation of wheat under either limited or sufficient N conditions.The data provide the TaNRT2.1-6B gene and the two associated SNP markers as promising powerful tools for breeding wheat cultivars with high N uptake ability and NUE.展开更多
Nitrate transporters(NRTs)are regulators of nitrate assimilation and transport.The genome sequences of TaNRT2L12-A,-B and-D were cloned from wheat(Triticum aestivum L.),and polymorphisms were analyzed by sequencing.Ta...Nitrate transporters(NRTs)are regulators of nitrate assimilation and transport.The genome sequences of TaNRT2L12-A,-B and-D were cloned from wheat(Triticum aestivum L.),and polymorphisms were analyzed by sequencing.TaNRT2L12-D in a germplasm population was highly conserved.However,38 single nucleotide polymorphisms(SNPs)in TaNRT2L12-A coding region and 11 SNPs in TaNRT2L12-B coding region were detected.Two derived cleaved amplified polymorphic sequences(dCAPS)markers A-CSNP1 and A-CSNP2 were developed for TaNRT2L12-A based on SNP-351 and SNP-729,and three haplotypes were identified in the germplasm population.B-CSNP1 and B-CSNP2 were developed for TaNRT2L12-B based on SNP-237 and SNP-1227,and three haplotypes were detected in the germplasm population.Association analyses between the markers and agronomic traits in 30 environments and phenotypic comparisons revealed that A-CSNP2-A is a superior allele of shorter plant height(PH),length of penultimate internode(LPI)and peduncle length(PL),B-CSNP2-G is a superior allele of higher grain number per spike(GNS).Hap-6B-1 containing both superior alleles B-CSNP1-C and B-CSNP2-A is a superior haplotype of 1 OOO-grain weight(TGW).Expression analysis showed that TaNRT2L12-B is mainly expressed in the root base and regulated by nitrate.Therefore,TaNRT2L12 may be involved in nitrate transport and signaling to regulate TGW in wheat.The superior alleles and dCAPS markers of TaNRT2L12-A/B are beneficial to genetic improvement and germplasm enhancement with molecular markers-assisted selection.展开更多
The objective of this study was to understand the morphological,physiological,and molecular responses of wheat roots to nitrate supply at seedling stage.Two wheat genotypes,Jimai 22 and Shannong 15,were grown in Hoagl...The objective of this study was to understand the morphological,physiological,and molecular responses of wheat roots to nitrate supply at seedling stage.Two wheat genotypes,Jimai 22 and Shannong 15,were grown in Hoagland＇s nutrient solution with different nitrate levels at seedling stage.Results indicated that the plant dry weight and N accumulation increased with the increase of nitrate supply.The number of axial root,total uptake area （TUA）,and active uptake area （AUA） increased with more nitrate supply.Correlation analysis indicated that significant positive correlations existed between N accumulation and dry weight,N accumulation and AUA,and N accumulation and AUA/TUA.Although,the expressions of NRT2.1,NRT2.2,and NRT2.3 decreased with nitrate supply increased,the expressions of NRT1,NRT2.1,and NRT2.3 could maintain high level at N3 treatment.The free amino acid and NO3- content in shoot also increased with the increased nitrate application,but no significant difference was found in root among the treatments.These results implied that the increase of N uptake by nitrate supply was due to the morphological and physiological responses of wheat roots and the high expression level of TaNRT genes.Similarly,the contribution of morphological,physiological,and molecular parameters was different between two genotypes of wheat.展开更多
基金funded by the National Natural Science Foundation of China(31972497).
文摘Multiple nitrate transporter(NRT)genes exist in the genome of bread wheat,and it is of great importance to identify the elite NRT genes for N-efficient wheat cultivar breeding.A candidate gene association study(CGAS)of six N use efficiency(NUE)related traits(grain N concentration(GNC),straw N concentration(SNC),grain yield(GY),grain N accumulation(GNA),shoot total N accumulation(STN)and N harvest index(NHI))was performed based on SNPs in 46 NRT2 genes using a panel composed of 286 wheat cultivars.CGAS identified TaNRT2.1-6B as an elite NRT gene that is significantly associated with four(NHI,SNC,GNA and GY)of the six NUE-related traits simultaneously.TaNRT2.1-6B is located on the plasma membrane and acts as a dual-affinity NRT.The overexpression of TaNRT2.1-6B increased the N influx and root growth of wheat,whereas gene silence lines resulted in the opposite effects.The overexpression of TaNRT2.1-6B also improved GY and N accumulation of wheat under either limited or sufficient N conditions.The data provide the TaNRT2.1-6B gene and the two associated SNP markers as promising powerful tools for breeding wheat cultivars with high N uptake ability and NUE.
基金This work was supported by the National Key Research and Development Program of China(2017YFD0300202)and the Agricultural Science and Tech no logy Inno vati on Program of Chinese Academy of Agricultural Sciences(ASTIP).
文摘Nitrate transporters(NRTs)are regulators of nitrate assimilation and transport.The genome sequences of TaNRT2L12-A,-B and-D were cloned from wheat(Triticum aestivum L.),and polymorphisms were analyzed by sequencing.TaNRT2L12-D in a germplasm population was highly conserved.However,38 single nucleotide polymorphisms(SNPs)in TaNRT2L12-A coding region and 11 SNPs in TaNRT2L12-B coding region were detected.Two derived cleaved amplified polymorphic sequences(dCAPS)markers A-CSNP1 and A-CSNP2 were developed for TaNRT2L12-A based on SNP-351 and SNP-729,and three haplotypes were identified in the germplasm population.B-CSNP1 and B-CSNP2 were developed for TaNRT2L12-B based on SNP-237 and SNP-1227,and three haplotypes were detected in the germplasm population.Association analyses between the markers and agronomic traits in 30 environments and phenotypic comparisons revealed that A-CSNP2-A is a superior allele of shorter plant height(PH),length of penultimate internode(LPI)and peduncle length(PL),B-CSNP2-G is a superior allele of higher grain number per spike(GNS).Hap-6B-1 containing both superior alleles B-CSNP1-C and B-CSNP2-A is a superior haplotype of 1 OOO-grain weight(TGW).Expression analysis showed that TaNRT2L12-B is mainly expressed in the root base and regulated by nitrate.Therefore,TaNRT2L12 may be involved in nitrate transport and signaling to regulate TGW in wheat.The superior alleles and dCAPS markers of TaNRT2L12-A/B are beneficial to genetic improvement and germplasm enhancement with molecular markers-assisted selection.
基金supported by the National Natural Science Foundation of China (30871477)the National Basic Research Program of China (973 Program,2009CB118602)the National Department of Public Benefit Research Foundation,China (200803037)
文摘The objective of this study was to understand the morphological,physiological,and molecular responses of wheat roots to nitrate supply at seedling stage.Two wheat genotypes,Jimai 22 and Shannong 15,were grown in Hoagland＇s nutrient solution with different nitrate levels at seedling stage.Results indicated that the plant dry weight and N accumulation increased with the increase of nitrate supply.The number of axial root,total uptake area （TUA）,and active uptake area （AUA） increased with more nitrate supply.Correlation analysis indicated that significant positive correlations existed between N accumulation and dry weight,N accumulation and AUA,and N accumulation and AUA/TUA.Although,the expressions of NRT2.1,NRT2.2,and NRT2.3 decreased with nitrate supply increased,the expressions of NRT1,NRT2.1,and NRT2.3 could maintain high level at N3 treatment.The free amino acid and NO3- content in shoot also increased with the increased nitrate application,but no significant difference was found in root among the treatments.These results implied that the increase of N uptake by nitrate supply was due to the morphological and physiological responses of wheat roots and the high expression level of TaNRT genes.Similarly,the contribution of morphological,physiological,and molecular parameters was different between two genotypes of wheat.
