Glutamine synthetase(GS)plays an important role in nitrogen(N)metabolism in cucumber.In this study,we cloned and sequenced the CsGS1 gene,and analyzed the expression patterns and subcellular localization of the GS1 pr...Glutamine synthetase(GS)plays an important role in nitrogen(N)metabolism in cucumber.In this study,we cloned and sequenced the CsGS1 gene,and analyzed the expression patterns and subcellular localization of the GS1 protein in response to different N conditions in order to determine its role in low-nitrogen(LN)tolerance.CsGS1 was abundantly expressed in the leaves of the low N-requiring cultivar D0328,while the high N-requiring cultivar D0422 showed similar expression levels across different tissues including leaves,shoots and roots.Furthermore,the GS1 protein was primarily localized in the cytoplasm of plant cells.Both cultivars were then transformed with the CsGS1 coding sequence or antisense sequence via Agrobacterium tumefaciens in order to overexpress and silence GS1 expression,respectively.Overexpression of CsGS1 significantly improved LN tolerance and photosynthetic parameters,and increased chlorophyll b content,biomass,plant height,root length,N accumulation and GS activity under LN condition compared to the control.CsGS1 silencing on the other hand significantly reduced the above indices.Taken together,CsGS1 is crucial for maintaining N metabolism in cucumber plants during N deprivation,and is a promising target for generating novel transgenic breeds with increasing nitrogen utilization efficiency.展开更多
In response to the demand for rapid geometric modeling in Monte Carlo radiation transportation calculations for large-scale and complex geometric scenes,functional improvements,and algorithm optimizations were perform...In response to the demand for rapid geometric modeling in Monte Carlo radiation transportation calculations for large-scale and complex geometric scenes,functional improvements,and algorithm optimizations were performed using CAD-to-Monte Carlo geometry conversion(CMGC)code.Boundary representation(BRep)to constructive solid geometry(CSG)conversion and visual CSG modeling were combined to address the problem of non-convertible geometries such as spline surfaces.The splitting surface assessment method in BRep-to-CSG conversion was optimized to reduce the number of Boolean operations using an Open Cascade.This,in turn,reduced the probability of CMGC conversion failure.The auxiliary surface generation algorithm was optimized to prevent the generation of redundant auxiliary surfaces that cause an excessive decomposition of CAD geometry solids.These optimizations enhanced the usability and stability of the CMGC model conversion.CMGC was applied successfully to the JMCT transportation calculations for the conceptual designs of five China Fusion Engineering Test Reactor(CFETR)blankets.The rapid replacement of different blanket schemes was achieved based on the baseline CFETR model.The geometric solid number of blankets ranged from hundreds to tens of thousands.The correctness of the converted CFETR models using CMGC was verified through comparisons with the MCNP calculation results.The CMGC supported radiation field evaluations for a large urban scene and detailed ship scene.This enabled the rapid conversion of CAD models with thousands of geometric solids into Monte Carlo CSG models.An analysis of the JMCT transportation simulation results further demonstrated the accuracy and effectiveness of the CMGC.展开更多
基金the funding support from Heilongjiang Postdoctoral Scientific Research Developmental Fund,China(LBH-Q16021)“Academic Backbone”Project of Northeast Agricultural University,China(18XG06)the National Science Foundation of Heilongjiang Province,China(LH2019C033)。
文摘Glutamine synthetase(GS)plays an important role in nitrogen(N)metabolism in cucumber.In this study,we cloned and sequenced the CsGS1 gene,and analyzed the expression patterns and subcellular localization of the GS1 protein in response to different N conditions in order to determine its role in low-nitrogen(LN)tolerance.CsGS1 was abundantly expressed in the leaves of the low N-requiring cultivar D0328,while the high N-requiring cultivar D0422 showed similar expression levels across different tissues including leaves,shoots and roots.Furthermore,the GS1 protein was primarily localized in the cytoplasm of plant cells.Both cultivars were then transformed with the CsGS1 coding sequence or antisense sequence via Agrobacterium tumefaciens in order to overexpress and silence GS1 expression,respectively.Overexpression of CsGS1 significantly improved LN tolerance and photosynthetic parameters,and increased chlorophyll b content,biomass,plant height,root length,N accumulation and GS activity under LN condition compared to the control.CsGS1 silencing on the other hand significantly reduced the above indices.Taken together,CsGS1 is crucial for maintaining N metabolism in cucumber plants during N deprivation,and is a promising target for generating novel transgenic breeds with increasing nitrogen utilization efficiency.
基金supported by the National Natural Science Foundation of China(No.U23B2067)Innovation Program of CAEP(No.CX20210045)。
文摘In response to the demand for rapid geometric modeling in Monte Carlo radiation transportation calculations for large-scale and complex geometric scenes,functional improvements,and algorithm optimizations were performed using CAD-to-Monte Carlo geometry conversion(CMGC)code.Boundary representation(BRep)to constructive solid geometry(CSG)conversion and visual CSG modeling were combined to address the problem of non-convertible geometries such as spline surfaces.The splitting surface assessment method in BRep-to-CSG conversion was optimized to reduce the number of Boolean operations using an Open Cascade.This,in turn,reduced the probability of CMGC conversion failure.The auxiliary surface generation algorithm was optimized to prevent the generation of redundant auxiliary surfaces that cause an excessive decomposition of CAD geometry solids.These optimizations enhanced the usability and stability of the CMGC model conversion.CMGC was applied successfully to the JMCT transportation calculations for the conceptual designs of five China Fusion Engineering Test Reactor(CFETR)blankets.The rapid replacement of different blanket schemes was achieved based on the baseline CFETR model.The geometric solid number of blankets ranged from hundreds to tens of thousands.The correctness of the converted CFETR models using CMGC was verified through comparisons with the MCNP calculation results.The CMGC supported radiation field evaluations for a large urban scene and detailed ship scene.This enabled the rapid conversion of CAD models with thousands of geometric solids into Monte Carlo CSG models.An analysis of the JMCT transportation simulation results further demonstrated the accuracy and effectiveness of the CMGC.
