The India plates continuous motion to the north, the convective removal to the thickening lithosphere caused by small-scale mantle convection and the effect of denudation on the uplifted plateau are regarded as main d...The India plates continuous motion to the north, the convective removal to the thickening lithosphere caused by small-scale mantle convection and the effect of denudation on the uplifted plateau are regarded as main driving forces that make the patterns of stress field of East Asia continent at present time. The method of numerical simulation is used to study the deformation and the stress field of East Asia continent under different boundary conditions, different denudation coefficients and different rock mechanics parameters within a trapezoid geological frame. Comparing with the results obtained by modern space geodetic technique (such as GPS) the results derived from seismological data show that the predicted data by our model can fit them very well. The degree of the fitness in the west is better than that in the east. These results imply that the main driving force of the deformation and the stress patterns of the west part of East Asia continent may come from the collision and compression between the India and the Eurasia plates. The interaction to the Pacific and the Philippines plates in the east part need to be considered. It also shows that the convective removal to the thickening lithosphere caused by small-scale mantle convection and the effect of denudation cannot be negligible in the evolution of the stress patterns.展开更多
The tectonic stress patterns were determined by a fuzzy comprehensive assessment method. Data of in-situ survey and fault information were utilized in the method. First, by making pressure and tension in the direction...The tectonic stress patterns were determined by a fuzzy comprehensive assessment method. Data of in-situ survey and fault information were utilized in the method. First, by making pressure and tension in the directions of along-river, cross-river, shear clockwise, and shear counterclockwise , 26 types of tectonic stress patterns were presented. And the stress vector of each pattern was obtained with FE software by taking unit displacement as boundary load. Then, by taking the 26 types of tectonic stress patterns as index set and 3 main stresses as factor set and choosing various operators, comparison of directions of computational stress vector and survey stress vector was made and the most possible tectonic stress pattern was obtained. Taking the 26 types of tectonic stress patterns as index set and strike angle as factor set, comparison of relationships between formation of fault and tectonic stress was made,and the tectonic stress patterns were assessed with known fault information. By summarizing the above assessment results, the most impossible tectonic stress pattern was obtained . Finally an engineering case was quoted to validate that the method is more feasible and reliable than traditional empirical method.展开更多
A two-dimensional finite element method (FEM) model that incorporates faults, elastic rock physical properties, topographical load due to gravity and far-field plate velocity boundary conditions was used to recogniz...A two-dimensional finite element method (FEM) model that incorporates faults, elastic rock physical properties, topographical load due to gravity and far-field plate velocity boundary conditions was used to recognize the seismogenic stress state along the fold-and-thrust belt of the Precordillera-Sierras Pampeanas ranges of western Argentina. A plane strain model with nine experiments was presented here to examine the fault strength with two major rock phyical properties: cohesion and angle of internal friction. Mohr-Coulomb failure criterion with bulk rock properties were applied to analyse faults. The stress field at any point of the model was assumed to be comprised of gravitational and tectonic components. The analysis was focused to recognize the seismogenic shear strain concentrated in the internal-cristaline domain of the orogene shown by the modeling. Modeling results are presented in terms of four parameters, i. e., (i) distributions, orientations, and magnitudes of principal stresses (σ1 and σ3), (ii) displacement vector1 (iii) strain distribution, and (iv) maximum shear stress (τmax) contour line within the model. The simulation results show that the compressive stress is distributed in and around the fault systems. The overall orientation of of σ1 is in horizontal directions, although reorientations do occur within some stress weaker parts, especially subsequent to the faults. A large-scale shear stress is accumulating along the active faults of Tapias-Villicum Fault (TVF), Salinas-Berros Fault (SBF), Ampacama-Niquizanga Fault (ANF) and Las Charas Fault (CF), which could act as local stress and strain modulators to localize the earthquakesoccurrence.展开更多
Based on years of month-to-month observations of sea surface temperature anomaly (SSTA) and wind stress anomaly, typical wind stress patterns in the tropical Pacific associated with ENSO are Studied with the technique...Based on years of month-to-month observations of sea surface temperature anomaly (SSTA) and wind stress anomaly, typical wind stress patterns in the tropical Pacific associated with ENSO are Studied with the techniques of linear regression and EOF analysis. The anomalous field, which is linearly correlated with ENSO, is found to be varying at low frequencies on the temporal scale and to be in four typical patterns of distribution horizontally.Pattern 1 is of the easterly anomaly and wind stress divergence in the equatorial region east of the date line. Pattern 2 is of the westerly anomaly and wind sttess convergence in the equatorial region east of the date line. Pattern 3 is of the westerly anomaly and wind stress convergence south of the Equator but east of the data line, with the easterly anomaly west of it. Pattern 4 is of the weak easerly anomaly east 160°W and the westerly anomaly west of 160°W. Wind stress fields linearly independent of ENSO are of a high-frequency process with a typical pattern off the Equator that has a large horizontal amplitude. Using an ocean anomaly-forcing model with the regressed wind stress anomaly field that is associated with ENSO, principal signals of ENSO are reproduced. It indicates the fundamental nature of the typical wind field anomaly patterns revealed for the genesis of El Nino.展开更多
This paper examines major active faults and the present-day tectonic stress field in the East Tibetan Plateau by integrating available data from published literature and proposes a block kinematics model of the region...This paper examines major active faults and the present-day tectonic stress field in the East Tibetan Plateau by integrating available data from published literature and proposes a block kinematics model of the region. It shows that the East Tibetan Plateau is dominated by strike-slip and reverse faulting stress regimes and that the maximum horizontal stress is roughly consistent with the contemporary velocity field, except for the west Qinling range where it parallels the striking of the major strike-slip faults. Active tectonics in the East Tibetan Plateau is characterized by three faulting systems. The left-slip Kunlun-Qinling faulting system combines the east Kunlun fault zone, sinistral oblique reverse faults along the Minshan range and two major NEE-striking faults cutting the west Qinling range, which accommodates eastward motion, at 10--14 mm/a, of the Chuan-Qing block. The left-slip Xianshuihe faulting system accommodated clockwise rotation of the Chuan-Dian block. The Longmenshan thrust faulting system forms the eastern margin of the East Tibetan Plateau and has been propagated to the SW of the Sichuan basin. Crustal shortening across the Longmenshan range seems low (2-4 mm/a) and absorbed only a small part of the eastward motion of the Chuan-Qing block. Most of this eastward motion has been transmitted to South China, which is moving SEE-ward at 7-9 mm/a. It is suggested from geophysical data interpretation that the crust and lithosphere of the East Tibetan Plateau is considerably thickened and theologically layered. The upper crust seems to be decoupled from the lower crust through a decollement zone at a depth of 15-20 kin, which involved the Longmenshan fault belt and propagated eastward to the SW of the Sichuan basin. The Wenchuan earthquake was just formed at the bifurcated point of this decollement system. A rheological boundary should exist beneath the Longmenshan fault belt where the lower crust of the East Tibetan Plateau and the lithospheric mantle of the Yangze block are juxtaposed.展开更多
A nearly free sustained copper (Cu) film system has been successfully fabricated by thermal evaporation deposition of Cu atoms on silicone oil surfaces, and a characteristic ordered pattern has been systematically s...A nearly free sustained copper (Cu) film system has been successfully fabricated by thermal evaporation deposition of Cu atoms on silicone oil surfaces, and a characteristic ordered pattern has been systematically studied. The ordered pattern, namely, band, is composed of a large number of parallel key-formed domains with different width w but nearly uniform length L; its characteristic values of w and L are very susceptible to the growth period, deposition rate and nominal film thickness. The formation mechanism of the ordered patterns is well explained in terms of the relaxation of the internal stress in the films, which is related to the nearly zero adhesion of the solid-liquid interface. By using a two-time deposition method, it is confirmed that the ordered patterns really form in the vacuum chamber.展开更多
The differences in satellite DNA methylation pattern of corn seedlings with various spontaneous chromosome aberration yields and changes in methylation pattern of these DNA sequences under different exposure modes of ...The differences in satellite DNA methylation pattern of corn seedlings with various spontaneous chromosome aberration yields and changes in methylation pattern of these DNA sequences under different exposure modes of acute UV-C and chronic gamma-irradiations have been investigated. The obtained experimental data and the conducted correlation analysis demonstrated the significant correlation between the satellite DNA methylation pattern varieties and chromosome aberration yields under various stress exposure modes. The role of satellite DNA methylation pattern variability and its changing in key responses to stress such as mobile elements’ activation, cell’s passage of checkpoints, and homological repair was discussed.展开更多
DOF(DNA binding with one zinc finger)是植物特异性转录因子,在植物抵御逆境胁迫过程中发挥着关键作用。通过生物信息学方法对藜麦DOF基因家族成员进行全基因组鉴定,并结合qRT-PCR技术解析该基因家族在外源NO调控干旱胁迫下的表达模...DOF(DNA binding with one zinc finger)是植物特异性转录因子,在植物抵御逆境胁迫过程中发挥着关键作用。通过生物信息学方法对藜麦DOF基因家族成员进行全基因组鉴定,并结合qRT-PCR技术解析该基因家族在外源NO调控干旱胁迫下的表达模式。结果表明,藜麦DOF基因家族共鉴定出25个家族成员,其氨基酸长度为143~558 aa,分子质量为16079.9~59102.2 Da,等电点介于4.52~9.60,疏水指数小于2,预测亚细胞定位均定位在细胞核;系统发育分析将DOF基因家族分为5个亚族,25个DOF基因均匀分布在13条染色体上,6对串联重复基因;启动子区共有31个与光响应、组织特异性、压力响应及植物激素相关的顺式作用元件;DOF5.3是蛋白互作网络的核心节点。不同组织器官表达分析表明,CqDOFs在藜麦各组织中均有表达且在花和叶中表达较强,在不同非生物胁迫条件下大部分CqDOFs基因在根中强烈响应;qRT-PCR分析表明,在NO调控的干旱胁迫条件下,16个CqDOFs基因的相对表达量均明显升高,其中CqDOF10在NO调控的干旱胁迫下表达量为干旱胁迫下该基因表达量的215.3倍,表明CqDOFs基因在藜麦响应干旱胁迫的调控机制中发挥着重要作用,外源NO能有效提高干旱胁迫下基因的表达。展开更多
CBF/DREB proteins play a critical role in abiotic stress-mediated gene expression and represent attractive regulons for plant breeding programs.However,no study has been conducted for CBF/DREB protein-related genes in...CBF/DREB proteins play a critical role in abiotic stress-mediated gene expression and represent attractive regulons for plant breeding programs.However,no study has been conducted for CBF/DREB protein-related genes in jujube(Ziziphus jujuba Mill.).In this study,twenty-five ZjDREB genes were identified and annotated from the jujube(Z.jujuba‘Dongzao’)genome.Detailed analysis,including gene classification,annotation,phylogenetic evaluation,conserved motif determination and expression profiling were performed on all genes.Phylogenetic analysis showed that ZjDREB proteins were divided into five subgroups(A1–A5),but lacking a subgroup A6 corresponding to AtDREBs.The ZjDREB genes were distributed in nine of twelve chromosomes in the genome.Additionally,the expression patterns of the DREB genes under different abiotic stresses were investigated using q RT-PCR.Nineteen ZjDREB genes were down-regulated under low temperature,in contrast six ZjDREB genes(01,03,05,11,23 and 24)were up-regulated.Under drought,salinity and high temperature conditions,expression of ZjDREB03,09,10,14,15,17 and 20 genes were induced and showed similar expression patterns,suggesting that various stress conditions share common elements in the signaling pathway.The results suggest that the family of DREB genes play an important role in abiotic stresses in jujube,and provide a foundation for further functional studies of this important class of transcriptional regulators.展开更多
Background: The SWEET (Sugars will eventually be exported transporters) gene family plays multiple roles in plant physiological activities and development process. It participates in reproductive development and in...Background: The SWEET (Sugars will eventually be exported transporters) gene family plays multiple roles in plant physiological activities and development process. It participates in reproductive development and in the process of sugar transport and absorption, plant senescence and stress responses and plant-pathogen interaction. However, thecomprehensive analysis of SWEET genes has not been reported in cotton. Results: In this study, we identified 22, 31, 55 and 60 SWEETgenes from the sequenced genomes of Gossypium orboreum, G. rairnondii, G. hirsutum and G. borbadense, respectively. Phylogenetic tree analysis showed that the SWEET genes could be divided into four groups, which were further classified into 14 sub-clades. Further analysis of chromosomal location, synteny analysis and gene duplication suggested that the orthologs showed a good collinearity and segmental duplication events played a crucial role in the expansion of the family in cotton. Specific MtN3_slv domains were highly conserved between Arabidopsis and cotton by exon-intron organization and motif analysis. In addition, the expression pattern in different tissues indicated that the duplicated genes in cotton might have acquired new functions as a result of sub-functionalization or neo-functionalization. The expression pattern of SWEET genes showed that the different genes were induced by diverse stresses. The identification and functional analysis of SWEET genes in cotton may provide more candidate genes for genetic modification. Conclusion: SWEET genes were classified into four clades in cotton. The expression patterns suggested that the duplicated genes might have experienced a functional divergence. This work provides insights into the evolution of SWEETgenes and more candidates for specific genetic modification, which will be useful in future research.展开更多
According to the latest data of geological structure, geophysics, in-situ stress measurement and focal mechanism,3-D tectonic stress field model in North China is built and 3-D tectonic stress field pattern of North C...According to the latest data of geological structure, geophysics, in-situ stress measurement and focal mechanism,3-D tectonic stress field model in North China is built and 3-D tectonic stress field pattern of North China aresimulated by finite element method. Then the overall characteristics and regional specific feature of North Chinaare studied. Finally, the influences of the valid dynamic boundary conditions of North China Block, active faultsand the inhomogeneity of crustal medium on tectonic stress field of North China are investigated.展开更多
基金The Development Program on National Key Basic Researches under the Project Mechanism and Prediction of Continental Strong Earthquakes (G19980407).
文摘The India plates continuous motion to the north, the convective removal to the thickening lithosphere caused by small-scale mantle convection and the effect of denudation on the uplifted plateau are regarded as main driving forces that make the patterns of stress field of East Asia continent at present time. The method of numerical simulation is used to study the deformation and the stress field of East Asia continent under different boundary conditions, different denudation coefficients and different rock mechanics parameters within a trapezoid geological frame. Comparing with the results obtained by modern space geodetic technique (such as GPS) the results derived from seismological data show that the predicted data by our model can fit them very well. The degree of the fitness in the west is better than that in the east. These results imply that the main driving force of the deformation and the stress patterns of the west part of East Asia continent may come from the collision and compression between the India and the Eurasia plates. The interaction to the Pacific and the Philippines plates in the east part need to be considered. It also shows that the convective removal to the thickening lithosphere caused by small-scale mantle convection and the effect of denudation cannot be negligible in the evolution of the stress patterns.
文摘The tectonic stress patterns were determined by a fuzzy comprehensive assessment method. Data of in-situ survey and fault information were utilized in the method. First, by making pressure and tension in the directions of along-river, cross-river, shear clockwise, and shear counterclockwise , 26 types of tectonic stress patterns were presented. And the stress vector of each pattern was obtained with FE software by taking unit displacement as boundary load. Then, by taking the 26 types of tectonic stress patterns as index set and 3 main stresses as factor set and choosing various operators, comparison of directions of computational stress vector and survey stress vector was made and the most possible tectonic stress pattern was obtained. Taking the 26 types of tectonic stress patterns as index set and strike angle as factor set, comparison of relationships between formation of fault and tectonic stress was made,and the tectonic stress patterns were assessed with known fault information. By summarizing the above assessment results, the most impossible tectonic stress pattern was obtained . Finally an engineering case was quoted to validate that the method is more feasible and reliable than traditional empirical method.
基金the Ministry of Education, Culture, Sports, Science and Technology (Monbukagakusho) of Japan for its financial support of this research.
文摘A two-dimensional finite element method (FEM) model that incorporates faults, elastic rock physical properties, topographical load due to gravity and far-field plate velocity boundary conditions was used to recognize the seismogenic stress state along the fold-and-thrust belt of the Precordillera-Sierras Pampeanas ranges of western Argentina. A plane strain model with nine experiments was presented here to examine the fault strength with two major rock phyical properties: cohesion and angle of internal friction. Mohr-Coulomb failure criterion with bulk rock properties were applied to analyse faults. The stress field at any point of the model was assumed to be comprised of gravitational and tectonic components. The analysis was focused to recognize the seismogenic shear strain concentrated in the internal-cristaline domain of the orogene shown by the modeling. Modeling results are presented in terms of four parameters, i. e., (i) distributions, orientations, and magnitudes of principal stresses (σ1 and σ3), (ii) displacement vector1 (iii) strain distribution, and (iv) maximum shear stress (τmax) contour line within the model. The simulation results show that the compressive stress is distributed in and around the fault systems. The overall orientation of of σ1 is in horizontal directions, although reorientations do occur within some stress weaker parts, especially subsequent to the faults. A large-scale shear stress is accumulating along the active faults of Tapias-Villicum Fault (TVF), Salinas-Berros Fault (SBF), Ampacama-Niquizanga Fault (ANF) and Las Charas Fault (CF), which could act as local stress and strain modulators to localize the earthquakesoccurrence.
文摘Based on years of month-to-month observations of sea surface temperature anomaly (SSTA) and wind stress anomaly, typical wind stress patterns in the tropical Pacific associated with ENSO are Studied with the techniques of linear regression and EOF analysis. The anomalous field, which is linearly correlated with ENSO, is found to be varying at low frequencies on the temporal scale and to be in four typical patterns of distribution horizontally.Pattern 1 is of the easterly anomaly and wind stress divergence in the equatorial region east of the date line. Pattern 2 is of the westerly anomaly and wind sttess convergence in the equatorial region east of the date line. Pattern 3 is of the westerly anomaly and wind stress convergence south of the Equator but east of the data line, with the easterly anomaly west of it. Pattern 4 is of the weak easerly anomaly east 160°W and the westerly anomaly west of 160°W. Wind stress fields linearly independent of ENSO are of a high-frequency process with a typical pattern off the Equator that has a large horizontal amplitude. Using an ocean anomaly-forcing model with the regressed wind stress anomaly field that is associated with ENSO, principal signals of ENSO are reproduced. It indicates the fundamental nature of the typical wind field anomaly patterns revealed for the genesis of El Nino.
基金the auspice of National Key Basic Project(973)(granted number 2008CB425702)National Science and Technology Project(granted Number SinoProbe-08)China Geological Survey project(granted number1212010670104)
文摘This paper examines major active faults and the present-day tectonic stress field in the East Tibetan Plateau by integrating available data from published literature and proposes a block kinematics model of the region. It shows that the East Tibetan Plateau is dominated by strike-slip and reverse faulting stress regimes and that the maximum horizontal stress is roughly consistent with the contemporary velocity field, except for the west Qinling range where it parallels the striking of the major strike-slip faults. Active tectonics in the East Tibetan Plateau is characterized by three faulting systems. The left-slip Kunlun-Qinling faulting system combines the east Kunlun fault zone, sinistral oblique reverse faults along the Minshan range and two major NEE-striking faults cutting the west Qinling range, which accommodates eastward motion, at 10--14 mm/a, of the Chuan-Qing block. The left-slip Xianshuihe faulting system accommodated clockwise rotation of the Chuan-Dian block. The Longmenshan thrust faulting system forms the eastern margin of the East Tibetan Plateau and has been propagated to the SW of the Sichuan basin. Crustal shortening across the Longmenshan range seems low (2-4 mm/a) and absorbed only a small part of the eastward motion of the Chuan-Qing block. Most of this eastward motion has been transmitted to South China, which is moving SEE-ward at 7-9 mm/a. It is suggested from geophysical data interpretation that the crust and lithosphere of the East Tibetan Plateau is considerably thickened and theologically layered. The upper crust seems to be decoupled from the lower crust through a decollement zone at a depth of 15-20 kin, which involved the Longmenshan fault belt and propagated eastward to the SW of the Sichuan basin. The Wenchuan earthquake was just formed at the bifurcated point of this decollement system. A rheological boundary should exist beneath the Longmenshan fault belt where the lower crust of the East Tibetan Plateau and the lithospheric mantle of the Yangze block are juxtaposed.
基金Project supported by the National Natural Science Foundation of China (Grant No 10574109)the Zhejiang Provincial Science and Technology Department (Grant No 2005C24008)the Zhejiang Provincial Natural Science Foundation (Grant No.Y604064)
文摘A nearly free sustained copper (Cu) film system has been successfully fabricated by thermal evaporation deposition of Cu atoms on silicone oil surfaces, and a characteristic ordered pattern has been systematically studied. The ordered pattern, namely, band, is composed of a large number of parallel key-formed domains with different width w but nearly uniform length L; its characteristic values of w and L are very susceptible to the growth period, deposition rate and nominal film thickness. The formation mechanism of the ordered patterns is well explained in terms of the relaxation of the internal stress in the films, which is related to the nearly zero adhesion of the solid-liquid interface. By using a two-time deposition method, it is confirmed that the ordered patterns really form in the vacuum chamber.
文摘The differences in satellite DNA methylation pattern of corn seedlings with various spontaneous chromosome aberration yields and changes in methylation pattern of these DNA sequences under different exposure modes of acute UV-C and chronic gamma-irradiations have been investigated. The obtained experimental data and the conducted correlation analysis demonstrated the significant correlation between the satellite DNA methylation pattern varieties and chromosome aberration yields under various stress exposure modes. The role of satellite DNA methylation pattern variability and its changing in key responses to stress such as mobile elements’ activation, cell’s passage of checkpoints, and homological repair was discussed.
文摘DOF(DNA binding with one zinc finger)是植物特异性转录因子,在植物抵御逆境胁迫过程中发挥着关键作用。通过生物信息学方法对藜麦DOF基因家族成员进行全基因组鉴定,并结合qRT-PCR技术解析该基因家族在外源NO调控干旱胁迫下的表达模式。结果表明,藜麦DOF基因家族共鉴定出25个家族成员,其氨基酸长度为143~558 aa,分子质量为16079.9~59102.2 Da,等电点介于4.52~9.60,疏水指数小于2,预测亚细胞定位均定位在细胞核;系统发育分析将DOF基因家族分为5个亚族,25个DOF基因均匀分布在13条染色体上,6对串联重复基因;启动子区共有31个与光响应、组织特异性、压力响应及植物激素相关的顺式作用元件;DOF5.3是蛋白互作网络的核心节点。不同组织器官表达分析表明,CqDOFs在藜麦各组织中均有表达且在花和叶中表达较强,在不同非生物胁迫条件下大部分CqDOFs基因在根中强烈响应;qRT-PCR分析表明,在NO调控的干旱胁迫条件下,16个CqDOFs基因的相对表达量均明显升高,其中CqDOF10在NO调控的干旱胁迫下表达量为干旱胁迫下该基因表达量的215.3倍,表明CqDOFs基因在藜麦响应干旱胁迫的调控机制中发挥着重要作用,外源NO能有效提高干旱胁迫下基因的表达。
基金funded by the National Natural Science Foundation of China(31372019)Key Laboratory of Urban Agriculture(North China)Ministry of Agriculture,P.R.China(kf2017015)the Beijing Municipal Education Commission(CEFF-PXM2017_014207_000043)
文摘CBF/DREB proteins play a critical role in abiotic stress-mediated gene expression and represent attractive regulons for plant breeding programs.However,no study has been conducted for CBF/DREB protein-related genes in jujube(Ziziphus jujuba Mill.).In this study,twenty-five ZjDREB genes were identified and annotated from the jujube(Z.jujuba‘Dongzao’)genome.Detailed analysis,including gene classification,annotation,phylogenetic evaluation,conserved motif determination and expression profiling were performed on all genes.Phylogenetic analysis showed that ZjDREB proteins were divided into five subgroups(A1–A5),but lacking a subgroup A6 corresponding to AtDREBs.The ZjDREB genes were distributed in nine of twelve chromosomes in the genome.Additionally,the expression patterns of the DREB genes under different abiotic stresses were investigated using q RT-PCR.Nineteen ZjDREB genes were down-regulated under low temperature,in contrast six ZjDREB genes(01,03,05,11,23 and 24)were up-regulated.Under drought,salinity and high temperature conditions,expression of ZjDREB03,09,10,14,15,17 and 20 genes were induced and showed similar expression patterns,suggesting that various stress conditions share common elements in the signaling pathway.The results suggest that the family of DREB genes play an important role in abiotic stresses in jujube,and provide a foundation for further functional studies of this important class of transcriptional regulators.
基金supported by the The National Key ResearchDevelopment Program of China(2016YFD0101400,2017YFD0101600)
文摘Background: The SWEET (Sugars will eventually be exported transporters) gene family plays multiple roles in plant physiological activities and development process. It participates in reproductive development and in the process of sugar transport and absorption, plant senescence and stress responses and plant-pathogen interaction. However, thecomprehensive analysis of SWEET genes has not been reported in cotton. Results: In this study, we identified 22, 31, 55 and 60 SWEETgenes from the sequenced genomes of Gossypium orboreum, G. rairnondii, G. hirsutum and G. borbadense, respectively. Phylogenetic tree analysis showed that the SWEET genes could be divided into four groups, which were further classified into 14 sub-clades. Further analysis of chromosomal location, synteny analysis and gene duplication suggested that the orthologs showed a good collinearity and segmental duplication events played a crucial role in the expansion of the family in cotton. Specific MtN3_slv domains were highly conserved between Arabidopsis and cotton by exon-intron organization and motif analysis. In addition, the expression pattern in different tissues indicated that the duplicated genes in cotton might have acquired new functions as a result of sub-functionalization or neo-functionalization. The expression pattern of SWEET genes showed that the different genes were induced by diverse stresses. The identification and functional analysis of SWEET genes in cotton may provide more candidate genes for genetic modification. Conclusion: SWEET genes were classified into four clades in cotton. The expression patterns suggested that the duplicated genes might have experienced a functional divergence. This work provides insights into the evolution of SWEETgenes and more candidates for specific genetic modification, which will be useful in future research.
文摘According to the latest data of geological structure, geophysics, in-situ stress measurement and focal mechanism,3-D tectonic stress field model in North China is built and 3-D tectonic stress field pattern of North China aresimulated by finite element method. Then the overall characteristics and regional specific feature of North Chinaare studied. Finally, the influences of the valid dynamic boundary conditions of North China Block, active faultsand the inhomogeneity of crustal medium on tectonic stress field of North China are investigated.