The allocation of annual growth in biomass to primary plant organs is a central theme in ecology due to its role in developing ecological theories and agricultural applications.Classic theories have significantly impr...The allocation of annual growth in biomass to primary plant organs is a central theme in ecology due to its role in developing ecological theories and agricultural applications.Classic theories have significantly improved our understanding of biomass allocation patterns influenced by various factors.However,increasing contrasting observations cannot be explained by classic theories.Recently,transient dynamic theory can resolve the problem.Here,we provide empirical evidence describing transient variations of biomass allocated to stems for four crop species(i.e.corn,soybean,flax,and wheat)in single and mixed systems.We show that plant ontogeny and increasing intraspecific competition promote variations in stem mass fractions.However,variations in stem mass fractions are reduced under strong interspecific competition.Plants with large total biomass have relatively stable stem mass fractions.These findings provide empirical foundations for integrating transient dynamics into general theoretical frameworks of biomass allocation patterns and may stabilize agricultural crop yields.展开更多
Bovine embryonic stem cell would be invaluable for researching the aspect of animal cloning, production transgenic animal and discussion of gene function in vitro. With the object of establishing an effective culture ...Bovine embryonic stem cell would be invaluable for researching the aspect of animal cloning, production transgenic animal and discussion of gene function in vitro. With the object of establishing an effective culture system for isolation and clone of bovine pluripotent stem cell, we cultured bovine embryos and mouse embryos including morula blastula and hatached blastula and obtained animal ICM on Primary murine embryonic fibroblast (Primary murine embryonic fibroblast, PMEF) feeder layer with tissue medium(DMEM supplemented with 15ml/100ml NBS,0.1μmol/L Na2SeO3, 0.1mmol/L p-mercaptoethanol, 1000ng/ml LIF, 10 ng/ml IGF, 1mmol/L necessary amino acid and 1mmol/L L-glutamine),then,we obtained mouse ICM and bovine ICM. Moreover, we isolated and cloned the 6 passage bovine ES like cells(12 cell lines) and 9 passage murine ES like cells (52 cell lines) deriving from bovine ICM and murine ICM respectively on the feeder layer of PMEF by disaggregating ICM and ES cell clones of bovine and murine into smaller clumps through digesting with 0.125g/100ml trypsin and 0.02g/100ml EDTA and scattering with a glass needle. The pluripotency of both murine and bovine ES like cells was identified with morphological character, histochemistry identification , karyotype analysis and differentiation of ES cells in vitro or in vivo. This result showed that bovine embryonic stem cell and murine embryonic stem cell had developmental pluripotency.展开更多
The distinctive features of proteomics are large-scale and high throughput. The key techniques of proteomics are two-dimensional gel electrophoresis, mass spectrometry and bioinformatics. Stem cell can differentiate i...The distinctive features of proteomics are large-scale and high throughput. The key techniques of proteomics are two-dimensional gel electrophoresis, mass spectrometry and bioinformatics. Stem cell can differentiate into all kinds of cells, tissues and organs. There are many proteins and cytokines involved in the process of differentiation. Applying proteomics techniques to the research of the complex process of stem cell differentiation is of great importance to study the mechanism and applications of stem cell differentiation.展开更多
植物生物量分配格局反映了环境对植物的选择和植物对环境的响应。在祁连山高寒退化草地,采用标准化主轴估计(standardized major axis estimation)方法,探讨甘肃臭草(Melica przewalskyi)茎、叶生物量变化及其分配策略对斑块不同发育阶...植物生物量分配格局反映了环境对植物的选择和植物对环境的响应。在祁连山高寒退化草地,采用标准化主轴估计(standardized major axis estimation)方法,探讨甘肃臭草(Melica przewalskyi)茎、叶生物量变化及其分配策略对斑块不同发育阶段(斑块形成、斑块扩散、斑块稳定及斑块衰退阶段)的响应。结果表明:随着甘肃臭草斑块的发育,甘肃臭草茎生物量积累呈先上升后下降趋势,茎生物量分配比例呈先下降后上升趋势;叶生物量积累及生物量分配比例在斑块形成、斑块扩散及斑块稳定阶段均呈逐渐上升趋势,斑块衰退阶段呈下降趋势;斑块形成阶段甘肃臭草茎叶生物量呈等速生长模式,斑块扩散及稳定阶段叶生物量的增长速度大于茎生物量的增长速度,斑块衰退阶段转为茎生物量的增长速度大于叶生物量的增长速度。随着斑块的发育,甘肃臭草由依靠增加叶干物质投入占领资源,转为减小叶生物量投入、提高茎生物量的增长速度。展开更多
叶片和茎的生长规律决定植物对光截取的模式以及与外界环境的物质交换面积,其生物量分配是研究植物生活史对策的一个重要途径。在石羊河上游高寒退化草地,采用标准化主轴估计(standardized major axis estimation,SMA)方法,研究了狼毒(S...叶片和茎的生长规律决定植物对光截取的模式以及与外界环境的物质交换面积,其生物量分配是研究植物生活史对策的一个重要途径。在石羊河上游高寒退化草地,采用标准化主轴估计(standardized major axis estimation,SMA)方法,研究了狼毒(Stellera chamaejasme)种群茎大小对茎与叶生物量分配的影响,以及对叶面积支持效率的影响。结果表明:狼毒种群茎干重与比叶重(LMA)、单叶面积、叶干重呈异速生长关系,SMA斜率分别为0.781(95%的置信区间,CI=0.71～0.94)、0.824(CI=0.77～0.95)和0.856(CI=0.79～0.99)。狼毒种群中较大茎的狼毒植株具有较高的叶生物量分配比例和叶面积支持效率,同时具有较高的比叶重,说明较大的狼毒采取以提高资源利用效率为主的适应策略,而相对较小的狼毒采取以快速生长为主的适应策略。展开更多
基金supported by the National Natural Science Foundation of China(grant 32225032,32101235)the National Key Research and Development Program of China(2023YFF0805600)the Top Leading Talents in Gansu Province to J.D.
文摘The allocation of annual growth in biomass to primary plant organs is a central theme in ecology due to its role in developing ecological theories and agricultural applications.Classic theories have significantly improved our understanding of biomass allocation patterns influenced by various factors.However,increasing contrasting observations cannot be explained by classic theories.Recently,transient dynamic theory can resolve the problem.Here,we provide empirical evidence describing transient variations of biomass allocated to stems for four crop species(i.e.corn,soybean,flax,and wheat)in single and mixed systems.We show that plant ontogeny and increasing intraspecific competition promote variations in stem mass fractions.However,variations in stem mass fractions are reduced under strong interspecific competition.Plants with large total biomass have relatively stable stem mass fractions.These findings provide empirical foundations for integrating transient dynamics into general theoretical frameworks of biomass allocation patterns and may stabilize agricultural crop yields.
基金supported by the National Natural Science Foundation(C36970359).
文摘Bovine embryonic stem cell would be invaluable for researching the aspect of animal cloning, production transgenic animal and discussion of gene function in vitro. With the object of establishing an effective culture system for isolation and clone of bovine pluripotent stem cell, we cultured bovine embryos and mouse embryos including morula blastula and hatached blastula and obtained animal ICM on Primary murine embryonic fibroblast (Primary murine embryonic fibroblast, PMEF) feeder layer with tissue medium(DMEM supplemented with 15ml/100ml NBS,0.1μmol/L Na2SeO3, 0.1mmol/L p-mercaptoethanol, 1000ng/ml LIF, 10 ng/ml IGF, 1mmol/L necessary amino acid and 1mmol/L L-glutamine),then,we obtained mouse ICM and bovine ICM. Moreover, we isolated and cloned the 6 passage bovine ES like cells(12 cell lines) and 9 passage murine ES like cells (52 cell lines) deriving from bovine ICM and murine ICM respectively on the feeder layer of PMEF by disaggregating ICM and ES cell clones of bovine and murine into smaller clumps through digesting with 0.125g/100ml trypsin and 0.02g/100ml EDTA and scattering with a glass needle. The pluripotency of both murine and bovine ES like cells was identified with morphological character, histochemistry identification , karyotype analysis and differentiation of ES cells in vitro or in vivo. This result showed that bovine embryonic stem cell and murine embryonic stem cell had developmental pluripotency.
基金This work was supported by the National Outstanding Youth Foundation of China (No. 30225038) and the National Key Research Project of China (No. 00CB510103).
文摘The distinctive features of proteomics are large-scale and high throughput. The key techniques of proteomics are two-dimensional gel electrophoresis, mass spectrometry and bioinformatics. Stem cell can differentiate into all kinds of cells, tissues and organs. There are many proteins and cytokines involved in the process of differentiation. Applying proteomics techniques to the research of the complex process of stem cell differentiation is of great importance to study the mechanism and applications of stem cell differentiation.
文摘植物生物量分配格局反映了环境对植物的选择和植物对环境的响应。在祁连山高寒退化草地,采用标准化主轴估计(standardized major axis estimation)方法,探讨甘肃臭草(Melica przewalskyi)茎、叶生物量变化及其分配策略对斑块不同发育阶段(斑块形成、斑块扩散、斑块稳定及斑块衰退阶段)的响应。结果表明:随着甘肃臭草斑块的发育,甘肃臭草茎生物量积累呈先上升后下降趋势,茎生物量分配比例呈先下降后上升趋势;叶生物量积累及生物量分配比例在斑块形成、斑块扩散及斑块稳定阶段均呈逐渐上升趋势,斑块衰退阶段呈下降趋势;斑块形成阶段甘肃臭草茎叶生物量呈等速生长模式,斑块扩散及稳定阶段叶生物量的增长速度大于茎生物量的增长速度,斑块衰退阶段转为茎生物量的增长速度大于叶生物量的增长速度。随着斑块的发育,甘肃臭草由依靠增加叶干物质投入占领资源,转为减小叶生物量投入、提高茎生物量的增长速度。
文摘叶片和茎的生长规律决定植物对光截取的模式以及与外界环境的物质交换面积,其生物量分配是研究植物生活史对策的一个重要途径。在石羊河上游高寒退化草地,采用标准化主轴估计(standardized major axis estimation,SMA)方法,研究了狼毒(Stellera chamaejasme)种群茎大小对茎与叶生物量分配的影响,以及对叶面积支持效率的影响。结果表明:狼毒种群茎干重与比叶重(LMA)、单叶面积、叶干重呈异速生长关系,SMA斜率分别为0.781(95%的置信区间,CI=0.71～0.94)、0.824(CI=0.77～0.95)和0.856(CI=0.79～0.99)。狼毒种群中较大茎的狼毒植株具有较高的叶生物量分配比例和叶面积支持效率,同时具有较高的比叶重,说明较大的狼毒采取以提高资源利用效率为主的适应策略,而相对较小的狼毒采取以快速生长为主的适应策略。
