The physical-mechanical properties of Populus x canadensis Moench and Populus x euramericana （Dode） Guinier cv. Gelrica were studied to provide theoret- ical and scientific bases for the directional breeding and eff...The physical-mechanical properties of Populus x canadensis Moench and Populus x euramericana （Dode） Guinier cv. Gelrica were studied to provide theoret- ical and scientific bases for the directional breeding and efficient use of artificial forests with P. canadensis and P. euramericana Gelrica. The results showed the air-dried density, basic density of P. canadensis were 0.468 g/cm3 and 0.372 g/cm3, respectively; the shrinkage coefficient of radial, tangential and volume were 0.133%, 0.270% and 0.553%, respectively;the modulus of elasticity in static bending, the bending strength and the compressive strength parallel to grain were 9 302.99 MPa, 79.69 MPa and 40.32 Mpa, respectively. As for the P. euramericana Gelrica, the air-dried density, basic densitywere 0.453 and 0.355 g/cm3, respectively; the shrink- age coefficient of radial, tangential and volume were 0.205%, 0.304% and 0.554%, respectively; the modulus of elasticity in static bending, the bending strength and the compressive strength parallel to grain were 9 014.44, 55.87 and 33.09 Mpa respectively. Comprehensive analysis of the indicators showed that the properties of P. canadensis were better than those of P.euramericana Gelrica.展开更多
: It was generally assumed that the accumulation of vegetative storage protein (VSP) in poplar trees and/or temperate hardwoods did not occur in spring. To test this assumption, the accumulation of the 32-kDa VSP and ...: It was generally assumed that the accumulation of vegetative storage protein (VSP) in poplar trees and/or temperate hardwoods did not occur in spring. To test this assumption, the accumulation of the 32-kDa VSP and the differential expression of a gene encoding for the protein in poplars were investigated using light and electron microscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and reverse transcription-polymerase chain reaction (RT-PCR). We report, for the first time, that poplar trees initiated VSP accumulation in new shoots during the development of new shoots in spring under conditions of high temperature and long days. The amount of 32-kDa VSP increased gradually in the stem of new shoots and in two-year-old branches, but there were no detectable changes in its abundance in the bark tissues of trunks during new shoot development. Based on the presence of a 286-bp DNA fragment that is identical to the VSP gene bspA, encoding for the 32-kDa VSP in Populus deltoids Bartr. ex Marsh., the differential expression of the 32-kDa VSP gene in P. canadensis Moench was revealed by RT-PCR. The results indicated that the 32-kDa VSP gene was expressed strongly in new shoots, relative weakly in two-year-old branches and was not expressed in the trunk during new shoot development. This pattern of VSP accumulation and VSP gene space-time differential expression may be an important mechanism by which stored nitrogen compounds are used preferentially to exogenously available nitrogen and, in addition, the dynamic pattern may also have a role in the regulation of nitrogen metabolism, especially nitrogen uptake by the roots.展开更多
【目的】分析镉胁迫下中辽1号杨的转录水平,筛选差异表达基因,挖掘与镉胁迫相关的功能基因,为深入探索中辽1号杨对镉胁迫响应的分子机制提供理论依据。【方法】以中辽1号杨为试验材料,采用盆栽试验的方法将其扦插于土壤Cd含量为20 mg/kg...【目的】分析镉胁迫下中辽1号杨的转录水平,筛选差异表达基因,挖掘与镉胁迫相关的功能基因,为深入探索中辽1号杨对镉胁迫响应的分子机制提供理论依据。【方法】以中辽1号杨为试验材料,采用盆栽试验的方法将其扦插于土壤Cd含量为20 mg/kg(M20)的花盆中,以不加Cd为对照(CK),80 d后采集不同处理中辽1号杨叶片进行转录组测序,使用DESeq2软件筛选CK与M20处理中辽1号杨的差异表达基因,将得到的差异基因在基因本体数据库(gene ontology,GO)、京都基因与基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)、蛋白相邻类聚簇数据库(clusters of orthologous groups of proteins,COG)中进行注释,分析差异表达基因在不同数据库中的注释信息。随机挑选6个差异表达基因(超氧化物歧化酶(SOD)、丝氨酸/苏氨酸蛋白激酶(STK)、脱落酸(ABA)、T复合蛋白1(TCP1)、MYB基因(MYB)、丝裂原活蛋白激酶12(MAPK12)),利用Primer 5软件设计特异性引物进行实时荧光定量PCR(RT-qPCR)试验,检测这6个基因表达水平的变化,验证转录组结果的准确性。【结果】在CK和M20处理的中辽1号杨中,共发现3812个差异表达基因,其中上调表达的有2209个,下调表达的有1603个。GO分析发现,差异表达基因注释到3大类49个功能组中,其中与代谢过程有关基因最多。转录组KEGG代谢通路分析发现,差异表达基因主要在信号转导途径、代谢途径和生物合成途径富集。COG分析发现,1455个差异基因被注释到22种分类中,其中一般功能预测基因注释最多,其次是信号转导机制基因。结合各数据库分析结果发现,Cd胁迫下中辽1号杨转录组的注释结果中代谢过程和信号转导过程相关基因较多。镉胁迫下差异表达基因最多的家族是ABC、MYB、WRKY、bHLH和NAC基因家族,挖掘出与镉胁迫相关基因WRKY家族基因47(WRKY47)、硝酸盐转运蛋白基因(NRT)、ABC家族转运蛋白基因2(ABC2)、苹果酸脱氢酶(MDH)、谷胱甘肽S-转移酶基因(GSTs)、NAC家族基因2(NAC2)的表达量显著上调,MYB家族基因44(MYB44)、重金属相关异戊二烯化植物蛋白基因39(HIPP39)的表达量显著下调。RT-qPCR结果显示,随机挑选6个差异表达基因表达量的变化趋势与转录组测序结果一致。【结论】镉胁迫后中辽1号杨转录组的差异表达基因主要富集在代谢过程和信号转导过程,挖掘出与镉胁迫相关基因,分别是WRKY47、NRT、ABC2、MDH、GSTs、NAC2、MYB44、HIPP39,为深入探索杨树对镉胁迫响应的分子机制提供了理论依据。展开更多
文摘The physical-mechanical properties of Populus x canadensis Moench and Populus x euramericana （Dode） Guinier cv. Gelrica were studied to provide theoret- ical and scientific bases for the directional breeding and efficient use of artificial forests with P. canadensis and P. euramericana Gelrica. The results showed the air-dried density, basic density of P. canadensis were 0.468 g/cm3 and 0.372 g/cm3, respectively; the shrinkage coefficient of radial, tangential and volume were 0.133%, 0.270% and 0.553%, respectively;the modulus of elasticity in static bending, the bending strength and the compressive strength parallel to grain were 9 302.99 MPa, 79.69 MPa and 40.32 Mpa, respectively. As for the P. euramericana Gelrica, the air-dried density, basic densitywere 0.453 and 0.355 g/cm3, respectively; the shrink- age coefficient of radial, tangential and volume were 0.205%, 0.304% and 0.554%, respectively; the modulus of elasticity in static bending, the bending strength and the compressive strength parallel to grain were 9 014.44, 55.87 and 33.09 Mpa respectively. Comprehensive analysis of the indicators showed that the properties of P. canadensis were better than those of P.euramericana Gelrica.
文摘: It was generally assumed that the accumulation of vegetative storage protein (VSP) in poplar trees and/or temperate hardwoods did not occur in spring. To test this assumption, the accumulation of the 32-kDa VSP and the differential expression of a gene encoding for the protein in poplars were investigated using light and electron microscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and reverse transcription-polymerase chain reaction (RT-PCR). We report, for the first time, that poplar trees initiated VSP accumulation in new shoots during the development of new shoots in spring under conditions of high temperature and long days. The amount of 32-kDa VSP increased gradually in the stem of new shoots and in two-year-old branches, but there were no detectable changes in its abundance in the bark tissues of trunks during new shoot development. Based on the presence of a 286-bp DNA fragment that is identical to the VSP gene bspA, encoding for the 32-kDa VSP in Populus deltoids Bartr. ex Marsh., the differential expression of the 32-kDa VSP gene in P. canadensis Moench was revealed by RT-PCR. The results indicated that the 32-kDa VSP gene was expressed strongly in new shoots, relative weakly in two-year-old branches and was not expressed in the trunk during new shoot development. This pattern of VSP accumulation and VSP gene space-time differential expression may be an important mechanism by which stored nitrogen compounds are used preferentially to exogenously available nitrogen and, in addition, the dynamic pattern may also have a role in the regulation of nitrogen metabolism, especially nitrogen uptake by the roots.
文摘【目的】分析镉胁迫下中辽1号杨的转录水平,筛选差异表达基因,挖掘与镉胁迫相关的功能基因,为深入探索中辽1号杨对镉胁迫响应的分子机制提供理论依据。【方法】以中辽1号杨为试验材料,采用盆栽试验的方法将其扦插于土壤Cd含量为20 mg/kg(M20)的花盆中,以不加Cd为对照(CK),80 d后采集不同处理中辽1号杨叶片进行转录组测序,使用DESeq2软件筛选CK与M20处理中辽1号杨的差异表达基因,将得到的差异基因在基因本体数据库(gene ontology,GO)、京都基因与基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)、蛋白相邻类聚簇数据库(clusters of orthologous groups of proteins,COG)中进行注释,分析差异表达基因在不同数据库中的注释信息。随机挑选6个差异表达基因(超氧化物歧化酶(SOD)、丝氨酸/苏氨酸蛋白激酶(STK)、脱落酸(ABA)、T复合蛋白1(TCP1)、MYB基因(MYB)、丝裂原活蛋白激酶12(MAPK12)),利用Primer 5软件设计特异性引物进行实时荧光定量PCR(RT-qPCR)试验,检测这6个基因表达水平的变化,验证转录组结果的准确性。【结果】在CK和M20处理的中辽1号杨中,共发现3812个差异表达基因,其中上调表达的有2209个,下调表达的有1603个。GO分析发现,差异表达基因注释到3大类49个功能组中,其中与代谢过程有关基因最多。转录组KEGG代谢通路分析发现,差异表达基因主要在信号转导途径、代谢途径和生物合成途径富集。COG分析发现,1455个差异基因被注释到22种分类中,其中一般功能预测基因注释最多,其次是信号转导机制基因。结合各数据库分析结果发现,Cd胁迫下中辽1号杨转录组的注释结果中代谢过程和信号转导过程相关基因较多。镉胁迫下差异表达基因最多的家族是ABC、MYB、WRKY、bHLH和NAC基因家族,挖掘出与镉胁迫相关基因WRKY家族基因47(WRKY47)、硝酸盐转运蛋白基因(NRT)、ABC家族转运蛋白基因2(ABC2)、苹果酸脱氢酶(MDH)、谷胱甘肽S-转移酶基因(GSTs)、NAC家族基因2(NAC2)的表达量显著上调,MYB家族基因44(MYB44)、重金属相关异戊二烯化植物蛋白基因39(HIPP39)的表达量显著下调。RT-qPCR结果显示,随机挑选6个差异表达基因表达量的变化趋势与转录组测序结果一致。【结论】镉胁迫后中辽1号杨转录组的差异表达基因主要富集在代谢过程和信号转导过程,挖掘出与镉胁迫相关基因,分别是WRKY47、NRT、ABC2、MDH、GSTs、NAC2、MYB44、HIPP39,为深入探索杨树对镉胁迫响应的分子机制提供了理论依据。
