Objective:To evaluate antioxidant,anti-inflammatory,hepatoprotective and vasorelaxant activities of Pupulus nigra flower buds ethanolic extract.Methods:Antioxidant and anti-inflammatory activities of the extract were ...Objective:To evaluate antioxidant,anti-inflammatory,hepatoprotective and vasorelaxant activities of Pupulus nigra flower buds ethanolic extract.Methods:Antioxidant and anti-inflammatory activities of the extract were assessed using respectively the ABTS test and the animal model of carrageenan-induced paw edema.Protection from hepatic toxicity caused by aluminum was examined by histopathologic analysis of liver sections.Vasorelaxant effect was estimated in endothelium-intact and-nibbed rings of porcine coronary arteries precontracted with high concentration of U466I9.Results:The results showed a moderate antioxidant activity(40%),but potent anti-inflammatory activity(49.9%)on carrageenan-induced mice paw edema,and also as revealed by histopathologic examination,complete protection against AlCl_3-induced hepatic toxicity.Relaxant effects of the same exlracl on vascular preparation from porcine aorta precontracted with high concentration of U466I9 were considerable at 10^(-1)g/L,and comparable(P>0.05)between endothelium-intact(67.74%,IC_(50)0.04 mg/ml.)and-rubbed(72.72%,IC_(50)=0.075 mg/ml,)aortic rings.Conclusions:The extract exerted significant anti-inflammatory,hepatoprotective and vasorelaxant activities,the latter being cndothelium-independent believed to be mediated mainly by the ability of components present in the extract to exert antioxidant properties,probably related to an inhibition of Ca^(2+)influx.展开更多
The role of plant eIF5A proteins in multiple biological processes, such as protein synthesis regulation, translation elongation, mRNA turnover, programmed cell death and stress tolerance is well known. Toward using th...The role of plant eIF5A proteins in multiple biological processes, such as protein synthesis regulation, translation elongation, mRNA turnover, programmed cell death and stress tolerance is well known. Toward using these powerful proteins to increase stress tolerance in agricultural plants, in the present study, we cloned and characterized PsneIFSA2 and PsneIFSA4 from young poplar （P. simonii × P. nigra） leaves. The deduced amino acid sequences of PsneIF5A2 and PsneIF5A4 were 98 % similar to each other, and they are orthologs of eIF5A 1 in Arabidopsis. In a subcellular localization analysis, PsneIF5A2 and PsneIF5A4 proteins were localized in the nucleus and cytoplasm, qRT-PCR analysis showed that PsneIF5A2 and PsneIF5A4 were transcribed in poplar flowers, stem, leaves, and roots. In addition, they were also induced by abiotic stresses. Transgenic yeast expressing PsneIF5A2 and PsneIF5A4 had increased salt, heavy metal, osmotic, oxidative tolerance. Our results suggest that PsneIF5A2 and PsneIF5A4 are excellent candidates for genetic engineering to improve salt and heavy metal tolerance in agricultural plants.展开更多
The European black poplar(Populus nigra L.)has been used as a germplasm resource for the breeding of new poplar varieties around the world.The identification and screening of its high nitrogen use efficiency genotypes...The European black poplar(Populus nigra L.)has been used as a germplasm resource for the breeding of new poplar varieties around the world.The identification and screening of its high nitrogen use efficiency genotypes could enable the breeding of new resource-efficient poplar varieties.The accessions were screened using MALDI-TOF MS genotyping technology for ammonium transporter(AMT)and nitrate transporters(NRT)genes against phenotypic data for seedling height and ground diameter traits,in both low and high nitrogen environments.Allele re-sequencing of seven genes related to root development was carried out using the minisequencing method.By cluster analysis,101 accessions of black poplar were divided into 4 populations,and it was concluded that Central Europe is the origin of the evolution of low-nitrogen and high-efficiency populations of European black poplar.Association study between SNP typing and seedling height and ground diameter traits showed that there were significant correlations between four SNP loci and growth traits under the contrasting N levels.We found that SNP3 and SNP4 in the PttAMT1;3 gene were significantly associated with seedling height traits,and that SNP2 and SNP7 in the PttAMT1;2 and PttAMT1;5 genes,respectively,were significantly associated with ground diameter traits.Thus,considerable allelic diversity is present within the candidate genes studied and can be utilized to develop functional markers to select for poplars with improved growth under N stress conditions.展开更多
DNA methylation, an epigenetic mechanism used by cells to control gene expression, has an important biological role in plant development and environmental fitness. Since plant DNA methylation is closely related to env...DNA methylation, an epigenetic mechanism used by cells to control gene expression, has an important biological role in plant development and environmental fitness. Since plant DNA methylation is closely related to environmental conditions, variation during the day is expected. Here, in genetically identical plants of Populus nigra clone N46, DNA methylation changes in leaves over a 24 h period were detected using the methylation-sensitive amplification polymorphism method. The results showed different DNA methylation patterns in mature poplar leaves: not only in individuals at the same time, but also in samples at each of the six time during the day. In addition, night samples had a higher percentage of methylation than in morning samples. However, no statistically significant differences were found among the samples gathered at different times. Similar results were obtained for three other P. nigra clones with different genetic backgrounds. Real time qPCR showed that the DNA methyltransferase genes Pt-MET1 and Pt-SOM1 involved in CG DNA methylation in poplar were stable over a 24 h period in leaves of P. nigra N46 compared with circadian-controlled genes. That could be part of the reason that methylation of CCGG sites is stable in those leaves. That DNA methylation differed even in genetically identical plants indicates the specificity of DNA methylation changes in their genomes. No statistically significant differences in methylation changes were found between day and night, suggesting that DNA methylation is more stable than expected and is unlikely to be involved in circadian regulation in plants.展开更多
Connection plays an important role in structural components and end jointing is one of the most common connections in structural applications. This study was designed to investigate some mechanical properties （MOE an...Connection plays an important role in structural components and end jointing is one of the most common connections in structural applications. This study was designed to investigate some mechanical properties （MOE and MOR） of solid wood samples manufactured from poplar （Populus nigra）, joined together through end jointing. As well, we studied combinations of lumber manufactured from 10-mm veneer, using a polyvinyl acetate adhesive. The results show that non-jointed lumber （control samples） have better bending properties （MOE and MOR） than jointed specimens and lumber made from laminated layers. On the whole, side-by- side joints have a negative effect on the MOR and MOE of laminated products, which is more pronounced in the MOR. By increasing the number of joints, the properties of combination of three-ply, i.e., bending strength and modulus of elasticity, decreased.展开更多
[ Objective ] This study aimed to analyze the functions of AP1 gene from Populus simonii × Populus nigra and to lay the theoretical foundation for shortening the breeding cycle of forest trees and investigating t...[ Objective ] This study aimed to analyze the functions of AP1 gene from Populus simonii × Populus nigra and to lay the theoretical foundation for shortening the breeding cycle of forest trees and investigating the flowering mechanism in poplar. [ Method] Plant expression vectors of AP1 genes were constructed and transformed into tobacco leaf disks with Agrobacterium-mediated method. Transgenic tobacco plants were identified by PCR. [ Result] AP1 genes were integrated into the genome of tobacco. Transgenic tobacco plants all presented an early flowering phenotype compared with wild-type tobacco. [ Conclusion] AP1 genes could promote early flowering in transgenic tobacco plants, which provided theoretical basis for molecular regulation of flowering in poplar.展开更多
基金Supported by Ministry of Higher Education and Scientific Research of Algeria(CNEPRU Grant No.F00620100006)
文摘Objective:To evaluate antioxidant,anti-inflammatory,hepatoprotective and vasorelaxant activities of Pupulus nigra flower buds ethanolic extract.Methods:Antioxidant and anti-inflammatory activities of the extract were assessed using respectively the ABTS test and the animal model of carrageenan-induced paw edema.Protection from hepatic toxicity caused by aluminum was examined by histopathologic analysis of liver sections.Vasorelaxant effect was estimated in endothelium-intact and-nibbed rings of porcine coronary arteries precontracted with high concentration of U466I9.Results:The results showed a moderate antioxidant activity(40%),but potent anti-inflammatory activity(49.9%)on carrageenan-induced mice paw edema,and also as revealed by histopathologic examination,complete protection against AlCl_3-induced hepatic toxicity.Relaxant effects of the same exlracl on vascular preparation from porcine aorta precontracted with high concentration of U466I9 were considerable at 10^(-1)g/L,and comparable(P>0.05)between endothelium-intact(67.74%,IC_(50)0.04 mg/ml.)and-rubbed(72.72%,IC_(50)=0.075 mg/ml,)aortic rings.Conclusions:The extract exerted significant anti-inflammatory,hepatoprotective and vasorelaxant activities,the latter being cndothelium-independent believed to be mediated mainly by the ability of components present in the extract to exert antioxidant properties,probably related to an inhibition of Ca^(2+)influx.
基金supported by the Program for New Century Excellent Talents in University(No.NCET-12-0808)National Natural Science Foundation of China(No.31370661)the Fundamental Research Funds for the Central Universities(No.2572014AA26)
文摘The role of plant eIF5A proteins in multiple biological processes, such as protein synthesis regulation, translation elongation, mRNA turnover, programmed cell death and stress tolerance is well known. Toward using these powerful proteins to increase stress tolerance in agricultural plants, in the present study, we cloned and characterized PsneIFSA2 and PsneIFSA4 from young poplar （P. simonii × P. nigra） leaves. The deduced amino acid sequences of PsneIF5A2 and PsneIF5A4 were 98 % similar to each other, and they are orthologs of eIF5A 1 in Arabidopsis. In a subcellular localization analysis, PsneIF5A2 and PsneIF5A4 proteins were localized in the nucleus and cytoplasm, qRT-PCR analysis showed that PsneIF5A2 and PsneIF5A4 were transcribed in poplar flowers, stem, leaves, and roots. In addition, they were also induced by abiotic stresses. Transgenic yeast expressing PsneIF5A2 and PsneIF5A4 had increased salt, heavy metal, osmotic, oxidative tolerance. Our results suggest that PsneIF5A2 and PsneIF5A4 are excellent candidates for genetic engineering to improve salt and heavy metal tolerance in agricultural plants.
基金This study was financially supported by the national key research and development program of China(Grant No.2016YFD060040)the National Natural Science Foundation of China(31870662)the Natural Science Foundation of key University of Fujian Province(JZ160477).
文摘The European black poplar(Populus nigra L.)has been used as a germplasm resource for the breeding of new poplar varieties around the world.The identification and screening of its high nitrogen use efficiency genotypes could enable the breeding of new resource-efficient poplar varieties.The accessions were screened using MALDI-TOF MS genotyping technology for ammonium transporter(AMT)and nitrate transporters(NRT)genes against phenotypic data for seedling height and ground diameter traits,in both low and high nitrogen environments.Allele re-sequencing of seven genes related to root development was carried out using the minisequencing method.By cluster analysis,101 accessions of black poplar were divided into 4 populations,and it was concluded that Central Europe is the origin of the evolution of low-nitrogen and high-efficiency populations of European black poplar.Association study between SNP typing and seedling height and ground diameter traits showed that there were significant correlations between four SNP loci and growth traits under the contrasting N levels.We found that SNP3 and SNP4 in the PttAMT1;3 gene were significantly associated with seedling height traits,and that SNP2 and SNP7 in the PttAMT1;2 and PttAMT1;5 genes,respectively,were significantly associated with ground diameter traits.Thus,considerable allelic diversity is present within the candidate genes studied and can be utilized to develop functional markers to select for poplars with improved growth under N stress conditions.
基金supported by National Nonprofit Institute Research Grant of Chinese Academy of Forestry(TGB2013010)
文摘DNA methylation, an epigenetic mechanism used by cells to control gene expression, has an important biological role in plant development and environmental fitness. Since plant DNA methylation is closely related to environmental conditions, variation during the day is expected. Here, in genetically identical plants of Populus nigra clone N46, DNA methylation changes in leaves over a 24 h period were detected using the methylation-sensitive amplification polymorphism method. The results showed different DNA methylation patterns in mature poplar leaves: not only in individuals at the same time, but also in samples at each of the six time during the day. In addition, night samples had a higher percentage of methylation than in morning samples. However, no statistically significant differences were found among the samples gathered at different times. Similar results were obtained for three other P. nigra clones with different genetic backgrounds. Real time qPCR showed that the DNA methyltransferase genes Pt-MET1 and Pt-SOM1 involved in CG DNA methylation in poplar were stable over a 24 h period in leaves of P. nigra N46 compared with circadian-controlled genes. That could be part of the reason that methylation of CCGG sites is stable in those leaves. That DNA methylation differed even in genetically identical plants indicates the specificity of DNA methylation changes in their genomes. No statistically significant differences in methylation changes were found between day and night, suggesting that DNA methylation is more stable than expected and is unlikely to be involved in circadian regulation in plants.
文摘Connection plays an important role in structural components and end jointing is one of the most common connections in structural applications. This study was designed to investigate some mechanical properties （MOE and MOR） of solid wood samples manufactured from poplar （Populus nigra）, joined together through end jointing. As well, we studied combinations of lumber manufactured from 10-mm veneer, using a polyvinyl acetate adhesive. The results show that non-jointed lumber （control samples） have better bending properties （MOE and MOR） than jointed specimens and lumber made from laminated layers. On the whole, side-by- side joints have a negative effect on the MOR and MOE of laminated products, which is more pronounced in the MOR. By increasing the number of joints, the properties of combination of three-ply, i.e., bending strength and modulus of elasticity, decreased.
基金Supported by National Natural Science Foundation of China(31370661)
文摘[ Objective ] This study aimed to analyze the functions of AP1 gene from Populus simonii × Populus nigra and to lay the theoretical foundation for shortening the breeding cycle of forest trees and investigating the flowering mechanism in poplar. [ Method] Plant expression vectors of AP1 genes were constructed and transformed into tobacco leaf disks with Agrobacterium-mediated method. Transgenic tobacco plants were identified by PCR. [ Result] AP1 genes were integrated into the genome of tobacco. Transgenic tobacco plants all presented an early flowering phenotype compared with wild-type tobacco. [ Conclusion] AP1 genes could promote early flowering in transgenic tobacco plants, which provided theoretical basis for molecular regulation of flowering in poplar.
