Although Pinus sibirica and Pinus koraiensis are resistant to cold or low temperatures in the cold temperate regions of the northern hemisphere,the former has a stronger cold resistance.Research has been limited to th...Although Pinus sibirica and Pinus koraiensis are resistant to cold or low temperatures in the cold temperate regions of the northern hemisphere,the former has a stronger cold resistance.Research has been limited to the comparison of physiological responses of the two species to cold stress.In this study,5-year-old seedlings of P.sibirica and P.koraiensis were subjected to six temperature treatments,[20℃(control),0℃,-20℃,-40℃,-60℃,and-80℃],under different stress periods(6,12,24,and 48 h).The results showed that differences in each physiological index were significant between P.sibirica and P.koraiensis,except for the permeability of cell membranes,reactive oxygen species,proline and soluble proteins.An ANOVA test indicated that there were extreme differences among the temperatures for each index,stress time and temperature 9 time for most indices.All indices showed a similar trend for P.sibirica and P.koraiensis with decreasing temperature or the extension of stress time.Soluble sugars and proline increased at 0 to-20℃and then remained unchanged with temperature decline.Other indices showed an increase from 20 to-20℃,stable from-20 to-40℃and a decrease from-40 to-80℃.All the indices increased and then declined along with the prolonged cold stress time,except for the control.From 0 to-40℃,the permeability of cell membranes,relative conductivity,reactive oxygen species and malonaldehyde of P.koraiensis seedlings were higher than in P.sibirica,but superoxide dismutase,peroxidase,catalase activity and soluble sugars,proline,and soluble proteins content emerged as opposite.This study compared the physiological mechanism responses to cold stress between P.sibirica and P.koraiensis to provide the basis for the introduction,distribution,and genetic improvement of these coniferous species.展开更多
Forty-three patients with chronic spinal cord injury for over 6 months were transplanted with bryonic olfactory ensheathing cells, 2-4 × 106, into multiple sites in the injured area under the sur-gical microscope...Forty-three patients with chronic spinal cord injury for over 6 months were transplanted with bryonic olfactory ensheathing cells, 2-4 × 106, into multiple sites in the injured area under the sur-gical microscope. The sympathetic skin response in patients was measured with an electromyo-graphy/evoked potential instrument 1 day before transplantation and 3-8 weeks after trans-tion. Spinal nerve function of patients was assessed using the American Spinal Injury Association impairment scale. The sympathetic skin response was elicited in 32 cases before olfactory en-sheathing celltransplantation, while it was observed in 34 cases after transplantation. tantly, sympathetic skin response latency decreased significantly and amplitude increased cantly after transplantation. Transplantation of olfactory ensheathing cells also improved American Spinal Injury Association scores for movement, pain and light touch. Our findings indicate that factory ensheathing celltransplantation improves motor, sensory and autonomic nerve functions in patients with chronic spinal cord injury.展开更多
Siberian Pine （Pinus sibirica） is an ecologically and eco-nomically important species in pristine forests throughout northern Rus-sia. Four provenances of P. sibirica were introduced from Mongolia and Russia to the ...Siberian Pine （Pinus sibirica） is an ecologically and eco-nomically important species in pristine forests throughout northern Rus-sia. Four provenances of P. sibirica were introduced from Mongolia and Russia to the Greater Xing’an Range （the Daxing’anling）, northeast China in 1993. The aim of this research was to study genetic variation and selection of the introduced four Pinus sibirica provenances. Heights （H）, basal diameters （BD）, survival rates （SR） and crown lengths （CL） of different families were measured as primary outcomes in different growth years. Results of data analyses demonstrated high coefficients of phenotypic variation （PCV） and heritability （H2） for H, BD and CL at 18 years after introduction. PCV and H2 increased with age. Correlations of＆amp;nbsp;growth traits between any two growth years were all significantly positive, but the correlation coefficient was smaller when the growth year interval was larger. Correlations between H and the original environment factors decreased gradually, indicating that with long-term subsistence in the new environment, the influence of the source environment declined. Colligation of multiple traits to estimate provenances showed that Novosibirsk, Tomsk, and Altai Mountains had higher survival rates and biomass, and proved more suitable for introduction and plantation in the Greater Xing’an Range in China.展开更多
A complete spinal cord injury model was established in experimental rabbits using the spinal cord clip compression method. Urodynamic examination was performed 2 weeks later to determine neurogenic bladder status. The...A complete spinal cord injury model was established in experimental rabbits using the spinal cord clip compression method. Urodynamic examination was performed 2 weeks later to determine neurogenic bladder status. The rabbits were treated with anodal block stimulation at sacral anterior roots for 4 weeks. Electrical stimulation of sacral anterior roots improved urodynamic parameters of neurogenic bladder in rabbit models of complete spinal cord injury, effectively promoted urinary function, and relieved urinary retention. Immunohistochemistry results showed that a balance was achieved among expression of muscarinic receptor subunits M2, M3, ATP-gated ion channel P2X3 receptors, and 132-adrenergic receptor, and nerve growth factor expression decreased. These results suggested that long-term sacral anterior root stimulation of anodal block could＇be used to treat neurogenic bladder in a rabbit model of complete spinal cord injury.展开更多
Estimating genetic parameters of parental lines through progeny testing and choosing good hybrid parents are important for genetically improving seed orchard trees.In this study, 24 tetraploid progeny seedlings were u...Estimating genetic parameters of parental lines through progeny testing and choosing good hybrid parents are important for genetically improving seed orchard trees.In this study, 24 tetraploid progeny seedlings were used as experimental materials, which came from test cross design：six tetraploid Betula platyphylla lines（Q33, Q13, Q103,Q19, Q83 and Q14） as female parents and four individual B. platyphylla diploid lines（F3, F4, F9 and F11） as male parents were crossed. Variance analysis of height, diameter, height-to-diameter ratio, and internodal distance showed that the differences between hybrid combinations reached highly significant levels. Using multi-objective decisionmaking, we performed a comprehensive assessment of the various hybrid combinations. Using a selection rate of 20 % of the standard, five hybrids were selected;their genetic gains in average height, diameter, height-todiameter ratio, and internodal distance were 20.95, 6.07,13.07 and 8.96 %, respectively. We also analyzed the combining ability and genetic parameter effect values of parents and hybrid combinations. The combined analysis revealed that Q13, Q103, Q33 and Q83 were superior females; F3, F4, and F9 were superior males; and F3 × Q13, F4 × Q83 and F9 × Q33 were superior hybrid combinations. The heights and diameters of these progenies were 22.49 and 11.48 % greater than average,respectively.展开更多
Betulin, oleanolic acid, and betulinic acid are naturally occurring pentacyclic triterpenoids that have significant medicinal value. Considerable amounts of these triterpenoids are available in the outer bark of white...Betulin, oleanolic acid, and betulinic acid are naturally occurring pentacyclic triterpenoids that have significant medicinal value. Considerable amounts of these triterpenoids are available in the outer bark of white birch. In this study, we used ultrasound-assisted extraction （UAE） to extract triterpenoids from birch bark rapidly and with high efficiency. Using high performance liquid chro- matography （HPLC）, three types of triterpenoids were separated and detected. We examined the differences among triterpenoids extracted from diploid versus tetra- ploid white birch. Then, we used factor analysis to screen out tetraploid white birches with comprehensively excel- lent performance. The results indicate that the optimum conditions for extraction include the use of ethanol as an extraction solvent, a solid-to-liquid ratio of 0.1 g/10 ml, ultrasonic power set at 100 W, a temperature of 60 ℃ and an extraction time of 15 min. A reversed-phase C18 col- umn （4.6 mm × 250 mm × 5 μm） with a column tem- perature of 30 ℃ and the mobile phase composed of A （acetonitrile） and B （0.1% aqueous phosphoric acid, v/v） at a flow rate of 0.5 ml/min were used, and the detection wavelength was 195 nm. No significant difference wasobserved between diploid and tetraploid white birch in terms of the content of three types of triterpenoids （at a confidence level of 0.05）. As triterpenoid content, height, and DBH （diameter at breast height） are strongly interre- lated, we used factor analysis to evaluate all individuals, and we screened out six plus trees with excellent com- prehensive characters.展开更多
New Zealand rabbits were randomly divided into an ischemia group （occlusion of the abdominal aorta for 60 minutes）, an ischemia-reperfusion group （occlusion of the abdominal aorta for 60 minutes followed by 48 hour...New Zealand rabbits were randomly divided into an ischemia group （occlusion of the abdominal aorta for 60 minutes）, an ischemia-reperfusion group （occlusion of the abdominal aorta for 60 minutes followed by 48 hours of reperfusion） and a sham-surgery group. Two-dimensional gel electrophoresis detected 49 differentially expressed proteins in spinal cord tissue from the ischemia and ischemia/ reperfusion groups and 23 of them were identified by mass spectrometry. In the ischemia group, the expression of eight proteins was up regulated, and that of the remaining four proteins was down regulated. In the ischemia/reperfusion group, the expression of four proteins was up regulated, and that of two proteins was down regulated. In the sham-surgery group, only one protein was detected. In the ischemia and ischemia/reperfusion groups, four proteins overlapped between groups with the same differential expression, including three that were up regulated and one down regulated. These proteins were related to energy metabolism, cell defense, inflammatory mechanism and cell signaling.展开更多
Auxin polar transport genes PIN(PINFORMED)determine the concentration gradient of auxin in plants.To understand the relationship between the development of different tissues in Betula pendula‘Dalecartica’,BpPIN gene...Auxin polar transport genes PIN(PINFORMED)determine the concentration gradient of auxin in plants.To understand the relationship between the development of different tissues in Betula pendula‘Dalecartica’,BpPIN gene expression and indole-3-acetic acid(IAA)content were analyzed using qRT-PCR,ELISA,and GUS staining.Gene expression of BpPIN genes and IAA levels in the leaves,buds,stems,xylem,and roots of B.pendula‘Dalecartica’and B.pendula as a control were measured.BpPIN1,BpPIN5 and BpPIN6 were upregulated during development in both species,suggesting a dominant role in the development of B.pendula‘Dalecartica’leaves.Moreover,BpPIN1 gene expression was positively associated with IAA levels during leaf,vein and petiole development in B.pendula‘Dalecartica’only.The correlation coefficient of the first three leaves was 0.69(P=0.04),while that of the first three petioles was 0.85(P=0.001).In addition,GUS staining of the pro-DR5::GUS transgenic line of cultivar was correlated with the results of BpPIN1 expression.Overall,these findings suggest that BpPIN1 is associated with the formation of lobed leaves in B.pendula‘Dalecartica’.展开更多
Development of transgenic plants with tolerance to environ- mental stress is an important goal of plant biotechnology. （LEA） proteins accumulate in seeds dur- ing late embryogenesis, where they protect cellular memb...Development of transgenic plants with tolerance to environ- mental stress is an important goal of plant biotechnology. （LEA） proteins accumulate in seeds dur- ing late embryogenesis, where they protect cellular membranes and macromolecules against drought. In this work, we transferred the Tamarix androssowii LEA gene into hybrids of Populus davidiana xp. bolleana. We compared relative rates of height growth, chlorophyll fluo- rescence kinetic parameters, and leaf Na＋ levels of six TaLEA-containing lines with non-transferred plants （NT）, all grown under 0.8% NaC1 stress condition. Survival percentages of transgenic lines were all higher than for NT controls after rehydration and the sur- vival percentage of SL2 was five-fold higher than for NT controls. Seed- ling height increased 48.7% in SL2 （from the onset of induced stress to the end of the growing season）, 31% more than for the NT controls. Chlorophyll fluorescence kinetic parameters showed a marked increase in photosynthetic capacity in SL2 and SL5. Na＋ levels in young leaves of transgenic lines were lower than in control NT leaves, but higher in yel- low and withered leaves, indicating improved salt tolerance in transgenic lines.展开更多
Betula L.(birch)is a pioneer hardwood tree species with ecological,economic,and evolutionary importance in the Northern Hemisphere.We sequenced the Betula platyphylla genome and assembled the sequences into 14 chromos...Betula L.(birch)is a pioneer hardwood tree species with ecological,economic,and evolutionary importance in the Northern Hemisphere.We sequenced the Betula platyphylla genome and assembled the sequences into 14 chromosomes.The Betula genome lacks evidence of recent whole-genome duplication and has the same paleoploidy level as Vitis vinifera and Prunus mume.Phylogenetic analysis of lignin pathway genes coupled with tissue-specific expression patterns provided clues for understanding the formation of higher ratios of syringyl to guaiacyl lignin observed in Betula species.Our transcriptome analysis of leaf tissues under a time-series cold stress experiment revealed the presence of the MEKK1–MKK2–MPK4 cascade and six additional mitogen-activated protein kinases that can be linked to a gene regulatory network involving many transcription factors and cold tolerance genes.Our genomic and transcriptome analyses provide insight into the structures,features,and evolution of the B.platyphylla genome.The chromosome-level genome and gene resources of B.platyphylla obtained in this study will facilitate the identification of important and essential genes governing important traits of trees and genetic improvement of B.platyphylla.展开更多
MADS-box transcription factors show highly diverse regulatory functions in a wide variety of organisms. In this study, we characterized a MADS-box gene （BpMADS12） from the white birch （Betula platyphylla Suk）. Thi...MADS-box transcription factors show highly diverse regulatory functions in a wide variety of organisms. In this study, we characterized a MADS-box gene （BpMADS12） from the white birch （Betula platyphylla Suk）. This gene is a member of the suppressor of overexpression of CO 1/tomato MADS 3 class of MADS-box genes. We generated lines overexpressing BpMADS12 and found that these had higher levels of lignin compared to that observed in nontransgenic lines. Transcriptome anal- ysis revealed numerous changes in gene expression patterns. In total, 8794 differentially expressed genes were identified, including 5006 upregulated unigenes and 3788 downregulated unigenes in BpMADS-overexpression lines. Differentially expressed genes involved in the pathways for lignin and brassinosteroid biosynthesis were significantly enriched and may have contributed to phenotypic changes. The results from a quantitative RT-PCR analysis were consistent those obtained with the transcriptome analysis.Our transcriptome analysis, in combination with measure- ment of lignin level, indicated that BpMADS12 promotes lignin synthesis through regulation of key enzymes in response to brassinosteroid signaling. These results suggest that this MADS-box protein is crucial to all subsequent structural events and provide a good foundation for studies aiming to elucidate the developmental mechanisms underlying formation of wood.展开更多
Poplar trees are excellent varieties widely used for gardening and greening.However,their single color and floating fluffy seeds are major disadvantages.Plant species or varieties with variegated leaves are desperatel...Poplar trees are excellent varieties widely used for gardening and greening.However,their single color and floating fluffy seeds are major disadvantages.Plant species or varieties with variegated leaves are desperately needed to meet various demands for gardens,urban greening and landscape decoration,as they produce rich foliage colors that are aesthetically pleasing and functional.In this study,we generated a golden leaf triploid poplar(P.alba×P.berlinensis)by repressing the expression of GLK(Golden2-like)genes in leaves.The triploid golden leaf poplar had reduced chlorophyll content but almost no change in the growth rate.It has great potential in landscaping once it passes safety assessments.展开更多
Cold is an abiotic stress that can greatly affect the growth and survival of plants.Here,we reported that an AP2/ERF family gene,BplERF1,isolated from Betula platyphylla played a contributing role in cold stress toler...Cold is an abiotic stress that can greatly affect the growth and survival of plants.Here,we reported that an AP2/ERF family gene,BplERF1,isolated from Betula platyphylla played a contributing role in cold stress tolerance.Overexpression of BplERF1 in B.platyphylla transgenic lines enhanced cold stress tolerance by increasing the scavenging capability and reducing H_(2)O_(2) and malondialdehyde(MDA)content in transgenic plants.Construction of BplERF-mediated multilayered hierarchical gene regulatory network(ML-hGRN),using Top-down GGM algorithm and the transcriptomic data of BplERF1 overexpression lines,led to the identification of five candidate target genes of BplERF1 which include MPK20,ERF9,WRKY53,WRKY70,and GIA1.All of them were then verified to be the true target genes of BplERF1 by chromatin-immunoprecipitation PCR(ChIP-PCR)assay.Our results indicate that BplERF1 is a positive regulator of cold tolerance and is capable of exerting regulation on the expression of cold signaling and regulatory genes,causing mitigation of reactive oxygen species.展开更多
Betula platyphylla Sukaczev tetraploids have significantly larger leaf, fruit and stoma (gigantic phenotype) than diploids of the same species;however, the mechanism underlying this difference remains unclear. Tetrapl...Betula platyphylla Sukaczev tetraploids have significantly larger leaf, fruit and stoma (gigantic phenotype) than diploids of the same species;however, the mechanism underlying this difference remains unclear. Tetraploid B. platyphylla transcriptome data have indicated that the expression of genes related to indole-3-acetic acid (IAA) biosynthesis and signal transduction was altered after genome duplication. IAA exerts pleiotropic effects on growth and development by inducing the expression of Aux/IAA. We identified 20 Aux/IAA genes (BpIAA1– BpIAA20) in B. platyphylla distributed across 10 chromosomes. Multiple alignment and motif analyses revealed that nine BpIAA proteins shared all four conserved domains. Phylogenetic analysis indicated that Aux/IAA families were divided into four subfamilies and that there were two pairs of BpIAA sister genes. The BpIAAs were differentially expressed in diploids and tetraploids. Moreover, the expression levels of the nine BpIAA genes were specifically up-regulated in tetraploids from June to September compared with May (except August 5th) in tetraploids, while they were down-regulated in diploids. IAA levels were more than twofold higher in tetraploids than diploids during the vegetative season. These results indicate that genome duplication of B. platyphylla caused the up-regulated of genes involved in IAA synthesis, and the increased concentration of IAA may induce the constitutive expression of 20 BpIAA genes. Therefore, the significant changes in the expression patterns of the BpIAAs contributed to the gigantic phenotype of tetraploids to some extent. Our research sheds light on the phenotypic variations observed in B. platyphylla tetraploids.展开更多
Stem growth habit is an important agronomic trait in soybean and is subject to artificial selection. This study aimed to provide a theory for genotypic selection of stem growth habit for breeding purposes by analyzing...Stem growth habit is an important agronomic trait in soybean and is subject to artificial selection. This study aimed to provide a theory for genotypic selection of stem growth habit for breeding purposes by analyzing the alleles of Gm Tfl1 gene in Chinese soybean varieties and establishing a database of Gm Tfl1 variation. Using knowledge of insertion and deletion(Indel) in the non-coding region and four single-nucleotide polymorphisms(SNPs) in the coding sequences of the Gm Tfl1 gene, four CAPS and one Indel markers were developed and used to test 1120 Chinese soybean varieties. We found that the dominant Gm Tfl1 allele was prevalent in accessions from the Northern ecoregion, whereas the recessive allele, Gmtfl1, was more common in the Southern ecoregion, and the proportions of Gm Tfl1 and recessive alleles were respectively 40.1% and 59.9% in the Huang-Huai ecoregion. The proportion of Gm Tfl1 decreased and that of Gmtfl1 increased, gradually from north to south. Allele Gm Tfl1-a was present in higher proportions in the Huang-Huai spring, Huang-Huai summer, and Northern spring sub-ecoregions than that in the other sub-ecoregions. Gm Tfl1-b was common in the Northeast spring, Northern spring and Southern summer sub-ecoregions. Gmtfl1-ta was found mainly in the Huang-Huai spring,Huang-Huai summer and Southern spring sub-ecoregions. The Gmtfl1-ab allele was distributed in all six soybean sub-ecoregions. The Gmtfl1-bb allele was distributed mainly in the Huang-Huai spring and summer and Southern spring and summer sub-ecoregions,but the Gmtfl1-tb allele was detected only in the Huang-Huai summer sub-ecoregion. The distributions of Gm Tfl1 and Gmtfl1 have shown no large changes in nearly 60 years of breeding, but the frequency of the recessive genotype Gmtfl1 has shown a rising trend in the last 20 years. This study provides a theoretical foundation for breeding new soybean varieties for different ecoregions.展开更多
White birch(Betula platyphylla)is precious material for pulpwood and widely distributed in 14 provinces of China.Previous study indicated that inhibited expression of a gene encoding an auxin amide synthase,BpGH3.5,in...White birch(Betula platyphylla)is precious material for pulpwood and widely distributed in 14 provinces of China.Previous study indicated that inhibited expression of a gene encoding an auxin amide synthase,BpGH3.5,in transgenic plants reduced the level of IAA–amino acid conjugation,resulting in more free IAA,thereby better growth of birch.Utilizing transgenic-B pGH3.5 lines to increase wood production in a wide range of environments is the goal for breeders.In three field trials here,we measured tree height,diameter at breast height,and volume of 16 BpGH3.5-transgenic 7-year-old white birch lines(including 12 antisense strand lines and 4 overexpression lines)and a wild-type white birch line from three sites that varied greatly in their environmental conditions.To select elite BpGH3.5-transgenic lines for each target environment,we used an additive main effects and multiplicative interaction model to analyze genotype by environment interaction,growth adaptability and stability.The selection criteria for elite transgenic lines were set as the average volume plus 0.75 times the standard deviation for the tested lines at each test site.Results showed that the effect of line and site for height was highly significant(P<0.01),and the effect of line×site was significant(P<0.05);selected as the elite lines were FG12,FG13 and FG27 at the Maoershan Experimental Forest Farm,FG13 and FG32 at the Shidaohe Forest Farm,and FG3 and FG31 at the Ecological Experiment Forest Farm.These seven high-yield,stable lines can now be tested in production trials or adjacent trial areas with similar environmental conditions,while the high-yield,unstable lines should be tested in production trials in areas deemed suitable for their growth.These results provide guidance on which released transgenic elite lines will grow best in a wide range of conditions.展开更多
Betula platyphylla is a native tree species in northern China that has high economic and medicinal value.We developed an efficient protocol for the induction of somatic embryogenesis in B.platyphalla from immature zyg...Betula platyphylla is a native tree species in northern China that has high economic and medicinal value.We developed an efficient protocol for the induction of somatic embryogenesis in B.platyphalla from immature zygotic embryos and assessed the effects of explant type,genotype,and plant growth regulators(PGRs)on embryogenic callus induction.Among the various explants evaluated,embryogenic callus was only produced from mature and immature zygotic embryos on medium with added 2,4-dichlorophenoxyacetic acid(2,4-D).Supplementation of 2,4-D-containing medium with cytokinins increased the frequency of embryogenic callus induction.On the 20 days after pollination,immature zygotic embryos that had been collected in mid-May yielded embryogenic tissue at the highest frequency(16.8%)when cultured on half-strength MS medium supplemented with 2.0 mg L^(-1)2,4-D and 0.2 mg L^(-1)6-benzylaminopurine(6-BA).The process of proliferation of embryogenic callus,somatic embryo formation,and subsequent plantlet conversion occurred under optimal culture conditions.When regenerated plants weretransplanted to soil,95%of them developed normally and grew vigorously.This somatic embryogenesis system required 3–4 months for the regeneration of B.platyphalla plantlets from immature zygotic embryos.展开更多
Mutagenized populations have provided important materials for introducing variation and identifying gene function in plants. In this study, an ethyl methanesulfonate（EMS）-induced soybean（Glycine max） population,co...Mutagenized populations have provided important materials for introducing variation and identifying gene function in plants. In this study, an ethyl methanesulfonate（EMS）-induced soybean（Glycine max） population,consisting of 21,600 independent M_2 lines, was developed.Over 1,000 M_（4（5））families, with diverse abnormal phenotypes for seed composition, seed shape, plant morphology and maturity that are stably expressed across different environments and generations were identified. Phenotypic analysis of the population led to the identification of a yellow pigmentation mutant, gyl, that displayed significantly decreased chlorophyll（Chl） content and abnormal chloroplast development. Sequence analysis showed that gyl is allelic to Minn Gold, where a different single nucleotide polymorphism variation in the Mg-chelatase subunit gene（ChlI1a） results in golden yellow leaves. A cleaved amplified polymorphic sequence marker was developed and may be applied to marker-assisted selection for the golden yellow phenotype in soybean breeding. We show that the newly developed soybean EMS mutant population has potential for functional genomics research and genetic improvement in soybean.展开更多
基金financially supported by National Key Research and Development Program of China(2017YFD0600601)
文摘Although Pinus sibirica and Pinus koraiensis are resistant to cold or low temperatures in the cold temperate regions of the northern hemisphere,the former has a stronger cold resistance.Research has been limited to the comparison of physiological responses of the two species to cold stress.In this study,5-year-old seedlings of P.sibirica and P.koraiensis were subjected to six temperature treatments,[20℃(control),0℃,-20℃,-40℃,-60℃,and-80℃],under different stress periods(6,12,24,and 48 h).The results showed that differences in each physiological index were significant between P.sibirica and P.koraiensis,except for the permeability of cell membranes,reactive oxygen species,proline and soluble proteins.An ANOVA test indicated that there were extreme differences among the temperatures for each index,stress time and temperature 9 time for most indices.All indices showed a similar trend for P.sibirica and P.koraiensis with decreasing temperature or the extension of stress time.Soluble sugars and proline increased at 0 to-20℃and then remained unchanged with temperature decline.Other indices showed an increase from 20 to-20℃,stable from-20 to-40℃and a decrease from-40 to-80℃.All the indices increased and then declined along with the prolonged cold stress time,except for the control.From 0 to-40℃,the permeability of cell membranes,relative conductivity,reactive oxygen species and malonaldehyde of P.koraiensis seedlings were higher than in P.sibirica,but superoxide dismutase,peroxidase,catalase activity and soluble sugars,proline,and soluble proteins content emerged as opposite.This study compared the physiological mechanism responses to cold stress between P.sibirica and P.koraiensis to provide the basis for the introduction,distribution,and genetic improvement of these coniferous species.
文摘Forty-three patients with chronic spinal cord injury for over 6 months were transplanted with bryonic olfactory ensheathing cells, 2-4 × 106, into multiple sites in the injured area under the sur-gical microscope. The sympathetic skin response in patients was measured with an electromyo-graphy/evoked potential instrument 1 day before transplantation and 3-8 weeks after trans-tion. Spinal nerve function of patients was assessed using the American Spinal Injury Association impairment scale. The sympathetic skin response was elicited in 32 cases before olfactory en-sheathing celltransplantation, while it was observed in 34 cases after transplantation. tantly, sympathetic skin response latency decreased significantly and amplitude increased cantly after transplantation. Transplantation of olfactory ensheathing cells also improved American Spinal Injury Association scores for movement, pain and light touch. Our findings indicate that factory ensheathing celltransplantation improves motor, sensory and autonomic nerve functions in patients with chronic spinal cord injury.
基金supported by grants Seedling Technology Rules of Siberia pine(No.2012-LY-183)
文摘Siberian Pine （Pinus sibirica） is an ecologically and eco-nomically important species in pristine forests throughout northern Rus-sia. Four provenances of P. sibirica were introduced from Mongolia and Russia to the Greater Xing’an Range （the Daxing’anling）, northeast China in 1993. The aim of this research was to study genetic variation and selection of the introduced four Pinus sibirica provenances. Heights （H）, basal diameters （BD）, survival rates （SR） and crown lengths （CL） of different families were measured as primary outcomes in different growth years. Results of data analyses demonstrated high coefficients of phenotypic variation （PCV） and heritability （H2） for H, BD and CL at 18 years after introduction. PCV and H2 increased with age. Correlations of＆amp;nbsp;growth traits between any two growth years were all significantly positive, but the correlation coefficient was smaller when the growth year interval was larger. Correlations between H and the original environment factors decreased gradually, indicating that with long-term subsistence in the new environment, the influence of the source environment declined. Colligation of multiple traits to estimate provenances showed that Novosibirsk, Tomsk, and Altai Mountains had higher survival rates and biomass, and proved more suitable for introduction and plantation in the Greater Xing’an Range in China.
文摘A complete spinal cord injury model was established in experimental rabbits using the spinal cord clip compression method. Urodynamic examination was performed 2 weeks later to determine neurogenic bladder status. The rabbits were treated with anodal block stimulation at sacral anterior roots for 4 weeks. Electrical stimulation of sacral anterior roots improved urodynamic parameters of neurogenic bladder in rabbit models of complete spinal cord injury, effectively promoted urinary function, and relieved urinary retention. Immunohistochemistry results showed that a balance was achieved among expression of muscarinic receptor subunits M2, M3, ATP-gated ion channel P2X3 receptors, and 132-adrenergic receptor, and nerve growth factor expression decreased. These results suggested that long-term sacral anterior root stimulation of anodal block could＇be used to treat neurogenic bladder in a rabbit model of complete spinal cord injury.
基金supported by National Science and Technology Supporting Topics of China(2012BAD01B05)
文摘Estimating genetic parameters of parental lines through progeny testing and choosing good hybrid parents are important for genetically improving seed orchard trees.In this study, 24 tetraploid progeny seedlings were used as experimental materials, which came from test cross design：six tetraploid Betula platyphylla lines（Q33, Q13, Q103,Q19, Q83 and Q14） as female parents and four individual B. platyphylla diploid lines（F3, F4, F9 and F11） as male parents were crossed. Variance analysis of height, diameter, height-to-diameter ratio, and internodal distance showed that the differences between hybrid combinations reached highly significant levels. Using multi-objective decisionmaking, we performed a comprehensive assessment of the various hybrid combinations. Using a selection rate of 20 % of the standard, five hybrids were selected;their genetic gains in average height, diameter, height-todiameter ratio, and internodal distance were 20.95, 6.07,13.07 and 8.96 %, respectively. We also analyzed the combining ability and genetic parameter effect values of parents and hybrid combinations. The combined analysis revealed that Q13, Q103, Q33 and Q83 were superior females; F3, F4, and F9 were superior males; and F3 × Q13, F4 × Q83 and F9 × Q33 were superior hybrid combinations. The heights and diameters of these progenies were 22.49 and 11.48 % greater than average,respectively.
基金financially supported by National Forestry Department Public Benefit Research Foundation of China(201204302)
文摘Betulin, oleanolic acid, and betulinic acid are naturally occurring pentacyclic triterpenoids that have significant medicinal value. Considerable amounts of these triterpenoids are available in the outer bark of white birch. In this study, we used ultrasound-assisted extraction （UAE） to extract triterpenoids from birch bark rapidly and with high efficiency. Using high performance liquid chro- matography （HPLC）, three types of triterpenoids were separated and detected. We examined the differences among triterpenoids extracted from diploid versus tetra- ploid white birch. Then, we used factor analysis to screen out tetraploid white birches with comprehensively excel- lent performance. The results indicate that the optimum conditions for extraction include the use of ethanol as an extraction solvent, a solid-to-liquid ratio of 0.1 g/10 ml, ultrasonic power set at 100 W, a temperature of 60 ℃ and an extraction time of 15 min. A reversed-phase C18 col- umn （4.6 mm × 250 mm × 5 μm） with a column tem- perature of 30 ℃ and the mobile phase composed of A （acetonitrile） and B （0.1% aqueous phosphoric acid, v/v） at a flow rate of 0.5 ml/min were used, and the detection wavelength was 195 nm. No significant difference wasobserved between diploid and tetraploid white birch in terms of the content of three types of triterpenoids （at a confidence level of 0.05）. As triterpenoid content, height, and DBH （diameter at breast height） are strongly interre- lated, we used factor analysis to evaluate all individuals, and we screened out six plus trees with excellent com- prehensive characters.
基金the National Natural Science Foundation of China,No. 30872609,30972153
文摘New Zealand rabbits were randomly divided into an ischemia group （occlusion of the abdominal aorta for 60 minutes）, an ischemia-reperfusion group （occlusion of the abdominal aorta for 60 minutes followed by 48 hours of reperfusion） and a sham-surgery group. Two-dimensional gel electrophoresis detected 49 differentially expressed proteins in spinal cord tissue from the ischemia and ischemia/ reperfusion groups and 23 of them were identified by mass spectrometry. In the ischemia group, the expression of eight proteins was up regulated, and that of the remaining four proteins was down regulated. In the ischemia/reperfusion group, the expression of four proteins was up regulated, and that of two proteins was down regulated. In the sham-surgery group, only one protein was detected. In the ischemia and ischemia/reperfusion groups, four proteins overlapped between groups with the same differential expression, including three that were up regulated and one down regulated. These proteins were related to energy metabolism, cell defense, inflammatory mechanism and cell signaling.
基金supported by the National Natural Science Foundation of China(NSFCGrant No.31670673)the 111 Project of China(Grant No.B16010)
文摘Auxin polar transport genes PIN(PINFORMED)determine the concentration gradient of auxin in plants.To understand the relationship between the development of different tissues in Betula pendula‘Dalecartica’,BpPIN gene expression and indole-3-acetic acid(IAA)content were analyzed using qRT-PCR,ELISA,and GUS staining.Gene expression of BpPIN genes and IAA levels in the leaves,buds,stems,xylem,and roots of B.pendula‘Dalecartica’and B.pendula as a control were measured.BpPIN1,BpPIN5 and BpPIN6 were upregulated during development in both species,suggesting a dominant role in the development of B.pendula‘Dalecartica’leaves.Moreover,BpPIN1 gene expression was positively associated with IAA levels during leaf,vein and petiole development in B.pendula‘Dalecartica’only.The correlation coefficient of the first three leaves was 0.69(P=0.04),while that of the first three petioles was 0.85(P=0.001).In addition,GUS staining of the pro-DR5::GUS transgenic line of cultivar was correlated with the results of BpPIN1 expression.Overall,these findings suggest that BpPIN1 is associated with the formation of lobed leaves in B.pendula‘Dalecartica’.
基金supported by the National High-Tech Research and Development Program of China,863 Program(Molecular Breeding and New Species Creating of Poplar)(Grant No.2011AA100201)
文摘Development of transgenic plants with tolerance to environ- mental stress is an important goal of plant biotechnology. （LEA） proteins accumulate in seeds dur- ing late embryogenesis, where they protect cellular membranes and macromolecules against drought. In this work, we transferred the Tamarix androssowii LEA gene into hybrids of Populus davidiana xp. bolleana. We compared relative rates of height growth, chlorophyll fluo- rescence kinetic parameters, and leaf Na＋ levels of six TaLEA-containing lines with non-transferred plants （NT）, all grown under 0.8% NaC1 stress condition. Survival percentages of transgenic lines were all higher than for NT controls after rehydration and the sur- vival percentage of SL2 was five-fold higher than for NT controls. Seed- ling height increased 48.7% in SL2 （from the onset of induced stress to the end of the growing season）, 31% more than for the NT controls. Chlorophyll fluorescence kinetic parameters showed a marked increase in photosynthetic capacity in SL2 and SL5. Na＋ levels in young leaves of transgenic lines were lower than in control NT leaves, but higher in yel- low and withered leaves, indicating improved salt tolerance in transgenic lines.
基金Forestry Industry Research Special Funds for Public Welfare Projects(No.201004046)the National High Technology Research and Development Program(“863”Program)of China(2011AA100202)+1 种基金Heilongjiang Touyan Innovation Team Program(Tree Genetics and Breeding Innovation Team)the 111 Project(B16010).
文摘Betula L.(birch)is a pioneer hardwood tree species with ecological,economic,and evolutionary importance in the Northern Hemisphere.We sequenced the Betula platyphylla genome and assembled the sequences into 14 chromosomes.The Betula genome lacks evidence of recent whole-genome duplication and has the same paleoploidy level as Vitis vinifera and Prunus mume.Phylogenetic analysis of lignin pathway genes coupled with tissue-specific expression patterns provided clues for understanding the formation of higher ratios of syringyl to guaiacyl lignin observed in Betula species.Our transcriptome analysis of leaf tissues under a time-series cold stress experiment revealed the presence of the MEKK1–MKK2–MPK4 cascade and six additional mitogen-activated protein kinases that can be linked to a gene regulatory network involving many transcription factors and cold tolerance genes.Our genomic and transcriptome analyses provide insight into the structures,features,and evolution of the B.platyphylla genome.The chromosome-level genome and gene resources of B.platyphylla obtained in this study will facilitate the identification of important and essential genes governing important traits of trees and genetic improvement of B.platyphylla.
基金financially supported by the National Science and Technology Program of China during the 12th Five-Year Plan Period(No.2013AA102704)the National Natural Science Foundation of China(NO:31200510)
文摘MADS-box transcription factors show highly diverse regulatory functions in a wide variety of organisms. In this study, we characterized a MADS-box gene （BpMADS12） from the white birch （Betula platyphylla Suk）. This gene is a member of the suppressor of overexpression of CO 1/tomato MADS 3 class of MADS-box genes. We generated lines overexpressing BpMADS12 and found that these had higher levels of lignin compared to that observed in nontransgenic lines. Transcriptome anal- ysis revealed numerous changes in gene expression patterns. In total, 8794 differentially expressed genes were identified, including 5006 upregulated unigenes and 3788 downregulated unigenes in BpMADS-overexpression lines. Differentially expressed genes involved in the pathways for lignin and brassinosteroid biosynthesis were significantly enriched and may have contributed to phenotypic changes. The results from a quantitative RT-PCR analysis were consistent those obtained with the transcriptome analysis.Our transcriptome analysis, in combination with measure- ment of lignin level, indicated that BpMADS12 promotes lignin synthesis through regulation of key enzymes in response to brassinosteroid signaling. These results suggest that this MADS-box protein is crucial to all subsequent structural events and provide a good foundation for studies aiming to elucidate the developmental mechanisms underlying formation of wood.
基金supported by the Applied Technology Research and Development Planning Program of Heilong-jiang Province(GA19B201)the Innovation Project of the State Key Laboratory of Tree Genetics and Breeding(Northeast Forestry University)(2014A02)+1 种基金the Heilongjiang Touyan Innovation Team Program(Tree Genetics and Breeding Innovation Team)the 111 Project(B16010).
文摘Poplar trees are excellent varieties widely used for gardening and greening.However,their single color and floating fluffy seeds are major disadvantages.Plant species or varieties with variegated leaves are desperately needed to meet various demands for gardens,urban greening and landscape decoration,as they produce rich foliage colors that are aesthetically pleasing and functional.In this study,we generated a golden leaf triploid poplar(P.alba×P.berlinensis)by repressing the expression of GLK(Golden2-like)genes in leaves.The triploid golden leaf poplar had reduced chlorophyll content but almost no change in the growth rate.It has great potential in landscaping once it passes safety assessments.
基金supported by the Applied Technology Research and Development Planning Program of Heilongjiang Province(GA19B201).
文摘Cold is an abiotic stress that can greatly affect the growth and survival of plants.Here,we reported that an AP2/ERF family gene,BplERF1,isolated from Betula platyphylla played a contributing role in cold stress tolerance.Overexpression of BplERF1 in B.platyphylla transgenic lines enhanced cold stress tolerance by increasing the scavenging capability and reducing H_(2)O_(2) and malondialdehyde(MDA)content in transgenic plants.Construction of BplERF-mediated multilayered hierarchical gene regulatory network(ML-hGRN),using Top-down GGM algorithm and the transcriptomic data of BplERF1 overexpression lines,led to the identification of five candidate target genes of BplERF1 which include MPK20,ERF9,WRKY53,WRKY70,and GIA1.All of them were then verified to be the true target genes of BplERF1 by chromatin-immunoprecipitation PCR(ChIP-PCR)assay.Our results indicate that BplERF1 is a positive regulator of cold tolerance and is capable of exerting regulation on the expression of cold signaling and regulatory genes,causing mitigation of reactive oxygen species.
基金supported by the National Natural Science Foundation of China(Grant Nos.31370660 and 31670673)the 111 Project(B16010)
文摘Betula platyphylla Sukaczev tetraploids have significantly larger leaf, fruit and stoma (gigantic phenotype) than diploids of the same species;however, the mechanism underlying this difference remains unclear. Tetraploid B. platyphylla transcriptome data have indicated that the expression of genes related to indole-3-acetic acid (IAA) biosynthesis and signal transduction was altered after genome duplication. IAA exerts pleiotropic effects on growth and development by inducing the expression of Aux/IAA. We identified 20 Aux/IAA genes (BpIAA1– BpIAA20) in B. platyphylla distributed across 10 chromosomes. Multiple alignment and motif analyses revealed that nine BpIAA proteins shared all four conserved domains. Phylogenetic analysis indicated that Aux/IAA families were divided into four subfamilies and that there were two pairs of BpIAA sister genes. The BpIAAs were differentially expressed in diploids and tetraploids. Moreover, the expression levels of the nine BpIAA genes were specifically up-regulated in tetraploids from June to September compared with May (except August 5th) in tetraploids, while they were down-regulated in diploids. IAA levels were more than twofold higher in tetraploids than diploids during the vegetative season. These results indicate that genome duplication of B. platyphylla caused the up-regulated of genes involved in IAA synthesis, and the increased concentration of IAA may induce the constitutive expression of 20 BpIAA genes. Therefore, the significant changes in the expression patterns of the BpIAAs contributed to the gigantic phenotype of tetraploids to some extent. Our research sheds light on the phenotypic variations observed in B. platyphylla tetraploids.
基金supported by the National Natural Science Foundation of China(31271753)the National Key Technology R&D Program of China(2012AA101106)+5 种基金the Agricultural Science and Technology Innovation Program(ASTIP)Development and Application of Molecular Markers in Cropsthe Agricultural Science and Technology Innovation Programthe National Key Basic Research Program of China(2009CB118400)the Crop Germplasm Resources Protection(2014NWB030,2015NWB030-05)the Platform of National Crop Germplasm Resources of China(2014-004,2015-004)
文摘Stem growth habit is an important agronomic trait in soybean and is subject to artificial selection. This study aimed to provide a theory for genotypic selection of stem growth habit for breeding purposes by analyzing the alleles of Gm Tfl1 gene in Chinese soybean varieties and establishing a database of Gm Tfl1 variation. Using knowledge of insertion and deletion(Indel) in the non-coding region and four single-nucleotide polymorphisms(SNPs) in the coding sequences of the Gm Tfl1 gene, four CAPS and one Indel markers were developed and used to test 1120 Chinese soybean varieties. We found that the dominant Gm Tfl1 allele was prevalent in accessions from the Northern ecoregion, whereas the recessive allele, Gmtfl1, was more common in the Southern ecoregion, and the proportions of Gm Tfl1 and recessive alleles were respectively 40.1% and 59.9% in the Huang-Huai ecoregion. The proportion of Gm Tfl1 decreased and that of Gmtfl1 increased, gradually from north to south. Allele Gm Tfl1-a was present in higher proportions in the Huang-Huai spring, Huang-Huai summer, and Northern spring sub-ecoregions than that in the other sub-ecoregions. Gm Tfl1-b was common in the Northeast spring, Northern spring and Southern summer sub-ecoregions. Gmtfl1-ta was found mainly in the Huang-Huai spring,Huang-Huai summer and Southern spring sub-ecoregions. The Gmtfl1-ab allele was distributed in all six soybean sub-ecoregions. The Gmtfl1-bb allele was distributed mainly in the Huang-Huai spring and summer and Southern spring and summer sub-ecoregions,but the Gmtfl1-tb allele was detected only in the Huang-Huai summer sub-ecoregion. The distributions of Gm Tfl1 and Gmtfl1 have shown no large changes in nearly 60 years of breeding, but the frequency of the recessive genotype Gmtfl1 has shown a rising trend in the last 20 years. This study provides a theoretical foundation for breeding new soybean varieties for different ecoregions.
基金supported by National Key R&D Program of China during the 14th Five-year Plan Period(2021YFD2200102)Heilongjiang Touyan Innovation Team Program(Tree Genetics and Breeding Innovation Team)。
文摘White birch(Betula platyphylla)is precious material for pulpwood and widely distributed in 14 provinces of China.Previous study indicated that inhibited expression of a gene encoding an auxin amide synthase,BpGH3.5,in transgenic plants reduced the level of IAA–amino acid conjugation,resulting in more free IAA,thereby better growth of birch.Utilizing transgenic-B pGH3.5 lines to increase wood production in a wide range of environments is the goal for breeders.In three field trials here,we measured tree height,diameter at breast height,and volume of 16 BpGH3.5-transgenic 7-year-old white birch lines(including 12 antisense strand lines and 4 overexpression lines)and a wild-type white birch line from three sites that varied greatly in their environmental conditions.To select elite BpGH3.5-transgenic lines for each target environment,we used an additive main effects and multiplicative interaction model to analyze genotype by environment interaction,growth adaptability and stability.The selection criteria for elite transgenic lines were set as the average volume plus 0.75 times the standard deviation for the tested lines at each test site.Results showed that the effect of line and site for height was highly significant(P<0.01),and the effect of line×site was significant(P<0.05);selected as the elite lines were FG12,FG13 and FG27 at the Maoershan Experimental Forest Farm,FG13 and FG32 at the Shidaohe Forest Farm,and FG3 and FG31 at the Ecological Experiment Forest Farm.These seven high-yield,stable lines can now be tested in production trials or adjacent trial areas with similar environmental conditions,while the high-yield,unstable lines should be tested in production trials in areas deemed suitable for their growth.These results provide guidance on which released transgenic elite lines will grow best in a wide range of conditions.
基金supported by the National Key Research and Development Programme of China(No.2017YFD0600603)the 111 Project(No.B16010)the Heilongjiang Touyan Innovation Team Program(Tree Genetics and Breeding Innovation Team)。
文摘Betula platyphylla is a native tree species in northern China that has high economic and medicinal value.We developed an efficient protocol for the induction of somatic embryogenesis in B.platyphalla from immature zygotic embryos and assessed the effects of explant type,genotype,and plant growth regulators(PGRs)on embryogenic callus induction.Among the various explants evaluated,embryogenic callus was only produced from mature and immature zygotic embryos on medium with added 2,4-dichlorophenoxyacetic acid(2,4-D).Supplementation of 2,4-D-containing medium with cytokinins increased the frequency of embryogenic callus induction.On the 20 days after pollination,immature zygotic embryos that had been collected in mid-May yielded embryogenic tissue at the highest frequency(16.8%)when cultured on half-strength MS medium supplemented with 2.0 mg L^(-1)2,4-D and 0.2 mg L^(-1)6-benzylaminopurine(6-BA).The process of proliferation of embryogenic callus,somatic embryo formation,and subsequent plantlet conversion occurred under optimal culture conditions.When regenerated plants weretransplanted to soil,95%of them developed normally and grew vigorously.This somatic embryogenesis system required 3–4 months for the regeneration of B.platyphalla plantlets from immature zygotic embryos.
基金supported by National Key R&D Program for Crop Breeding (2016YFD0100201)the Crop Germplasm Resources Protection (2014NWB030, 2015NWB030-05)+1 种基金Platform of National Crop Germplasm Resources of China (2014-004, 2015-004)The Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences (CAAS)
文摘Mutagenized populations have provided important materials for introducing variation and identifying gene function in plants. In this study, an ethyl methanesulfonate（EMS）-induced soybean（Glycine max） population,consisting of 21,600 independent M_2 lines, was developed.Over 1,000 M_（4（5））families, with diverse abnormal phenotypes for seed composition, seed shape, plant morphology and maturity that are stably expressed across different environments and generations were identified. Phenotypic analysis of the population led to the identification of a yellow pigmentation mutant, gyl, that displayed significantly decreased chlorophyll（Chl） content and abnormal chloroplast development. Sequence analysis showed that gyl is allelic to Minn Gold, where a different single nucleotide polymorphism variation in the Mg-chelatase subunit gene（ChlI1a） results in golden yellow leaves. A cleaved amplified polymorphic sequence marker was developed and may be applied to marker-assisted selection for the golden yellow phenotype in soybean breeding. We show that the newly developed soybean EMS mutant population has potential for functional genomics research and genetic improvement in soybean.
