Hybridization remains an important method for breeding new poplar varieties.It results in significant variation in leaf phenotype among parents and offspring,and among offspring themselves.This study aimed to investig...Hybridization remains an important method for breeding new poplar varieties.It results in significant variation in leaf phenotype among parents and offspring,and among offspring themselves.This study aimed to investigate whether leaf shape variations were similar in offspring produced from reciprocal crosses.Specifically,two hybrid combinations were produced:the direct cross with Populus ussuriensis as the maternal parent and P.simonii×P.nigra as the paternal parent(HY53),and the reciprocal cross with P.simonii×P.nigra as the maternal parent and P.ussuriensis as the paternal parent(HY268).Using 3-month-old rooted cuttings from 40 clones(36 F1 hybrids and their parents)growing in a greenhouse,we measured and analyzed 14 leaf morphological traits to assess genetic variation and heterosis.The results showed HY53 clones generally exhibited greater average height than HY268 clones.Leaf phenotypes differed between the two hybrid combinations,with significant differences observed among parents and offspring for almost all traits,as revealed by analysis of variance(ANOVA).The phenotypic coefficient of variation was higher in HY268 clones.Additionally,leaf traits demonstrated high repeatability.Notably,some hybrid offspring exhibited positive or negative mid-parent heterosis,as well as over-parent heterosis for certain leaf phenotypes.The systematic cluster analysis further indicated distinct separation among HY268 clones.This research provides valuable materials for poplar breeding and offers insights into hybrid vigor in wood plants.The findings highlight the importance of reciprocal crossing in influencing leaf phenotype variation and heterosis,offering practical insights for future breeding strategies.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
We investigated phenotypic variation ofPopulus simonii from five provenances in northern China. Our results show that significant differences exist between plants of different provenances in morphological and physiolo...We investigated phenotypic variation ofPopulus simonii from five provenances in northern China. Our results show that significant differences exist between plants of different provenances in morphological and physiological traits, except for leaf-stalk length and the number of leaf margins. The coefficient of variation for all traits ranges from 14.77% to 81.49%. The mean phenotypic coefficient of differentiation （VST） is 47.1%, which means that the variation within provenances is the major source for phenotypic variation in P. simonii. Given our cluster analysis of provenances based on an average linkage computing method, the five provenances ofP. simonii investigated could be divided into three groups. Our results provide a theoretical basis for genetic resource conservation and provenance selection of natural P. simonii in northern China.展开更多
Aldehydes play an important role in atmospheric chemistry and plant direct and indirect defense against environmental stresses.In this study,the emissions of saturated C6-C10 aldehydes from Populus simonii × P.py...Aldehydes play an important role in atmospheric chemistry and plant direct and indirect defense against environmental stresses.In this study,the emissions of saturated C6-C10 aldehydes from Populus simonii × P.pyramidalis ＇Opera 8277＇ cuttings were examined by using a gas chromatography/mass spectrometry（GC/MS） technique at three levels of light intensity（400,800 and 1 200 μmol·m-2·s-1）.A positive correlation between the emissions of these aldehydes and light intensity was found.Moreover,nordi-hydroguaiaretic acid（NDGA）,a special inhibitor of lipoxygenase（LOX）,significantly inhibited the emissions of C6-C9 aldehydes at three levels of light intensity,but did not influence the emission of decanal（C10）.The emissions of C6-C10 aldehydes in NDGA treated poplar cuttings,exhibited the same positive correlation with light intensity.The results indicated that LOX pathway contributes to the emissions of C6-C9 aldehydes,whereas some pathways regulated by light intensity might be a universal mechanism for emissions of C6-C10 aldehydes.展开更多
A reliable,efficient anther culture system,the dominant technique for generating haploid plants in breeding programs,that can be used for generating transgenic poplar plants has been needed.In the present study,theref...A reliable,efficient anther culture system,the dominant technique for generating haploid plants in breeding programs,that can be used for generating transgenic poplar plants has been needed.In the present study,therefore,an anther culture system was developed using isolated mid-and late-uninucleate anthers of poplar(Populus simonii x P.nigra).From a combination of SSR and ploidy analyses,six double haploid and two haploid lines were characterized from 86 plants grown from 16 regenerated anther cultured lines.After 48 months of development,two plant lines from the regenerated plants maintained their haploid level in vitro for over 2 years.A number of haploid plants from the different lines weretransferred to soil.The leaves of these transplants were then used as explants for transformation with the APETALA1(AP1) gene using Agrobacterium tumefaciens.Overexpression of AP1 in haploid poplar induced early flowering with obvious petals when ectopically expressed.To our knowledge,this is the first report on changes in flowering time in AP1-trangenic poplar,which is important for elucidating the regulatory mechanism of tree flower development.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
Pollen development and floral morphology of Populus pseudo-simonii were investigated by stain-squashing and anatomical techniques. It took approximately 16 days for the pollen to develop from pollen mother cells to ma...Pollen development and floral morphology of Populus pseudo-simonii were investigated by stain-squashing and anatomical techniques. It took approximately 16 days for the pollen to develop from pollen mother cells to mature pollen in the green-house. Meiosis of pollen mother cells was regularly applied and completed by a process of simultaneous cytokinesis. Pollen development was considerably asynchronous. The meiotic division was initiated at the bulgy middle position of the flower bud and proceeded towards the tip and base of the bud. The number and size of the nucleoli varied during pollen development and at most eight nucleoli formed in each daughter nucleus at the meiotic telophase, suggesting a paleopolyploid origin of the genus Populus. An association between floral morphology and pollen development was found and the ratio of width to length of flower buds or catkins presented an S-shaped curve related to pollen development as a function of time. The investigation on the pollen development and floral morphology ofP. pseudo-simonii is important for further cross breeding programs of the section Tacamahaca.展开更多
Populus simonii Carr., one of the main poplar tree species, is cultivated widely in Northeast and Northwest China in protection and timber forests. Plant phenology plays an important role in timber production by contr...Populus simonii Carr., one of the main poplar tree species, is cultivated widely in Northeast and Northwest China in protection and timber forests. Plant phenology plays an important role in timber production by controlling the growing period (i.e., the period between the leaf unfolding and the leaf turning yellow). It is important to understand this control mechanism and to improve the accuracy of the simulation of leaf unfolding phenology for P. simonii in order to determine accurately the timber production of P. simonii plantations. In this study, based on phenological observation data from 10 agricultural meteorological stations in Heilongjiang Province, China, model simulation was employed to determine the control mechanism of leaf unfolding of P. simonii. Furthermore, the predicting effects of nine phenology-simulating models for P. simonii leaf unfolding were evaluated and the distribution characteristics of P. simonii leaf unfolding in China in 2015 were simulated. The results show that P. simonii leaf unfolding is sensitive to air temperature;consequently, climate warming could advance the P. simonii leaf unfolding process. The phenological model based on air temperature could be better suited for simulating P. simonii leaf unfolding, with 76.7% of the calibration data of absolute error being less than three days. The performance of the models based solely on forcing requirements was found superior to that of the models incorporating chilling. If it was imperative that the chilling threshold is reached, the south of the Yunnan, Guangdong, and Guangxi provinces would be unsuitable for planting P. simonii. In this regard, the phenology model based on the chilling threshold as necessary condition was indicated a more reasonable model for the distribution characteristics of P. simonii leaf unfolding.展开更多
As an important ecological tree species in northern China, Populus simonii plays a crucial role in maintaining ecological balance and promoting environmental sustainability. The academic community has conducted a seri...As an important ecological tree species in northern China, Populus simonii plays a crucial role in maintaining ecological balance and promoting environmental sustainability. The academic community has conducted a series of in-depth studies on this species, covering key areas such as genomics, survival mechanisms, and genetic breeding. Through the analysis of the genomic structure and function of P. simonii, we have not only revealed the molecular basis for its adaptation to harsh environments but also identified key genes that promote its growth and resistance to pests and diseases. Furthermore, exploring the survival mechanisms of P. simonii has deepened our understanding of its stress resistance traits, including how it effectively copes with abiotic stresses such as drought, salinization, and heavy metal pollution. In genetic breeding, significant progress has been made through the application of modern biotechnology, improving the growth rate and wood quality of P. simonii and enhancing its environmental adaptability and disease resistance. These research findings have not only enriched our knowledge of the biological characteristics of P. simonii but also provided a solid scientific foundation for its application in ecological restoration, forestry production, and environmental management.展开更多
理解新疆杨(Populus alba var.pyramidalis)耗水特征对制定沙地人工林科学用水灌溉策略以及林场经营建设具有重要意义。采用包裹式树干茎流仪测定新疆杨液流,并对毛乌素沙地的环境因子进行长期监测。结果表明:新疆杨晴天液流速率最大,...理解新疆杨(Populus alba var.pyramidalis)耗水特征对制定沙地人工林科学用水灌溉策略以及林场经营建设具有重要意义。采用包裹式树干茎流仪测定新疆杨液流,并对毛乌素沙地的环境因子进行长期监测。结果表明:新疆杨晴天液流速率最大,阴天次之,雨天最小,日液流累计量分别为16.38、12.56、2.22 L,晴天和阴天的液流速率接近。5、6、7、8、9、10月的日平均液流量分别为12.12、14.07、14.08、11.60、8.73、3.92 L,5—8月是新疆杨主要的耗水期,累计耗水量为1722.53 L。新疆杨液流与净辐射、饱和水汽压差、气温、太阳辐射、土壤热通量、土壤温度显著正相关,相关系数分别为0.656、0.641、0.634、0.625、0.605、0.467;与土壤湿度、空气相对湿度、降水量显著负相关,相关系数分别为-0.340、-0.233、-0.178;与风速相关性不显著。净辐射对于新疆杨液流的影响最大。展开更多
Tyrosine decarboxylase(TyDC)converts tyrosine to tyramine and plays a crucial role in secondary metabolite reactions,development,and stress responses in plants.Currently,the biological role of TyDC proteins from trees...Tyrosine decarboxylase(TyDC)converts tyrosine to tyramine and plays a crucial role in secondary metabolite reactions,development,and stress responses in plants.Currently,the biological role of TyDC proteins from trees is unknown.This study provided evidence showing that poplar PaTyDC4 functions in wood development and drought stress response.PaTyDC4 is preferentially expressed in wood-forming cells in stems.Overexpression of PaTyDC4 in poplars under the control of a xylem-specific promoter resulted in an increase in the ratio of xylem to phloem width,vessel cell area,and lignin accumulation in the stems.Biochemical assays revealed that PaTyDC4 was a component of the PaC3H17-PaMYB199 module-mediated pathway.In poplar stems,Pa TyDC4 expression was directly suppressed by PaMYB199,which was attenuated by the interaction between PaC3H17 and PaMYB199.In addition,Pa TyDC4 overexpression lines showed stronger drought tolerance than the wild-type lines,with higher photosynthetic capacity and lower levels of H_(2)O_(2).These results indicate that PaTyDC4 promotes xylem differentiation and lignin deposition during secondary growth and confers drought tolerance.Our findings may be useful for the genetic modification of biomass and drought resistance in trees.展开更多
Short rotation plantation forestry(SRF)is being widely adopted to increase wood production,in order to meet global demand for wood products.However,to ensure maximum gains from SRF,optimised management regimes need to...Short rotation plantation forestry(SRF)is being widely adopted to increase wood production,in order to meet global demand for wood products.However,to ensure maximum gains from SRF,optimised management regimes need to be established by integrating robust predictions and an understanding of mechanisms underlying tree growth.Hybrid ecophysiological models,such as potentially useable light sum equation(PULSE)models,are useful tools requiring minimal input data that meet the requirements of SRF.PULSE models have been tested and calibrated for different evergreen conifers and broadleaves at both juvenile and mature stages of tree growth with coarse soil and climate data.Therefore,it is prudent to question:can adding detailed soil and climatic data reduce errors in this type of model?In addition,PULSE techniques have not been used to model deciduous species,which are a challenge for ecophysiological models due to their phenology.This study developed a PULSE model for a clonal Populus tomentosa plantation in northern China using detailed edaphic and climatic data.The results showed high precision and low bias in height(m)and basal area(m^(2)·ha^(-1))predictions.While detailed edaphoclimatic data produce highly precise predictions and a good mechanistic understanding,the study suggested that local climatic data could also be employed.The study showed that PULSE modelling in combination with coarse level of edaphic and local climate data resulted in reasonably precise tree growth prediction and minimal bias.展开更多
With the rapid development of nuclear energy,the removal of radioactive iodine generated during spent fuel reprocessing has become increasingly important.Based on the unique straw-like structure of populus tomentosa f...With the rapid development of nuclear energy,the removal of radioactive iodine generated during spent fuel reprocessing has become increasingly important.Based on the unique straw-like structure of populus tomentosa fiber(PTF)and the highly active iodine vapor capture ability of zero-valent silver nanoparticles(PTF@Ag^(0)NP),an Ag^(0)NP composite functional material with highly efficient iodine vapor capture capability was synthesized from biowaste PTF through ultrasonic and hightemperature hydrothermal methods in this study.The iodine capture experiment demonstrated that PTF@Ag^(0)NP exhibits rapid iodine capture efficiency,reaching dynamic equilibrium within 4 h and a maximum capture capacity of 1008.1 mg/g.Density functional theory calculations show that PTF@Ag^(0)NP exhibits extremely high chemical reactivity toward iodine,with a reaction binding energy of-2.88 e V.Additionally,the molecular dynamics of PTF@Ag^(0)NP indicate that there is no atomic displacement at 77?C,indicating the excellent temperature stability of the material at the operating temperature.The capture mechanism suggests that iodine vapor primarily reacts with Ag^(0)NP to form Ag I,and that the hydroxyl groups in PTF can also effectively capture iodine vapor by adsorption induction.In conclusion,PTF@Ag^(0)NP is expected to be an effective candidate adsorbent material for removing radioactive iodine vapor from exhaust gases during spent fuel reprocessing.展开更多
基金supported by“National Key R&D Program of China(2021YFD2200203)”“the Fundamental Research Funds for the Central Universities(No.2572022AW02 and No.2572023CT19)”。
文摘Hybridization remains an important method for breeding new poplar varieties.It results in significant variation in leaf phenotype among parents and offspring,and among offspring themselves.This study aimed to investigate whether leaf shape variations were similar in offspring produced from reciprocal crosses.Specifically,two hybrid combinations were produced:the direct cross with Populus ussuriensis as the maternal parent and P.simonii×P.nigra as the paternal parent(HY53),and the reciprocal cross with P.simonii×P.nigra as the maternal parent and P.ussuriensis as the paternal parent(HY268).Using 3-month-old rooted cuttings from 40 clones(36 F1 hybrids and their parents)growing in a greenhouse,we measured and analyzed 14 leaf morphological traits to assess genetic variation and heterosis.The results showed HY53 clones generally exhibited greater average height than HY268 clones.Leaf phenotypes differed between the two hybrid combinations,with significant differences observed among parents and offspring for almost all traits,as revealed by analysis of variance(ANOVA).The phenotypic coefficient of variation was higher in HY268 clones.Additionally,leaf traits demonstrated high repeatability.Notably,some hybrid offspring exhibited positive or negative mid-parent heterosis,as well as over-parent heterosis for certain leaf phenotypes.The systematic cluster analysis further indicated distinct separation among HY268 clones.This research provides valuable materials for poplar breeding and offers insights into hybrid vigor in wood plants.The findings highlight the importance of reciprocal crossing in influencing leaf phenotype variation and heterosis,offering practical insights for future breeding strategies.
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supported by grants from the Changjiang Scholars Program of the Ministry of Education of China (Prof. Bailian Li)the National Natural Science Foundation of China (Grant Nos. 30600479,30872042)+3 种基金the Major Science Foundation of the Ministry of Education of China (Grant No. 307006)the Foundation for the Author of National Excellent Doctoral Dissertation of the China (Grant No. 200770)the Program for New Century Excellent Talents in University (Grant No. NCET-07-0084)the Introduction of Foreign Advanced Agricultural Science and Technology into China (Grant No. 2009-4-22)
文摘We investigated phenotypic variation ofPopulus simonii from five provenances in northern China. Our results show that significant differences exist between plants of different provenances in morphological and physiological traits, except for leaf-stalk length and the number of leaf margins. The coefficient of variation for all traits ranges from 14.77% to 81.49%. The mean phenotypic coefficient of differentiation （VST） is 47.1%, which means that the variation within provenances is the major source for phenotypic variation in P. simonii. Given our cluster analysis of provenances based on an average linkage computing method, the five provenances ofP. simonii investigated could be divided into three groups. Our results provide a theoretical basis for genetic resource conservation and provenance selection of natural P. simonii in northern China.
基金supported by National Natural Science Foundation of China (30871727 31071817)+1 种基金the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality (PXM20090142076309)the Beijing Science and Technology Plan Program (Z080005032508017)
文摘Aldehydes play an important role in atmospheric chemistry and plant direct and indirect defense against environmental stresses.In this study,the emissions of saturated C6-C10 aldehydes from Populus simonii × P.pyramidalis ＇Opera 8277＇ cuttings were examined by using a gas chromatography/mass spectrometry（GC/MS） technique at three levels of light intensity（400,800 and 1 200 μmol·m-2·s-1）.A positive correlation between the emissions of these aldehydes and light intensity was found.Moreover,nordi-hydroguaiaretic acid（NDGA）,a special inhibitor of lipoxygenase（LOX）,significantly inhibited the emissions of C6-C9 aldehydes at three levels of light intensity,but did not influence the emission of decanal（C10）.The emissions of C6-C10 aldehydes in NDGA treated poplar cuttings,exhibited the same positive correlation with light intensity.The results indicated that LOX pathway contributes to the emissions of C6-C9 aldehydes,whereas some pathways regulated by light intensity might be a universal mechanism for emissions of C6-C10 aldehydes.
基金supported by The Fundamental Research Funds for the Central Universities(2572015EA01)the Innovation Project of State Key Laboratory of Tree Genetics and Breeding(Northeast Forestry University+1 种基金grant number 2013A04)Natural Science Fund of Heilongjiang Province(No.QC2015035)
文摘A reliable,efficient anther culture system,the dominant technique for generating haploid plants in breeding programs,that can be used for generating transgenic poplar plants has been needed.In the present study,therefore,an anther culture system was developed using isolated mid-and late-uninucleate anthers of poplar(Populus simonii x P.nigra).From a combination of SSR and ploidy analyses,six double haploid and two haploid lines were characterized from 86 plants grown from 16 regenerated anther cultured lines.After 48 months of development,two plant lines from the regenerated plants maintained their haploid level in vitro for over 2 years.A number of haploid plants from the different lines weretransferred to soil.The leaves of these transplants were then used as explants for transformation with the APETALA1(AP1) gene using Agrobacterium tumefaciens.Overexpression of AP1 in haploid poplar induced early flowering with obvious petals when ectopically expressed.To our knowledge,this is the first report on changes in flowering time in AP1-trangenic poplar,which is important for elucidating the regulatory mechanism of tree flower development.
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.
基金supported by the National Natural Science Foundation of China (Grant No. 30671708)the National Key Technology R&D Programme of the 11th Five-Year Plan of China (Grant No. 2006BAD32B01)
文摘Pollen development and floral morphology of Populus pseudo-simonii were investigated by stain-squashing and anatomical techniques. It took approximately 16 days for the pollen to develop from pollen mother cells to mature pollen in the green-house. Meiosis of pollen mother cells was regularly applied and completed by a process of simultaneous cytokinesis. Pollen development was considerably asynchronous. The meiotic division was initiated at the bulgy middle position of the flower bud and proceeded towards the tip and base of the bud. The number and size of the nucleoli varied during pollen development and at most eight nucleoli formed in each daughter nucleus at the meiotic telophase, suggesting a paleopolyploid origin of the genus Populus. An association between floral morphology and pollen development was found and the ratio of width to length of flower buds or catkins presented an S-shaped curve related to pollen development as a function of time. The investigation on the pollen development and floral morphology ofP. pseudo-simonii is important for further cross breeding programs of the section Tacamahaca.
文摘Populus simonii Carr., one of the main poplar tree species, is cultivated widely in Northeast and Northwest China in protection and timber forests. Plant phenology plays an important role in timber production by controlling the growing period (i.e., the period between the leaf unfolding and the leaf turning yellow). It is important to understand this control mechanism and to improve the accuracy of the simulation of leaf unfolding phenology for P. simonii in order to determine accurately the timber production of P. simonii plantations. In this study, based on phenological observation data from 10 agricultural meteorological stations in Heilongjiang Province, China, model simulation was employed to determine the control mechanism of leaf unfolding of P. simonii. Furthermore, the predicting effects of nine phenology-simulating models for P. simonii leaf unfolding were evaluated and the distribution characteristics of P. simonii leaf unfolding in China in 2015 were simulated. The results show that P. simonii leaf unfolding is sensitive to air temperature;consequently, climate warming could advance the P. simonii leaf unfolding process. The phenological model based on air temperature could be better suited for simulating P. simonii leaf unfolding, with 76.7% of the calibration data of absolute error being less than three days. The performance of the models based solely on forcing requirements was found superior to that of the models incorporating chilling. If it was imperative that the chilling threshold is reached, the south of the Yunnan, Guangdong, and Guangxi provinces would be unsuitable for planting P. simonii. In this regard, the phenology model based on the chilling threshold as necessary condition was indicated a more reasonable model for the distribution characteristics of P. simonii leaf unfolding.
文摘As an important ecological tree species in northern China, Populus simonii plays a crucial role in maintaining ecological balance and promoting environmental sustainability. The academic community has conducted a series of in-depth studies on this species, covering key areas such as genomics, survival mechanisms, and genetic breeding. Through the analysis of the genomic structure and function of P. simonii, we have not only revealed the molecular basis for its adaptation to harsh environments but also identified key genes that promote its growth and resistance to pests and diseases. Furthermore, exploring the survival mechanisms of P. simonii has deepened our understanding of its stress resistance traits, including how it effectively copes with abiotic stresses such as drought, salinization, and heavy metal pollution. In genetic breeding, significant progress has been made through the application of modern biotechnology, improving the growth rate and wood quality of P. simonii and enhancing its environmental adaptability and disease resistance. These research findings have not only enriched our knowledge of the biological characteristics of P. simonii but also provided a solid scientific foundation for its application in ecological restoration, forestry production, and environmental management.
基金Financial support was obtained from National Natural Science Foundation of China(Grant Nos.32101549 and 32201585)Natural Science Foundation of Shandong Province,China(Grant No.ZR202112010288)+2 种基金Science&Technology Specific Projects in Agricultural High-tech Industrial Demonstration Area of the Yellow River Delta(Grant No.2022SZX39)Technical Innovation and Application Development Special Project of Chongqing(Grant No.CSTB2022TIAD-LDX0013)the Taishan Scholar Program of Shandong(Grant No.tsqn202103092)。
文摘Tyrosine decarboxylase(TyDC)converts tyrosine to tyramine and plays a crucial role in secondary metabolite reactions,development,and stress responses in plants.Currently,the biological role of TyDC proteins from trees is unknown.This study provided evidence showing that poplar PaTyDC4 functions in wood development and drought stress response.PaTyDC4 is preferentially expressed in wood-forming cells in stems.Overexpression of PaTyDC4 in poplars under the control of a xylem-specific promoter resulted in an increase in the ratio of xylem to phloem width,vessel cell area,and lignin accumulation in the stems.Biochemical assays revealed that PaTyDC4 was a component of the PaC3H17-PaMYB199 module-mediated pathway.In poplar stems,Pa TyDC4 expression was directly suppressed by PaMYB199,which was attenuated by the interaction between PaC3H17 and PaMYB199.In addition,Pa TyDC4 overexpression lines showed stronger drought tolerance than the wild-type lines,with higher photosynthetic capacity and lower levels of H_(2)O_(2).These results indicate that PaTyDC4 promotes xylem differentiation and lignin deposition during secondary growth and confers drought tolerance.Our findings may be useful for the genetic modification of biomass and drought resistance in trees.
基金The National Key Research and Development Program of China(Grant No.2021YFD2201203)the 5·5 Engineering Research&Innovation Team Project of Beijing Forestry University(No.BLRC2023C05)the Key Research and Development Program of Shandong Province(No.2021SFGC02050102)。
文摘Short rotation plantation forestry(SRF)is being widely adopted to increase wood production,in order to meet global demand for wood products.However,to ensure maximum gains from SRF,optimised management regimes need to be established by integrating robust predictions and an understanding of mechanisms underlying tree growth.Hybrid ecophysiological models,such as potentially useable light sum equation(PULSE)models,are useful tools requiring minimal input data that meet the requirements of SRF.PULSE models have been tested and calibrated for different evergreen conifers and broadleaves at both juvenile and mature stages of tree growth with coarse soil and climate data.Therefore,it is prudent to question:can adding detailed soil and climatic data reduce errors in this type of model?In addition,PULSE techniques have not been used to model deciduous species,which are a challenge for ecophysiological models due to their phenology.This study developed a PULSE model for a clonal Populus tomentosa plantation in northern China using detailed edaphic and climatic data.The results showed high precision and low bias in height(m)and basal area(m^(2)·ha^(-1))predictions.While detailed edaphoclimatic data produce highly precise predictions and a good mechanistic understanding,the study suggested that local climatic data could also be employed.The study showed that PULSE modelling in combination with coarse level of edaphic and local climate data resulted in reasonably precise tree growth prediction and minimal bias.
基金supported by the Sichuan Outstanding Young Scientific and Technological Talents Project(No.2021JDJQ0016)Doctoral Initiation Project of China West Normal University(No.22k E043)and Science and Technology Project of Sichuan Province(No.2022NSFSC0388)。
文摘With the rapid development of nuclear energy,the removal of radioactive iodine generated during spent fuel reprocessing has become increasingly important.Based on the unique straw-like structure of populus tomentosa fiber(PTF)and the highly active iodine vapor capture ability of zero-valent silver nanoparticles(PTF@Ag^(0)NP),an Ag^(0)NP composite functional material with highly efficient iodine vapor capture capability was synthesized from biowaste PTF through ultrasonic and hightemperature hydrothermal methods in this study.The iodine capture experiment demonstrated that PTF@Ag^(0)NP exhibits rapid iodine capture efficiency,reaching dynamic equilibrium within 4 h and a maximum capture capacity of 1008.1 mg/g.Density functional theory calculations show that PTF@Ag^(0)NP exhibits extremely high chemical reactivity toward iodine,with a reaction binding energy of-2.88 e V.Additionally,the molecular dynamics of PTF@Ag^(0)NP indicate that there is no atomic displacement at 77?C,indicating the excellent temperature stability of the material at the operating temperature.The capture mechanism suggests that iodine vapor primarily reacts with Ag^(0)NP to form Ag I,and that the hydroxyl groups in PTF can also effectively capture iodine vapor by adsorption induction.In conclusion,PTF@Ag^(0)NP is expected to be an effective candidate adsorbent material for removing radioactive iodine vapor from exhaust gases during spent fuel reprocessing.
