L-Lysine was produced by a microbial process utilizing a Corynebacterium glutamicum （ATCC 21799） strain. L-Lysine was purified from the cultivated medium by fixed-bed and simulated moving bed （SMB） chromatography....L-Lysine was produced by a microbial process utilizing a Corynebacterium glutamicum （ATCC 21799） strain. L-Lysine was purified from the cultivated medium by fixed-bed and simulated moving bed （SMB） chromatography. The separation conditions including pH, eluent concentration and Lys+ and Lys2+ adsorption isotherms were studied in batch adsorption. The column capacity, eluent flow rate and eluent concentration have been studied in fixed-bed chromatography. Maximum purification rate of lysine was obtained as 0.066 （g/（g·h）） （per gram resin and per hour） at an eluent flow rate of 10 （mL/min） in fixed-bed chromatography. The results obtained from SMB were 0.11 （g/（g·h）） for L-lysine purification rate and 96% for L-lysine recovery.展开更多
Genetic engineering of forest tree species is regarded as a strategy to reduce worldwide pressure on natural forests, to conserve genetic resources and ameliorate stress on global climate, and to meet growing demand f...Genetic engineering of forest tree species is regarded as a strategy to reduce worldwide pressure on natural forests, to conserve genetic resources and ameliorate stress on global climate, and to meet growing demand for forest wood and timber products. Genetic engineering approaches toward the control or management of fungal pathogens, arthropod herbivores, bacterial and viral diseases, the use of pest resistance genes, and weed competitors are being studied. Although the production of transgenic trees is relatively recent and only a few species have been successfully genetically engineered in forest tree species, very useful and valuable information is available on the application of transgenic trees. Genes involved in important agricultural traits such as herbicide resistance, insect resistance, and wood quality have been isolated and have been used to genetically engineer trees. New technologies of plant molecular biology and genomics now make it possible high-efficient genetic improvement of forest trees. Genetic engineering promises to expand greatly the potential for genetic manipulation as new genes of commercial interest are discovered and utilized. Lignification is a process essential to the nature and evolution of vascular plants that is still poorly understood, even though it has been studied for more than a century. Recent studies on mutant and transgenic plants indicate that lignification may be far more flexible than previously realized. Rines with a mutation affecting the biosynthesis of the major lignin precursor, coniferyl alcohol, show a high level of an unusual subunit, dihydroconiferyl alcohol. It is also unusual as a plant polymer in that there are no plant enzymes for its degradation. These results have significant implications regarding the tradiational definition of lignin, and highlight the need for a better understanding of the lignin precursor biosynthetic pathway. In this review, we describe the progress made recently in genetic engineering of forest tree species.展开更多
Doubled haploid(DH)plants have been widely used for breeding and biological research in crops.Pop ulus spp.have been used as model woody plant species for biological research.However,the induction of DH poplar plants ...Doubled haploid(DH)plants have been widely used for breeding and biological research in crops.Pop ulus spp.have been used as model woody plant species for biological research.However,the induction of DH poplar plants is onerous,and limited biological or breeding work has been carried out on DH individuals or populations.In this study,we provide an effective protocol for poplar haploid induction based on an anther culture method.A total of 96 whole DH plant lines were obtained using an F1hybrid of Populus simonii×P.nigra as a donor tree.The phenotypes of the DH population showed exceptionally high variance when compared to those of half-sib progeny of the donor tree.Each DH line displayed distinct features compared to those of the other DH lines or the donor tree.Additionally,some excellent homozygous lines have the potential to be model plants in genetic and breeding studies.展开更多
The Betula genus contains pentacyclic triterpenoid betulin known for its environmental adaptation and medicinal properties.However,the mechanisms underlying betulin biosynthesis responding to climate change remain unc...The Betula genus contains pentacyclic triterpenoid betulin known for its environmental adaptation and medicinal properties.However,the mechanisms underlying betulin biosynthesis responding to climate change remain unclear.In this study,the role of epigenetic modification(DNA methylation) in betulin biosynthesis was examined and how climatic factors influence it.Whole-genome bisulfite sequencing was performed for greenhouse-grown Chinese white birch(Betula platyphylla Sukaczev) treated with DNA methylation inhibitor zebularine(ZEB) and a natural birch population in Northeast China.ZEB treatment significantly affected the CHH methylation level of transposable elements and betulin content in a hormesis dose-dependent manner.The methylation and expression of bHLH9,a key transcriptional factor controlling betulin biosynthesis,were also consistently affected by ZEB treatment as a hormetic dose-response.In the natural population,there was a positive correlation between promoter methylation of bHLH9 and summer precipitation,while winter temperature was negatively correlated.Thus climate-dependent methylation of bHLH9 regulates the expression of downstream genes involved in betulin biosynthesis.This study highlights the role of environmental signals to induce epigenetic changes that result in betulin production,possibly helping to develop resilient plants to combat ongoing climate change and enhance secondary metabolite production.展开更多
Populus spp.have long been used as model woody plant species for molecular biology research.However,tissues of poplar are often recalcitrant to experimental procedures for molecular studies.We generated a hormone auto...Populus spp.have long been used as model woody plant species for molecular biology research.However,tissues of poplar are often recalcitrant to experimental procedures for molecular studies.We generated a hormone autotrophic poplar suspension cell line from a hybrid of Populus alba×P.berolinensis‘Yinzhong’,named Qu-2.Qu-2 cells are suitable as a model biological system for studying woody plants.Qu-2 cells have many advantages over suspension cell lines derived so far from any other woody plants.Qu-2 cells are very easy to cultivate and can grow on several common plant culture media without the addition of any plant hormone.They show exceptionally high growth rates,reaching an approximately 150-fold increase in biomass after one week of culturing.Another important unique characteristic of Qu-2 cells is that they can be cryopreserved and readily reactivated.Qu-2 cells are suitable for molecular manipulations such as protoplast production,transient transformation,and RNA-seq analysis.Therefore,Qu-2 cells have the great potential to be an excellent model cell line in tree molecular biological research,ranging from physiology to gene function.The Qu-2 cells will be made available to the plant community for research.展开更多
文摘L-Lysine was produced by a microbial process utilizing a Corynebacterium glutamicum （ATCC 21799） strain. L-Lysine was purified from the cultivated medium by fixed-bed and simulated moving bed （SMB） chromatography. The separation conditions including pH, eluent concentration and Lys+ and Lys2+ adsorption isotherms were studied in batch adsorption. The column capacity, eluent flow rate and eluent concentration have been studied in fixed-bed chromatography. Maximum purification rate of lysine was obtained as 0.066 （g/（g·h）） （per gram resin and per hour） at an eluent flow rate of 10 （mL/min） in fixed-bed chromatography. The results obtained from SMB were 0.11 （g/（g·h）） for L-lysine purification rate and 96% for L-lysine recovery.
文摘Genetic engineering of forest tree species is regarded as a strategy to reduce worldwide pressure on natural forests, to conserve genetic resources and ameliorate stress on global climate, and to meet growing demand for forest wood and timber products. Genetic engineering approaches toward the control or management of fungal pathogens, arthropod herbivores, bacterial and viral diseases, the use of pest resistance genes, and weed competitors are being studied. Although the production of transgenic trees is relatively recent and only a few species have been successfully genetically engineered in forest tree species, very useful and valuable information is available on the application of transgenic trees. Genes involved in important agricultural traits such as herbicide resistance, insect resistance, and wood quality have been isolated and have been used to genetically engineer trees. New technologies of plant molecular biology and genomics now make it possible high-efficient genetic improvement of forest trees. Genetic engineering promises to expand greatly the potential for genetic manipulation as new genes of commercial interest are discovered and utilized. Lignification is a process essential to the nature and evolution of vascular plants that is still poorly understood, even though it has been studied for more than a century. Recent studies on mutant and transgenic plants indicate that lignification may be far more flexible than previously realized. Rines with a mutation affecting the biosynthesis of the major lignin precursor, coniferyl alcohol, show a high level of an unusual subunit, dihydroconiferyl alcohol. It is also unusual as a plant polymer in that there are no plant enzymes for its degradation. These results have significant implications regarding the tradiational definition of lignin, and highlight the need for a better understanding of the lignin precursor biosynthetic pathway. In this review, we describe the progress made recently in genetic engineering of forest tree species.
基金supported by the National Key R&D Program of China(2021YFD2200203)Heilongjiang Province Key R&D Program of China(GA21B010)+1 种基金Heilongjiang Touyan Innovation Team Program(Tree Genetics and Breeding Innovation Team)Heilongjiang Postdoctoral Financial Assistance(LBH-Z21097)。
文摘Doubled haploid(DH)plants have been widely used for breeding and biological research in crops.Pop ulus spp.have been used as model woody plant species for biological research.However,the induction of DH poplar plants is onerous,and limited biological or breeding work has been carried out on DH individuals or populations.In this study,we provide an effective protocol for poplar haploid induction based on an anther culture method.A total of 96 whole DH plant lines were obtained using an F1hybrid of Populus simonii×P.nigra as a donor tree.The phenotypes of the DH population showed exceptionally high variance when compared to those of half-sib progeny of the donor tree.Each DH line displayed distinct features compared to those of the other DH lines or the donor tree.Additionally,some excellent homozygous lines have the potential to be model plants in genetic and breeding studies.
基金the National Non-profi t Institute Research Grant of the Chinese Academy of Forestry(CAFYBB2019ZY003)the National Natural Science Foundation of China(31871220 and 31801444)+2 种基金the Innovation Project of State Key Laboratory of Tree Genetics andBreeding(Northeast Forestry University)(2013A06)the Fundamental Research Funds for the Central Universities(2572017DA06 and 2572020DP01)Heilongjiang Provincial Natural Science Foundation of China(LH2021C005).
文摘The Betula genus contains pentacyclic triterpenoid betulin known for its environmental adaptation and medicinal properties.However,the mechanisms underlying betulin biosynthesis responding to climate change remain unclear.In this study,the role of epigenetic modification(DNA methylation) in betulin biosynthesis was examined and how climatic factors influence it.Whole-genome bisulfite sequencing was performed for greenhouse-grown Chinese white birch(Betula platyphylla Sukaczev) treated with DNA methylation inhibitor zebularine(ZEB) and a natural birch population in Northeast China.ZEB treatment significantly affected the CHH methylation level of transposable elements and betulin content in a hormesis dose-dependent manner.The methylation and expression of bHLH9,a key transcriptional factor controlling betulin biosynthesis,were also consistently affected by ZEB treatment as a hormetic dose-response.In the natural population,there was a positive correlation between promoter methylation of bHLH9 and summer precipitation,while winter temperature was negatively correlated.Thus climate-dependent methylation of bHLH9 regulates the expression of downstream genes involved in betulin biosynthesis.This study highlights the role of environmental signals to induce epigenetic changes that result in betulin production,possibly helping to develop resilient plants to combat ongoing climate change and enhance secondary metabolite production.
基金supported by the National Key Research and Development Program of China(2016YFD0600106)the National Natural Science Foundation of China(31670675)the Fundamental Research Funds for the Central Universities(2572018CL01 and 2572018CL02).
文摘Populus spp.have long been used as model woody plant species for molecular biology research.However,tissues of poplar are often recalcitrant to experimental procedures for molecular studies.We generated a hormone autotrophic poplar suspension cell line from a hybrid of Populus alba×P.berolinensis‘Yinzhong’,named Qu-2.Qu-2 cells are suitable as a model biological system for studying woody plants.Qu-2 cells have many advantages over suspension cell lines derived so far from any other woody plants.Qu-2 cells are very easy to cultivate and can grow on several common plant culture media without the addition of any plant hormone.They show exceptionally high growth rates,reaching an approximately 150-fold increase in biomass after one week of culturing.Another important unique characteristic of Qu-2 cells is that they can be cryopreserved and readily reactivated.Qu-2 cells are suitable for molecular manipulations such as protoplast production,transient transformation,and RNA-seq analysis.Therefore,Qu-2 cells have the great potential to be an excellent model cell line in tree molecular biological research,ranging from physiology to gene function.The Qu-2 cells will be made available to the plant community for research.
