Sustainable aviation fuel(SAF)production from biomass and biowaste streams is an attractive option for decarbonizing the aviation sector,one of the most-difficult-to-electrify transportation sectors.Despite ongoing co...Sustainable aviation fuel(SAF)production from biomass and biowaste streams is an attractive option for decarbonizing the aviation sector,one of the most-difficult-to-electrify transportation sectors.Despite ongoing commercialization efforts using ASTM-certified pathways(e.g.,lipid conversion,Fischer-Tropsch synthesis),production capacities are still inadequate due to limited feedstock supply and high production costs.New conversion technologies that utilize lignocellulosic feedstocks are needed to meet these challenges and satisfy the rapidly growing market.Combining bio-and chemo-catalytic approaches can leverage advantages from both methods,i.e.,high product selectivity via biological conversion,and the capability to build C-C chains more efficiently via chemical catalysis.Herein,conversion routes,catalysis,and processes for such pathways are discussed,while key challenges and meaningful R&D opportunities are identified to guide future research activities in the space.Bio-and chemo-catalytic conversion primarily utilize the carbohydrate fraction of lignocellulose,leaving lignin as a waste product.This makes lignin conversion to SAF critical in order to utilize whole biomass,thereby lowering overall production costs while maximizing carbon efficiencies.Thus,lignin valorization strategies are also reviewed herein with vital research areas identified,such as facile lignin depolymerization approaches,highly integrated conversion systems,novel process configurations,and catalysts for the selective cleavage of aryl C-O bonds.The potential efficiency improvements available via integrated conversion steps,such as combined biological and chemo-catalytic routes,along with the use of different parallel pathways,are identified as key to producing all components of a cost-effective,100%SAF.展开更多
Blastopsylla occidentalis Taylor是原产于澳大利亚的木虱种类,目前已经扩散到北美、南美、非洲、欧洲和亚洲。本文记述了B.occidentalis在中国的发生,并首次记录了其在澳大利亚以外的地区被寄生。这个种依赖于桉属Eucalyptus植物,其...Blastopsylla occidentalis Taylor是原产于澳大利亚的木虱种类,目前已经扩散到北美、南美、非洲、欧洲和亚洲。本文记述了B.occidentalis在中国的发生,并首次记录了其在澳大利亚以外的地区被寄生。这个种依赖于桉属Eucalyptus植物,其寄主超过20种,这可能是使其在世界范围扩散的一个重要因素。指出了B.occidentalis与桉树芽木虱Blastopsylla barbara Li为同种异名。展开更多
AIM: To investigate p53 mutation and p21 expression in hepatocarcinogenesis induced by hepatitis B virus (HBV) and aflatoxin B1 (AFB1) in tree shrews, and to reveal the role of these genes in hepatocarcinogenesis.METH...AIM: To investigate p53 mutation and p21 expression in hepatocarcinogenesis induced by hepatitis B virus (HBV) and aflatoxin B1 (AFB1) in tree shrews, and to reveal the role of these genes in hepatocarcinogenesis.METHODS: Tree shrews were divided into four groups:group A, those infected with HBV and fed with AFB1 (n = 39);group B, those infected with HBV alone (n = 28); group C,those fed with AFB1 alone (n = 29); and group D, normal controls (n = 20). The tree shrews underwent liver biopsies once every 15 wk. Expression of p53 and p21 proteins and genes in the biopsies and tumor tissues of the experimental tree shrews was detected, respectively, by immunohistochemistry,and by Southem blotting and reverse transcription-polymerase chain reaction and sequencing.RESULTS: The incidence of hepatocellular carcinomas (HCC) was higher in group A (66.7%) than that in group B (3.57%) and C (30%). The time of HCC occurrence was also earlier in group A than that in group C (120.0±16.6 wk vs 153.3±5.8 wk, respectively, P<0.01). p53 protein was not detected by immunohistochemistry in all groups before the 75^th wk of the experiment. At the 105^th wk, the positive rates fo p53 were 78.6%, 60% and 71.4% in groups A, B and C, respectively, which were significantly higher than that in group D (10%) (all P<0.05). An abnormal band of p53 gene was observed in groups A and C. The mutation points of p53gene in tree shrews with HCC were at codons 275, 78 and 13. The nucleotide sequence and amino acid sequence of tree shrew's wild-type p53 showed 91.7% and 93.4% homologies with those of human p53,respectively. The immunopositivity for p21 was found before HCC development. The incidence of HCC was significantly higher in tree shrews that were positive for p21 than those negative for p21 (80.0% vs 11.0%, P<0.001).The incidence of HCC in p21 positive animals in group A was significantly higher than those positive for p21 in group C (P<O.05).CONCLUSION: A remarkable synergistic effect on HCC development exists between HBV and AFB1. p53 mutation promotes the development of HCC. HBV and AFB1 may synergistically induce p53 gene mutation, and stimulate ras gene expression, ras gene is activated at the earlier stage during hepatocarcinogenesis, p21 protein may be an early marker, and the alterations of p53 may be a late event in the development of HCC.展开更多
AIM To examine the relationship between serum autotaxin(ATX) concentrations and clinicopathological findings in non-alcoholic fatty liver disease(NAFLD) patients.METHODS One hundred eighty-six NAFLD patients who had u...AIM To examine the relationship between serum autotaxin(ATX) concentrations and clinicopathological findings in non-alcoholic fatty liver disease(NAFLD) patients.METHODS One hundred eighty-six NAFLD patients who had undergone liver biopsy between 2008 and 2017 were retrospectively enrolled.Serum samples were collected at the time of biopsy and ATX was measured by enzyme immunoassays.Sera obtained from 160 healthy,nonobese individuals were used as controls.Histological findings were graded according to an NAFLD scoring system and correlations with serum ATX were calculated by Spearman's test.Diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve(AUC).Cut-off values were identified by the Youden index,and the nearest clinically applicable value to the cutoff was considered the optimal threshold for clinical convenience.RESULTS Serum ATX levels were significantly higher in NAFLD patients than in controls(0.86 mg/L vs 0.76 mg/L,P < 0.001) and correlated significantly with ballooning score and fibrosis stage(r = 0.36,P < 0.001 and r = 0.45,P < 0.001,respectively).Such tendencies were stronger in female patients.There were no remarkable relationships between ATX and serum alanine aminotransferase,lipid profiles,or steatosis scores.The AUC values of ATX for predicting the presence of fibrosis(≥ F1),significant fibrosis(≥ F2),severe fibrosis(≥ F3),and cirrhosis(F4),were all more than 0.70 in respective analyses.CONCLUSION Serum ATX levels may at least partially reflect histological severity in NAFLD.展开更多
Objective: Labisia pumila var. alata, commonly known as 'Kacip Fatimah' or 'Selusuh Fatimah' in Southeast Asia, is traditionally used by members of the Malay community because of its post-partum medici...Objective: Labisia pumila var. alata, commonly known as 'Kacip Fatimah' or 'Selusuh Fatimah' in Southeast Asia, is traditionally used by members of the Malay community because of its post-partum medicinal properties. Its various pharmaceutical applications cause an excessive harvesting and lead to serious shortage in natural habitat. Thus, this in vitro propagation study investigated the effects of different plant growth regulators (PGRs) on in vitro leaf and stem explants of L. pumila. Methods: The capabilities of callus, shoot, and root formation were evaluated by culturing both explants on Murashige and Skoog (MS) medium supplemented with various PGRs at the concentrations of 0, 1, 3, 5, and 7 mg/L. Results: Medium supplemented with 3 mg/L indole-3-butyric acid (IBA) showed the optimal callogenesis from both leaf and stem explants with (72.34±19.55)% and (70.40±14.14)% efficacy, respectively. IBA was also found to be the most efficient PGR for root induction. A total of (50.00±7.07)% and (77.78±16.47)% of root formation were obtained from the in vitro stem and leaf explants after being cultured for (26.5±5.0) and (30.0±8.5) d in the medium supplemented with 1 and 3 mg/L of IBA, respectively. Shoot formation was only observed in stem explant, with the maximum percentage of formation ((100.00±0.00)%) that was obtained in 1 mg/L zeatin after (11.0±2.8) d of culture. Conclusions: Callus, roots, and shoots can be induced from in vitro leaf and stem explants of L. pumila through the manipulation of types and concentrations of PGRs.展开更多
Objective: Heavy ion beam, which has emerged as a new mutagen in the mutation breeding of crops and ornamental plants, is expected to result in the induction of novel mutations. This study investigates the morphologic...Objective: Heavy ion beam, which has emerged as a new mutagen in the mutation breeding of crops and ornamental plants, is expected to result in the induction of novel mutations. This study investigates the morphological and biochemical responses of Oryza sativa toward different doses of carbon ion beam irradiation. Methods: In this study, the dry seeds of O. sativa were irradiated at 0, 20, 40, 60, 80, 100, and 120 Gy, followed by in-vitro germination under controlled conditions. Morphological and biochemical studies were conducted to investigate the morphological and physiological responses of O. sativa towards ion beam irradiation. Results: The study demonstrated that low doses(10 Gy) of ion beam have a stimulating effect on the height, root length, and fresh weight of the plantlets but not on the number of leaves. Meanwhile, doses higher than 10 Gy caused reductions in all the morphological parameters studied as compared to the control samples. The highest total soluble protein content [(2.11±0.47) mg/g FW] was observed in plantlets irradiated at 20 Gy. All irradiated plantlets were found to have 0.85% to 58.32% higher specific activity of peroxidase as compared to the control samples. The present study also revealed that low doses of ion beam(10 and 20 Gy) had negligible effect on the total chlorophyll content of O. sativa plantlets while 40 Gy had a stimulating effect on the chlorophyll content. Plantlets irradiated between 40 to 120 Gy were shown to be 0.38% to 9.98% higher in total soluble nitrogen content which, however, was not significantly different from the control samples. Conclusions: Carbon ion beam irradiation administered at low to moderate doses of 10 to 40 Gy may induce O. sativa mutants with superior characteristics.展开更多
Non-coding RNAs(ncRNAs),that is,RNAs not translated into proteins,are crucial regulators of a variety of biological processes in plants.While protein-encoding genes have been relatively well-annotated in sequenced gen...Non-coding RNAs(ncRNAs),that is,RNAs not translated into proteins,are crucial regulators of a variety of biological processes in plants.While protein-encoding genes have been relatively well-annotated in sequenced genomes,accounting for a small portion of the genome space in plants,the universe of plant ncRNAs is rapidly expanding.Recent advances in experimental and computational technologies have generated a great momentum for discovery and functional characterization of ncRNAs.Here we summarize the classification and known biological functions of plant ncRNAs,review the application of next-generation sequencing(NGS)technology and ribosome profiling technology to ncRNA discovery in horticultural plants and discuss the application of new technologies,especially the new genome-editing tool clustered regularly interspaced short palindromic repeat(CRISPR)/CRISPR-associated protein 9(Cas9)systems,to functional characterization of plant ncRNAs.展开更多
Campylobacter jejuni(C. jejuni),a Gram-negative microaerophilic bacterium,is a predominant cause of bacterial foodborne gastroenteritis in humans worldwide. Despite its importance as a major foodborne pathogen,our und...Campylobacter jejuni(C. jejuni),a Gram-negative microaerophilic bacterium,is a predominant cause of bacterial foodborne gastroenteritis in humans worldwide. Despite its importance as a major foodborne pathogen,our understanding of the molecular mechanisms underlying C. jejuni stress survival and pathogenesis is limited. Inorganic polyphosphate(poly P) has been shown to play significant roles in bacterial resistance to stress and virulence in many pathogenic bacteria. C. jejuni contains the complete repertoire of enzymes required for poly P metabolism. Recent work in our laboratory and others have demonstrated that poly P controls a plethora of C. jejuni properties that impact its ability to survive in the environment as well as to colonize/infect mammalian hosts. This review article summarizes the current literature on the role of poly P in C. jejuni stress survival and virulence and discusses on how poly P-related enzymes can be exploited for therapeutic/prevention purposes. Additionally,the review article identifies potential areas for future investigation that would enhance our understanding of the role of poly P in C. jejuni and other bacteria,which ultimately would facilitate design of effective therapeutic/preventive strategies to reduce not only the burden of C. jejuni-caused foodborne infections but also of other bacterial infections in humans.展开更多
Protein kinases(PKs)have evolved as the largest family of molecular switches that regulate protein activities associated with almost all essential cellular functions.Only a fraction of plant PKs,however,have been func...Protein kinases(PKs)have evolved as the largest family of molecular switches that regulate protein activities associated with almost all essential cellular functions.Only a fraction of plant PKs,however,have been functionally characterized even in model plant species.In the present study,the entire grapevine kinome was identified and annotated using the most recent version of the grapevine genome.A total of 1168 PK-encoding genes were identified and classified into 20 groups and 121 families,with the RLK-Pelle group being the largest,with 872 members.The 1168 kinase genes were unevenly distributed over all 19 chromosomes,and both tandem and segmental duplications contributed to the expansion of the grapevine kinome,especially of the RLK-Pelle group.Ka/Ks values indicated that most of the tandem and segmental duplication events were under purifying selection.The grapevine kinome families exhibited different expression patterns during plant development and in response to various stress treatments,with many being coexpressed.The comprehensive annotation of grapevine kinase genes,their patterns of expression and coexpression,and the related information facilitate a more complete understanding of the roles of various grapevine kinases in growth and development,responses to abiotic stress,and evolutionary history.展开更多
Objective: To evaluate the anti-inflammatory property of both glycyrrhizic acid(GA)and glabridin in reducing inflammation to accelerate wound regeneration on 3T3-L1 and NIH-3T3 fibroblast cell lines.Methods: Cell prol...Objective: To evaluate the anti-inflammatory property of both glycyrrhizic acid(GA)and glabridin in reducing inflammation to accelerate wound regeneration on 3T3-L1 and NIH-3T3 fibroblast cell lines.Methods: Cell proliferation and viability assay(MTT assay), scratch wound healing assays,and quantitative real-time PCR were conducted to investigate the effects on cell proliferation,cell migration, and expression of CXC chemokine ligand 5 inflammation gene respectively.Results: Results showed that at a low concentration of 1 × 10^(-8)mol/L, glabridin down regulated cell proliferation in NIH-3T3 significantly, suggesting its involvement in ERK1/2 signaling pathway. GA and glabridin significantly accelerated cell migration through wound healing in both 3T3-L1 and NIH-3T3 and significantly down regulated the expression of CXC chemokine ligand 5 in 3T3-L1 at concentration 1 × 10^(-8)mol/L,indicating the possible involvement of nuclear factor-k B and cyclooxygenase 2 transcriptions modulation.Conclusions: Both GA and glabridin can serve as potential treatment for chronic inflammatory disease, and glabridin as an oncogenic inhibitor due to its anti-proliferative property.展开更多
This study took advantage of resorufin cellobioside as a fluorescent substrate to determine the distribution of cellulase activity in cellulosic biomass fermentation systems. Cellulolytic biofilms were found to expres...This study took advantage of resorufin cellobioside as a fluorescent substrate to determine the distribution of cellulase activity in cellulosic biomass fermentation systems. Cellulolytic biofilms were found to express nearly four orders greater cellulase activity compared to planktonic cultures of Clostridium thermocellum and Caldicellulosiruptor obsidiansis, which can be primarily attributed to the high cell concentration and surface attachment. The formation of biofilms results in cellulases being secreted close to their substrates, which appears to be an energetically favorable stategy for insoluble substrate utilization. For the same reason,cellulases should be closely associated with the surfaces of suspended cell in soluble substrate-fed culture, which has been verified with cellobiose-fed cultures of C. thermocellum and C. obsidiansis. This study addressed the importance of cellulase activity distribution in cellulosic biomass fermentation, and provided theoretical foundation for the leading role of biofilm in cellulose degradation. System optimization and reactor designs that promote biofilm formation in cellulosic biomass hydrolysis may promise an improved cellulosic biofuel process.展开更多
Glycosyltransferases of the Cellulose Synthase Like D(CS/D)subfamily have been reported to be involved in tip growth and stem development in Arabidopsis.The csld2 and csld3 mutants are root hair defective and the csld...Glycosyltransferases of the Cellulose Synthase Like D(CS/D)subfamily have been reported to be involved in tip growth and stem development in Arabidopsis.The csld2 and csld3 mutants are root hair defective and the csld5 mutant has reduced stem growth.In this study,we produced double and triple knockout mutants of CSLD2,CSLD3,and CSLD5.Unlike the single mutants and the csld2/csld3 double mutant,the csld2/csld5,csld3/csld5,and csld2/csld3/csld5 mutants were dwarfed and showed severely reduced viability.This demonstrates that the cooperative activities of CSLD2,CSLD3,and CSLD5 are required for normal Arabidopsis development,and that they are involved in important processes besides the specialized role in tip growth.The mutant phenotypes indicate that CSLD2 and CSLD3 have overlapping functions with CSLD5 in early plant development,whereas the CSLD2 and CSLD3 proteins are non-redundant.To determine the biochemical function of CSLD proteins,we used transient expression in tobacco leaves.Microsomes containing heterologously expressed CSLD5 transferred mannose from GDP-mannose onto endogenous acceptors.The same activity was detected when CSLD2 and CSLD3 were coexpressed but not when they were expressed separately.With monosaccharides as exogenous acceptors,microsomal preparations from CSLD5-expressing plants mediated the transfer of mannose from GDP-mannose onto mannose.These results were supported by immunodetection studies that showed reduced levels of a mannan epitope in the cell walls of stem interfascicular fibers and xylem vessels of the csld2/csld3/csld5 mutant.展开更多
Paraquat (PQ) was administered intraperitoneally to male Wistar rats at a dose of 30 mg/kg.This dose caused mortality in 14% of the animals and significantly increased the lung wet weight by 28 and 93% at 2 and 3 days...Paraquat (PQ) was administered intraperitoneally to male Wistar rats at a dose of 30 mg/kg.This dose caused mortality in 14% of the animals and significantly increased the lung wet weight by 28 and 93% at 2 and 3 days after treatment, respectively, compared to controls.The activity of several enzymes present in the lung was affected by PQ treatment.Pulmonary angiotensin-converting enzyme activity was significantly reduced at 4 h after PQ treatment and remained 32-36% below control levels during the following 3-day observation period.Alkaline phosphatase activity in the lung was significantly decreased by 26-33% at 1,2, and 3 days after PQ treatment.Lung glucose-6-phosphate dehydrogenase activity demonstrated a drop at 4 h, recovery to control levels at 1 day.and a subsequent rise to levels 45-55% higher than control levels at 2 and 3 days.Glutathione reductase activity in the lung decreased significantly by 21% at 2 and 3 days.These changes in enzyme activities, which may reflect effects on different cell populations of the lung and processes of damage and reparation, may prove to be useful as biochemical indicators of PQ toxicity.展开更多
Small secreted proteins(SSPs)are less than 250 amino acids in length and are actively transported out of cells through conventional protein secretion pathways or unconventional protein secretion pathways.In plants,SSP...Small secreted proteins(SSPs)are less than 250 amino acids in length and are actively transported out of cells through conventional protein secretion pathways or unconventional protein secretion pathways.In plants,SSPs have been found to play important roles in various processes,including plant growth and development,plant response to abiotic and biotic stresses,and beneficial plant–microbe interactions.Over the past 10 years,substantial progress has been made in the identification and functional characterization of SSPs in several plant species relevant to agriculture,bioenergy,and horticulture.Yet,there are potentially a lot of SSPs that have not been discovered in plant genomes,which is largely due to limitations of existing computational algorithms.Recent advances in genomics,transcriptomics,and proteomics research,as well as the development of new computational algorithms based on machine learning,provide unprecedented capabilities for genome-wide discovery of novel SSPs in plants.In this review,we summarize known SSPs and their functions in various plant species.Then we provide an update on the computational and experimental approaches that can be used to discover new SSPs.Finally,we discuss strategies for elucidating the biological functions of SSPs in plants.展开更多
Four local mushroom species, viz. Auricularis polytricha, Lentinus edodes, Agrocybe sp and Pleurotus flabellatus were grown under submerged culture and screened for endopolysaccharides. The fermentation was done in 25...Four local mushroom species, viz. Auricularis polytricha, Lentinus edodes, Agrocybe sp and Pleurotus flabellatus were grown under submerged culture and screened for endopolysaccharides. The fermentation was done in 250 ml working volume Erlenmeyer flask and the fermentation curves for all species were established. Pleurotus flabellatus has the highest rate of biomass production at the rate of 0.180 g/L/day, at 10 days hence chosen for further investigation. Two additional media, viz. Mushroom Complete Media (MCM) and Yeast Malt (YM) were selected to be compared with potato extract(PE) media used initially. MCM media produced the highest biomass productivity at the rate of 0.311 g/L/day. Pleurotus flabellatus biomass was extracted using modified Mizuno method and the endopolysaccharide obtained was tested for β-glucan. The yield of β-glucan was 7.70 ± 1.11 g/100g. The polysaccharides were purified using column chromatography to yield four fractions. The fourth fraction F4, gave the highest molecular weight at 3.058 × 106 Dalton (11.8%) and 1.282 × 104 Dalton (88.2%). The mushroom, P. flabbelatus was cultured using air-lift bioreactor, and the highest productivity was obtained at air-flowrate 2 L/min, yielding 2.25 g/L/day. The yield of biomass against substrate used (glucose consumption) Yb/s was 0.78 g/g.展开更多
A significant challenge in bacterial detection is the identification of viable bacteria over debris, specifically post decontamination. Of increasing concern are antibiotic resistant strains that require accurate and ...A significant challenge in bacterial detection is the identification of viable bacteria over debris, specifically post decontamination. Of increasing concern are antibiotic resistant strains that require accurate and rapid post decontamination analysis. Current strategies are fraught with disadvantages and most of them are not selective for viable bacteria. However, bacteria are critically dependent upon iron sequestration, synthesizing and releasing siderophores (SDPs) to tightly bind iron, with the subsequent uptake of iron bound SDPs. This is a highly conserved process that occurs only in intact bacteria. Herein we report a facile method to use bacterial SDPs to selectively and rapidly identify only viable bacteria in complex matrices, and discriminate them from their dead counterparts. Desferrioxamine B (Desf B) tethered to a glass slide is used to specifically capture viable bacteria from a mixture of viable and dead Escherichia coli, as demonstrated by fluorescence microscopy. We re- port both direct conjugation of Desf B on thin-film-coated glass slides as well as biotin-streptavidin conjugation strategies, both of which are successful in the said goal. We have analyzed the density of images obtained upon fluorescence staining using edge detection with a Canny edge detector. This novel application of a software analysis tool originally developed for satellite imaging to biological staining allows for accurate quantitation of observed data.展开更多
The genus Populus has long been used for environmental,agroforestry and industrial applications worldwide.Today Populus is also recognized as a desirable crop for biofuel production and a model tree for physiological ...The genus Populus has long been used for environmental,agroforestry and industrial applications worldwide.Today Populus is also recognized as a desirable crop for biofuel production and a model tree for physiological and ecological research.As such,various modern biotechnologies,including CRISPR/Cas9-based techniques,have been actively applied to Populus for genetic and genomic improvements for traits such as increased growth rate and tailored lignin composition.However,CRISPR/Cas9 has been primarily used as the active Cas9 form to create knockouts in the hybrid poplar clone“717-1B4”(P.tremula x P.alba clone INRA 717-1B4).Alternative CRISPR/Cas9-based technologies,e.g.those involving modified Cas9 for gene activation and base editing,have not been evaluated in most Populus species for their efficacy.Here we employed a deactivated Cas9(dCas9)-based CRISPR activation(CRISPRa)technique to fine-tune the expression of two target genes,TPX2 and LecRLK-G which play important roles in plant growth and defense response,in hybrid poplar clone“717-1B4”and poplar clone“WV94”(P.deltoides“WV94”),respectively.We observed that CRISPRa resulted in 1.2-fold to 7.0-fold increase in target gene expression through transient expression in protoplasts and Agrobacterium-mediated stable transformation,demonstrating the effectiveness of dCas9-based CRISPRa system in Populus.In addition,we applied Cas9 nickase(nCas9)-based cytosine base editor(CBE)to precisely introduce premature stop codons via C-to-T conversion,with an efficiency of 13%–14%,in the target gene PLATZ which encodes a transcription factor involved in plant fungal pathogen response in hybrid poplar clone“717-1B4”.Overall,we showcase the successful application of CRISPR/Cas-based technologies in gene expression regulation and precise gene engineering in two Populus species,facilitating the adoption of emerging genome editing tools in woody species.展开更多
Adventitious rooting(AR)is critical to the propagation,breeding,and genetic engineering of trees.The capacity for plants to undergo this process is highly heritable and of a polygenic nature;however,the basis of its g...Adventitious rooting(AR)is critical to the propagation,breeding,and genetic engineering of trees.The capacity for plants to undergo this process is highly heritable and of a polygenic nature;however,the basis of its genetic variation is largely uncharacterized.To identify genetic regulators of AR,we performed a genome-wide association study(GWAS)using 1148 genotypes of Populus trichocarpa.GWASs are often limited by the abilities of researchers to collect precise phenotype data on a high-throughput scale;to help overcome this limitation,we developed a computer vision system to measure an array of traits related to adventitious root development in poplar,including temporal measures of lateral and basal root length and area.GWAS was performed using multiple methods and significance thresholds to handle non-normal phenotype statistics and to gain statistical power.These analyses yielded a total of 277 unique associations,suggesting that genes that control rooting include regulators of hormone signaling,cell division and structure,reactive oxygen species signaling,and other processes with known roles in root development.Numerous genes with uncharacterized functions and/or cryptic roles were also identified.These candidates provide targets for functional analysis,including physiological and epistatic analyses,to better characterize the complex polygenic regulation of AR.展开更多
Loblolly pine residue prepared with and without zeolite ZSM-5 was pyrolyzed at 600℃ and the pyrolysis oil was hydrogenated using formic acid as a hydrogen source, in the presence of a Ru/activated carbon catalyst. As...Loblolly pine residue prepared with and without zeolite ZSM-5 was pyrolyzed at 600℃ and the pyrolysis oil was hydrogenated using formic acid as a hydrogen source, in the presence of a Ru/activated carbon catalyst. As indicated by the pyrolysis yield, addition of the zeolite ZSM-5 increased the yield of light oil but decreased the yield of heavy oil. The pyrolysis oils were analyzed by 13C-,31P-,19F-nuclear magnetic resonance(NMR), and heteronuclear single quantum coherence or heteronuclear single quantum correlation nuclear magnetic resonance(HSQC-NMR), demonstrating that the zeolite ZSM-5 can efficiently induce decarboxylation reactions and decrease the content of aliphatic hydroxyl groups in the heavy oil by 57%.After hydrogenation of the pyrolysis oil, the aromatic carbon content decreased by 78%, with a significant increase in the aliphatic carbon content.展开更多
基金supported by the Center for Bioenergy Innovation(CBI)supported by the Office of Biological and Environmental Research in the DOE Office of Science and led by Oak Ridge National Laboratory.Oak Ridge National Laboratory is managed by UT-Battelle,LLC for the US DOE under Contract Number DE-AC05-00OR22725+2 种基金authored in part by the Na-tional Renewable Energy Laboratory,operated by Alliance for Sustainable Energy,LLC,for the U.S.Department of Energy(DOE)under Contract No.DE-LC-000L054provided by the U.S.Department of Energy(DOE),Office of Energy Efficiency and Renewable Energy(EERE),and Bioenergy Technologies Office(BETO)at the Pacific Northwest National Laboratory(PNNL)under Contract No.DE-AC05-76RL01830supported by Laboratory Directed Research and Development(LDRD)funding from Argonne National Laboratory,provided by the Director,Office of Science,of the U.S.Department of Energy under Contract No.DE-AC02-06CH11357。
文摘Sustainable aviation fuel(SAF)production from biomass and biowaste streams is an attractive option for decarbonizing the aviation sector,one of the most-difficult-to-electrify transportation sectors.Despite ongoing commercialization efforts using ASTM-certified pathways(e.g.,lipid conversion,Fischer-Tropsch synthesis),production capacities are still inadequate due to limited feedstock supply and high production costs.New conversion technologies that utilize lignocellulosic feedstocks are needed to meet these challenges and satisfy the rapidly growing market.Combining bio-and chemo-catalytic approaches can leverage advantages from both methods,i.e.,high product selectivity via biological conversion,and the capability to build C-C chains more efficiently via chemical catalysis.Herein,conversion routes,catalysis,and processes for such pathways are discussed,while key challenges and meaningful R&D opportunities are identified to guide future research activities in the space.Bio-and chemo-catalytic conversion primarily utilize the carbohydrate fraction of lignocellulose,leaving lignin as a waste product.This makes lignin conversion to SAF critical in order to utilize whole biomass,thereby lowering overall production costs while maximizing carbon efficiencies.Thus,lignin valorization strategies are also reviewed herein with vital research areas identified,such as facile lignin depolymerization approaches,highly integrated conversion systems,novel process configurations,and catalysts for the selective cleavage of aryl C-O bonds.The potential efficiency improvements available via integrated conversion steps,such as combined biological and chemo-catalytic routes,along with the use of different parallel pathways,are identified as key to producing all components of a cost-effective,100%SAF.
文摘Blastopsylla occidentalis Taylor是原产于澳大利亚的木虱种类,目前已经扩散到北美、南美、非洲、欧洲和亚洲。本文记述了B.occidentalis在中国的发生,并首次记录了其在澳大利亚以外的地区被寄生。这个种依赖于桉属Eucalyptus植物,其寄主超过20种,这可能是使其在世界范围扩散的一个重要因素。指出了B.occidentalis与桉树芽木虱Blastopsylla barbara Li为同种异名。
基金Supported by the National Natural Science Foundation of China,No.39260033Natural Science Foundation of Guangxi,No.0143058
文摘AIM: To investigate p53 mutation and p21 expression in hepatocarcinogenesis induced by hepatitis B virus (HBV) and aflatoxin B1 (AFB1) in tree shrews, and to reveal the role of these genes in hepatocarcinogenesis.METHODS: Tree shrews were divided into four groups:group A, those infected with HBV and fed with AFB1 (n = 39);group B, those infected with HBV alone (n = 28); group C,those fed with AFB1 alone (n = 29); and group D, normal controls (n = 20). The tree shrews underwent liver biopsies once every 15 wk. Expression of p53 and p21 proteins and genes in the biopsies and tumor tissues of the experimental tree shrews was detected, respectively, by immunohistochemistry,and by Southem blotting and reverse transcription-polymerase chain reaction and sequencing.RESULTS: The incidence of hepatocellular carcinomas (HCC) was higher in group A (66.7%) than that in group B (3.57%) and C (30%). The time of HCC occurrence was also earlier in group A than that in group C (120.0±16.6 wk vs 153.3±5.8 wk, respectively, P<0.01). p53 protein was not detected by immunohistochemistry in all groups before the 75^th wk of the experiment. At the 105^th wk, the positive rates fo p53 were 78.6%, 60% and 71.4% in groups A, B and C, respectively, which were significantly higher than that in group D (10%) (all P<0.05). An abnormal band of p53 gene was observed in groups A and C. The mutation points of p53gene in tree shrews with HCC were at codons 275, 78 and 13. The nucleotide sequence and amino acid sequence of tree shrew's wild-type p53 showed 91.7% and 93.4% homologies with those of human p53,respectively. The immunopositivity for p21 was found before HCC development. The incidence of HCC was significantly higher in tree shrews that were positive for p21 than those negative for p21 (80.0% vs 11.0%, P<0.001).The incidence of HCC in p21 positive animals in group A was significantly higher than those positive for p21 in group C (P<O.05).CONCLUSION: A remarkable synergistic effect on HCC development exists between HBV and AFB1. p53 mutation promotes the development of HCC. HBV and AFB1 may synergistically induce p53 gene mutation, and stimulate ras gene expression, ras gene is activated at the earlier stage during hepatocarcinogenesis, p21 protein may be an early marker, and the alterations of p53 may be a late event in the development of HCC.
文摘AIM To examine the relationship between serum autotaxin(ATX) concentrations and clinicopathological findings in non-alcoholic fatty liver disease(NAFLD) patients.METHODS One hundred eighty-six NAFLD patients who had undergone liver biopsy between 2008 and 2017 were retrospectively enrolled.Serum samples were collected at the time of biopsy and ATX was measured by enzyme immunoassays.Sera obtained from 160 healthy,nonobese individuals were used as controls.Histological findings were graded according to an NAFLD scoring system and correlations with serum ATX were calculated by Spearman's test.Diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve(AUC).Cut-off values were identified by the Youden index,and the nearest clinically applicable value to the cutoff was considered the optimal threshold for clinical convenience.RESULTS Serum ATX levels were significantly higher in NAFLD patients than in controls(0.86 mg/L vs 0.76 mg/L,P < 0.001) and correlated significantly with ballooning score and fibrosis stage(r = 0.36,P < 0.001 and r = 0.45,P < 0.001,respectively).Such tendencies were stronger in female patients.There were no remarkable relationships between ATX and serum alanine aminotransferase,lipid profiles,or steatosis scores.The AUC values of ATX for predicting the presence of fibrosis(≥ F1),significant fibrosis(≥ F2),severe fibrosis(≥ F3),and cirrhosis(F4),were all more than 0.70 in respective analyses.CONCLUSION Serum ATX levels may at least partially reflect histological severity in NAFLD.
文摘Objective: Labisia pumila var. alata, commonly known as 'Kacip Fatimah' or 'Selusuh Fatimah' in Southeast Asia, is traditionally used by members of the Malay community because of its post-partum medicinal properties. Its various pharmaceutical applications cause an excessive harvesting and lead to serious shortage in natural habitat. Thus, this in vitro propagation study investigated the effects of different plant growth regulators (PGRs) on in vitro leaf and stem explants of L. pumila. Methods: The capabilities of callus, shoot, and root formation were evaluated by culturing both explants on Murashige and Skoog (MS) medium supplemented with various PGRs at the concentrations of 0, 1, 3, 5, and 7 mg/L. Results: Medium supplemented with 3 mg/L indole-3-butyric acid (IBA) showed the optimal callogenesis from both leaf and stem explants with (72.34±19.55)% and (70.40±14.14)% efficacy, respectively. IBA was also found to be the most efficient PGR for root induction. A total of (50.00±7.07)% and (77.78±16.47)% of root formation were obtained from the in vitro stem and leaf explants after being cultured for (26.5±5.0) and (30.0±8.5) d in the medium supplemented with 1 and 3 mg/L of IBA, respectively. Shoot formation was only observed in stem explant, with the maximum percentage of formation ((100.00±0.00)%) that was obtained in 1 mg/L zeatin after (11.0±2.8) d of culture. Conclusions: Callus, roots, and shoots can be induced from in vitro leaf and stem explants of L. pumila through the manipulation of types and concentrations of PGRs.
基金supported by the Nuclear Safety Research Association(NSRA),Japan
文摘Objective: Heavy ion beam, which has emerged as a new mutagen in the mutation breeding of crops and ornamental plants, is expected to result in the induction of novel mutations. This study investigates the morphological and biochemical responses of Oryza sativa toward different doses of carbon ion beam irradiation. Methods: In this study, the dry seeds of O. sativa were irradiated at 0, 20, 40, 60, 80, 100, and 120 Gy, followed by in-vitro germination under controlled conditions. Morphological and biochemical studies were conducted to investigate the morphological and physiological responses of O. sativa towards ion beam irradiation. Results: The study demonstrated that low doses(10 Gy) of ion beam have a stimulating effect on the height, root length, and fresh weight of the plantlets but not on the number of leaves. Meanwhile, doses higher than 10 Gy caused reductions in all the morphological parameters studied as compared to the control samples. The highest total soluble protein content [(2.11±0.47) mg/g FW] was observed in plantlets irradiated at 20 Gy. All irradiated plantlets were found to have 0.85% to 58.32% higher specific activity of peroxidase as compared to the control samples. The present study also revealed that low doses of ion beam(10 and 20 Gy) had negligible effect on the total chlorophyll content of O. sativa plantlets while 40 Gy had a stimulating effect on the chlorophyll content. Plantlets irradiated between 40 to 120 Gy were shown to be 0.38% to 9.98% higher in total soluble nitrogen content which, however, was not significantly different from the control samples. Conclusions: Carbon ion beam irradiation administered at low to moderate doses of 10 to 40 Gy may induce O. sativa mutants with superior characteristics.
基金This research is supported by the Department of Energy(DOE),Office of Science,Genomic Science Program under Award Number DE-SC0008834Oak Ridge National Laboratory is managed by UT-Battelle,LLC for the US DOE under Contract Number DE-AC05-00OR22725.This manuscript has been authored by UT-Battelle,LLC under Contract No.DE-AC05-00OR22725 with the U.S.
文摘Non-coding RNAs(ncRNAs),that is,RNAs not translated into proteins,are crucial regulators of a variety of biological processes in plants.While protein-encoding genes have been relatively well-annotated in sequenced genomes,accounting for a small portion of the genome space in plants,the universe of plant ncRNAs is rapidly expanding.Recent advances in experimental and computational technologies have generated a great momentum for discovery and functional characterization of ncRNAs.Here we summarize the classification and known biological functions of plant ncRNAs,review the application of next-generation sequencing(NGS)technology and ribosome profiling technology to ncRNA discovery in horticultural plants and discuss the application of new technologies,especially the new genome-editing tool clustered regularly interspaced short palindromic repeat(CRISPR)/CRISPR-associated protein 9(Cas9)systems,to functional characterization of plant ncRNAs.
基金Supported by Ohio Agricultural Research and Development Center,the Ohio State University,and the Agriculture and Food Research Initiative,No.2012-68003-19679
文摘Campylobacter jejuni(C. jejuni),a Gram-negative microaerophilic bacterium,is a predominant cause of bacterial foodborne gastroenteritis in humans worldwide. Despite its importance as a major foodborne pathogen,our understanding of the molecular mechanisms underlying C. jejuni stress survival and pathogenesis is limited. Inorganic polyphosphate(poly P) has been shown to play significant roles in bacterial resistance to stress and virulence in many pathogenic bacteria. C. jejuni contains the complete repertoire of enzymes required for poly P metabolism. Recent work in our laboratory and others have demonstrated that poly P controls a plethora of C. jejuni properties that impact its ability to survive in the environment as well as to colonize/infect mammalian hosts. This review article summarizes the current literature on the role of poly P in C. jejuni stress survival and virulence and discusses on how poly P-related enzymes can be exploited for therapeutic/prevention purposes. Additionally,the review article identifies potential areas for future investigation that would enhance our understanding of the role of poly P in C. jejuni and other bacteria,which ultimately would facilitate design of effective therapeutic/preventive strategies to reduce not only the burden of C. jejuni-caused foodborne infections but also of other bacterial infections in humans.
基金This research was financially supported in part by the Priority Academic of Jiangsu Province and the Tennessee Agricultural Experiment Station Hatch Project 1009395Kaikai Zhu was supported by the China Scholarship Council(CSC,No.201606850052).
文摘Protein kinases(PKs)have evolved as the largest family of molecular switches that regulate protein activities associated with almost all essential cellular functions.Only a fraction of plant PKs,however,have been functionally characterized even in model plant species.In the present study,the entire grapevine kinome was identified and annotated using the most recent version of the grapevine genome.A total of 1168 PK-encoding genes were identified and classified into 20 groups and 121 families,with the RLK-Pelle group being the largest,with 872 members.The 1168 kinase genes were unevenly distributed over all 19 chromosomes,and both tandem and segmental duplications contributed to the expansion of the grapevine kinome,especially of the RLK-Pelle group.Ka/Ks values indicated that most of the tandem and segmental duplication events were under purifying selection.The grapevine kinome families exhibited different expression patterns during plant development and in response to various stress treatments,with many being coexpressed.The comprehensive annotation of grapevine kinase genes,their patterns of expression and coexpression,and the related information facilitate a more complete understanding of the roles of various grapevine kinases in growth and development,responses to abiotic stress,and evolutionary history.
基金Support by the Exploratory Research Grants Scheme(ERGS/1/2012/STG08/TAYLOR/03/2),Ministry of Higher Education,Malaysia
文摘Objective: To evaluate the anti-inflammatory property of both glycyrrhizic acid(GA)and glabridin in reducing inflammation to accelerate wound regeneration on 3T3-L1 and NIH-3T3 fibroblast cell lines.Methods: Cell proliferation and viability assay(MTT assay), scratch wound healing assays,and quantitative real-time PCR were conducted to investigate the effects on cell proliferation,cell migration, and expression of CXC chemokine ligand 5 inflammation gene respectively.Results: Results showed that at a low concentration of 1 × 10^(-8)mol/L, glabridin down regulated cell proliferation in NIH-3T3 significantly, suggesting its involvement in ERK1/2 signaling pathway. GA and glabridin significantly accelerated cell migration through wound healing in both 3T3-L1 and NIH-3T3 and significantly down regulated the expression of CXC chemokine ligand 5 in 3T3-L1 at concentration 1 × 10^(-8)mol/L,indicating the possible involvement of nuclear factor-k B and cyclooxygenase 2 transcriptions modulation.Conclusions: Both GA and glabridin can serve as potential treatment for chronic inflammatory disease, and glabridin as an oncogenic inhibitor due to its anti-proliferative property.
基金supported by the Bio Energy Science Center (BESC), which is a US Department of Energy Bioenergy Research Center supported by the Office of Biological and Environmental Research in the DOE Office of Science.Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the US Department of Energy under contract DE-AC05-00OR22725
文摘This study took advantage of resorufin cellobioside as a fluorescent substrate to determine the distribution of cellulase activity in cellulosic biomass fermentation systems. Cellulolytic biofilms were found to express nearly four orders greater cellulase activity compared to planktonic cultures of Clostridium thermocellum and Caldicellulosiruptor obsidiansis, which can be primarily attributed to the high cell concentration and surface attachment. The formation of biofilms results in cellulases being secreted close to their substrates, which appears to be an energetically favorable stategy for insoluble substrate utilization. For the same reason,cellulases should be closely associated with the surfaces of suspended cell in soluble substrate-fed culture, which has been verified with cellobiose-fed cultures of C. thermocellum and C. obsidiansis. This study addressed the importance of cellulase activity distribution in cellulosic biomass fermentation, and provided theoretical foundation for the leading role of biofilm in cellulose degradation. System optimization and reactor designs that promote biofilm formation in cellulosic biomass hydrolysis may promise an improved cellulosic biofuel process.
文摘Glycosyltransferases of the Cellulose Synthase Like D(CS/D)subfamily have been reported to be involved in tip growth and stem development in Arabidopsis.The csld2 and csld3 mutants are root hair defective and the csld5 mutant has reduced stem growth.In this study,we produced double and triple knockout mutants of CSLD2,CSLD3,and CSLD5.Unlike the single mutants and the csld2/csld3 double mutant,the csld2/csld5,csld3/csld5,and csld2/csld3/csld5 mutants were dwarfed and showed severely reduced viability.This demonstrates that the cooperative activities of CSLD2,CSLD3,and CSLD5 are required for normal Arabidopsis development,and that they are involved in important processes besides the specialized role in tip growth.The mutant phenotypes indicate that CSLD2 and CSLD3 have overlapping functions with CSLD5 in early plant development,whereas the CSLD2 and CSLD3 proteins are non-redundant.To determine the biochemical function of CSLD proteins,we used transient expression in tobacco leaves.Microsomes containing heterologously expressed CSLD5 transferred mannose from GDP-mannose onto endogenous acceptors.The same activity was detected when CSLD2 and CSLD3 were coexpressed but not when they were expressed separately.With monosaccharides as exogenous acceptors,microsomal preparations from CSLD5-expressing plants mediated the transfer of mannose from GDP-mannose onto mannose.These results were supported by immunodetection studies that showed reduced levels of a mannan epitope in the cell walls of stem interfascicular fibers and xylem vessels of the csld2/csld3/csld5 mutant.
文摘Paraquat (PQ) was administered intraperitoneally to male Wistar rats at a dose of 30 mg/kg.This dose caused mortality in 14% of the animals and significantly increased the lung wet weight by 28 and 93% at 2 and 3 days after treatment, respectively, compared to controls.The activity of several enzymes present in the lung was affected by PQ treatment.Pulmonary angiotensin-converting enzyme activity was significantly reduced at 4 h after PQ treatment and remained 32-36% below control levels during the following 3-day observation period.Alkaline phosphatase activity in the lung was significantly decreased by 26-33% at 1,2, and 3 days after PQ treatment.Lung glucose-6-phosphate dehydrogenase activity demonstrated a drop at 4 h, recovery to control levels at 1 day.and a subsequent rise to levels 45-55% higher than control levels at 2 and 3 days.Glutathione reductase activity in the lung decreased significantly by 21% at 2 and 3 days.These changes in enzyme activities, which may reflect effects on different cell populations of the lung and processes of damage and reparation, may prove to be useful as biochemical indicators of PQ toxicity.
文摘Small secreted proteins(SSPs)are less than 250 amino acids in length and are actively transported out of cells through conventional protein secretion pathways or unconventional protein secretion pathways.In plants,SSPs have been found to play important roles in various processes,including plant growth and development,plant response to abiotic and biotic stresses,and beneficial plant–microbe interactions.Over the past 10 years,substantial progress has been made in the identification and functional characterization of SSPs in several plant species relevant to agriculture,bioenergy,and horticulture.Yet,there are potentially a lot of SSPs that have not been discovered in plant genomes,which is largely due to limitations of existing computational algorithms.Recent advances in genomics,transcriptomics,and proteomics research,as well as the development of new computational algorithms based on machine learning,provide unprecedented capabilities for genome-wide discovery of novel SSPs in plants.In this review,we summarize known SSPs and their functions in various plant species.Then we provide an update on the computational and experimental approaches that can be used to discover new SSPs.Finally,we discuss strategies for elucidating the biological functions of SSPs in plants.
文摘Four local mushroom species, viz. Auricularis polytricha, Lentinus edodes, Agrocybe sp and Pleurotus flabellatus were grown under submerged culture and screened for endopolysaccharides. The fermentation was done in 250 ml working volume Erlenmeyer flask and the fermentation curves for all species were established. Pleurotus flabellatus has the highest rate of biomass production at the rate of 0.180 g/L/day, at 10 days hence chosen for further investigation. Two additional media, viz. Mushroom Complete Media (MCM) and Yeast Malt (YM) were selected to be compared with potato extract(PE) media used initially. MCM media produced the highest biomass productivity at the rate of 0.311 g/L/day. Pleurotus flabellatus biomass was extracted using modified Mizuno method and the endopolysaccharide obtained was tested for β-glucan. The yield of β-glucan was 7.70 ± 1.11 g/100g. The polysaccharides were purified using column chromatography to yield four fractions. The fourth fraction F4, gave the highest molecular weight at 3.058 × 106 Dalton (11.8%) and 1.282 × 104 Dalton (88.2%). The mushroom, P. flabbelatus was cultured using air-lift bioreactor, and the highest productivity was obtained at air-flowrate 2 L/min, yielding 2.25 g/L/day. The yield of biomass against substrate used (glucose consumption) Yb/s was 0.78 g/g.
文摘A significant challenge in bacterial detection is the identification of viable bacteria over debris, specifically post decontamination. Of increasing concern are antibiotic resistant strains that require accurate and rapid post decontamination analysis. Current strategies are fraught with disadvantages and most of them are not selective for viable bacteria. However, bacteria are critically dependent upon iron sequestration, synthesizing and releasing siderophores (SDPs) to tightly bind iron, with the subsequent uptake of iron bound SDPs. This is a highly conserved process that occurs only in intact bacteria. Herein we report a facile method to use bacterial SDPs to selectively and rapidly identify only viable bacteria in complex matrices, and discriminate them from their dead counterparts. Desferrioxamine B (Desf B) tethered to a glass slide is used to specifically capture viable bacteria from a mixture of viable and dead Escherichia coli, as demonstrated by fluorescence microscopy. We re- port both direct conjugation of Desf B on thin-film-coated glass slides as well as biotin-streptavidin conjugation strategies, both of which are successful in the said goal. We have analyzed the density of images obtained upon fluorescence staining using edge detection with a Canny edge detector. This novel application of a software analysis tool originally developed for satellite imaging to biological staining allows for accurate quantitation of observed data.
文摘The genus Populus has long been used for environmental,agroforestry and industrial applications worldwide.Today Populus is also recognized as a desirable crop for biofuel production and a model tree for physiological and ecological research.As such,various modern biotechnologies,including CRISPR/Cas9-based techniques,have been actively applied to Populus for genetic and genomic improvements for traits such as increased growth rate and tailored lignin composition.However,CRISPR/Cas9 has been primarily used as the active Cas9 form to create knockouts in the hybrid poplar clone“717-1B4”(P.tremula x P.alba clone INRA 717-1B4).Alternative CRISPR/Cas9-based technologies,e.g.those involving modified Cas9 for gene activation and base editing,have not been evaluated in most Populus species for their efficacy.Here we employed a deactivated Cas9(dCas9)-based CRISPR activation(CRISPRa)technique to fine-tune the expression of two target genes,TPX2 and LecRLK-G which play important roles in plant growth and defense response,in hybrid poplar clone“717-1B4”and poplar clone“WV94”(P.deltoides“WV94”),respectively.We observed that CRISPRa resulted in 1.2-fold to 7.0-fold increase in target gene expression through transient expression in protoplasts and Agrobacterium-mediated stable transformation,demonstrating the effectiveness of dCas9-based CRISPRa system in Populus.In addition,we applied Cas9 nickase(nCas9)-based cytosine base editor(CBE)to precisely introduce premature stop codons via C-to-T conversion,with an efficiency of 13%–14%,in the target gene PLATZ which encodes a transcription factor involved in plant fungal pathogen response in hybrid poplar clone“717-1B4”.Overall,we showcase the successful application of CRISPR/Cas-based technologies in gene expression regulation and precise gene engineering in two Populus species,facilitating the adoption of emerging genome editing tools in woody species.
文摘Adventitious rooting(AR)is critical to the propagation,breeding,and genetic engineering of trees.The capacity for plants to undergo this process is highly heritable and of a polygenic nature;however,the basis of its genetic variation is largely uncharacterized.To identify genetic regulators of AR,we performed a genome-wide association study(GWAS)using 1148 genotypes of Populus trichocarpa.GWASs are often limited by the abilities of researchers to collect precise phenotype data on a high-throughput scale;to help overcome this limitation,we developed a computer vision system to measure an array of traits related to adventitious root development in poplar,including temporal measures of lateral and basal root length and area.GWAS was performed using multiple methods and significance thresholds to handle non-normal phenotype statistics and to gain statistical power.These analyses yielded a total of 277 unique associations,suggesting that genes that control rooting include regulators of hormone signaling,cell division and structure,reactive oxygen species signaling,and other processes with known roles in root development.Numerous genes with uncharacterized functions and/or cryptic roles were also identified.These candidates provide targets for functional analysis,including physiological and epistatic analyses,to better characterize the complex polygenic regulation of AR.
基金supported by the US Department of Energy(DOE)(project:DE-EE0003144)the National Key Research and Development Program of China(No.2017YFB0307900)the Foundation of Guangxi Key Laboratory of Clean Pulp&Papermaking and Pollution Control(No.KF201713).
文摘Loblolly pine residue prepared with and without zeolite ZSM-5 was pyrolyzed at 600℃ and the pyrolysis oil was hydrogenated using formic acid as a hydrogen source, in the presence of a Ru/activated carbon catalyst. As indicated by the pyrolysis yield, addition of the zeolite ZSM-5 increased the yield of light oil but decreased the yield of heavy oil. The pyrolysis oils were analyzed by 13C-,31P-,19F-nuclear magnetic resonance(NMR), and heteronuclear single quantum coherence or heteronuclear single quantum correlation nuclear magnetic resonance(HSQC-NMR), demonstrating that the zeolite ZSM-5 can efficiently induce decarboxylation reactions and decrease the content of aliphatic hydroxyl groups in the heavy oil by 57%.After hydrogenation of the pyrolysis oil, the aromatic carbon content decreased by 78%, with a significant increase in the aliphatic carbon content.
