Carotenoid biosynthesis and accumulation are important in determining nutritional and commercial value of crop products.Yellow pigmentation of mature kernels caused by carotenoids is considered a vital quality trait i...Carotenoid biosynthesis and accumulation are important in determining nutritional and commercial value of crop products.Yellow pigmentation of mature kernels caused by carotenoids is considered a vital quality trait in foxtail millet,an ancient and widely cultivated cereal crop across the world.Genomic regions associated with yellow pigment content(YPC),lutein and zeaxanthin in foxtail millet grains were identified by genome-wide association analysis(GWAS),and SiPSY1(Phytoene synthase 1 which regulates formation of the 40-carbon backbone of carotenoids)was confirmed as the main contributor to all three components by knockout and overexpression analysis.SiPSY1 was expressed in seedlings,leaves,panicles,and mature seeds,and was subcellularly localized to chloroplasts.Transcription of SiPSY1 in 15 DAP immature grains was responsible for YPC in mature seeds.Selection of SiPSY1 combined with increased YPC in mature grains during domestication of foxtail millet was confirmed.Haplotype analysis suggested that expression level of SiPSY1 could be a selection target for future breeding programs,and a KASP marker was developed for selection of favorable SiPSY1 alleles in breeding.The results of this work will benefit nutritional and commercial improvement of foxtail millet varieties,as well as other cereal crops.展开更多
Pruning is time-consuming and laborious in watermelon cultivation,which can not meet the needs for simplified cultivation in the future.The development of branchless lines will provide important germplasms for breedin...Pruning is time-consuming and laborious in watermelon cultivation,which can not meet the needs for simplified cultivation in the future.The development of branchless lines will provide important germplasms for breeding watermelon varieties and is an important method for genetic improvement.In this study,the watermelon accession,Wu Cha Zao(WCZ)is a branchless inbred line that carries the branchless gene Clbl,which was used as the donor parent to develop branchless near isogenic lines(NILs).To construct the NILs of Clbl,WCZ crossed with the normal branching watermelon inbred line WT20 which was used as the recurrent parent.The co-segregating markers dCAPS10 and Indel1 with Clbl were used for foreground selection,and a total of 108 SSR markers was selected with good polymorphism between two parental lines for background selection which had relatively uniform distribution across 11 chromosomes.Using these markers to select individuals from the BC_(1)F_(1),BC_(2)F_(1),and BC_(2)F_(2) generations,three NILs with a proportion of recurrent parent genome(PRPG)>99%were finally obtained.The lateral branch and plant height phenotypes did not significantly differ between the NILs and WCZ,indicating that the NILs of Clbl under the genetic background of WT20 has been successfully developed.These results provide ideal materials for further in-depth analysis of the genetic mechanisms of lateral branch development and ideal plant architecture breeding in watermelon.展开更多
The cotton cultivar DELTAOPAL is resistant under field as well as under glasshouse conditions to the Brazilian isolates of Xanthomonas axonopodis pv. malvacearum (Xam). Segregating populations derived from the cross b...The cotton cultivar DELTAOPAL is resistant under field as well as under glasshouse conditions to the Brazilian isolates of Xanthomonas axonopodis pv. malvacearum (Xam). Segregating populations derived from the cross between this cultivar and one susceptible cv. BRS ITA 90, were utilized to identify molecular marker linked with the resistance gene to Xam by “Bulk Segregant Analysis (BSA)”. Two hundred and twenty microsatellite (Single Sequence Repeat—SSR) primers were tested. The amplification products were visualized in polyacrylamide gels stained with silver nitrate. Only one primer was informative and showed polymorphism between the DNA of the parents and their respective bulks of homozygous F2 populations contrasting for resistance and susceptibility, and hence was used to analyze DNA of 120 F2 populations. The microsatellite primer yielded one band of 80 bp linked with the resistance locus, which was absent in the susceptible parent as well as in the bulk of the homozygous susceptible plants of the cross. The segregation ratio as determined by phenotypic analysis was 3R:1S. It is believed that the microsatellite marker was linked with the resistance locus and hence may offer new perspectives for marker assisted selection against the angular leaf spot disease of cotton. It is however, felt necessary to repeat the microsatellite analysis and make sure that the primer is tightly linked with the resistance locus and at the same time verify the genetic distance between the marker and the resistance locus.展开更多
Selection and use of molecular markers for evaluation of DNA polymorphism in plants are couple of the most important approaches in the field of molecular genetics.The assessment of genetic diversity using morphologica...Selection and use of molecular markers for evaluation of DNA polymorphism in plants are couple of the most important approaches in the field of molecular genetics.The assessment of genetic diversity using morphological markers is not sufficient due to little differentiating traits among the species,genera or their individuals.Morphological markers are not only highly influenced by environmental factors but skilled assessment is also prerequisite to find the variations in plant genetic resources.Therefore,molecular markers are considered as efficient tools for detailed DNA based characterization of fruit crops.Molecular markers provide new directions to the efforts of plant breeders particularly in genetic variability,gene tags,gene localization,taxonomy,genetic diversity,phylogenetic analysis and also play an important role to decrease the time required for development of new and excellent cultivars.The success of molecular markers technology in genetic improvement programs depends on the close relationship among the plant breeders,biotechnologists,skilled manpower and good financial support.The present review describes application and success of molecular markers technology used for genetic improvement in different fruit crops.展开更多
The oil palm (<i>Elaeis</i> <i>guineensis</i> Jacq.) is one of the major cultivated crops among the economically important palm species. It is cultivated mainly for its edible oil. For a perenn...The oil palm (<i>Elaeis</i> <i>guineensis</i> Jacq.) is one of the major cultivated crops among the economically important palm species. It is cultivated mainly for its edible oil. For a perennial crop like oil palm, the use of Marker Assisted Selection (MAS) techniques helps to reduce the breeding cycle and improve the economic products. Genetic and physical maps are important for sequencing experiments since they show the exact positions of genes and other distinctive features in the chromosomal DNA. This review focuses on the role of genome mapping in oil palm breeding. It assesses the role of genome mapping in oil palm breeding and discusses the major factors affecting such mapping. Generating a high-density map governed by several factors, for instance, marker type, marker density, number of mapped population, and software used are the major issues treated. The general conclusion is that genome mapping is pivotal in the construction of a genetic linkage map. It helps to detect QTL and identify genes that control quantitative traits in oil palm. In perspective, the use of high-density molecular markers with a large number of markers, a large number mapping population, and up-to-date softw<span style="color:;">are </span><span>is necessary</span><span style="color:;"> for oil pal</span>m genome mapping.展开更多
With over 10 million points of genetic variation from person to person, every individual’s genome is unique and provides a highly reliable form of identification. This is because the genetic code is specific to each ...With over 10 million points of genetic variation from person to person, every individual’s genome is unique and provides a highly reliable form of identification. This is because the genetic code is specific to each individual and does not change over time. Genetic information has been used to identify individuals in a variety of contexts, such as criminal investigations, paternity tests, and medical research. In this study, each individual’s genetic makeup has been formatted to create a secure, unique code that incorporates various elements, such as species, gender, and the genetic identification code itself. The combinations of markers required for this code have been derived from common single nucleotide polymorphisms (SNPs), points of variation found in the human genome. The final output is in the form of a 24 numerical code with each number having three possible combinations. The custom code can then be utilized to create various modes of identification on the decentralized blockchain network as well as personalized services and products that offer users a novel way to uniquely identify themselves in ways that were not possible before.展开更多
Genetic transformation has become a promising tool for improvement of a variety of crop species. However, transferring genes across species, the presence of selectable marker genes, and bacteria-derived vector backbon...Genetic transformation has become a promising tool for improvement of a variety of crop species. However, transferring genes across species, the presence of selectable marker genes, and bacteria-derived vector backbone sequences have raised considerable health and environmental concerns. Intragenic vector system-based intragenesis/cisgenesis is a new method using transgenic approach to achieving traditional breeding objectives but circumventing many of the associated shortcomings. We report here the development of an intragenic vector by assembling a T-DNA-like fragment and a buffering sequence following the left border from Citrus clementina into the backbone of the binary vector pCB302. Recovery of citrus regenerants is performed under non-selective conditions and positive intra-/cisgenic regenerants were identified through PCR analysis. Transformation efficiencies obtained in Arabidopsis and “Duncan” grapefruit were ~3% and ~0.67%, respectively, demonstrating the potential of the system for development of “foreign DNA-free” intra-/cisgenic citrus cultivars.展开更多
Gray leaf spot(GLS)caused by Cercospora zeae-maydis and C.zeina is an extremely devastating leaf disease that limits maize production annually.The use of GLS-resistant maize hybrids is the most cost-effective approach...Gray leaf spot(GLS)caused by Cercospora zeae-maydis and C.zeina is an extremely devastating leaf disease that limits maize production annually.The use of GLS-resistant maize hybrids is the most cost-effective approach for reducing losses.Resistance to GLS is quantitatively inherited in maize(Zea mays L.)and further sources of resistance remain to be analyzed.Here,we detected qRgls1.06,a major quantitative trait locus for GLS resistance in bin 1.06 that explained approximately 55%of the phenotype variance.Fine mapping over 2 consecutive years localized qRgls1.06 to a 2.38-Mb region.Homozygous qRgls1.06^(WGR/WGR) plants in DZ01 background displayed higher GLS resistance and 100-grain weight than DZ01 plants.The GLS responses of several susceptible elite inbred lines were improved by the introduction of qRgls1.06 by marker-assisted backcrossing.Our findings extend the understanding of the genetic basis of resistance to GLS and provide a set of resistant germplasm for genetic improvement of resistance to GLS in maize.展开更多
A boll infection caused by non-traditional cotton pathogens was first reported to occur in the southeastern U.S. Cotton Belt (year 2000) and has since spread to Texas causing significant yield losses. This study was a...A boll infection caused by non-traditional cotton pathogens was first reported to occur in the southeastern U.S. Cotton Belt (year 2000) and has since spread to Texas causing significant yield losses. This study was aimed towards investigating the verde plant bug (<em>Creontiades signatus</em>) link between interior boll disease in Texas, USA. Using glasshouse grown bolls, bacteria recovered from locules with disease symptoms from field-grown cotton bolls caged with the piercing-sucking <em>C. signatus</em> were analyzed for the capacity to inflict the disease. For pathogenicity testing, spontaneously generated rifampicin resistant (Rifr) variants were utilized to track the antibiotic resistant bacterium and deter growth of endophytic and contaminating bacteria. To simulate <em>C. signatus</em> feeding, a needle (31 gauge) was employed to inoculate bolls at 13 - 15 days after flower bloom. Bacterial suspensions ranged from 10<sup>1</sup> - 10<sup>6</sup> colony forming units/ml. Field infection symptoms were duplicated after two weeks of bacterial exposure. Infectious strains were best categorized as <em>Serratia marcescens</em> based on traditional carbon utilization and enzyme production testing, and a 99% nucleotide sequence identity of 16S ribosomal DNA. Putative <em>S. marcescens</em> representatives isolated from rotted bolls exposed to<em> C. signatus</em> were shown to reproduce field infection symptoms upon inoculation into greenhouse grown fruit. <em>Serratia</em> spp. can inflict disease in alfalfa, cucurbits, and sunflower. The presented data are the first to definitively show that a <em>Serratia</em> sp. has the capacity to infect cotton.展开更多
The methylotrophic budding yeast Pichia pastoris has been utilized to the production of a variety of heterologous recombinant proteins owing to the strong inducible alcohol oxidase promoter(pAOX1).However,it is diffic...The methylotrophic budding yeast Pichia pastoris has been utilized to the production of a variety of heterologous recombinant proteins owing to the strong inducible alcohol oxidase promoter(pAOX1).However,it is difficult to use P.pastoris as the chassis cell factory for high-valuable metabolite biosynthesis due to the low homologous recombination(HR)efficiency and the limitation of handy selective markers,especially in the condition of multistep biosynthetic pathways.Hence,we developed a novel CRISPR/Cas9 system with highly editing efficiencies and recyclable auxotrophic selective marker(HiEE-ReSM)to facilitate cell factory in P.pastoris.Firstly,we improved the HR rates of P.pastoris through knocking out the non-homologous-end-joining gene(Δku70)and overexpressing HR-related proteins(RAD52 and RAD59),resulting in higher positive rate compared to the basal strain,achieved 97%.Then,we used the uracil biosynthetic genes PpURA3 as the reverse screening marker,which can improve the recycling efficiency of marker.Meanwhile,the HR rate is still 100%in uracil auxotrophic yeast.Specially,we improved the growth rate of uracil auxotrophic yeast strains by overexpressing the uracil transporter(scFUR4)to increase the uptake of exogenous uracil from medium.Meanwhile,we explored the optimal concentration of uracil(90 mg/L)for strain growth.In the end,the HiEE-ReSM system has been applied for the inositol production(250 mg/L)derived from methanol in P.pastoris.The systems will contribute to P.pastoris as an attractive cell factory for the complex compound biosynthesis through multistep metabolic pathway engineering and will be a useful tool to improve one carbon(C1)bio-utilization.展开更多
Pod shattering can lead to devastating yield loss of soybean and has been a negatively selected trait in soybean domestication and breeding.Nevertheless,a significant portion of soybean cultivars are still pod shatter...Pod shattering can lead to devastating yield loss of soybean and has been a negatively selected trait in soybean domestication and breeding.Nevertheless,a significant portion of soybean cultivars are still pod shattering-susceptible,limiting their regional and climatic adaptabilities.Here we performed genetic diagnosis on the shattering-susceptible trait of a national registered cultivar,Huachun6(HC6),and found that HC6 carries the susceptible genotype of a candidate Pod dehiscence 1(PDH1)gene,which exists in a significant portion of soybean cultivars.We next performed genome editing on PDH1 gene by clustered regularly interspaced short palindromic repeats(CRISPR)-CRISPR-associated protein 9(Cas9).In T2 progenies,several transgene-free lines with pdh1 mutations were characterized without affecting major agronomic traits.The pdh1 mutation significantly improved the pod shattering resistance which is associated with aberrant lignin distribution in inner sclerenchyma.Our work demonstrated that precision breeding by genome editing on PDH1 holds great potential for precisely improving pod shattering resistance and adaptability of soybean cultivars.展开更多
基金the National Natural Science Foundation of China(U21A20216)the National Key Research and Development Program of China(2018YFD1000705/2018YFD1000700)+2 种基金Fundamental Research Funds of the Chinese Academy of Agricultural Sciences(Grant to Guanqing Jia,1610092016116,Y2017JC15)China Agricultural Research System(CARS06-14.5-A04)State Key Laboratory of Crop Gene Resources and Breeding,Key Laboratory of Grain Crop Genetic Resources Evaluation and Utilization,Key Laboratory of Crop Gene Resource and Germplasm Enhancement(MOA),and Technology Innovation Program of the Chinese Academy of Agricultural Sciences.
文摘Carotenoid biosynthesis and accumulation are important in determining nutritional and commercial value of crop products.Yellow pigmentation of mature kernels caused by carotenoids is considered a vital quality trait in foxtail millet,an ancient and widely cultivated cereal crop across the world.Genomic regions associated with yellow pigment content(YPC),lutein and zeaxanthin in foxtail millet grains were identified by genome-wide association analysis(GWAS),and SiPSY1(Phytoene synthase 1 which regulates formation of the 40-carbon backbone of carotenoids)was confirmed as the main contributor to all three components by knockout and overexpression analysis.SiPSY1 was expressed in seedlings,leaves,panicles,and mature seeds,and was subcellularly localized to chloroplasts.Transcription of SiPSY1 in 15 DAP immature grains was responsible for YPC in mature seeds.Selection of SiPSY1 combined with increased YPC in mature grains during domestication of foxtail millet was confirmed.Haplotype analysis suggested that expression level of SiPSY1 could be a selection target for future breeding programs,and a KASP marker was developed for selection of favorable SiPSY1 alleles in breeding.The results of this work will benefit nutritional and commercial improvement of foxtail millet varieties,as well as other cereal crops.
基金supported by the National Natural Science Foundation of China(Grant Nos.32102389,32172602,32172574)the Funding of Joint Research on Agricultural Varietie Improvement of Henan Province(Grant No.2022010503)+4 种基金the Zhongyuan Youth Talent Support Program(Grant No.ZYQR201912161)the Program for Science&Technology Innovation Talents in Universities of Henan Province(Grant No.21HASTIT038)the Key Scientific and Technological Project of Henan Province(Grant No.202102110045)the Major Science and Technology Project of Henan Province(Grant No.221100110400)the Science and Technology Innovation Fund of Henan Agricultural University(Grant No.KJCX2021A14).
文摘Pruning is time-consuming and laborious in watermelon cultivation,which can not meet the needs for simplified cultivation in the future.The development of branchless lines will provide important germplasms for breeding watermelon varieties and is an important method for genetic improvement.In this study,the watermelon accession,Wu Cha Zao(WCZ)is a branchless inbred line that carries the branchless gene Clbl,which was used as the donor parent to develop branchless near isogenic lines(NILs).To construct the NILs of Clbl,WCZ crossed with the normal branching watermelon inbred line WT20 which was used as the recurrent parent.The co-segregating markers dCAPS10 and Indel1 with Clbl were used for foreground selection,and a total of 108 SSR markers was selected with good polymorphism between two parental lines for background selection which had relatively uniform distribution across 11 chromosomes.Using these markers to select individuals from the BC_(1)F_(1),BC_(2)F_(1),and BC_(2)F_(2) generations,three NILs with a proportion of recurrent parent genome(PRPG)>99%were finally obtained.The lateral branch and plant height phenotypes did not significantly differ between the NILs and WCZ,indicating that the NILs of Clbl under the genetic background of WT20 has been successfully developed.These results provide ideal materials for further in-depth analysis of the genetic mechanisms of lateral branch development and ideal plant architecture breeding in watermelon.
基金The present research was conducted under the financial support of IMA,MT,Brazil.
文摘The cotton cultivar DELTAOPAL is resistant under field as well as under glasshouse conditions to the Brazilian isolates of Xanthomonas axonopodis pv. malvacearum (Xam). Segregating populations derived from the cross between this cultivar and one susceptible cv. BRS ITA 90, were utilized to identify molecular marker linked with the resistance gene to Xam by “Bulk Segregant Analysis (BSA)”. Two hundred and twenty microsatellite (Single Sequence Repeat—SSR) primers were tested. The amplification products were visualized in polyacrylamide gels stained with silver nitrate. Only one primer was informative and showed polymorphism between the DNA of the parents and their respective bulks of homozygous F2 populations contrasting for resistance and susceptibility, and hence was used to analyze DNA of 120 F2 populations. The microsatellite primer yielded one band of 80 bp linked with the resistance locus, which was absent in the susceptible parent as well as in the bulk of the homozygous susceptible plants of the cross. The segregation ratio as determined by phenotypic analysis was 3R:1S. It is believed that the microsatellite marker was linked with the resistance locus and hence may offer new perspectives for marker assisted selection against the angular leaf spot disease of cotton. It is however, felt necessary to repeat the microsatellite analysis and make sure that the primer is tightly linked with the resistance locus and at the same time verify the genetic distance between the marker and the resistance locus.
文摘Selection and use of molecular markers for evaluation of DNA polymorphism in plants are couple of the most important approaches in the field of molecular genetics.The assessment of genetic diversity using morphological markers is not sufficient due to little differentiating traits among the species,genera or their individuals.Morphological markers are not only highly influenced by environmental factors but skilled assessment is also prerequisite to find the variations in plant genetic resources.Therefore,molecular markers are considered as efficient tools for detailed DNA based characterization of fruit crops.Molecular markers provide new directions to the efforts of plant breeders particularly in genetic variability,gene tags,gene localization,taxonomy,genetic diversity,phylogenetic analysis and also play an important role to decrease the time required for development of new and excellent cultivars.The success of molecular markers technology in genetic improvement programs depends on the close relationship among the plant breeders,biotechnologists,skilled manpower and good financial support.The present review describes application and success of molecular markers technology used for genetic improvement in different fruit crops.
文摘The oil palm (<i>Elaeis</i> <i>guineensis</i> Jacq.) is one of the major cultivated crops among the economically important palm species. It is cultivated mainly for its edible oil. For a perennial crop like oil palm, the use of Marker Assisted Selection (MAS) techniques helps to reduce the breeding cycle and improve the economic products. Genetic and physical maps are important for sequencing experiments since they show the exact positions of genes and other distinctive features in the chromosomal DNA. This review focuses on the role of genome mapping in oil palm breeding. It assesses the role of genome mapping in oil palm breeding and discusses the major factors affecting such mapping. Generating a high-density map governed by several factors, for instance, marker type, marker density, number of mapped population, and software used are the major issues treated. The general conclusion is that genome mapping is pivotal in the construction of a genetic linkage map. It helps to detect QTL and identify genes that control quantitative traits in oil palm. In perspective, the use of high-density molecular markers with a large number of markers, a large number mapping population, and up-to-date softw<span style="color:;">are </span><span>is necessary</span><span style="color:;"> for oil pal</span>m genome mapping.
文摘With over 10 million points of genetic variation from person to person, every individual’s genome is unique and provides a highly reliable form of identification. This is because the genetic code is specific to each individual and does not change over time. Genetic information has been used to identify individuals in a variety of contexts, such as criminal investigations, paternity tests, and medical research. In this study, each individual’s genetic makeup has been formatted to create a secure, unique code that incorporates various elements, such as species, gender, and the genetic identification code itself. The combinations of markers required for this code have been derived from common single nucleotide polymorphisms (SNPs), points of variation found in the human genome. The final output is in the form of a 24 numerical code with each number having three possible combinations. The custom code can then be utilized to create various modes of identification on the decentralized blockchain network as well as personalized services and products that offer users a novel way to uniquely identify themselves in ways that were not possible before.
基金This research was supported by grants from the Citrus Research and Development Foundation and National Science Foundation(IOS-0842716)awarded to ZM.
文摘Genetic transformation has become a promising tool for improvement of a variety of crop species. However, transferring genes across species, the presence of selectable marker genes, and bacteria-derived vector backbone sequences have raised considerable health and environmental concerns. Intragenic vector system-based intragenesis/cisgenesis is a new method using transgenic approach to achieving traditional breeding objectives but circumventing many of the associated shortcomings. We report here the development of an intragenic vector by assembling a T-DNA-like fragment and a buffering sequence following the left border from Citrus clementina into the backbone of the binary vector pCB302. Recovery of citrus regenerants is performed under non-selective conditions and positive intra-/cisgenic regenerants were identified through PCR analysis. Transformation efficiencies obtained in Arabidopsis and “Duncan” grapefruit were ~3% and ~0.67%, respectively, demonstrating the potential of the system for development of “foreign DNA-free” intra-/cisgenic citrus cultivars.
基金This work was supported by the National Key Laboratory of Crop Genetic Improvement Self-Research Program(ZW18B0101)the China Scholarship Council(201908420122)+1 种基金the Teachers’Scientific Ability Cultivation Foundation of Hubei University of Arts and Science(PYSB20201001)the Xiangyang Youth Science and Technology Talent Development Plan.
文摘Gray leaf spot(GLS)caused by Cercospora zeae-maydis and C.zeina is an extremely devastating leaf disease that limits maize production annually.The use of GLS-resistant maize hybrids is the most cost-effective approach for reducing losses.Resistance to GLS is quantitatively inherited in maize(Zea mays L.)and further sources of resistance remain to be analyzed.Here,we detected qRgls1.06,a major quantitative trait locus for GLS resistance in bin 1.06 that explained approximately 55%of the phenotype variance.Fine mapping over 2 consecutive years localized qRgls1.06 to a 2.38-Mb region.Homozygous qRgls1.06^(WGR/WGR) plants in DZ01 background displayed higher GLS resistance and 100-grain weight than DZ01 plants.The GLS responses of several susceptible elite inbred lines were improved by the introduction of qRgls1.06 by marker-assisted backcrossing.Our findings extend the understanding of the genetic basis of resistance to GLS and provide a set of resistant germplasm for genetic improvement of resistance to GLS in maize.
文摘A boll infection caused by non-traditional cotton pathogens was first reported to occur in the southeastern U.S. Cotton Belt (year 2000) and has since spread to Texas causing significant yield losses. This study was aimed towards investigating the verde plant bug (<em>Creontiades signatus</em>) link between interior boll disease in Texas, USA. Using glasshouse grown bolls, bacteria recovered from locules with disease symptoms from field-grown cotton bolls caged with the piercing-sucking <em>C. signatus</em> were analyzed for the capacity to inflict the disease. For pathogenicity testing, spontaneously generated rifampicin resistant (Rifr) variants were utilized to track the antibiotic resistant bacterium and deter growth of endophytic and contaminating bacteria. To simulate <em>C. signatus</em> feeding, a needle (31 gauge) was employed to inoculate bolls at 13 - 15 days after flower bloom. Bacterial suspensions ranged from 10<sup>1</sup> - 10<sup>6</sup> colony forming units/ml. Field infection symptoms were duplicated after two weeks of bacterial exposure. Infectious strains were best categorized as <em>Serratia marcescens</em> based on traditional carbon utilization and enzyme production testing, and a 99% nucleotide sequence identity of 16S ribosomal DNA. Putative <em>S. marcescens</em> representatives isolated from rotted bolls exposed to<em> C. signatus</em> were shown to reproduce field infection symptoms upon inoculation into greenhouse grown fruit. <em>Serratia</em> spp. can inflict disease in alfalfa, cucurbits, and sunflower. The presented data are the first to definitively show that a <em>Serratia</em> sp. has the capacity to infect cotton.
基金Key-Area Research and Development Program of Guangdong Province(2022B1111080005)the National Key Research and Development Program of China(2020YFA0907800 and 2021YFA0911000)+5 种基金the National Natural Science Foundation of China(NSFC 32071416)the Shenzhen Institute of Synthetic Biology Scientific Research Program(Grant No.JCHZ20200003)Shenzhen Key Laboratory for the Intelligent Microbial Manufacturing of Medicines(ZDSYS20210623091810032)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0480000)the China Postdoctoral Science Foundation(2020M682973)Guangdong Basic and Applied Basic Research Foundation(2020A1515110927).
文摘The methylotrophic budding yeast Pichia pastoris has been utilized to the production of a variety of heterologous recombinant proteins owing to the strong inducible alcohol oxidase promoter(pAOX1).However,it is difficult to use P.pastoris as the chassis cell factory for high-valuable metabolite biosynthesis due to the low homologous recombination(HR)efficiency and the limitation of handy selective markers,especially in the condition of multistep biosynthetic pathways.Hence,we developed a novel CRISPR/Cas9 system with highly editing efficiencies and recyclable auxotrophic selective marker(HiEE-ReSM)to facilitate cell factory in P.pastoris.Firstly,we improved the HR rates of P.pastoris through knocking out the non-homologous-end-joining gene(Δku70)and overexpressing HR-related proteins(RAD52 and RAD59),resulting in higher positive rate compared to the basal strain,achieved 97%.Then,we used the uracil biosynthetic genes PpURA3 as the reverse screening marker,which can improve the recycling efficiency of marker.Meanwhile,the HR rate is still 100%in uracil auxotrophic yeast.Specially,we improved the growth rate of uracil auxotrophic yeast strains by overexpressing the uracil transporter(scFUR4)to increase the uptake of exogenous uracil from medium.Meanwhile,we explored the optimal concentration of uracil(90 mg/L)for strain growth.In the end,the HiEE-ReSM system has been applied for the inositol production(250 mg/L)derived from methanol in P.pastoris.The systems will contribute to P.pastoris as an attractive cell factory for the complex compound biosynthesis through multistep metabolic pathway engineering and will be a useful tool to improve one carbon(C1)bio-utilization.
基金supported by Innovative Research Groups of the Natural Science Foundation of Hebei province(C2020301020).
文摘Pod shattering can lead to devastating yield loss of soybean and has been a negatively selected trait in soybean domestication and breeding.Nevertheless,a significant portion of soybean cultivars are still pod shattering-susceptible,limiting their regional and climatic adaptabilities.Here we performed genetic diagnosis on the shattering-susceptible trait of a national registered cultivar,Huachun6(HC6),and found that HC6 carries the susceptible genotype of a candidate Pod dehiscence 1(PDH1)gene,which exists in a significant portion of soybean cultivars.We next performed genome editing on PDH1 gene by clustered regularly interspaced short palindromic repeats(CRISPR)-CRISPR-associated protein 9(Cas9).In T2 progenies,several transgene-free lines with pdh1 mutations were characterized without affecting major agronomic traits.The pdh1 mutation significantly improved the pod shattering resistance which is associated with aberrant lignin distribution in inner sclerenchyma.Our work demonstrated that precision breeding by genome editing on PDH1 holds great potential for precisely improving pod shattering resistance and adaptability of soybean cultivars.
