Reductive soil disinfestation(RSD)is commonly employed for soil remediation in greenhouse cultivation.However,its influence on antibiotic resistance genes(ARGs)in soil remains uncertain.This study investigated the dyn...Reductive soil disinfestation(RSD)is commonly employed for soil remediation in greenhouse cultivation.However,its influence on antibiotic resistance genes(ARGs)in soil remains uncertain.This study investigated the dynamic changes in soil communities,potential bacterial pathogens,and ARG profiles under various organicmaterial treatments during RSD,including distillers’grains,potato peel,peanut vine,and peanut vine combined with charcoal.Results revealed that applying diverse organic materials in RSD significantly altered bacterial community composition and diminished the relative abundance of potential bacterial pathogens(P<0.05).The relative abundance of high-risk ARGs decreased by 10.7%-30.6%after RSD treatments,the main decreased ARG subtypeswere AAC(3)_Via,dfrA1,ErmB,lnuB,aadA.Actinobacteria was the primary host of ARGs and was suppressed by RSD.Soil physicochemical properties,such as total nitrogen,soil pH,total carbon,were crucial factors affecting ARG profiles.Our findings demonstrated that RSD treatment inhibited pathogenic bacteria and could be an option for reducing high-risk ARG proliferation in soil.展开更多
The effects of disinfectants and plasmid-based antibiotic resistance genes(ARGs)on the growth of microorganisms and the plasmid-mediated transfer of ARGs in the water and biofilm of the drinkingwater distribution syst...The effects of disinfectants and plasmid-based antibiotic resistance genes(ARGs)on the growth of microorganisms and the plasmid-mediated transfer of ARGs in the water and biofilm of the drinkingwater distribution system under simulated conditionswere explored.The heterotrophic plate count of the water in reactors with 0.1 mg/L NaClO and NH_(2)Cl was higher than in the control groups.Therewas no similar phenomenon in biofilm.In thewater of reactors containing NaClO,the aphA and bla geneswere lower than in the antibiotic resistant bacteria group,while both genes were higher in the water of reactors with NH_(2)Cl than in the control group.Chloramine may promote the transfer of ARGs in the water phase.Both genes in the biofilm of the reactors containing chlorine were lower than the control group.Correlation analysis between ARGs and water quality parameters revealed that the copy numbers of the aphA gene were significantly positively correlated with the copy numbers of the bla gene in water and significantly negatively correlated in biofilm(p<0.05).The results of the sequencing assay showed that bacteria in the biofilm,in the presence of disinfectant,were primarily Gram-negative.1.0 mg/L chlorine decreased the diversity of the community in the biofilm.The relative abundance of some bacteria that may undergo transfer increased in the biofilm of the reactor containing 0.1 mg/L chlorine.展开更多
Asian rice comprises two major subspecies:Xian(X)and Geng(G),and the diverged resistance genes(R)have provided a foundation for breeding improved cultivars to control rice blast disease.After conducting two-phase alle...Asian rice comprises two major subspecies:Xian(X)and Geng(G),and the diverged resistance genes(R)have provided a foundation for breeding improved cultivars to control rice blast disease.After conducting two-phase allele mining using six updated FNP marker systems,the functional haplotypes at Pit,Pib,and Pi63 strictly diverged into the X-populations and were defined as X-R loci,while those at Pi54,Pi37,and Pi36 into the G-populations as G-R loci.The genic diversity at the three X-R loci(16 alleles)was twofold higher than that at the three G-R loci(8 alleles),and the allelic diversity in the Southern region(21 alleles)was nearly double that in the Northeastern region(11 alleles).Both observations reflect a significant difference in genetic diversity between X-and G-populations,and indicate that the effective R-genes mainly originated from X-subspecies.Based on the allelic structures characterized by a set of 10 parameters,8 and 16 alleles were respectively recognized as favorable and promising ones for the regional breeding programs.The genotypic structures of the two regional populations were almost different,indicating that the diverged alleles have been further assembled into two series of regional genotypes through long-term breeding programs,despite the presence of one-third of region-common alleles.The genotypic diversity in the Southern region(55 genotypes)was nearly twice as high as that in the Northeastern region(28),which perfectly reflects the aforementioned differences in both genic and allelic diversities.After analyzing the genotypic structures using a set of 13 parameters,4 and 23 genotypes,respectively,can be recommended as the favorable and promising ones for the regional breeding programs.The case study serves as a concrete sample of how to identify the favorable and promising alleles and genotypes,and beneficial parents based their comprehensive population structures for gene-designed breeding.展开更多
Because of the recent widespread usage of antibiotics,the acquisition and dissemination of antibiotic-resistance genes(ARGs)were prevalent in the majority of habitats.Generally,the biological wastewater treatment proc...Because of the recent widespread usage of antibiotics,the acquisition and dissemination of antibiotic-resistance genes(ARGs)were prevalent in the majority of habitats.Generally,the biological wastewater treatment processes used in wastewater treatment plants have a limited efficiencies of antibiotics resistant bacteria(ARB)disinfection and ARGs degradation and even promote the proliferation of ARGs.Problematically,ARB and ARGs in effluent pose potential risks if they are not further treated.Photocatalytic oxidation is considered a promising disinfection technology,where the photocatalytic process generates many free radicals that enhance the interaction between light and deoxyribonucleic acid(DNA)for ARB elimination and subsequent degradation of ARGs.This reviewaims to illustrate the progress of photocatalytic oxidation technology for removing antibiotics resistant(AR)from wastewater in recent years.We discuss the sources and transfer of ARGs in wastewater.The overall removal efficiencies of ultraviolet radiation(UV)/chlorination,UV/ozone,UV/H_(2)O_(2),and UV/sulfate-radical based system for ARB and ARGs,as well as the experimental parameters and removal mechanisms,are systematically discussed.The contribution of photocatalytic materials based on TiO_(2) and g-C_(3)N_(4) to the inactivation of ARB and degradation of ARGs is highlighted,producingmany free radicals to attack ARB and ARGs while effectively limiting the horizontal gene transfer(HGT)in wastewater.Finally,based on the reviewed studies,future research directions are proposed to realize specific photocatalytic oxidation technology applications and overcome current challenges.展开更多
Microalgae-bacteria system is an emerging alternative for sustainable wastewater treatment.Exploring the structure and diversity of microbial community in microalgae-bacteria system under sulfadiazine stress can contr...Microalgae-bacteria system is an emerging alternative for sustainable wastewater treatment.Exploring the structure and diversity of microbial community in microalgae-bacteria system under sulfadiazine stress can contribute to the understanding of the sulfadiazine behavior in environments.Furthermore,as important carriers of antibiotic resistance genes(ARGs),microalgae can influence the profiles of ARGs either directly or indirectly through the secretion of metabolites.However,the effects of sulfadiazine on ARGs dissemination of microalgae-bacteria systems remain underreported.Herein,the impacts of sulfadiazine(1 mg/L)on the structural diversity and metabolic activity of microorganisms were examined in microalgae-bacteria systems.Results showed thatmicroalgae-bacteria system could remove NH_(4)^(+)-N better(about 72.3%)than activated sludge system,and hydrolysis was the first step in sulfadiazine degradation.A high level of intI1(5.7×10^(4) copies/mL)was detected in the initial media of the microalgae-bacteria system.Microalgae could hamper the rate of horizontal gene transfer activation.Compared with activated sludge system,the abundance of sul genes(sul1,sul2,sul3,and sulA)was significantly lowered after treating with microalgae-bacteria system.Additionally,the number of proteins and the sum of polysaccharides in the extracellular polymeric substances of the activated sludge system were lower than those of themicroalgae-bacteria system.Microalgae can altermicrobial communities.The genus Rozellomycota predominated all samples.Fungi with relatively high abundance increased in the microalgae-bacteria system,including Dipodascaceae,Rhodotorula,and Geotrichum.These results offer valuable insights into the application processes involving microalgae-bacteria system.展开更多
The objective of this study is to quantitatively reveal the main genetic carrier of antibiotic resistance genes(ARGs)for blocking their environmental dissemination.The distribution of ARGs in chromosomes,plasmids,and ...The objective of this study is to quantitatively reveal the main genetic carrier of antibiotic resistance genes(ARGs)for blocking their environmental dissemination.The distribution of ARGs in chromosomes,plasmids,and phages for understanding their respective contributions to the development of antimicrobial resistance in aerobic biofilm consortium under increasing stresses of oxytetracycline,streptomycin,and tigecyclinewere revealed based on metagenomics analysis.Results showed that the plasmids harbored 49.2%-83.9%of resistomes,which was higher(p<0.001)than chromosomes(2.0%-35.6%),and no ARGs were detected in phage contigs under the strict alignment standard of over 80%identity used in this study.Plasmids and chromosomes tended to encode different types of ARGs,whose abundances all increased with the hike of antibiotic concentrations,and the variety of ARGs encoded by plasmids(14 types and 64 subtypes)was higher than that(11 types and 27 subtypes)of chromosomes.The dosing of the three antibiotics facilitated the transposition and recombination of ARGs on plasmids,mediated by transposable and integrable transfer elements,which increased the co-occurrence of associated and unassociated ARGs.The results quantitatively proved that plasmids dominate the proliferation of ARGs in aerobic biofilm driven by antibiotic selection,which should be a key target for blocking ARG dissemination.展开更多
As an emerging environmental contaminant,antibiotic resistance genes(ARGs)in tap water have attracted great attention.Although studies have provided ARG profiles in tap water,research on their abundance levels,composi...As an emerging environmental contaminant,antibiotic resistance genes(ARGs)in tap water have attracted great attention.Although studies have provided ARG profiles in tap water,research on their abundance levels,composition characteristics,and potential threat is still insufficient.Here,9 household tap water samples were collected from the Guangdong-Hong Kong-Macao Greater Bay Area(GBA)in China.Additionally,75 sets of environmental sample data(9 types)were downloaded from the public database.Metagenomics was then performed to explore the differences in the abundance and composition of ARGs.221 ARG subtypes consisting of 17 types were detected in tap water.Although the ARG abundance in tap water was not significantly different from that found in drinking water plants and reservoirs,their composition varied.In tap water samples,the three most abundant classes of resistance genes were multidrug,fosfomycin and MLS(macrolide-lincosamidestreptogramin)ARGs,and their corresponding subtypes ompR,fosX and macB were also the most abundant ARG subtypes.Regarding the potential mobility,vanS had the highest abundance on plasmids and viruses,but the absence of key genes rendered resistance to vancomycin ineffective.Generally,the majority of ARGs present in tap water were those that have not been assessed and are currently not listed as high-threat level ARG families based on the World Health Organization Guideline.Although the current potential threat to human health posed by ARGs in tap water is limited,with persistent transfer and accumulation,especially in pathogens,the potential danger to human health posed by ARGs should not be ignored.展开更多
In recent years,the biodegradable plastics has extensively used in industry,agriculture,and daily life.Herein,the effects of two biodegradable microplastics(BMPs),poly(butyleneadipate-co-terephthalate)(PBAT)and polyhy...In recent years,the biodegradable plastics has extensively used in industry,agriculture,and daily life.Herein,the effects of two biodegradable microplastics(BMPs),poly(butyleneadipate-co-terephthalate)(PBAT)and polyhydroxyalkanoate(PHA),on soil sulfamethoxazole(SMX)degradation and sul genes development were comparatively studied based on the type,dosage,and state.The addition of virgin BMPs significantly increased soil DOC following a sequential order PBAT>PHA and high dose>low dose.Meanwhile virgin PBAT significantly reduced soil pH.In general,the addition of BMPs not only promoted soil SMX degradation but also increased the abundance of sul genes,with an exception that pH reduction in virgin PBAT inhibited the proliferation of sul genes.The driving effects of BMPs on soil microbial diversity following the same order as that on DOC.Specific bacteria stimulated by BMPs,such as Arthrobacter and two genera affiliated with phylum TM7,accounted for the accelerated degradation of SMX.Intriguingly,UV-aging hindered the release of DOC from BMPs and the reduction in pH,mitigated the stimulation of microbial communities,and ultimately reduced the promotion effect of BMPs on SMX degradation and sul genes proliferation.Our results suggest that more attention should be paid to the proliferation risk of ARGs in the environment affected by BMPs and UV-aging can be employed sometimes to reduce this risk.展开更多
Partially modified Bt Cry1Ac gene and the arrowhead proteinase inhibitor (API) gene were used to construct a plant transformation vector pBtiA and this construct was transferred into the genome of the hybrid popla...Partially modified Bt Cry1Ac gene and the arrowhead proteinase inhibitor (API) gene were used to construct a plant transformation vector pBtiA and this construct was transferred into the genome of the hybrid poplar 741 [ Populus alba L.×( P. davidiana Dode+ P. simonii Carr.)× P. tomentosa Carr.] by Agrobacterium _ mediated transformation. Ten kanamycin resistant plants have been regenerated. Upon insect bioassay using Clostera anachoreta (Fabricius), three of the examined plants were demonstrated to be highly resistant to the testing insects. The mortality of insect larvae on one plant was higher than 90% in 6 days after infestation and the growth of the survival larvae were seriously inhibited. Results of PCR and Southern blot analysis indicated that both Bt Cry1Ac gene and API gene were integrated as a single copy into the genomes of these three plants when Cry1Ac gene fragment was used as the probe. Protein dot blot immunoassay and ELISA analysis revealed that at least the Cry1Ac protein was produced in these three transgenic plants and the expression levels were estimated to be approximately 0.015% of the leaf total soluble protein. This is the first report on insect resistant transgenic hybrid poplar 741 that expresses two insecticidal protein genes.展开更多
Pi-ta and Pi-b, the first cloned rice blast resistant genes, have been wide- ly used in rice blast resistance breeding for their lasting and stable resistance. To define the distribution of Pi-ta and Pi-b in japonica ...Pi-ta and Pi-b, the first cloned rice blast resistant genes, have been wide- ly used in rice blast resistance breeding for their lasting and stable resistance. To define the distribution of Pi-ta and Pi-b in japonica rice in Jiangsu, the genotypes of resistance genes Pi-ta and Pi-b in 40 varieties and 665 new lines were detected using functional markers of Pi-ta/pi-ta and Pi-b^pi-b alleles. The results showed that the resistance alleles of Pi-ta and Pi-b were widely spread in japonica rice varieties, and the distribution frequency of Pi-b was higher than that of Pi-ta. Most of the Lianjing serial varieties didn＇t carry the two resistance genes, but the two resistance genes were widely distributed in Wujing serial varieties. There was no significant dif- ference in distribution frequency of Pi-ta between new lines and commercial vari- eties. However, the distribution frequency of Pi-b in new lines was higher than that in commercial varieties. It was indicated that artificial selection was conducive to the improvement of distribution frequency of Pi-b in rice varieties. Among the 4 genotypes, the distribution frequency of pi-taJPi-b was highest （60.0%）, followed by Pi-ta/ Pi-b （33.5%） and pi-ta/pi-b （3.9%）. The frequency of Pi-taJpi-b was lowest, account- ing for only 2.6%. In terms of source of resistance genes in the four combinations, the resistant allele Pi-ta might be from parents of Wuxiangjing14, Wujing15 or Nanjing44, and Pi-b might come from parents of Wujing13, Wuxiangjing14, Wujing15 or Nanjing44. The analysis on the genotypic frequencies in offspring of the rice vari- eties showed that the resistance genotype of Pi-ta/Pi-b had the highest frequency in the cross combination of Nanjing44//Wujing13/Kantou194.展开更多
Yunmai52, developed by crossing with common wheat-Haynaldia villosa6AL/6VS translocation line 92R149 as a resistant parent in 1992, was a common wheat cultivar approved and released in 2007 in Yunnan Province, China, ...Yunmai52, developed by crossing with common wheat-Haynaldia villosa6AL/6VS translocation line 92R149 as a resistant parent in 1992, was a common wheat cultivar approved and released in 2007 in Yunnan Province, China, which is characterized by high resistance to powdery mildew and stripe rust. In this study,an F_2 population derived from a cross K78S/Yunmai52 was constructed to investigate the resistance genes, where K78 S is a wheat male sterile line susceptible to powdery mildew and stripe rust. Phenotypic identification of the parents, F_1 and F_2 populations and chi-square analyses showed that F_1 population was immune to stripe rust and powdery mildew; the segregation ratio of resistance and susceptibility to powdery mildew（χ~2=1.10χ~2_（1,0.05）=3.84） and stripe rust（χ~2=0.15χ~2_（1,0.05）=3.84） fit to a 3：1 ratio in F_2 population, indicating that Yunmai52 harbors a dominant stripe rust resistance gene and a dominant powdery mildew resistance gene. The individuals were further detected with a marker co-segregated with Pm21（SCAR_（1400）） and two markers closely linked with Yr26（XWe173 and Xbarc181）. The results showed that polymorphic bands could be amplified between the parents and between resistance and susceptibility gene pools at the same locus. Randomly 96 individuals of F_2 population were selected for verification. The results showed that the phenotype was significantly correlated with the genotype. The detection accuracy of markers SCAR_（1400）, XWe173 and Xbarc181 was 100%, 97.91% and 92.70%, respectively.Yunmai52 harbored powdery mildew resistance gene Pm21 and stripe rust resistance gene Yr26, which were both derived from 6AL/6VS translocation line 92R149.In addition, the results also demonstrate that Pm21 and Yr26 are two genes conferring durable resistance to powdery mildew and stripe rust in wheat.展开更多
Rice blast is one of the important diseases in major rice producing areas of China. The main blast resistance genes Pi-ta and Pi-b showed broad-spectrum and durable resistance to rice blast in many rice growing areas ...Rice blast is one of the important diseases in major rice producing areas of China. The main blast resistance genes Pi-ta and Pi-b showed broad-spectrum and durable resistance to rice blast in many rice growing areas of China, which have been widely utilized in rice breeding and commercial production. In this study, on the basis of detection and verification of the genotypes of 22 rice varieties har- boring known blast resistance genes （Pi-ta and Pi-b） and blast susceptibility genes （pi-ta and pi-b）, two multiple PCR systems for these genes were established by us- ing the functional markers of blast resistance genes Pi-ta and Pi-b as well as blast susceptibility genes pi-ta and pi-b, respectively. Specifically, multiple PCR system I could simultaneously detect blast resistance genes Pi-ta and Pi-b, while system II could detect simultaneously blast susceptibility genes pi-ta and pi-b. In addition, the genotypes of 336 high generation breeding materials were detected with these two multiple PCR systems. The results were highly consistent with those of conventional single mark detection, indicating that these two multiplex PCR systems were stable, reliable and time-saving. The established multiplex PCR systems may serve as a rapid and efficient method to identify and screen rice germplasm resources and can be applied in marker-assisted selection to polymerize multiple genes for blast resis- tance in rice breeding.展开更多
Rice blast disease, caused by Magnaporthe oryzae, threatens global food security. The rice blast pathosystem is a longstanding model system for understanding plant-microbe interactions. In order to elucidate the coevo...Rice blast disease, caused by Magnaporthe oryzae, threatens global food security. The rice blast pathosystem is a longstanding model system for understanding plant-microbe interactions. In order to elucidate the coevolution of the host and pathogen, and provide the appropriate methods for preventing or controlling rice blast disease, researchers have focused on the evolution of virulence factors and resistance genes. Thus far, more than 30 rice blast resistance（R） genes and 12 avirulence（Avr） genes have been cloned. This review summarizes the cloned rice blast R genes, cloned Avr genes of M. oryzae and the interaction between them. This discussion also considers some of the major unanswered questions concerning this pathosystem and the opportunities for future investigations.展开更多
Two pairs of degenerate primers were designed based on nucleotide-binding site (NBS) and serine/threonine kinase domain. PCR was performed with the primers and cDNA from the Triticum aestivum-Haynaldia villosa translo...Two pairs of degenerate primers were designed based on nucleotide-binding site (NBS) and serine/threonine kinase domain. PCR was performed with the primers and cDNA from the Triticum aestivum-Haynaldia villosa translocation line 6VS/6AL. Amplified products were cloned and sequenced. Nine clones with NBS and one with serine/threonine kinase domain were obtained. The NBS clones were classified to six groups according to their nucleotide sequence identities (90% or higher). These resistance gene analogs (RGAs) all have open reading frames (ORF), and their amino acid sequences show high similarity to Yr10 in wheat, Mla1 and Mla6 in barley, RPS2 in Arabidopsis and other resistance (R) genes with conserved motifs. They were preliminarily mapped on the chromosomes of homoeologous groups 1, 2 and 5 of common wheat by nulli-tetrasomic analysis. The 5'-end sequence of an RGA N5 was obtained by 5'-RACE PCR. It encodes six leucine zipper (LZ) and has high sequence similarity to RPS2.展开更多
The occurrence of antibiotic resistance genes （ARGs） was investigated and quantified in 20 water samples collected in the Beijiang River, South China. Sulfonamide- and tetracycline-resistant bacteria were present in...The occurrence of antibiotic resistance genes （ARGs） was investigated and quantified in 20 water samples collected in the Beijiang River, South China. Sulfonamide- and tetracycline-resistant bacteria were present in 17 and 14 of the collected 20 samples. For sulfonamide ARGs, sulI and sulII were frequently observed in the Beijiang River. The levels of sulI were higher than sulII （p 〈 0.05）, with the mean values of （1.41 ± 1.12） × 10-2 and （1.58 ± 1.71） × 10-3 copies/16S rDNA, respectively. For tetracycline ARGs, tetG had the highest frequency, 100%, followed by tetA （85%）, tetO （85%）, tetC （70%）, tetX （60%）, tetM （40%） and tetQ （20%）, while tetE and tetS were not detected in all the samples from the Beijiang River. On the other hand, tetC had the highest concentration, ranging from 8.30 × 10-2 to 13.20 copies/16S rDNA. The poor correlation between ARGs and antibiotic concentrations revealed that the self-amplification and persistence of ARGs were the reasons that made ARGs exist in the water environment even though the antibiotic selecting pressure was absent. Because so few field measurements have been conducted for investigating the levels of ARGs in rivers in South China, this study provides an important insight on better understanding the occurrence and spread of ARGs in such an ecosystem.展开更多
Rice is one of the most important food crops in the world.Weeds seriously affect the rice yield and grain quality.In recent years,there are tremendous progresses in the research and application of herbicideresistant g...Rice is one of the most important food crops in the world.Weeds seriously affect the rice yield and grain quality.In recent years,there are tremendous progresses in the research and application of herbicideresistant genes in rice worldwide.This article reviews the working mechanisms of six herbicides(glyphosate,glufosinate,acetolactate synthase inhibitor herbicides,acetyl-Co A carboxylase inhibitor herbicides,hydroxyhenylpyruvate dioxygenase(HPPD)inhibitor herbicides and dinitroaniline herbicides),the resistance mutations of the corresponding herbicide-target genes,and the herbicide detoxification mechanisms by non-target genes.Examples are provided on herbicide-resistant rice materials obtained by transformation of exogenous resistance genes,by artificial mutagenesis and mutant screening,and by modifying the target genes through gene editing.This paper also introduces the current application of herbicide-resistant rice,points out problems that may be caused by utilization of herbicide resistant rice and solutions to the problems,and discusses the future prospects for the development of herbicideresistant rice.展开更多
[ Objective ] The paper was to confirm the resistance genes and resistant parents of rice against bacterial blight that could be used in Guangxi Province. [ Method] The dominant pathogenic types Ⅳ of Xanthomonas Oryz...[ Objective ] The paper was to confirm the resistance genes and resistant parents of rice against bacterial blight that could be used in Guangxi Province. [ Method] The dominant pathogenic types Ⅳ of Xanthomonas Oryzae pv. Oryzae in Guangxi were inoculated on a set of monogenic rice lines, the main hybrid rice parents in Guangxi and some important rice germplasm resources, and its resistant and susceptible conditions were investigated. [ Result ] IRBBS, IRBB7 and CBB23 were the resistant rice parents with resistance against pathogenic type IV, which contained resistance genes xa5, Xa7 and Xa23, respectively, and were identified to be the effective resistance genes against pathogenic type Ⅳ of X. Oryzae in Guangxi. [ Conclusion] The results provided basis for resistance breeding against bacterial blight.展开更多
Once contaminate the drinking water source,antibiotic resistance genes(ARGs)will propagate in drinking water systems and pose a serious risk to human health.Therefore,the drinking water treatment processes(DWTPs)are c...Once contaminate the drinking water source,antibiotic resistance genes(ARGs)will propagate in drinking water systems and pose a serious risk to human health.Therefore,the drinking water treatment processes(DWTPs)are critical to manage the risks posed by ARGs.This study summarizes the prevalence of ARGs in raw water sources and treated drinking water worldwide.In addition,the removal efficiency of ARGs and related mechanisms by different DWTPs are reviewed.Abiotic and biotic factors that affect ARGs elimination are also discussed.The data on presence of ARGs in drinking water help come to the conclusion that ARGs pollution is prevalent and deserves a high priority.Generally,DWTPs indeed achieve ARGs removal,but some biological treatment processes such as biological activated carbon filtration may promote antibiotic resistance due to the enrichment of ARGs in the biofilm.The finding that disinfection and membrane filtration are superior to other DWTPs adds weight to the advice that DWTPs should adopt multiple disinfection barriers,as well as keep sufficient chlorine residuals to inhibit re-growth of ARGs during subsequent distribution.Mechanistically,DWTPs obtain direct and inderect ARGs reduction through DNA damage and interception of host bacterias of ARGs.Thus,escaping of intracellular ARGs to extracellular environment,induced by DWTPs,should be advoided.This review provides the theoretical support for developping efficient reduction technologies of ARGs.Future study should focus on ARGs controlling in terms of transmissibility or persistence through DWTPs due to their biological related nature and ubiquitous presence of biofilm in the treatment unit.展开更多
Rice blast is one of the most destructive diseases affecting rice production worldwide.The development and rational use of resistant varieties has been the most effective and economical measure to control blast.In thi...Rice blast is one of the most destructive diseases affecting rice production worldwide.The development and rational use of resistant varieties has been the most effective and economical measure to control blast.In this review,we summarized the cloning and utilization of rice blast resistance genes,such as Pi1,Pi2,Pi9,Pi54,Pigm and Piz-t.We concluded that three main problems in the current breeding of rice blast resistance are:availability of few R(resistance)genes that confer resistance to both seedling and panicle blast,the resistance effect of pyramided lines is not the result of a simple accumulation of resistance spectrum,and only a few R genes have been successfully used for molecular breeding.Therefore,novel utilization strategies for rice blast R genes in molecular breeding were proposed,such as accurately understanding the utilization of R genes in main modern rice varieties,creating a core resistant germplasm with excellent comprehensive traits,screening and utilizing broadspectrum and durable resistance gene combinations.Lastly,the trends and possible development direction of blast resistance improvement were also discussed,including new genes regulating resistance identified via GWAS(genome-wide association study)and improving rice blast resistance using genetic editing.展开更多
The objective of this study was to characterize yellow （stripe） rust resistance gene（s） in 52 commercial wheat cultivars from Yunnan Province in China, and to provide information for their rational deployment in f...The objective of this study was to characterize yellow （stripe） rust resistance gene（s） in 52 commercial wheat cultivars from Yunnan Province in China, and to provide information for their rational deployment in field. Seedlings of wheat cultivars were inoculated with 25 differential isolates ofPuccinia striiformis from foreign and home to postulate resistance genes to yellow rust, and then validated by pedigree. There were 10 probable resistance genes characterized in these cultivars, in which, Yr9 was most commonly postulated to be present in thirteen cultivars. Yr21, the second, was present in four cultivars. Yr8, the third, were present in three cultivars. Yr6, Yrl 7 and Yr26, the fourth, was present in two cultivars respectively. The other gene（s） such as, Yr2＋YrA, Yr7 and Yr27, were only present in single cultivar（s）; unknown gene（s） or gene（s） combination（s） were present in 22 cultivars. One cultivar （Yunmai 42） had no resistance gene tested in this study. Cultivars such as Yunmai 52, Mian 1971-98, Kunmai 4, and Yunmai 56 carried effective genes and can be popularized mainly; Yr9 should be planted with other Yr genes. In the meantime other effective genes should be introduced to realize gene diversity for controlling wheat yellow rust. Yunmai 42 should be reduced to avoid rust breakout. Unknown gene cultivars should be utilized and be researched deeply.展开更多
基金supported by the Key Research and Development Program of Shandong Province,China(No 2021CXGC010803)Pan’an County Chinese Medicine Industry Project(No.PZYF202103).
文摘Reductive soil disinfestation(RSD)is commonly employed for soil remediation in greenhouse cultivation.However,its influence on antibiotic resistance genes(ARGs)in soil remains uncertain.This study investigated the dynamic changes in soil communities,potential bacterial pathogens,and ARG profiles under various organicmaterial treatments during RSD,including distillers’grains,potato peel,peanut vine,and peanut vine combined with charcoal.Results revealed that applying diverse organic materials in RSD significantly altered bacterial community composition and diminished the relative abundance of potential bacterial pathogens(P<0.05).The relative abundance of high-risk ARGs decreased by 10.7%-30.6%after RSD treatments,the main decreased ARG subtypeswere AAC(3)_Via,dfrA1,ErmB,lnuB,aadA.Actinobacteria was the primary host of ARGs and was suppressed by RSD.Soil physicochemical properties,such as total nitrogen,soil pH,total carbon,were crucial factors affecting ARG profiles.Our findings demonstrated that RSD treatment inhibited pathogenic bacteria and could be an option for reducing high-risk ARG proliferation in soil.
基金supported by the Natural Science Foundation of China(No.52070145,51778453).
文摘The effects of disinfectants and plasmid-based antibiotic resistance genes(ARGs)on the growth of microorganisms and the plasmid-mediated transfer of ARGs in the water and biofilm of the drinkingwater distribution system under simulated conditionswere explored.The heterotrophic plate count of the water in reactors with 0.1 mg/L NaClO and NH_(2)Cl was higher than in the control groups.Therewas no similar phenomenon in biofilm.In thewater of reactors containing NaClO,the aphA and bla geneswere lower than in the antibiotic resistant bacteria group,while both genes were higher in the water of reactors with NH_(2)Cl than in the control group.Chloramine may promote the transfer of ARGs in the water phase.Both genes in the biofilm of the reactors containing chlorine were lower than the control group.Correlation analysis between ARGs and water quality parameters revealed that the copy numbers of the aphA gene were significantly positively correlated with the copy numbers of the bla gene in water and significantly negatively correlated in biofilm(p<0.05).The results of the sequencing assay showed that bacteria in the biofilm,in the presence of disinfectant,were primarily Gram-negative.1.0 mg/L chlorine decreased the diversity of the community in the biofilm.The relative abundance of some bacteria that may undergo transfer increased in the biofilm of the reactor containing 0.1 mg/L chlorine.
基金funded by grants from the National Key R&D Project(2023YFD1400201-02,2023YFD1400203-02)the National Natural Science Foundation of China(31870137)+1 种基金the National Transgenic Research Project(2015ZX08001-002)the Key R&D Project of Guangdong Province(2022B0202060005).
文摘Asian rice comprises two major subspecies:Xian(X)and Geng(G),and the diverged resistance genes(R)have provided a foundation for breeding improved cultivars to control rice blast disease.After conducting two-phase allele mining using six updated FNP marker systems,the functional haplotypes at Pit,Pib,and Pi63 strictly diverged into the X-populations and were defined as X-R loci,while those at Pi54,Pi37,and Pi36 into the G-populations as G-R loci.The genic diversity at the three X-R loci(16 alleles)was twofold higher than that at the three G-R loci(8 alleles),and the allelic diversity in the Southern region(21 alleles)was nearly double that in the Northeastern region(11 alleles).Both observations reflect a significant difference in genetic diversity between X-and G-populations,and indicate that the effective R-genes mainly originated from X-subspecies.Based on the allelic structures characterized by a set of 10 parameters,8 and 16 alleles were respectively recognized as favorable and promising ones for the regional breeding programs.The genotypic structures of the two regional populations were almost different,indicating that the diverged alleles have been further assembled into two series of regional genotypes through long-term breeding programs,despite the presence of one-third of region-common alleles.The genotypic diversity in the Southern region(55 genotypes)was nearly twice as high as that in the Northeastern region(28),which perfectly reflects the aforementioned differences in both genic and allelic diversities.After analyzing the genotypic structures using a set of 13 parameters,4 and 23 genotypes,respectively,can be recommended as the favorable and promising ones for the regional breeding programs.The case study serves as a concrete sample of how to identify the favorable and promising alleles and genotypes,and beneficial parents based their comprehensive population structures for gene-designed breeding.
基金supported by the National Natural Science Foundation of China (Nos.52100182 and 52300204)the the Science and Technology Innovation Program of Hunan Province (No.2023RC3122).
文摘Because of the recent widespread usage of antibiotics,the acquisition and dissemination of antibiotic-resistance genes(ARGs)were prevalent in the majority of habitats.Generally,the biological wastewater treatment processes used in wastewater treatment plants have a limited efficiencies of antibiotics resistant bacteria(ARB)disinfection and ARGs degradation and even promote the proliferation of ARGs.Problematically,ARB and ARGs in effluent pose potential risks if they are not further treated.Photocatalytic oxidation is considered a promising disinfection technology,where the photocatalytic process generates many free radicals that enhance the interaction between light and deoxyribonucleic acid(DNA)for ARB elimination and subsequent degradation of ARGs.This reviewaims to illustrate the progress of photocatalytic oxidation technology for removing antibiotics resistant(AR)from wastewater in recent years.We discuss the sources and transfer of ARGs in wastewater.The overall removal efficiencies of ultraviolet radiation(UV)/chlorination,UV/ozone,UV/H_(2)O_(2),and UV/sulfate-radical based system for ARB and ARGs,as well as the experimental parameters and removal mechanisms,are systematically discussed.The contribution of photocatalytic materials based on TiO_(2) and g-C_(3)N_(4) to the inactivation of ARB and degradation of ARGs is highlighted,producingmany free radicals to attack ARB and ARGs while effectively limiting the horizontal gene transfer(HGT)in wastewater.Finally,based on the reviewed studies,future research directions are proposed to realize specific photocatalytic oxidation technology applications and overcome current challenges.
基金supported by the Key Research Program of Wuhan(No.2022022202015015)the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(No.2022TS13)+1 种基金the key projects of National Natural Science Foundation of China(No.2019YFC0408503)Shanghai Tongji Gao Tingyao Environmental Technology Development Foundation.
文摘Microalgae-bacteria system is an emerging alternative for sustainable wastewater treatment.Exploring the structure and diversity of microbial community in microalgae-bacteria system under sulfadiazine stress can contribute to the understanding of the sulfadiazine behavior in environments.Furthermore,as important carriers of antibiotic resistance genes(ARGs),microalgae can influence the profiles of ARGs either directly or indirectly through the secretion of metabolites.However,the effects of sulfadiazine on ARGs dissemination of microalgae-bacteria systems remain underreported.Herein,the impacts of sulfadiazine(1 mg/L)on the structural diversity and metabolic activity of microorganisms were examined in microalgae-bacteria systems.Results showed thatmicroalgae-bacteria system could remove NH_(4)^(+)-N better(about 72.3%)than activated sludge system,and hydrolysis was the first step in sulfadiazine degradation.A high level of intI1(5.7×10^(4) copies/mL)was detected in the initial media of the microalgae-bacteria system.Microalgae could hamper the rate of horizontal gene transfer activation.Compared with activated sludge system,the abundance of sul genes(sul1,sul2,sul3,and sulA)was significantly lowered after treating with microalgae-bacteria system.Additionally,the number of proteins and the sum of polysaccharides in the extracellular polymeric substances of the activated sludge system were lower than those of themicroalgae-bacteria system.Microalgae can altermicrobial communities.The genus Rozellomycota predominated all samples.Fungi with relatively high abundance increased in the microalgae-bacteria system,including Dipodascaceae,Rhodotorula,and Geotrichum.These results offer valuable insights into the application processes involving microalgae-bacteria system.
基金supported by the National Natural Science Foundation of China(Nos.52091545 and 51978645).
文摘The objective of this study is to quantitatively reveal the main genetic carrier of antibiotic resistance genes(ARGs)for blocking their environmental dissemination.The distribution of ARGs in chromosomes,plasmids,and phages for understanding their respective contributions to the development of antimicrobial resistance in aerobic biofilm consortium under increasing stresses of oxytetracycline,streptomycin,and tigecyclinewere revealed based on metagenomics analysis.Results showed that the plasmids harbored 49.2%-83.9%of resistomes,which was higher(p<0.001)than chromosomes(2.0%-35.6%),and no ARGs were detected in phage contigs under the strict alignment standard of over 80%identity used in this study.Plasmids and chromosomes tended to encode different types of ARGs,whose abundances all increased with the hike of antibiotic concentrations,and the variety of ARGs encoded by plasmids(14 types and 64 subtypes)was higher than that(11 types and 27 subtypes)of chromosomes.The dosing of the three antibiotics facilitated the transposition and recombination of ARGs on plasmids,mediated by transposable and integrable transfer elements,which increased the co-occurrence of associated and unassociated ARGs.The results quantitatively proved that plasmids dominate the proliferation of ARGs in aerobic biofilm driven by antibiotic selection,which should be a key target for blocking ARG dissemination.
基金supported by the National Key R&D Program of China(No.2022YFE0103200)the Hubei Provincial Natural Science Foundation of China(No.2021CFB016)the National Natural Science Foundation of China(No.52100217).
文摘As an emerging environmental contaminant,antibiotic resistance genes(ARGs)in tap water have attracted great attention.Although studies have provided ARG profiles in tap water,research on their abundance levels,composition characteristics,and potential threat is still insufficient.Here,9 household tap water samples were collected from the Guangdong-Hong Kong-Macao Greater Bay Area(GBA)in China.Additionally,75 sets of environmental sample data(9 types)were downloaded from the public database.Metagenomics was then performed to explore the differences in the abundance and composition of ARGs.221 ARG subtypes consisting of 17 types were detected in tap water.Although the ARG abundance in tap water was not significantly different from that found in drinking water plants and reservoirs,their composition varied.In tap water samples,the three most abundant classes of resistance genes were multidrug,fosfomycin and MLS(macrolide-lincosamidestreptogramin)ARGs,and their corresponding subtypes ompR,fosX and macB were also the most abundant ARG subtypes.Regarding the potential mobility,vanS had the highest abundance on plasmids and viruses,but the absence of key genes rendered resistance to vancomycin ineffective.Generally,the majority of ARGs present in tap water were those that have not been assessed and are currently not listed as high-threat level ARG families based on the World Health Organization Guideline.Although the current potential threat to human health posed by ARGs in tap water is limited,with persistent transfer and accumulation,especially in pathogens,the potential danger to human health posed by ARGs should not be ignored.
基金supported by the National Key Plan for Research and Development of China(Nos.2022YFE0120300 and 2020YFC1806902)the National Natural Science Foundation of China(Nos.42161134002,81991535,and 41877058)the Natural Science Foundation of Fujian Province,China(No.2022J01509).
文摘In recent years,the biodegradable plastics has extensively used in industry,agriculture,and daily life.Herein,the effects of two biodegradable microplastics(BMPs),poly(butyleneadipate-co-terephthalate)(PBAT)and polyhydroxyalkanoate(PHA),on soil sulfamethoxazole(SMX)degradation and sul genes development were comparatively studied based on the type,dosage,and state.The addition of virgin BMPs significantly increased soil DOC following a sequential order PBAT>PHA and high dose>low dose.Meanwhile virgin PBAT significantly reduced soil pH.In general,the addition of BMPs not only promoted soil SMX degradation but also increased the abundance of sul genes,with an exception that pH reduction in virgin PBAT inhibited the proliferation of sul genes.The driving effects of BMPs on soil microbial diversity following the same order as that on DOC.Specific bacteria stimulated by BMPs,such as Arthrobacter and two genera affiliated with phylum TM7,accounted for the accelerated degradation of SMX.Intriguingly,UV-aging hindered the release of DOC from BMPs and the reduction in pH,mitigated the stimulation of microbial communities,and ultimately reduced the promotion effect of BMPs on SMX degradation and sul genes proliferation.Our results suggest that more attention should be paid to the proliferation risk of ARGs in the environment affected by BMPs and UV-aging can be employed sometimes to reduce this risk.
基金ThePresidentialFoundationofTheChineseAcademyofSciences NaturalScienceFoundationofHebeiProvince China
文摘Partially modified Bt Cry1Ac gene and the arrowhead proteinase inhibitor (API) gene were used to construct a plant transformation vector pBtiA and this construct was transferred into the genome of the hybrid poplar 741 [ Populus alba L.×( P. davidiana Dode+ P. simonii Carr.)× P. tomentosa Carr.] by Agrobacterium _ mediated transformation. Ten kanamycin resistant plants have been regenerated. Upon insect bioassay using Clostera anachoreta (Fabricius), three of the examined plants were demonstrated to be highly resistant to the testing insects. The mortality of insect larvae on one plant was higher than 90% in 6 days after infestation and the growth of the survival larvae were seriously inhibited. Results of PCR and Southern blot analysis indicated that both Bt Cry1Ac gene and API gene were integrated as a single copy into the genomes of these three plants when Cry1Ac gene fragment was used as the probe. Protein dot blot immunoassay and ELISA analysis revealed that at least the Cry1Ac protein was produced in these three transgenic plants and the expression levels were estimated to be approximately 0.015% of the leaf total soluble protein. This is the first report on insect resistant transgenic hybrid poplar 741 that expresses two insecticidal protein genes.
文摘Pi-ta and Pi-b, the first cloned rice blast resistant genes, have been wide- ly used in rice blast resistance breeding for their lasting and stable resistance. To define the distribution of Pi-ta and Pi-b in japonica rice in Jiangsu, the genotypes of resistance genes Pi-ta and Pi-b in 40 varieties and 665 new lines were detected using functional markers of Pi-ta/pi-ta and Pi-b^pi-b alleles. The results showed that the resistance alleles of Pi-ta and Pi-b were widely spread in japonica rice varieties, and the distribution frequency of Pi-b was higher than that of Pi-ta. Most of the Lianjing serial varieties didn＇t carry the two resistance genes, but the two resistance genes were widely distributed in Wujing serial varieties. There was no significant dif- ference in distribution frequency of Pi-ta between new lines and commercial vari- eties. However, the distribution frequency of Pi-b in new lines was higher than that in commercial varieties. It was indicated that artificial selection was conducive to the improvement of distribution frequency of Pi-b in rice varieties. Among the 4 genotypes, the distribution frequency of pi-taJPi-b was highest （60.0%）, followed by Pi-ta/ Pi-b （33.5%） and pi-ta/pi-b （3.9%）. The frequency of Pi-taJpi-b was lowest, account- ing for only 2.6%. In terms of source of resistance genes in the four combinations, the resistant allele Pi-ta might be from parents of Wuxiangjing14, Wujing15 or Nanjing44, and Pi-b might come from parents of Wujing13, Wuxiangjing14, Wujing15 or Nanjing44. The analysis on the genotypic frequencies in offspring of the rice vari- eties showed that the resistance genotype of Pi-ta/Pi-b had the highest frequency in the cross combination of Nanjing44//Wujing13/Kantou194.
基金Supported by National 863 Program of China(2011AA10A106)Director Fund of the Institute of Food Crops+1 种基金Yunnan Academy of Agricultural Sciences(2013LZS003)Program for Science and Technology Innovation Talents of Yunnan Province(2012HC008)~~
文摘Yunmai52, developed by crossing with common wheat-Haynaldia villosa6AL/6VS translocation line 92R149 as a resistant parent in 1992, was a common wheat cultivar approved and released in 2007 in Yunnan Province, China, which is characterized by high resistance to powdery mildew and stripe rust. In this study,an F_2 population derived from a cross K78S/Yunmai52 was constructed to investigate the resistance genes, where K78 S is a wheat male sterile line susceptible to powdery mildew and stripe rust. Phenotypic identification of the parents, F_1 and F_2 populations and chi-square analyses showed that F_1 population was immune to stripe rust and powdery mildew; the segregation ratio of resistance and susceptibility to powdery mildew（χ~2=1.10χ~2_（1,0.05）=3.84） and stripe rust（χ~2=0.15χ~2_（1,0.05）=3.84） fit to a 3：1 ratio in F_2 population, indicating that Yunmai52 harbors a dominant stripe rust resistance gene and a dominant powdery mildew resistance gene. The individuals were further detected with a marker co-segregated with Pm21（SCAR_（1400）） and two markers closely linked with Yr26（XWe173 and Xbarc181）. The results showed that polymorphic bands could be amplified between the parents and between resistance and susceptibility gene pools at the same locus. Randomly 96 individuals of F_2 population were selected for verification. The results showed that the phenotype was significantly correlated with the genotype. The detection accuracy of markers SCAR_（1400）, XWe173 and Xbarc181 was 100%, 97.91% and 92.70%, respectively.Yunmai52 harbored powdery mildew resistance gene Pm21 and stripe rust resistance gene Yr26, which were both derived from 6AL/6VS translocation line 92R149.In addition, the results also demonstrate that Pm21 and Yr26 are two genes conferring durable resistance to powdery mildew and stripe rust in wheat.
基金Supported by Agricultural Science and Technology Independent Innovation Fund of Jiangsu Province[CX(12)1003]Science and Technology Support Program of Jiangsu Province(BE2013301)Special Fund for the Construction of Modern Agriculture Industry System of China(CARS-01-47)~~
文摘Rice blast is one of the important diseases in major rice producing areas of China. The main blast resistance genes Pi-ta and Pi-b showed broad-spectrum and durable resistance to rice blast in many rice growing areas of China, which have been widely utilized in rice breeding and commercial production. In this study, on the basis of detection and verification of the genotypes of 22 rice varieties har- boring known blast resistance genes （Pi-ta and Pi-b） and blast susceptibility genes （pi-ta and pi-b）, two multiple PCR systems for these genes were established by us- ing the functional markers of blast resistance genes Pi-ta and Pi-b as well as blast susceptibility genes pi-ta and pi-b, respectively. Specifically, multiple PCR system I could simultaneously detect blast resistance genes Pi-ta and Pi-b, while system II could detect simultaneously blast susceptibility genes pi-ta and pi-b. In addition, the genotypes of 336 high generation breeding materials were detected with these two multiple PCR systems. The results were highly consistent with those of conventional single mark detection, indicating that these two multiplex PCR systems were stable, reliable and time-saving. The established multiplex PCR systems may serve as a rapid and efficient method to identify and screen rice germplasm resources and can be applied in marker-assisted selection to polymerize multiple genes for blast resis- tance in rice breeding.
基金support from the National Natural Science Foundation of China (U1405212)the National Key Research and Development Program of China (2016YFD0300707)+1 种基金the Natural Science Foundation of Fujian Province, China (2017J01618)the 100 Talent Project from Fujian Province to Dr.Daniel J.Ebbole (Texas A&M University, USA)
文摘Rice blast disease, caused by Magnaporthe oryzae, threatens global food security. The rice blast pathosystem is a longstanding model system for understanding plant-microbe interactions. In order to elucidate the coevolution of the host and pathogen, and provide the appropriate methods for preventing or controlling rice blast disease, researchers have focused on the evolution of virulence factors and resistance genes. Thus far, more than 30 rice blast resistance（R） genes and 12 avirulence（Avr） genes have been cloned. This review summarizes the cloned rice blast R genes, cloned Avr genes of M. oryzae and the interaction between them. This discussion also considers some of the major unanswered questions concerning this pathosystem and the opportunities for future investigations.
文摘Two pairs of degenerate primers were designed based on nucleotide-binding site (NBS) and serine/threonine kinase domain. PCR was performed with the primers and cDNA from the Triticum aestivum-Haynaldia villosa translocation line 6VS/6AL. Amplified products were cloned and sequenced. Nine clones with NBS and one with serine/threonine kinase domain were obtained. The NBS clones were classified to six groups according to their nucleotide sequence identities (90% or higher). These resistance gene analogs (RGAs) all have open reading frames (ORF), and their amino acid sequences show high similarity to Yr10 in wheat, Mla1 and Mla6 in barley, RPS2 in Arabidopsis and other resistance (R) genes with conserved motifs. They were preliminarily mapped on the chromosomes of homoeologous groups 1, 2 and 5 of common wheat by nulli-tetrasomic analysis. The 5'-end sequence of an RGA N5 was obtained by 5'-RACE PCR. It encodes six leucine zipper (LZ) and has high sequence similarity to RPS2.
基金supported by the National Natural Science Foundation of China (No. 21177162)
文摘The occurrence of antibiotic resistance genes （ARGs） was investigated and quantified in 20 water samples collected in the Beijiang River, South China. Sulfonamide- and tetracycline-resistant bacteria were present in 17 and 14 of the collected 20 samples. For sulfonamide ARGs, sulI and sulII were frequently observed in the Beijiang River. The levels of sulI were higher than sulII （p 〈 0.05）, with the mean values of （1.41 ± 1.12） × 10-2 and （1.58 ± 1.71） × 10-3 copies/16S rDNA, respectively. For tetracycline ARGs, tetG had the highest frequency, 100%, followed by tetA （85%）, tetO （85%）, tetC （70%）, tetX （60%）, tetM （40%） and tetQ （20%）, while tetE and tetS were not detected in all the samples from the Beijiang River. On the other hand, tetC had the highest concentration, ranging from 8.30 × 10-2 to 13.20 copies/16S rDNA. The poor correlation between ARGs and antibiotic concentrations revealed that the self-amplification and persistence of ARGs were the reasons that made ARGs exist in the water environment even though the antibiotic selecting pressure was absent. Because so few field measurements have been conducted for investigating the levels of ARGs in rivers in South China, this study provides an important insight on better understanding the occurrence and spread of ARGs in such an ecosystem.
基金supported by the Natural Science Foundation of Guangdong Province(2018B030308008)National Natural Science Foundation of China(U1901203 and 31901532)+2 种基金Major Program of Guangdong Basic and Applied Research(2019B030302006)Shenzhen Commission on Innovation and Technology Programs JCYJ20180507181837997)China Postdoctoral Science Foundation(2018 M633069 and 2019 M652920)。
文摘Rice is one of the most important food crops in the world.Weeds seriously affect the rice yield and grain quality.In recent years,there are tremendous progresses in the research and application of herbicideresistant genes in rice worldwide.This article reviews the working mechanisms of six herbicides(glyphosate,glufosinate,acetolactate synthase inhibitor herbicides,acetyl-Co A carboxylase inhibitor herbicides,hydroxyhenylpyruvate dioxygenase(HPPD)inhibitor herbicides and dinitroaniline herbicides),the resistance mutations of the corresponding herbicide-target genes,and the herbicide detoxification mechanisms by non-target genes.Examples are provided on herbicide-resistant rice materials obtained by transformation of exogenous resistance genes,by artificial mutagenesis and mutant screening,and by modifying the target genes through gene editing.This paper also introduces the current application of herbicide-resistant rice,points out problems that may be caused by utilization of herbicide resistant rice and solutions to the problems,and discusses the future prospects for the development of herbicideresistant rice.
文摘[ Objective ] The paper was to confirm the resistance genes and resistant parents of rice against bacterial blight that could be used in Guangxi Province. [ Method] The dominant pathogenic types Ⅳ of Xanthomonas Oryzae pv. Oryzae in Guangxi were inoculated on a set of monogenic rice lines, the main hybrid rice parents in Guangxi and some important rice germplasm resources, and its resistant and susceptible conditions were investigated. [ Result ] IRBBS, IRBB7 and CBB23 were the resistant rice parents with resistance against pathogenic type IV, which contained resistance genes xa5, Xa7 and Xa23, respectively, and were identified to be the effective resistance genes against pathogenic type Ⅳ of X. Oryzae in Guangxi. [ Conclusion] The results provided basis for resistance breeding against bacterial blight.
基金supported by the National Science and Technology Major Projects for Water Pollution Control and Treatment(No.2017ZX07201-003)the Science and Technology Program of Zhejiang Province(No.LQ19E080023)the Zhejiang Public welfare technology research program(No.GG21E080021)。
文摘Once contaminate the drinking water source,antibiotic resistance genes(ARGs)will propagate in drinking water systems and pose a serious risk to human health.Therefore,the drinking water treatment processes(DWTPs)are critical to manage the risks posed by ARGs.This study summarizes the prevalence of ARGs in raw water sources and treated drinking water worldwide.In addition,the removal efficiency of ARGs and related mechanisms by different DWTPs are reviewed.Abiotic and biotic factors that affect ARGs elimination are also discussed.The data on presence of ARGs in drinking water help come to the conclusion that ARGs pollution is prevalent and deserves a high priority.Generally,DWTPs indeed achieve ARGs removal,but some biological treatment processes such as biological activated carbon filtration may promote antibiotic resistance due to the enrichment of ARGs in the biofilm.The finding that disinfection and membrane filtration are superior to other DWTPs adds weight to the advice that DWTPs should adopt multiple disinfection barriers,as well as keep sufficient chlorine residuals to inhibit re-growth of ARGs during subsequent distribution.Mechanistically,DWTPs obtain direct and inderect ARGs reduction through DNA damage and interception of host bacterias of ARGs.Thus,escaping of intracellular ARGs to extracellular environment,induced by DWTPs,should be advoided.This review provides the theoretical support for developping efficient reduction technologies of ARGs.Future study should focus on ARGs controlling in terms of transmissibility or persistence through DWTPs due to their biological related nature and ubiquitous presence of biofilm in the treatment unit.
基金the National Key Research and Development Program of China(Grant No.2017YFD0100400)the Key Studying and Developing Project of Jiangsu Province for Modern Agriculture(Grant No.BE2018351)+9 种基金the Major Project of Jiangsu Province for Significant New Varieties Development(Grant No.PZCZ201702)the Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding(Grant No.BM2018003)the National Natural Science Foundation of China(Grant No.31971868)the National Modern Agricultural Industry Technology System Special Fund(Grant No.CARS-01-60)the‘333’Project of Jiangsu Province(Grant No.BRA2017163)the Key Studying and Developing Project of Yangzhou City for Modern Agriculture(Grant No.YZ2018048)the Jiangsu Agricultural Science and Technology Innovation Fund[(Grant Nos.CX(18)1003)and CX(18)2022)]Open Research Fund of State Key Laboratory for Biology of Plant Diseases and Insect Pests(Grant No.SKLOF 201909)Opening Foundation of Key Laboratory of Plant Functional Genomics of the Ministry of Education(Grant No.ML201806)Fund of Institute of Agricultural Sciences for Lixiahe Region in Jiangsu(Grant No.SJ17201).
文摘Rice blast is one of the most destructive diseases affecting rice production worldwide.The development and rational use of resistant varieties has been the most effective and economical measure to control blast.In this review,we summarized the cloning and utilization of rice blast resistance genes,such as Pi1,Pi2,Pi9,Pi54,Pigm and Piz-t.We concluded that three main problems in the current breeding of rice blast resistance are:availability of few R(resistance)genes that confer resistance to both seedling and panicle blast,the resistance effect of pyramided lines is not the result of a simple accumulation of resistance spectrum,and only a few R genes have been successfully used for molecular breeding.Therefore,novel utilization strategies for rice blast R genes in molecular breeding were proposed,such as accurately understanding the utilization of R genes in main modern rice varieties,creating a core resistant germplasm with excellent comprehensive traits,screening and utilizing broadspectrum and durable resistance gene combinations.Lastly,the trends and possible development direction of blast resistance improvement were also discussed,including new genes regulating resistance identified via GWAS(genome-wide association study)and improving rice blast resistance using genetic editing.
基金support by the Ministry of Science and Technology,China (2011CB100403)the Ministry of Agriculture,China (200903035)the Special Project from State Key Laboratory for Biology of Plant Diseases and Insect Pests,Chinese Academy of Agricltural Sciences (SKL2009OP09)
文摘The objective of this study was to characterize yellow （stripe） rust resistance gene（s） in 52 commercial wheat cultivars from Yunnan Province in China, and to provide information for their rational deployment in field. Seedlings of wheat cultivars were inoculated with 25 differential isolates ofPuccinia striiformis from foreign and home to postulate resistance genes to yellow rust, and then validated by pedigree. There were 10 probable resistance genes characterized in these cultivars, in which, Yr9 was most commonly postulated to be present in thirteen cultivars. Yr21, the second, was present in four cultivars. Yr8, the third, were present in three cultivars. Yr6, Yrl 7 and Yr26, the fourth, was present in two cultivars respectively. The other gene（s） such as, Yr2＋YrA, Yr7 and Yr27, were only present in single cultivar（s）; unknown gene（s） or gene（s） combination（s） were present in 22 cultivars. One cultivar （Yunmai 42） had no resistance gene tested in this study. Cultivars such as Yunmai 52, Mian 1971-98, Kunmai 4, and Yunmai 56 carried effective genes and can be popularized mainly; Yr9 should be planted with other Yr genes. In the meantime other effective genes should be introduced to realize gene diversity for controlling wheat yellow rust. Yunmai 42 should be reduced to avoid rust breakout. Unknown gene cultivars should be utilized and be researched deeply.
