A transcriptomic database was constructed to study the biocontrol mechanisms of Trichoderma harzianum ACCC30371 using high quality UniGenes following growth in eight culture media[(1/2PD,minimal medium MM(containing d...A transcriptomic database was constructed to study the biocontrol mechanisms of Trichoderma harzianum ACCC30371 using high quality UniGenes following growth in eight culture media[(1/2PD,minimal medium MM(containing dextrose 10 g L^-1),C starvation medium(derived from MM without dextrose),N starvation medium(derived from MM without ammonium sulphate),and four kinds of phytopathogenic fungi cell wall media].A 4 Gbp transcriptome was generated and 96.7%of the database had a sequencing error rate less than 1%.A total of 25,013 UniGene sequences were obtained with a mean length of 1135 nt.There were 2571 sequences longer than 3000 nt.The National Center for Biotechnology Information Accession number of this transcriptome is SRR8382572.There were 16,360 Unigenes annotated to the Nr protein database,9875 to the SwissProt database,10,266 to the KEGG database,7164 to the COG database,and 1508 to the GO database along with their protein functional annotations.There were 16,723 functional genes identified.We identified 402 bio-control genes,including 14 related to competition,311 to mycoparasitism,76 to antibiosis,and one related to eliciting a plant response.This shows that T.harzianum ACCC30371 has integrated biocontrol mechanisms,and of these mechanisms,mycoparasitism is the most prevalent.Antibiosis and induced systemic resistance also play important roles.These results provide a foundation for further research into the biocontrol mechanisms of Trichoderma,as well as the development and utilization of biological fungicides.展开更多
Biocontrol by Trichoderma has been studied mainly with selected isolates of T. harzianum, T. atroviride and T. asperellum, which are members of sections Pachybasium and Trichoderma. In contrast, species from section L...Biocontrol by Trichoderma has been studied mainly with selected isolates of T. harzianum, T. atroviride and T. asperellum, which are members of sections Pachybasium and Trichoderma. In contrast, species from section Longibrachiatum have only rarely been studied. On the other hand, one taxon from this section-Hypocrea jecorina (anamorph: Trichoderma reesei)-has been widely used for the production of cellulolytic and hemicellulolytic enzymes and recombinant proteins. As far as Trichoderma is concerned, molecular genetic methods and tools are most advanced in H. jecorina, and its genome has recently been fully sequenced, thus making this taxon a model organism for the genus. Here we will demonstrate that H. jecorina is able to antagonize plant pathogenic fungi in plate confrontation tests, and can protect tomato and cucumber plants against Pythium ultimum blight. Using this as a model case, we made use of available H. jecorina mutants to investigate (a) whether carbon catabolite repression via the Cre1-regulator protein has an impact on biocontrol, and (b) whether cellulase gene expression is necessary for biocontrol of P. ultimum. In the first case, plate confrontation tests and in planta experiments yielded opposite results, i.e. while a Cre1 mutant was more active in antagonization of fungi on plates, the survival rates of P. ultimum-inoculated cucumber plants was lower than with the H. jecorina wild-type strain. Mutants of H. jecorina, unable to form cellulases, were still able to antagonize fungi on plates and provided similar protection of tomatos against P. ultimum as the wild type, indicating that the pronounced biocontrol ability of H. jecorina against fungi with cellulose-containing cell-walls is not due to its high cellulolytic activity. A strain disrupted in the light-modulator gene envoy (Schmoll et al., ms submitted) exhibited in planta biocontrol activity strongly exceeding that of the wild-type strain, thereby providing a first link between Trichoderma biocontrol and light. In view of the numerous other metabolic and regulatory mutants of H. jecorina available, we suggest that this fungus should increasingly be used in basic studies on the biochemistry and genetics of biocontrol.展开更多
Streptomyces rubrogriseus HDZ-9-47,isolated from eggs of Meloidogyne spp.,was evaluated as a potential biocontrol agent of Meloidogyne incognita under in vitro and protective field.Microscopic observations showed that...Streptomyces rubrogriseus HDZ-9-47,isolated from eggs of Meloidogyne spp.,was evaluated as a potential biocontrol agent of Meloidogyne incognita under in vitro and protective field.Microscopic observations showed that HDZ-9-47 parasitized eggs of M.incognita within 7 days.In vitro,the culture filtrate of HDZ-9-47 caused 97.0%mortality of second-stage juveniles(J2s)of M.incognita and inhibited more than 50%egg hatching.In the field,compared with the control,the rootknot index and J2s density in the treatment of drench the broth contained 1012 HDZ-9-47 spores were respectively reduced by 51.1 and 80.7%at 90 days post transplantation,which were better than that in other application doses and methods.In addition,reduction rates of root-knot index and J2s density of the treatment of combined application of HDZ-9-47 with biofumigation was 87.1 and 91.0%,respectively,better than either of HDZ-9-47 or biofumigation used alone or fosthiazate treatment.And tomato yield also increased by 16.1%.Together,our results suggest that HDZ-9-47 could be an effective biocontrol agent of M.incognita,and that application of HDZ-9-47 combined with cabbage residue biofumigation was a promising and sustainable option for M.incognita control.展开更多
Modern agribusiness plays a vital role in safeguarding and improving the production,quality,and quantity of food,feed,fiber,and fuel.Growing concerns over the impact of chemical pesticides on health and the environmen...Modern agribusiness plays a vital role in safeguarding and improving the production,quality,and quantity of food,feed,fiber,and fuel.Growing concerns over the impact of chemical pesticides on health and the environment have stimulated the industry to search for alternative and greener solutions.Over the last years,the RNA interference(RNAi)process has been identified as a very promising new approach to complement the arsenal of foliar spray,soil,or seed treatments applied as chemical and biological pest control agents,and of plant-incorporated protectants(PIPs).RNA-based active ingredients(AIs)possess a unique mode of action and can be implemented via both genetic modification(GM)and biocontrol approaches.RNA-based AIs promise to deliver the selectivity and sustainability desired in future crop protection agents.This is due to their utilization of a natural process to exert control and their high level of selectivity,which leads to reduced risk for non-target organisms(NTOs).This review discusses the advantages and limitations of RNA-based solutions in crop protection and recent research progress toward RNA-based biocontrols against the Colorado potato beetle(CPB),corn rootworm(CRW),and soy stink bug(SSB).Many challenges still exist on the road to the implementation of a broad range of RNA-based products and their widespread use and application.Despite these challenges,it can be expected that RNA-based AIs will become valuable new tools complementing the current arsenal of crop-protection solutions.展开更多
Methicillin-resistant Staphylococcus aureus (MRSA) is among the most alarming pathogens affecting both humans and the global bovine industry. The current control measures in hospitals and on farms for MRSA have proven...Methicillin-resistant Staphylococcus aureus (MRSA) is among the most alarming pathogens affecting both humans and the global bovine industry. The current control measures in hospitals and on farms for MRSA have proven to be inadequate leaving a need for new rapid control methods to curb MRSA infections in situ. New control measures for bacterial infection are widely sought, with particular interest in the applications for bacteriophages (phages) as a biocontrol or therapeutic agent. The current study uses a wild highly lytic phage isolated from cow’s milk taken from three farms in Baghdad, Iraq. The resulting phage was able to rescue 100% of the mice from a median lethal dose (LD50) or (1 × 108 CFU mL-1 per mouse) for MRSA wild isolates achieved when the phage: bacteria ratio was 100:1. Even when treatment was delayed for 6 h post lethal infection, to the point where all mice were moribund, 80% of them were rescued by a single injection of this phage preparation. Based on the current results, a comprehensive study is needed to guide further research on the MRSA phage as a biocontrol for MRSA mastitis in dairy cows to replace or reduce the use of antibiotics in animal husbandry.展开更多
This study investigates the biocontrol potential of Trichoderma asperellum mutants against Rhizoctonia solani, Alternaria alternata, and Fusarium oxysporum and growth promotion of Populus davidiana 9 P. alba var.pyram...This study investigates the biocontrol potential of Trichoderma asperellum mutants against Rhizoctonia solani, Alternaria alternata, and Fusarium oxysporum and growth promotion of Populus davidiana 9 P. alba var.pyramidalis(Pd Pap poplar) seedlings. A T-DNA insertion mutant library of T. asperellum was constructed using Agrobacterium tumefaciens-mediated transformation.Sixty-five positive transformants(T1–T65) were obtained.Growth rates of the mutants T39 and T45 were the same,39.68% faster than the WT. In toxin tolerance tests, only T39 had greater tolerance to A. alternata fermentation broth than the WT, but mutant T45 had the same tolerance as the WT to all fermentation broths. Furthermore, T39 and T45 had a greater antagonistic ability than the WT strain against R. solani and A. alternata. The inhibition rate of the mutants T39 and T45 against A. alternata are 73.92% and80.76%, respectively, and 63.51% and 63.74%, respectively. Furthermore, the three strains increased the activities of superoxide dismutases, peroxidase, catalase(CAT)and phenylalanine ammonia lyase(PAL) in Pd Pap seedling leaves. CAT and PAL activity in the Pd Pap seedling leaveswas 11.25 and 5.50 times higher, respectively, in the presence of T39 than in the control group and 12 and 6.35 times higher, respectively, in the presence of T45 than in the control group. All three strains promoted seedling growth and the root and stem development, especially mutant T45. Mutants T39 and T45 reduced the incidence of pathogenic fungi in poplar and stimulated poplar seedling growth.展开更多
Fungi and bacteria as insecticides have been tested to control forest pests for more than ten years, they are the saine kind of biocontrol agent with the different conentrations. thesame kind of the biocontrol agent w...Fungi and bacteria as insecticides have been tested to control forest pests for more than ten years, they are the saine kind of biocontrol agent with the different conentrations. thesame kind of the biocontrol agent with the different origin areas, and the mixtures of the different kinds of biocontrol agents. The infection mechanism of virus was discussed. moreover. the mfluence of these biocontrol agents on the small animals was also evaluated.展开更多
The increasingly strict regulation of the use of phytosanitary products and the will of the populations to move towards sustainable development allow bio-sourced products and more particularly for biocontrol in the fi...The increasingly strict regulation of the use of phytosanitary products and the will of the populations to move towards sustainable development allow bio-sourced products and more particularly for biocontrol in the field of pesticides to progress. The study carried out here concerns the evaluation of the potency of Bacillus amyloliquefaciens Bc2 and Trichoderma harzianum to fight against strawberry cultures infected with anthracnose (Fragaria × ananassa Duch.). The studies were carried out in the laboratory and in the field. The results indicate that B. amyloliquefaciens Bc2 and Trichoderma harzianum TR are effective for the biological control of anthracnose, gray mold and powdery mildew on strawberries grown in field conditions. The increase in plant size and the number of fruits produced with these control agents has also been observed.展开更多
This study was to evaluate the ecological risk of strain E26 (Agrobacterium sp. ) by detecting its survival in waters and its effects on rhizosphere microorganisms. The data showed that E26 could not be detected in di...This study was to evaluate the ecological risk of strain E26 (Agrobacterium sp. ) by detecting its survival in waters and its effects on rhizosphere microorganisms. The data showed that E26 could not be detected in distilled water, tap water, river water, and rainwater after 36, 36, 8, and 9 days, respectively. E26 did not reveal significant effects on the population of bacteria, fungi, and actinomyces in rhizosphere soil and on the root surface of grapevines.展开更多
[Objectives]The paper was to study the toxicity of 9 biocontrol microbial products to adult population of Lasioderrma serricorne.[Methods]Nine biocontrol microbes were used as test materials to study their toxicity to...[Objectives]The paper was to study the toxicity of 9 biocontrol microbial products to adult population of Lasioderrma serricorne.[Methods]Nine biocontrol microbes were used as test materials to study their toxicity to the experimental population of L.serricorne adults.[Results]The toxicities of these biocontrol microbes from low to high at 5 d post spraying were:Luhai Beauveria bassiana powder(LC_(50)=462.752×10^(8) spores/L),Meichongzhi B.bassiana powder(LC_(50)=9713.157×10^(8) spores/L),Yiqiang Bio B.bassiana powder(LC_(50)=11203.321×10^(8)spores/L),Nongbao Bio B.bassiana powder(LC_(50)=12188.866×10^(8) spores/L),Yeshengwang B.bassiana powder(LC_(50)=21685.532×10^(8) spores/L);Fatu Bacillus thuringiensis suspension(LC_(50)=1.0844×10^(8) IU/L),Laojite B.thuringiensis suspension(LC_(50)=2.056×10^(8) IU/L),Lujinwa B.thuringiensis powder(LC_(50)=2.273×10^(8) IU/L),Nongbao Bio B.thuringiensis powder(LC_(50)=18.399×10^(8) spores/L).The toxicities of these biocontrol microbes from low to high at 10 d post spraying were:Nongbao Bio B.bassiana powder(LC_(50)=0.072×10^(8) spores/L),Yiqiang Bio B.bassiana powder(LC_(50)=2.484×10^(8) spores/L),Luhai B.bassiana powder(LC_(50)=44.551×10^(8) spores/L),Meichongzhi B.bassiana powder(LC_(50)=96.447×10^(8) spores/L),Yeshengwang B.bassiana powder(LC_(50)=723.347×10^(8) spores/L);Lujinwa B.thuringiensis powder(LC_(50)=0.0001×10^(8) IU/L),Fatu B.thuringiensis suspension(LC_(50)=0.045×10^(8) IU/L),Laojite B.thuringiensis suspension(LC_(50)=0.0644×10^(8) IU/L),Nongbao Bio B.thuringiensis powder(LC_(50)=1.899×10^(8) spores/L).The toxicities of these biocontrol microbes from low to high at 15 d post spraying were:Meichongzhi B.bassiana powder(LC_(50)=0.001×10^(8) spores/L),Nongbao Bio B.bassiana powder(LC_(50)=0.01×10^(8) spores/L),Yiqiang Bio B.bassiana powder(LC_(50)=0.084×10^(8) spores/L),Luhai B.bassiana powder(LC_(50)=2.370×10^(8) spores/L),Yeshengwang B.bassiana powder(LC_(50)=8.915×10^(8)spores/L);Lujinwa B.thuringiensis powder(LC_(50)=0.16×10^(4) IU/L),Laojite B.thuringiensis suspension(LC_(50)=0.185×10^(4) IU/L),Fatu B.thuringiensis suspension(LC_(50)=32.211×10^(4) IU/L),Nongbao Bio B.thuringiensis powder(LC_(50)=1590×10^(4) spores/L).[Conclusions]According to the three stages of tube rubbing,it is found that the control effects of Lujinwa B.thuringiensis powder and Meichongzhi B.bassiana powder are the best,and the results will provide technical support for the biological control of L.serricorne adults.展开更多
The“oil stain disease”has become a phytosanitary status that involves economic losses for farmers who produce gulupa(Passiflora edulis Sims).For this reason,this research aimed to evaluate the biocontrol activity of...The“oil stain disease”has become a phytosanitary status that involves economic losses for farmers who produce gulupa(Passiflora edulis Sims).For this reason,this research aimed to evaluate the biocontrol activity of Bacillus subtilis ATCC 55033 in a culture medium based on fermented millet as a biocontrol product of the disease.Initially,metabolite production of seven strains of B.subtilis and a reference strain B.s(ATCC 55033)was evaluated;in addition,the in vitro antagonistic ability was evaluated against Xanthomonas axonopodis.Two experiments were performed under in vitro conditions:(1)study of the presence of halos of hemolysis due to metabolite production;(2)analysis of the antagonistic ability by using double layer.It was observed that concerning the average,a number five times bigger of halos of hemolysis and 10 times bigger halos of inhibition in vitro on the growth of X.axonopodis in the strains B.s(ATCC 55033)and B.s TB2 over other strains.Subsequently,the evaluation was performed under greenhouse conditions,based on a randomized block design,in which two treatments were applied over the soil:(1)application of the fermented medium based on millet with B.s ATCC 55033,24 h before X.a inoculation;(2)application of 5 d post-inoculation.It was observed that the treatment,previous infective process,obtained an average percentage of severity equal to 42.044%.In addition,after the evaluation month,a foliage restoration was presented.In conclusion,it is suggested that these products could act as inducers in the plant systemic resistance to trigger defense responses to infection of X.a.展开更多
The present study evaluates the possible modes of action of antagonistic bacteria and their tolerance to UV radiation, temperature and osmotic stress. The partial 16S-23S rRNA gene sequencing of eight antagonistic bac...The present study evaluates the possible modes of action of antagonistic bacteria and their tolerance to UV radiation, temperature and osmotic stress. The partial 16S-23S rRNA gene sequencing of eight antagonistic bacteria had a high match with three bacterial genera: <em>Curtobacterium</em>, <em>Pantoea</em> and <em>Bacillus</em>. In this study, the three <em>Bacillus</em> isolates showed the most relevant production of enzymes, volatile organic compounds and antibiosis against <em>Exserohilum turcicum</em>. Respect to UV radiation and temperature <em>Pantoea</em> and <em>Bacillus</em> isolates were more tolerant;whereas the eight isolates were tolerant to osmotic stress in varying degree. The three <em>Bacillus</em> isolates have the greatest potential as biocontrol agents for foliar diseases in maize. The antagonistic action could be explained through different modes of action such as enzymes, volatile organic compounds and/or direct antibiosis by other secondary metabolites. <em>Bacillus</em> isolates tolerance to environmental stresses including UV radiation, temperature and osmotic stress is relevant for survival and persistence on the leaf surface. This work provides new information about the mode of action of antagonistic bacteria with proven efficacy against maize leaf pathogens. In addition, it provides information about the tolerance of antagonistic bacteria against different stress conditions. The data of the present study could contribute to the development of a successful foliar biofungicide.展开更多
The quantity of bio-laboratories and bio-factories in Uzbekistan increases every year.In 1970,there were only 4,in 1971,16,in 1985,710,in 1990,774,and in 2000,790.At present there
Our study consists of a careful literature review carried out with the aim of better understanding the models developed in the field of biocontrol of postharvest fungal rot in apples(PHFRA)over the past two decades.It...Our study consists of a careful literature review carried out with the aim of better understanding the models developed in the field of biocontrol of postharvest fungal rot in apples(PHFRA)over the past two decades.It aims,more specifically,to shed light on the progress made by examining the products developed,their nature,their target pathogens,their effectiveness,theirs modes of action and the stage of their development.The post-harvest biocontrol of apples has made remarkable progress during the last twenty years of research.Several products(yeasts,bacteria,filamentous fungi and actinomycetes)have been selected.Some,are already marketed,others are at different stages of development.However,several points limit the optimal use of microbial antagonists in the bio-management of post-harvest apple rots as an alternative to chemicals.It is,in fact,still necessary to develop appropriate formulations of these microbial biocontrol agents,to better study their mechanisms of action,to test them under commercial conditions and against a broad spectrum of pathogens and hosts.However,although sometimes considered less effective than chemical treatments,biocontrol products based on microorganisms have major advantages for an application in an integrated post-harvest apple protection strategy.展开更多
Current biological control methods to prevent pre-harvest aflatoxin contamination of corn, cottonseed, and ground and tree nuts involve field inoculation of non-aflatoxigenic Aspergillus flavus. To date, the efficacy ...Current biological control methods to prevent pre-harvest aflatoxin contamination of corn, cottonseed, and ground and tree nuts involve field inoculation of non-aflatoxigenic Aspergillus flavus. To date, the efficacy of this approach requires annual reapplication of the biocontrol agent. The reason for this requirement is uncertain. To track the dispersal and test the longevity of these strains, we prepared fluorescent biocontrol strains by incorporating into them the gene expressing the enhanced green fluorescent protein (eGFP). We first investigated the effects of eGFP transformation on the ability of the fluorescent fungus to compete with its non-fluorescent homolog, and then with other heterologous non-aflatoxigenic strains as well as with aflatoxigenic isolates. Our findings indicate that, in these studies, detection of fluorescence was variable, with some fluorescent strains exhibiting enhanced growth and sporulation post-transformation. In our tests, not all transformed strains proved to be good candidates for tracking because their fluorescence was reduced over the course of our study. Most of the transformed strains retained fluorescence and showed robust colony growth in an artificial competitor environment;therefore, they should be suited for further trial under more natural settings. Our ultimate objective is to determine if out-crossing between biocontrol strains and native field populations is occurring in a natural setting.展开更多
Trichoderma species have shown efficiency on biocontrol of phytopathogens.For commercial application,it must be propagated in mass scale using a cost-effective method.As an alternative way to effectively deliver bioco...Trichoderma species have shown efficiency on biocontrol of phytopathogens.For commercial application,it must be propagated in mass scale using a cost-effective method.As an alternative way to effectively deliver biocontrol fungi inoculum to the field;seven agro-based wastes including rice bran,biochar,empty fruit bunches,coconut fibre,compost,topsoil and mixed soil were used in this study for evaluating mass multiplication of Trichoderma species.Based on the evaluation of colony-forming units(cfu)among the agro-based waste media used,coconut fibre is the most suitable in promoting the sporulation of Trichoderma asperellum and T.harzianum.Trichoderma asperellum C1667 showed the higher micropropagule count through incubation period compared to T.harzianum C1675.After 120 days on the agro-based waste media,T.asperellum C1667 and T.harzianum C1675 produced the highest(7.717×10^(5)cfu/g and 6.836±13.79×10^(5)cfu/g)coconut fibres,respectively.Meanwhile,the mixed soil appeared with the lowest cfu.Coconut fibres were shown as a great biocomposting medium for both Trichoderma species.Findings of the present study are valuable for disease management using agro-based wastes as a cost-effective medium for biocontrol agents like Trichoderma species.展开更多
Several bacterial strains were isolated from different rhizospheres.Among these,strain PDY7 exhibited strong antibacterial activity against the rice bacterial blight(BB)pathogen Xanthomonas oryzae pv.oryzae(Xoo)by the...Several bacterial strains were isolated from different rhizospheres.Among these,strain PDY7 exhibited strong antibacterial activity against the rice bacterial blight(BB)pathogen Xanthomonas oryzae pv.oryzae(Xoo)by the laboratory dual plate assays.The antibacterial property of the strain PDY7 was further investigated for the production of 2,4-diacetylphloroglucinol(DAPG),which amplified a characteristic of 629-bp DNA fragment by PCR-based screening method using phlD primers.The application of phlD positive strains was carefully evaluated for disease control and growth promotion of rice plants under field conditions.The selected strain PDY7 suppressed the rice BB by 58.83%and51.88%under glass house and field conditions,respectively.In addition,the strain PDY7 showed significant two-fold increase in root length(18.08 cm),shoot length(29.81 cm),and grain yield(96.07g).Strain PDY7 promoted the growth of rice plants by production of indole-3-acetic acid(IAA),which was determined by high performance liquid chromatography(HPLC)analysis.Our findings suggest that PDY7 belongs to the P.fluorescens group and can serve as potential biocontrol of BB as well as biofertilizer agent for growth promotion of rice.展开更多
Bacillus thuringiensis Bt185 and its insecticidal spectrum-expanded engineering strains are considered as potential biocontrol agents to soil insect Holotrichia parallela,Holotrichia oblita or Anomala corpulenta.Here ...Bacillus thuringiensis Bt185 and its insecticidal spectrum-expanded engineering strains are considered as potential biocontrol agents to soil insect Holotrichia parallela,Holotrichia oblita or Anomala corpulenta.Here we reported the complete genome of strain Bt185,it harbors eight plasmids,and plasmid p BT1850294 carries three cry8 genes.展开更多
Recently there have been many reports about soil diseases controlled by Trichoderma, but few could be applied on agriculture production in large areas. T23 isolated from soil around plant roots in the field by Biopest...Recently there have been many reports about soil diseases controlled by Trichoderma, but few could be applied on agriculture production in large areas. T23 isolated from soil around plant roots in the field by Biopesticide Engineering Center of Shenyang Agricultural University could control effectively Cucurbits Fusarium Wilt. The effects of 9 microelements which include copper, zinc, iron, boron, molybdenum, calcium, manganese, magnesium, potassium and frequently-used chemical fungicides, such as-carbendazim, thiram, thiophanate-methyl, chlorothalonil and hymexazol on the growth and the amounts of spores of Fusarium oxysporum FJ and Trichoderma T23 were studied. The effects of those factors on control effect of T23 to melon diseases were discussed and gave basis for the screening of synergistic agents and fungicides in controlling synergistically the pathogen. The results showed that copper sulfate, zinc sulfate, ferric sulfate and boric acid at concentration of 10-1000 μg/mL had the stronger inhibition to F. oxysporum, while weaker inhibition to Trichoderma. Ammonium molybdate, ferrous sulfate, calcium sulfate and potassium dihydrogen phosphate were the ideal the synergistic agent for accelerating the growth and sporulation of Trichoderma, and germination of melon seeds and growth of melon radicle. Melon Fusarium wilt was controlled by Trichoderma combined with ammonium molybdate and calcium sulfate. The relative control effect reached to 73.95%-71.36%. Several fungicides used generally in soil had a different effect on the growth of F. oxysporum and Trichoderma. Carbendazim appeared a strong inhibition to the growth of two strains, with EC50 of 3.01 mg/L and 0.75. mg/L, respectively. Trichoderma had the strong resistance to thiram which control to Fusarium oxysporum was not ideal in field. Hymexazol which EC50 was 261 mg/L and Trichoderma had the synergistical effect on controlling to F. oxysporum. Trichoderma could reproduce in soil treated with hymexazol at ratio of 2000-4000. Relative control effect of hymexazol combined with Trichoderma to oxysporum reached to 79.26%,. which was higher by 15.19% and 38.75% than the solo controlling effect respectively.展开更多
基金The work was supported by the Fundamental Research Funds of the Central University,China(Grant Number 2572017AA03 and Grant Number 2572014BA15).
文摘A transcriptomic database was constructed to study the biocontrol mechanisms of Trichoderma harzianum ACCC30371 using high quality UniGenes following growth in eight culture media[(1/2PD,minimal medium MM(containing dextrose 10 g L^-1),C starvation medium(derived from MM without dextrose),N starvation medium(derived from MM without ammonium sulphate),and four kinds of phytopathogenic fungi cell wall media].A 4 Gbp transcriptome was generated and 96.7%of the database had a sequencing error rate less than 1%.A total of 25,013 UniGene sequences were obtained with a mean length of 1135 nt.There were 2571 sequences longer than 3000 nt.The National Center for Biotechnology Information Accession number of this transcriptome is SRR8382572.There were 16,360 Unigenes annotated to the Nr protein database,9875 to the SwissProt database,10,266 to the KEGG database,7164 to the COG database,and 1508 to the GO database along with their protein functional annotations.There were 16,723 functional genes identified.We identified 402 bio-control genes,including 14 related to competition,311 to mycoparasitism,76 to antibiosis,and one related to eliciting a plant response.This shows that T.harzianum ACCC30371 has integrated biocontrol mechanisms,and of these mechanisms,mycoparasitism is the most prevalent.Antibiosis and induced systemic resistance also play important roles.These results provide a foundation for further research into the biocontrol mechanisms of Trichoderma,as well as the development and utilization of biological fungicides.
文摘Biocontrol by Trichoderma has been studied mainly with selected isolates of T. harzianum, T. atroviride and T. asperellum, which are members of sections Pachybasium and Trichoderma. In contrast, species from section Longibrachiatum have only rarely been studied. On the other hand, one taxon from this section-Hypocrea jecorina (anamorph: Trichoderma reesei)-has been widely used for the production of cellulolytic and hemicellulolytic enzymes and recombinant proteins. As far as Trichoderma is concerned, molecular genetic methods and tools are most advanced in H. jecorina, and its genome has recently been fully sequenced, thus making this taxon a model organism for the genus. Here we will demonstrate that H. jecorina is able to antagonize plant pathogenic fungi in plate confrontation tests, and can protect tomato and cucumber plants against Pythium ultimum blight. Using this as a model case, we made use of available H. jecorina mutants to investigate (a) whether carbon catabolite repression via the Cre1-regulator protein has an impact on biocontrol, and (b) whether cellulase gene expression is necessary for biocontrol of P. ultimum. In the first case, plate confrontation tests and in planta experiments yielded opposite results, i.e. while a Cre1 mutant was more active in antagonization of fungi on plates, the survival rates of P. ultimum-inoculated cucumber plants was lower than with the H. jecorina wild-type strain. Mutants of H. jecorina, unable to form cellulases, were still able to antagonize fungi on plates and provided similar protection of tomatos against P. ultimum as the wild type, indicating that the pronounced biocontrol ability of H. jecorina against fungi with cellulose-containing cell-walls is not due to its high cellulolytic activity. A strain disrupted in the light-modulator gene envoy (Schmoll et al., ms submitted) exhibited in planta biocontrol activity strongly exceeding that of the wild-type strain, thereby providing a first link between Trichoderma biocontrol and light. In view of the numerous other metabolic and regulatory mutants of H. jecorina available, we suggest that this fungus should increasingly be used in basic studies on the biochemistry and genetics of biocontrol.
基金financially supported by the National Basic Research Program of China (2013CB127501)the National Key Research and Development Program of China (2016YFD0201003)the National Natural Science Foundation of China (31272021, 31571987)
文摘Streptomyces rubrogriseus HDZ-9-47,isolated from eggs of Meloidogyne spp.,was evaluated as a potential biocontrol agent of Meloidogyne incognita under in vitro and protective field.Microscopic observations showed that HDZ-9-47 parasitized eggs of M.incognita within 7 days.In vitro,the culture filtrate of HDZ-9-47 caused 97.0%mortality of second-stage juveniles(J2s)of M.incognita and inhibited more than 50%egg hatching.In the field,compared with the control,the rootknot index and J2s density in the treatment of drench the broth contained 1012 HDZ-9-47 spores were respectively reduced by 51.1 and 80.7%at 90 days post transplantation,which were better than that in other application doses and methods.In addition,reduction rates of root-knot index and J2s density of the treatment of combined application of HDZ-9-47 with biofumigation was 87.1 and 91.0%,respectively,better than either of HDZ-9-47 or biofumigation used alone or fosthiazate treatment.And tomato yield also increased by 16.1%.Together,our results suggest that HDZ-9-47 could be an effective biocontrol agent of M.incognita,and that application of HDZ-9-47 combined with cabbage residue biofumigation was a promising and sustainable option for M.incognita control.
文摘Modern agribusiness plays a vital role in safeguarding and improving the production,quality,and quantity of food,feed,fiber,and fuel.Growing concerns over the impact of chemical pesticides on health and the environment have stimulated the industry to search for alternative and greener solutions.Over the last years,the RNA interference(RNAi)process has been identified as a very promising new approach to complement the arsenal of foliar spray,soil,or seed treatments applied as chemical and biological pest control agents,and of plant-incorporated protectants(PIPs).RNA-based active ingredients(AIs)possess a unique mode of action and can be implemented via both genetic modification(GM)and biocontrol approaches.RNA-based AIs promise to deliver the selectivity and sustainability desired in future crop protection agents.This is due to their utilization of a natural process to exert control and their high level of selectivity,which leads to reduced risk for non-target organisms(NTOs).This review discusses the advantages and limitations of RNA-based solutions in crop protection and recent research progress toward RNA-based biocontrols against the Colorado potato beetle(CPB),corn rootworm(CRW),and soy stink bug(SSB).Many challenges still exist on the road to the implementation of a broad range of RNA-based products and their widespread use and application.Despite these challenges,it can be expected that RNA-based AIs will become valuable new tools complementing the current arsenal of crop-protection solutions.
文摘Methicillin-resistant Staphylococcus aureus (MRSA) is among the most alarming pathogens affecting both humans and the global bovine industry. The current control measures in hospitals and on farms for MRSA have proven to be inadequate leaving a need for new rapid control methods to curb MRSA infections in situ. New control measures for bacterial infection are widely sought, with particular interest in the applications for bacteriophages (phages) as a biocontrol or therapeutic agent. The current study uses a wild highly lytic phage isolated from cow’s milk taken from three farms in Baghdad, Iraq. The resulting phage was able to rescue 100% of the mice from a median lethal dose (LD50) or (1 × 108 CFU mL-1 per mouse) for MRSA wild isolates achieved when the phage: bacteria ratio was 100:1. Even when treatment was delayed for 6 h post lethal infection, to the point where all mice were moribund, 80% of them were rescued by a single injection of this phage preparation. Based on the current results, a comprehensive study is needed to guide further research on the MRSA phage as a biocontrol for MRSA mastitis in dairy cows to replace or reduce the use of antibiotics in animal husbandry.
基金supported by the National High Technology Research and Development Program(13th Five-Year Plan Program,Grant Number 2016YFC0501505)the Fundamental Research Funds of the Central University,China(Grant Number 2572017CA06)。
文摘This study investigates the biocontrol potential of Trichoderma asperellum mutants against Rhizoctonia solani, Alternaria alternata, and Fusarium oxysporum and growth promotion of Populus davidiana 9 P. alba var.pyramidalis(Pd Pap poplar) seedlings. A T-DNA insertion mutant library of T. asperellum was constructed using Agrobacterium tumefaciens-mediated transformation.Sixty-five positive transformants(T1–T65) were obtained.Growth rates of the mutants T39 and T45 were the same,39.68% faster than the WT. In toxin tolerance tests, only T39 had greater tolerance to A. alternata fermentation broth than the WT, but mutant T45 had the same tolerance as the WT to all fermentation broths. Furthermore, T39 and T45 had a greater antagonistic ability than the WT strain against R. solani and A. alternata. The inhibition rate of the mutants T39 and T45 against A. alternata are 73.92% and80.76%, respectively, and 63.51% and 63.74%, respectively. Furthermore, the three strains increased the activities of superoxide dismutases, peroxidase, catalase(CAT)and phenylalanine ammonia lyase(PAL) in Pd Pap seedling leaves. CAT and PAL activity in the Pd Pap seedling leaveswas 11.25 and 5.50 times higher, respectively, in the presence of T39 than in the control group and 12 and 6.35 times higher, respectively, in the presence of T45 than in the control group. All three strains promoted seedling growth and the root and stem development, especially mutant T45. Mutants T39 and T45 reduced the incidence of pathogenic fungi in poplar and stimulated poplar seedling growth.
文摘Fungi and bacteria as insecticides have been tested to control forest pests for more than ten years, they are the saine kind of biocontrol agent with the different conentrations. thesame kind of the biocontrol agent with the different origin areas, and the mixtures of the different kinds of biocontrol agents. The infection mechanism of virus was discussed. moreover. the mfluence of these biocontrol agents on the small animals was also evaluated.
文摘The increasingly strict regulation of the use of phytosanitary products and the will of the populations to move towards sustainable development allow bio-sourced products and more particularly for biocontrol in the field of pesticides to progress. The study carried out here concerns the evaluation of the potency of Bacillus amyloliquefaciens Bc2 and Trichoderma harzianum to fight against strawberry cultures infected with anthracnose (Fragaria × ananassa Duch.). The studies were carried out in the laboratory and in the field. The results indicate that B. amyloliquefaciens Bc2 and Trichoderma harzianum TR are effective for the biological control of anthracnose, gray mold and powdery mildew on strawberries grown in field conditions. The increase in plant size and the number of fruits produced with these control agents has also been observed.
文摘This study was to evaluate the ecological risk of strain E26 (Agrobacterium sp. ) by detecting its survival in waters and its effects on rhizosphere microorganisms. The data showed that E26 could not be detected in distilled water, tap water, river water, and rainwater after 36, 36, 8, and 9 days, respectively. E26 did not reveal significant effects on the population of bacteria, fungi, and actinomyces in rhizosphere soil and on the root surface of grapevines.
基金Science and Technology Project of China Tobacco Guizhou Provincial Corporation(201918)Science and Technology Foundation of General Administration of Quality Supervision,Inspection and Quarantine of the People's Republic of China(2017IK257,2017IK261,2016IK075,2014IK022)+3 种基金Science and Technology Foundation of Guizhou Province(J[2013]2149)Humanities and Social Science Research Project of Guizhou Education Department(2022ZC016)Theoretical Innovation Project of Guizhou Province(Joint Project)(GZLCLH-2021-169)Construction of Guizhou Academic Pioneer.
文摘[Objectives]The paper was to study the toxicity of 9 biocontrol microbial products to adult population of Lasioderrma serricorne.[Methods]Nine biocontrol microbes were used as test materials to study their toxicity to the experimental population of L.serricorne adults.[Results]The toxicities of these biocontrol microbes from low to high at 5 d post spraying were:Luhai Beauveria bassiana powder(LC_(50)=462.752×10^(8) spores/L),Meichongzhi B.bassiana powder(LC_(50)=9713.157×10^(8) spores/L),Yiqiang Bio B.bassiana powder(LC_(50)=11203.321×10^(8)spores/L),Nongbao Bio B.bassiana powder(LC_(50)=12188.866×10^(8) spores/L),Yeshengwang B.bassiana powder(LC_(50)=21685.532×10^(8) spores/L);Fatu Bacillus thuringiensis suspension(LC_(50)=1.0844×10^(8) IU/L),Laojite B.thuringiensis suspension(LC_(50)=2.056×10^(8) IU/L),Lujinwa B.thuringiensis powder(LC_(50)=2.273×10^(8) IU/L),Nongbao Bio B.thuringiensis powder(LC_(50)=18.399×10^(8) spores/L).The toxicities of these biocontrol microbes from low to high at 10 d post spraying were:Nongbao Bio B.bassiana powder(LC_(50)=0.072×10^(8) spores/L),Yiqiang Bio B.bassiana powder(LC_(50)=2.484×10^(8) spores/L),Luhai B.bassiana powder(LC_(50)=44.551×10^(8) spores/L),Meichongzhi B.bassiana powder(LC_(50)=96.447×10^(8) spores/L),Yeshengwang B.bassiana powder(LC_(50)=723.347×10^(8) spores/L);Lujinwa B.thuringiensis powder(LC_(50)=0.0001×10^(8) IU/L),Fatu B.thuringiensis suspension(LC_(50)=0.045×10^(8) IU/L),Laojite B.thuringiensis suspension(LC_(50)=0.0644×10^(8) IU/L),Nongbao Bio B.thuringiensis powder(LC_(50)=1.899×10^(8) spores/L).The toxicities of these biocontrol microbes from low to high at 15 d post spraying were:Meichongzhi B.bassiana powder(LC_(50)=0.001×10^(8) spores/L),Nongbao Bio B.bassiana powder(LC_(50)=0.01×10^(8) spores/L),Yiqiang Bio B.bassiana powder(LC_(50)=0.084×10^(8) spores/L),Luhai B.bassiana powder(LC_(50)=2.370×10^(8) spores/L),Yeshengwang B.bassiana powder(LC_(50)=8.915×10^(8)spores/L);Lujinwa B.thuringiensis powder(LC_(50)=0.16×10^(4) IU/L),Laojite B.thuringiensis suspension(LC_(50)=0.185×10^(4) IU/L),Fatu B.thuringiensis suspension(LC_(50)=32.211×10^(4) IU/L),Nongbao Bio B.thuringiensis powder(LC_(50)=1590×10^(4) spores/L).[Conclusions]According to the three stages of tube rubbing,it is found that the control effects of Lujinwa B.thuringiensis powder and Meichongzhi B.bassiana powder are the best,and the results will provide technical support for the biological control of L.serricorne adults.
文摘The“oil stain disease”has become a phytosanitary status that involves economic losses for farmers who produce gulupa(Passiflora edulis Sims).For this reason,this research aimed to evaluate the biocontrol activity of Bacillus subtilis ATCC 55033 in a culture medium based on fermented millet as a biocontrol product of the disease.Initially,metabolite production of seven strains of B.subtilis and a reference strain B.s(ATCC 55033)was evaluated;in addition,the in vitro antagonistic ability was evaluated against Xanthomonas axonopodis.Two experiments were performed under in vitro conditions:(1)study of the presence of halos of hemolysis due to metabolite production;(2)analysis of the antagonistic ability by using double layer.It was observed that concerning the average,a number five times bigger of halos of hemolysis and 10 times bigger halos of inhibition in vitro on the growth of X.axonopodis in the strains B.s(ATCC 55033)and B.s TB2 over other strains.Subsequently,the evaluation was performed under greenhouse conditions,based on a randomized block design,in which two treatments were applied over the soil:(1)application of the fermented medium based on millet with B.s ATCC 55033,24 h before X.a inoculation;(2)application of 5 d post-inoculation.It was observed that the treatment,previous infective process,obtained an average percentage of severity equal to 42.044%.In addition,after the evaluation month,a foliage restoration was presented.In conclusion,it is suggested that these products could act as inducers in the plant systemic resistance to trigger defense responses to infection of X.a.
文摘The present study evaluates the possible modes of action of antagonistic bacteria and their tolerance to UV radiation, temperature and osmotic stress. The partial 16S-23S rRNA gene sequencing of eight antagonistic bacteria had a high match with three bacterial genera: <em>Curtobacterium</em>, <em>Pantoea</em> and <em>Bacillus</em>. In this study, the three <em>Bacillus</em> isolates showed the most relevant production of enzymes, volatile organic compounds and antibiosis against <em>Exserohilum turcicum</em>. Respect to UV radiation and temperature <em>Pantoea</em> and <em>Bacillus</em> isolates were more tolerant;whereas the eight isolates were tolerant to osmotic stress in varying degree. The three <em>Bacillus</em> isolates have the greatest potential as biocontrol agents for foliar diseases in maize. The antagonistic action could be explained through different modes of action such as enzymes, volatile organic compounds and/or direct antibiosis by other secondary metabolites. <em>Bacillus</em> isolates tolerance to environmental stresses including UV radiation, temperature and osmotic stress is relevant for survival and persistence on the leaf surface. This work provides new information about the mode of action of antagonistic bacteria with proven efficacy against maize leaf pathogens. In addition, it provides information about the tolerance of antagonistic bacteria against different stress conditions. The data of the present study could contribute to the development of a successful foliar biofungicide.
文摘The quantity of bio-laboratories and bio-factories in Uzbekistan increases every year.In 1970,there were only 4,in 1971,16,in 1985,710,in 1990,774,and in 2000,790.At present there
文摘Our study consists of a careful literature review carried out with the aim of better understanding the models developed in the field of biocontrol of postharvest fungal rot in apples(PHFRA)over the past two decades.It aims,more specifically,to shed light on the progress made by examining the products developed,their nature,their target pathogens,their effectiveness,theirs modes of action and the stage of their development.The post-harvest biocontrol of apples has made remarkable progress during the last twenty years of research.Several products(yeasts,bacteria,filamentous fungi and actinomycetes)have been selected.Some,are already marketed,others are at different stages of development.However,several points limit the optimal use of microbial antagonists in the bio-management of post-harvest apple rots as an alternative to chemicals.It is,in fact,still necessary to develop appropriate formulations of these microbial biocontrol agents,to better study their mechanisms of action,to test them under commercial conditions and against a broad spectrum of pathogens and hosts.However,although sometimes considered less effective than chemical treatments,biocontrol products based on microorganisms have major advantages for an application in an integrated post-harvest apple protection strategy.
文摘Current biological control methods to prevent pre-harvest aflatoxin contamination of corn, cottonseed, and ground and tree nuts involve field inoculation of non-aflatoxigenic Aspergillus flavus. To date, the efficacy of this approach requires annual reapplication of the biocontrol agent. The reason for this requirement is uncertain. To track the dispersal and test the longevity of these strains, we prepared fluorescent biocontrol strains by incorporating into them the gene expressing the enhanced green fluorescent protein (eGFP). We first investigated the effects of eGFP transformation on the ability of the fluorescent fungus to compete with its non-fluorescent homolog, and then with other heterologous non-aflatoxigenic strains as well as with aflatoxigenic isolates. Our findings indicate that, in these studies, detection of fluorescence was variable, with some fluorescent strains exhibiting enhanced growth and sporulation post-transformation. In our tests, not all transformed strains proved to be good candidates for tracking because their fluorescence was reduced over the course of our study. Most of the transformed strains retained fluorescence and showed robust colony growth in an artificial competitor environment;therefore, they should be suited for further trial under more natural settings. Our ultimate objective is to determine if out-crossing between biocontrol strains and native field populations is occurring in a natural setting.
基金supported by the Putra Grant(IPS),Universiti Putra Malaysia[grant numbers UPM/700-2/1/GP-IPS/2017/9577700].
文摘Trichoderma species have shown efficiency on biocontrol of phytopathogens.For commercial application,it must be propagated in mass scale using a cost-effective method.As an alternative way to effectively deliver biocontrol fungi inoculum to the field;seven agro-based wastes including rice bran,biochar,empty fruit bunches,coconut fibre,compost,topsoil and mixed soil were used in this study for evaluating mass multiplication of Trichoderma species.Based on the evaluation of colony-forming units(cfu)among the agro-based waste media used,coconut fibre is the most suitable in promoting the sporulation of Trichoderma asperellum and T.harzianum.Trichoderma asperellum C1667 showed the higher micropropagule count through incubation period compared to T.harzianum C1675.After 120 days on the agro-based waste media,T.asperellum C1667 and T.harzianum C1675 produced the highest(7.717×10^(5)cfu/g and 6.836±13.79×10^(5)cfu/g)coconut fibres,respectively.Meanwhile,the mixed soil appeared with the lowest cfu.Coconut fibres were shown as a great biocomposting medium for both Trichoderma species.Findings of the present study are valuable for disease management using agro-based wastes as a cost-effective medium for biocontrol agents like Trichoderma species.
基金supported by the Australian Research Council International Linkage Fellowship(No.LX0560210)the National Natural Science Foundation of China(No.30600082).
文摘Several bacterial strains were isolated from different rhizospheres.Among these,strain PDY7 exhibited strong antibacterial activity against the rice bacterial blight(BB)pathogen Xanthomonas oryzae pv.oryzae(Xoo)by the laboratory dual plate assays.The antibacterial property of the strain PDY7 was further investigated for the production of 2,4-diacetylphloroglucinol(DAPG),which amplified a characteristic of 629-bp DNA fragment by PCR-based screening method using phlD primers.The application of phlD positive strains was carefully evaluated for disease control and growth promotion of rice plants under field conditions.The selected strain PDY7 suppressed the rice BB by 58.83%and51.88%under glass house and field conditions,respectively.In addition,the strain PDY7 showed significant two-fold increase in root length(18.08 cm),shoot length(29.81 cm),and grain yield(96.07g).Strain PDY7 promoted the growth of rice plants by production of indole-3-acetic acid(IAA),which was determined by high performance liquid chromatography(HPLC)analysis.Our findings suggest that PDY7 belongs to the P.fluorescens group and can serve as potential biocontrol of BB as well as biofertilizer agent for growth promotion of rice.
基金supported by the National Natural Science Foundation of China (31301731, 31428020)the National Science and Technology Major Project (2014ZX08009013B)
文摘Bacillus thuringiensis Bt185 and its insecticidal spectrum-expanded engineering strains are considered as potential biocontrol agents to soil insect Holotrichia parallela,Holotrichia oblita or Anomala corpulenta.Here we reported the complete genome of strain Bt185,it harbors eight plasmids,and plasmid p BT1850294 carries three cry8 genes.
文摘Recently there have been many reports about soil diseases controlled by Trichoderma, but few could be applied on agriculture production in large areas. T23 isolated from soil around plant roots in the field by Biopesticide Engineering Center of Shenyang Agricultural University could control effectively Cucurbits Fusarium Wilt. The effects of 9 microelements which include copper, zinc, iron, boron, molybdenum, calcium, manganese, magnesium, potassium and frequently-used chemical fungicides, such as-carbendazim, thiram, thiophanate-methyl, chlorothalonil and hymexazol on the growth and the amounts of spores of Fusarium oxysporum FJ and Trichoderma T23 were studied. The effects of those factors on control effect of T23 to melon diseases were discussed and gave basis for the screening of synergistic agents and fungicides in controlling synergistically the pathogen. The results showed that copper sulfate, zinc sulfate, ferric sulfate and boric acid at concentration of 10-1000 μg/mL had the stronger inhibition to F. oxysporum, while weaker inhibition to Trichoderma. Ammonium molybdate, ferrous sulfate, calcium sulfate and potassium dihydrogen phosphate were the ideal the synergistic agent for accelerating the growth and sporulation of Trichoderma, and germination of melon seeds and growth of melon radicle. Melon Fusarium wilt was controlled by Trichoderma combined with ammonium molybdate and calcium sulfate. The relative control effect reached to 73.95%-71.36%. Several fungicides used generally in soil had a different effect on the growth of F. oxysporum and Trichoderma. Carbendazim appeared a strong inhibition to the growth of two strains, with EC50 of 3.01 mg/L and 0.75. mg/L, respectively. Trichoderma had the strong resistance to thiram which control to Fusarium oxysporum was not ideal in field. Hymexazol which EC50 was 261 mg/L and Trichoderma had the synergistical effect on controlling to F. oxysporum. Trichoderma could reproduce in soil treated with hymexazol at ratio of 2000-4000. Relative control effect of hymexazol combined with Trichoderma to oxysporum reached to 79.26%,. which was higher by 15.19% and 38.75% than the solo controlling effect respectively.
