Phytophthora infestans control is a long-standing problem that has caused ongoing difficulties and brought limited success for over a century.Traditional methods,such as fungicides,have drawbacks including high cost,r...Phytophthora infestans control is a long-standing problem that has caused ongoing difficulties and brought limited success for over a century.Traditional methods,such as fungicides,have drawbacks including high cost,restrictions on organic farming,potential risks to the environment and human health,and the development of resistant strains.In this study,we employed cutting-edge computer-based techniques,including Quantitative Structure-Activity Relationship(QSAR)modeling and molecular docking simulations,to uncover new fungicidal compounds and gain insights into their specific mechanisms of action against P.infestans.QSAR modeling on the number of compounds tested as P.infestans inhibitors was performed using an interactive OCHEM web platform.The predictive ability of the developed classification models had a balanced accuracy(BA)of 77–85%for the training set and BA?89–93%for the validation external test set.During the in vitro testing against P.infestans,thirteen synthesized 2-oxoimidazolidine-4-sulfonamides demonstrated inhibition rates,ranging from 23.6%to 87.4%.The fungicidal potential of six of these fungicides ranged from 79.3%to 87.4%,which is comparable to the activity of known fungicides.Acute toxicity results using the well-known aquatic marker Daphnia magna showed that the most active sulfonamides 3d,3f,3h,3j,3k,and 3l,with LC_(50) values ranging from 13.7 to 52.9 mg/L,are low-toxicity compounds.The molecular docking results demonstrated a potential mechanism of the antifungal action of the studied 2-oxoimidazolidin-4-sulfonamide derivatives via the inhibition of fungal CYP51,a sterol biosynthesis enzyme.展开更多
A complete cDNA of potato Phytophthora infestans-induced hypersensitive response-related protein gene (POTHR-1) was cloned using rapid amplification of cDNA ends (RACE) strategy according to a fragment sequence which ...A complete cDNA of potato Phytophthora infestans-induced hypersensitive response-related protein gene (POTHR-1) was cloned using rapid amplification of cDNA ends (RACE) strategy according to a fragment sequence which we had cloned using suppression subtractive hybridization (SSH) technique. The potato POTHR-1 gene encodes a protein of 225 amino acids, which shares 81% identity with tobacco hin1 gene-enoded protein (harpin-induced protein). Southern blot revealed that there are two to three copies of POTHR-1 in potato genome. The POTHR-1 gene expression in potato leaves showed that its transcripts accumulated remarkably in leaves after 36 h inoculation with P. infestans. Mechanical wounding and jasmonic acid (JA) could induce the POTHR-1 gene expression and osmotic stress just induce a slight accumulation of POTHR-1 gene mRNA, while salicylic acid (SA) had no detectable function on the induction accumulation of POTHR-1 gene transcripts. The potato POTHR-1 gene may preferentially associate with hypersensitive response (HR) or biotic cell death during interaction between host and pathogen.展开更多
Tomato is an important horticultural and economic crop cultivated worldwide.As Phytophthora infestans becomes a huge threat to tomato production,it is necessary to study the resistance mechanisms of tomato against P.i...Tomato is an important horticultural and economic crop cultivated worldwide.As Phytophthora infestans becomes a huge threat to tomato production,it is necessary to study the resistance mechanisms of tomato against P.infestans.Our previous research has found that miR482 might be involved in tomato–P.infestans interaction.In this study,miR482b precursor was cloned from Solanum pimpinellifolium“L3708”and miR482b was shown to decrease in abundance in tomato following P.infestans infection.Compared to wild-type tomato plants,tomato plants that overexpressed miR482b displayed more serious disease symptoms after P.infestans infection,with more necrotic cells,longer lesion diameters,and increased P.infestans abundance.Meanwhile,silencing of miR482b was performed by short tandem target mimic(STTM),resulting in enhancement of tomato resistance to P.infestans.Using miRNA and degradome data sets,NBS–LRR disease-resistance genes targeted by miR482b were validated.Negative correlation between the expression of miR482b and its target genes was found in all miR482b-overexpressing and-silencing tomato plants.Our results provide insight into tomato miR482b involved in the response to P.infestans infection,and demonstrate that miR482b–NBS–LRR is an important component in the network of tomato–P.infestans interaction.展开更多
In order to elucidate the contributions of JA in orchestrating disease resistance in potato plants,the potato genotype‘SD20’,which exhibits strong resistance against the highly virulent Phytophthora infestans isolat...In order to elucidate the contributions of JA in orchestrating disease resistance in potato plants,the potato genotype‘SD20’,which exhibits strong resistance against the highly virulent Phytophthora infestans isolate CN152,while infected by the super virulent isolate 2013-18-306,was treated with exogenous JA and then challenged by inoculation with 2013-18-306.The results showed that exogenously applied JA significantly delayed the onset and alleviated the symptoms of late blight,indicating exogenous JA could induce resistance to P.infestans in the early biotrophic stage of infection in‘SD20’plants.To further clarify the role of JA in the early defense response and identify key genes involved in JA signal transduction,gene expression profiling via RNA sequencing(RNA-seq)in‘SD20’plants treated with exogenously applied JA was performed.A total of 2927 differentially expressed genes were specifically induced,the majority encoded transcription factors,protein kinases,secondary metabolites,defense enzymes and disease resistance related proteins.GO functional annotation and KEGG metabolic pathway analysis showed that exogenously applied JA rapidly induced the expression of genes related to immune response regulation,pathogen defense,and other biological processes,and stimulated endogenous JA synthesis and signal transduction,and the overall early pathogen defense response in‘SD20’.These results provide useful information in understanding the JA’s function involved in pathogen defense responses and a theoretical basis for the application of JA in potato production.展开更多
Over 170 years after the infamous Irish Potato Famine,potato late blight(PLB)caused by Phytophthora infestans remains the single most devastating disease of global potato production,causing up to 10 billion USD in yie...Over 170 years after the infamous Irish Potato Famine,potato late blight(PLB)caused by Phytophthora infestans remains the single most devastating disease of global potato production,causing up to 10 billion USD in yield loss and management costs.Through decades of research,growers and agronomists in the field as well as laboratory scientists have made significant progress in understanding the molecular pathogenesis process of this critical pathosystem and effective management strategies to control PLB.Yet,the need to feed an ever-increasing global population under changing climate demands continued improvement in efficient and sustainable PLB management schemes that can be implemented across a broad economic spectrum.In this review,we briefly summarize the current understanding of the molecular interaction between P.infestans and its host plants,highlight the current integrated pest management strategy to control PLB on local and continental scales,and discuss the potential of further improvement of sustainable PLB control through genetic enhancement of crop resistance and emerging crop protection technologies.展开更多
The isolates of Phytophthora infestans on tomato in the Guangxi Zhuang Autonomous Region, China, were determined for the sensitivities to metalaxyl, cymoxanil and dimethomorph to give the basic information for integra...The isolates of Phytophthora infestans on tomato in the Guangxi Zhuang Autonomous Region, China, were determined for the sensitivities to metalaxyl, cymoxanil and dimethomorph to give the basic information for integrating disease management. Sensitivities were tested by measuring the radial growth on agar medium amended with fungicide, compared with the floating-leaf-disk method. 239 isolates were collected from eight tomato growing areas during 2000-2006. The testing results indicated that the frequencies of sensitive, intermediate, and resistant isolates to metalaxyl were 42.26, 35.98, and 23.53%, respectively. Variations in sensitivities amongst isolates from different areas or different years were very high for metalaxyl. All isolates from Tianlin and Wuxuan were sensitive to metalaxyl, but the metalaxyl-resistant isolates predominated in Tianyang, with the frequency of 51.35%. The EC50 values of certain isolates from Tianyang were higher than 500 μg·mL^-1 and their resistance levels were over 100 000 folds. Cymoxanil has been used for nearly 10 years in Guangxi, and dimethomorph has been used for 5-6 years. However, there was no decrease in sensitivity of P. infestans populations and the sensitivities of the pathogen were nearly normally distributed. Hence, their mean ECs0 value [cymoxanil （0.1647 ±0.0255） μg·mL^-1, dimethomorph （0.0970 ± 0.0052） μg·mL^-1 could be used as the baseline sensitivities for monitoring the field resistance development. The comparison with the floating-leaf-disk method indicates that both the techniques provided equivalent results. These studies suggested that metalaxyl can be continuously applied in Tianlin, Wuxuan, and Nanning due to the resistant isolates that have not been found, while for those areas with resistant isolate, the use of metalaxyl should be reduced or alternated, and cymoxanil or dimethomorph was recommended for controlling late blight disease of tomato.展开更多
Ninety isolates collected from five different provinces and cities (Hebei, Yunan, Sichuan, Chongqing, Inner Mongolia ) during 1997 - 1998 were tested with potato clones possessed 8 dominant mono-genes R1, R3, R4, R6, ...Ninety isolates collected from five different provinces and cities (Hebei, Yunan, Sichuan, Chongqing, Inner Mongolia ) during 1997 - 1998 were tested with potato clones possessed 8 dominant mono-genes R1, R3, R4, R6, R7, R9, R10, R11 and the combination of R1-R4 of the international late blight differential host. It concluded that: (1) in the 90 isolates tested 21 different races were detected, of which the 1.3.4. 7. 9. 10. 11 was very common with frequency of 32. 2%, followed by 1. 3. 4. 6. 7. 9. 10. 11 and 3.4.7. 9. 11 with frequency of 10.0%; (2) all tested resistant genes were compatible to the virulent gene of isolates of Phytophthora infestans assayed, which indicated that the virulent genes were very common in the tested population of Phytophthora infestans.展开更多
Plant pathogenic fungi produce mycotoxins which may lead host plants to produce disease symptoms and may have a significant positive role in the course of disease development.The putative Phytophthora infestans toxins...Plant pathogenic fungi produce mycotoxins which may lead host plants to produce disease symptoms and may have a significant positive role in the course of disease development.The putative Phytophthora infestans toxins were prepared by culturing in liquid medium（60 g rye and 10% tomato juice L-1） for 1 mon at 17℃,filtering through four layers of cheesecloth and being precipitated by ammonium sulfate.The resulted putative toxin solutions were used to study the effects on 3 potato varieties（both leaf and tuber tissues）.The results show that potato leaves and tubers exhibit symptoms similar to the late blight resulted from P.infestans infection.Potato varieties reacting differentially to both the toxin dilutions and toxins produced by different P.infestans isolates suggested the presence of toxin-mediated specificities between potato and P.infestans.Potato leaf and tuber tissues have different and contrary reactions to the toxin.Toxin-mediated specificities are likely present between potato and P.infestans.展开更多
Abstract [ Objective ] This study aimed to investigate the phenotypic characteristics of Phytophthora infestans from Guizhou Province. The metalaxyl resistance, mating type and isozyme genotype of 292 P. infestans st...Abstract [ Objective ] This study aimed to investigate the phenotypic characteristics of Phytophthora infestans from Guizhou Province. The metalaxyl resistance, mating type and isozyme genotype of 292 P. infestans strains isolated from Guizhou Province were analyzed. [ Result] Metalaxyl-resistant P. infestans strains were found in different areas of Guizhou Province. Resistant, moderately resistant and susceptible strains accounted for 35.62% , 33.90% and 30.48% , re- spectively. Both mating types A1 and A2 were found, which accounted for 65.38% and 34.62%, respectively. P. infestans strains isolated from Guizhou Province mainly belonged to Gpi genotypes 100/100 and 100/100/111, accounting for 50.68% and 43.84%, respectively. [ Conclusion] This study provides the theoretical basis for the prevention and control of potato late blight in Guizhou Province.展开更多
Phytophthora infestans is a highly destructive plant path- ogen that causes late blight disease in plants such as potato and tomato （Fry and Goodwin, 1997）. As a typical oomycete, the primary infective propagule of ...Phytophthora infestans is a highly destructive plant path- ogen that causes late blight disease in plants such as potato and tomato （Fry and Goodwin, 1997）. As a typical oomycete, the primary infective propagule of P. infestans is the sporangium, which can either germinate directly or release biflagellate zoospores that encyst and germinate on the host subsequently （Grenville-Briggs et al., 2005）. Due to abundant formation of the sporangia and prolific sporulation, P. infestans can spread quickly in the host tissues and cause extensive necrosis of the infected plants （Kamoun and Smart, 2005）.展开更多
[ Objective] The paper was to screen the antagonistic Bacillus spp. strains against Phytophthora infestans （Mont.） de Bary and analyze its lipepeptide substances. [ Methods] Using flat isolation and culture method, ...[ Objective] The paper was to screen the antagonistic Bacillus spp. strains against Phytophthora infestans （Mont.） de Bary and analyze its lipepeptide substances. [ Methods] Using flat isolation and culture method, the bacteria that could produce Bacillus spp. were isolated from rhizosphere soil, and carried out primary and secondary screening by confrontation culture. The lipopeptide substances of Y-3 strain with better antifungal effect were carried out I-IPLC analysis. [Result] Nine strains of bacteria had certain antagonistic effects against P. infestans in primary screening, Y-1 and Y-3 strains had significant inhibition effect against the growth of P. infestans in secondary screening, with inhibition rate higher than 80% ; the crude extract of lipepeptide produced by Y-3 strain had better antagonistic effect against P. infestans, with inhibition rate higher than 90%. HPLC analysis showed that the crude extract of lipepeptide mainly contained 8 components. [ Conclusion] The lipopeptide substances produced by Y-3 strain had significant inhibition effect, which had potential application value for biological control of potato late blight.展开更多
Late blight caused by the oomycete Phytophthora infestans Montagne de Bary is a devastating disease on potato production. A total of six parameters affecting the PCR system in P. infestans were investigated based on t...Late blight caused by the oomycete Phytophthora infestans Montagne de Bary is a devastating disease on potato production. A total of six parameters affecting the PCR system in P. infestans were investigated based on the template DNA of the isolate HH06-23 and EST-SSR primer pair Pi08N. The results showed that the optimal annealing temperature was 63 ℃, and the optimum PCR system of EST-SSR was 25 ng template DNA, 0.5 mmol·L^-1 dNTPs, 2 μL 10×Buffer （Mg^2＋ free）, 1.75 mmol·L^-1 MgCl2, 15 pmol primer, and 1.2 U Taq DNA polymerase in total 20 μL reaction system. The PCR program was initial denaturation at 94℃ for 2 rain, followed by 35 cycles of 94℃ for 30 s, 63℃ for 30 s, and 72℃ for 30 s, then a final extension step was 72℃ for 7 min, and held at 4℃. In addition, using the optimal PCR system, a total of 20 isolates of P. infestans were used for testing the stability and polymorphism of the PCR amplification. The clarity and abundant polymorphism indicated that this system was stable and suitable for researching the genetic diversity ofP. infestans population.展开更多
A total of 104 isolates including two Korean isolates and three Japanese isolates of Phytophthora infestans collected from Heilongjiang and Jilin Provinces from 2006 to 2008 were used to determine their mating types,m...A total of 104 isolates including two Korean isolates and three Japanese isolates of Phytophthora infestans collected from Heilongjiang and Jilin Provinces from 2006 to 2008 were used to determine their mating types,metalaxyl resistance,and RAPD genotypes.All the isolates of P.infestans collected from Heilongjiang and Jilin Provinces belonged to A 1 mating type,and no A 2 mating type was detected.Frequencies of metalaxyl resistant isolates were 94.4%,47.8% and 75.0% in 2006,2007 and 2008,respectively.Accord...展开更多
The occurrence of sexual reproduction accelerates the population genetic variation of Phytophthora infestans and makes it more difficult to control.The systematic analysis of the differentiation of phenotype(mating ty...The occurrence of sexual reproduction accelerates the population genetic variation of Phytophthora infestans and makes it more difficult to control.The systematic analysis of the differentiation of phenotype(mating type and metalaxyl sensitivity)and genotype(mtDNA haplotype and SSR genotype)of 65 single oospore strains of P.infestans was carried out in this article.Five test strains were isolated from Heilongjiang Province and Mongolia Autonomous Region.The experiment results showed that the isolation ratio of metalaxyl resistance(MR:HR)of single oospore strains produced through the cross of medium resistance and high resistant parents was 18:13;the isolation ratio of the metalaxyl resistance(S:MR:HR)of single oospore strains produced through the cross of sensitive and high resistant parents was 4:12:7.The progenies of single oospore strains produced through self-fertility parents with medium resistance were all of the medium resistance.The mating types A1:A2 was greater than 1:1 in single oospore strains of the progenies,which did not conform to the Mendel's law of inheritance.All single oospore strains of the progenies inherited mitochondrial DNA fragments from only one parent.Sexual recombination of single oospore strains was verified by using two pairs of SSR primers(Pi4B and Pi4G).At the locus of Pi4B and Pi4G in the cross of KS-37 and KS-25,the separation frequencies of allele were 19:12 and 14:17,respectively.They produced two new genotype strains.This study could provide a basis for formulating disease control strategies.展开更多
Chagas disease is endemic in south America. One of the major preventive actions is removing the vector TI （Triatoma infestans） from household. Although households are frequently sprayed to eliminate TI, pets and dom...Chagas disease is endemic in south America. One of the major preventive actions is removing the vector TI （Triatoma infestans） from household. Although households are frequently sprayed to eliminate TI, pets and domestic animals are natural storage for vector survival. This work proposes TI elimination from farm animals using IVM （ivermectin）, as a new strategy to Chagas disease control. Rhode island hens were divided into TG （treatment groups） and CG （control groups）. TG received IVM while CG received DMSO. TI used in the assay was fifth instar nymphs. Hens served as food source for TI. Blood was extracted for IVM chromatographic pharmacokinetic analysis. The pharmacokinetic models that best fitted the IVM plasma profiles were determined by means of the minimum Akaike information criterion estimation （MAICE） test. In TG nymphs mortality was 23.25% to 47.5% at 24-120 h, respectively. IVM plasma profile showed a first-order one-compartment model with a rapid absorption reaching a Cmax （maximum concentration） of 64.7 ± 15.4 ng/mL at 48 h （Troop） post-application. Our data shows that TI mortality is directly related to the plasma concentration of IVM and is up to 47.5% at 120 h. Therefore, ivermectin may have a potential effect on controlling TI vector in peri-domestic level.展开更多
Phytophthora infestans,the causative agent of potato late blight,poses a destructive threat to global agricultural production.Herein,a 3D DNA scaff old is elaborately designed as DNA tracks for accelerating the walkin...Phytophthora infestans,the causative agent of potato late blight,poses a destructive threat to global agricultural production.Herein,a 3D DNA scaff old is elaborately designed as DNA tracks for accelerating the walking process of the quadruped walker,further accompanied by the perylene-3,4,9,10-tetracarboxylic dianhydride(PTCDA)/CdS/TiO_(2)photoelectrode for the detection of RNA in Phytophthora infestans.Upon interaction with the target RNA,the quadruped walker was released to expeditiously walk along the 3D DNA scaff old and initiate the unfolding of hairpin 1(H1),where H1 could completely pair with the alkaline phosphatase-modified hairpin 2(AP-H2).Impressively,compared to traditional DNA track,the unique structure of the 3D DNA scaff old with equidistant binding sites and high continuity endowed the quadruped walker with a faster walking rate and better reaction efficiency.Consequently,a substantial quantity of AP-H2 was anchored,causing the hydrolysis of ascorbic acid 2-phosphate(AAP)into ascorbic acid(AA)by the immobilized AP.AA,as an active electron donor,can significantly increase the photocurrent signal.Thus,the proposed biosensor presents remarkable sensitivity in RNA detection with a detection limit down to 3.3 fM.This strategy of designing a 3D DNA scaff old as a DNA track provides a high-efficiency sensing platform and a valuable potential application for other biomarker detection.展开更多
The yield and quality of tomatoes(Solanum lycopersicum)is seriously affected by Phytophthora infestans.The long non-coding RNA(lnc RNA)Sl-lnc RNA39896 is induced after P.infestans infection and was previously predicte...The yield and quality of tomatoes(Solanum lycopersicum)is seriously affected by Phytophthora infestans.The long non-coding RNA(lnc RNA)Sl-lnc RNA39896 is induced after P.infestans infection and was previously predicted to act as an endogenous target mimic(eTM)for the micro RNA Sl-miR166b,which function in stress responses.Here,we further examined the role of Sl-lncRNA39896 and Sl-mi R166b in tomato resistance to P.infestans.Sl-miR166b levels were higher in Sl-lnc RNA39896-knockout mutants than in wild-type plants,and the mutants displayed enhanced resistance to P.infestans.A six-point mutation in the region of Sl-lncRNA39896 that binds to Sl-miR166b disabled the interaction,suggesting that Sl-lnc RNA39896 acts as an e TM for Sl-mi R166b.Overexpressing Sl-miR166b yielded a similar phenotype to that produced by Sl-lncRNA39896-knockout,whereas silencing of Sl-mi R166b impaired resistance.We verified that Sl-miR166b cleaved transcripts of its target classⅢhomeodomain-leucine zipper genes Sl HDZ34and Sl HDZ45.Silencing of Sl HDZ34/45 decreased pathogen accumulation in plants infected with P.infestans.Additionally,jasmonic acid and ethylene contents were elevated following infection in the plants with enhanced resistance.Sl-lnc RNA39896is the first known lnc RNA to negatively regulate resistance to P.infestans in tomato.We propose a novel mechanism in which the lnc RNA39896–mi R166b–HDZ module modulates resistance to P.infestans.展开更多
Using a subtractive hybridization （SH）/cDNA-AFLP combinational approach, differentially expressed genes involved in the potato-Phytophthora infestans interaction were identified. These included genes potentially con...Using a subtractive hybridization （SH）/cDNA-AFLP combinational approach, differentially expressed genes involved in the potato-Phytophthora infestans interaction were identified. These included genes potentially controlling pathogenesis or avr genes in P. infestans as well as those potentially involved in potato resistance or susceptibility to this pathogen. Forty-one differentially expressed transcript, derived fragments （TDFs）, resulting from the interaction, were cloned and sequenced. Two TDFs, suggested as potential pathogenicity factors, have sequence similarity to N-succinyl diaminopimelate aminotransferase and a transcriptional regulator, TetR family gene, respectively. Two other TDFs, suggested as potential avr genes, have sequence similarity to an EST sequence from Avr41Cf.41Avr91Cf- 9 and a P. infestans avirulence-associated gene, respectively. Genes＇ expression and origin were confirmed using Southern blots, Northern blots and qRT-PCR, he., potential resistance gene DL81 was induced at 12 hpi in the moderately resistant cultivar, whereas it was down-regulated as early as 6 hpi in the susceptible cultivar. On the other hand, DL21 was induced at 6 hpi （3.38-fold） in response to the highly aggressive isolate （US8） and strongly up-regulated thereafter （25.13-fold at 120 hpi.）, whereas it was only slightly up-regulated in response to the weakly aggressive isolate US11 （3.82-fold at 96 hpi）, suggesting its potential involvement as a susceptibility gene.展开更多
基金supported by the BASF Open Innovative Platform(Project OI39).
文摘Phytophthora infestans control is a long-standing problem that has caused ongoing difficulties and brought limited success for over a century.Traditional methods,such as fungicides,have drawbacks including high cost,restrictions on organic farming,potential risks to the environment and human health,and the development of resistant strains.In this study,we employed cutting-edge computer-based techniques,including Quantitative Structure-Activity Relationship(QSAR)modeling and molecular docking simulations,to uncover new fungicidal compounds and gain insights into their specific mechanisms of action against P.infestans.QSAR modeling on the number of compounds tested as P.infestans inhibitors was performed using an interactive OCHEM web platform.The predictive ability of the developed classification models had a balanced accuracy(BA)of 77–85%for the training set and BA?89–93%for the validation external test set.During the in vitro testing against P.infestans,thirteen synthesized 2-oxoimidazolidine-4-sulfonamides demonstrated inhibition rates,ranging from 23.6%to 87.4%.The fungicidal potential of six of these fungicides ranged from 79.3%to 87.4%,which is comparable to the activity of known fungicides.Acute toxicity results using the well-known aquatic marker Daphnia magna showed that the most active sulfonamides 3d,3f,3h,3j,3k,and 3l,with LC_(50) values ranging from 13.7 to 52.9 mg/L,are low-toxicity compounds.The molecular docking results demonstrated a potential mechanism of the antifungal action of the studied 2-oxoimidazolidin-4-sulfonamide derivatives via the inhibition of fungal CYP51,a sterol biosynthesis enzyme.
文摘A complete cDNA of potato Phytophthora infestans-induced hypersensitive response-related protein gene (POTHR-1) was cloned using rapid amplification of cDNA ends (RACE) strategy according to a fragment sequence which we had cloned using suppression subtractive hybridization (SSH) technique. The potato POTHR-1 gene encodes a protein of 225 amino acids, which shares 81% identity with tobacco hin1 gene-enoded protein (harpin-induced protein). Southern blot revealed that there are two to three copies of POTHR-1 in potato genome. The POTHR-1 gene expression in potato leaves showed that its transcripts accumulated remarkably in leaves after 36 h inoculation with P. infestans. Mechanical wounding and jasmonic acid (JA) could induce the POTHR-1 gene expression and osmotic stress just induce a slight accumulation of POTHR-1 gene mRNA, while salicylic acid (SA) had no detectable function on the induction accumulation of POTHR-1 gene transcripts. The potato POTHR-1 gene may preferentially associate with hypersensitive response (HR) or biotic cell death during interaction between host and pathogen.
基金This work was supported by Grants from the NFSC(Nos.31471880 and 61472061).
文摘Tomato is an important horticultural and economic crop cultivated worldwide.As Phytophthora infestans becomes a huge threat to tomato production,it is necessary to study the resistance mechanisms of tomato against P.infestans.Our previous research has found that miR482 might be involved in tomato–P.infestans interaction.In this study,miR482b precursor was cloned from Solanum pimpinellifolium“L3708”and miR482b was shown to decrease in abundance in tomato following P.infestans infection.Compared to wild-type tomato plants,tomato plants that overexpressed miR482b displayed more serious disease symptoms after P.infestans infection,with more necrotic cells,longer lesion diameters,and increased P.infestans abundance.Meanwhile,silencing of miR482b was performed by short tandem target mimic(STTM),resulting in enhancement of tomato resistance to P.infestans.Using miRNA and degradome data sets,NBS–LRR disease-resistance genes targeted by miR482b were validated.Negative correlation between the expression of miR482b and its target genes was found in all miR482b-overexpressing and-silencing tomato plants.Our results provide insight into tomato miR482b involved in the response to P.infestans infection,and demonstrate that miR482b–NBS–LRR is an important component in the network of tomato–P.infestans interaction.
基金supported by the National Natural Science Foundation of China (Grant No. 31561143006)Breeding Program of Shandong Province, China (Grant No. 2017LZGC001)Taishan Scholars Program of Shandong Province, China (Grant No. 2016-2020)
文摘In order to elucidate the contributions of JA in orchestrating disease resistance in potato plants,the potato genotype‘SD20’,which exhibits strong resistance against the highly virulent Phytophthora infestans isolate CN152,while infected by the super virulent isolate 2013-18-306,was treated with exogenous JA and then challenged by inoculation with 2013-18-306.The results showed that exogenously applied JA significantly delayed the onset and alleviated the symptoms of late blight,indicating exogenous JA could induce resistance to P.infestans in the early biotrophic stage of infection in‘SD20’plants.To further clarify the role of JA in the early defense response and identify key genes involved in JA signal transduction,gene expression profiling via RNA sequencing(RNA-seq)in‘SD20’plants treated with exogenously applied JA was performed.A total of 2927 differentially expressed genes were specifically induced,the majority encoded transcription factors,protein kinases,secondary metabolites,defense enzymes and disease resistance related proteins.GO functional annotation and KEGG metabolic pathway analysis showed that exogenously applied JA rapidly induced the expression of genes related to immune response regulation,pathogen defense,and other biological processes,and stimulated endogenous JA synthesis and signal transduction,and the overall early pathogen defense response in‘SD20’.These results provide useful information in understanding the JA’s function involved in pathogen defense responses and a theoretical basis for the application of JA in potato production.
基金supported by the National Natural Science Foundation of China (32130088)the Guangdong Major Project of Basic and Applied Basic Research,China(2021B0301030004) to Dong Suomengthe Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences (CAAS-ASTIP) to Zhou Shaoqun
文摘Over 170 years after the infamous Irish Potato Famine,potato late blight(PLB)caused by Phytophthora infestans remains the single most devastating disease of global potato production,causing up to 10 billion USD in yield loss and management costs.Through decades of research,growers and agronomists in the field as well as laboratory scientists have made significant progress in understanding the molecular pathogenesis process of this critical pathosystem and effective management strategies to control PLB.Yet,the need to feed an ever-increasing global population under changing climate demands continued improvement in efficient and sustainable PLB management schemes that can be implemented across a broad economic spectrum.In this review,we briefly summarize the current understanding of the molecular interaction between P.infestans and its host plants,highlight the current integrated pest management strategy to control PLB on local and continental scales,and discuss the potential of further improvement of sustainable PLB control through genetic enhancement of crop resistance and emerging crop protection technologies.
文摘The isolates of Phytophthora infestans on tomato in the Guangxi Zhuang Autonomous Region, China, were determined for the sensitivities to metalaxyl, cymoxanil and dimethomorph to give the basic information for integrating disease management. Sensitivities were tested by measuring the radial growth on agar medium amended with fungicide, compared with the floating-leaf-disk method. 239 isolates were collected from eight tomato growing areas during 2000-2006. The testing results indicated that the frequencies of sensitive, intermediate, and resistant isolates to metalaxyl were 42.26, 35.98, and 23.53%, respectively. Variations in sensitivities amongst isolates from different areas or different years were very high for metalaxyl. All isolates from Tianlin and Wuxuan were sensitive to metalaxyl, but the metalaxyl-resistant isolates predominated in Tianyang, with the frequency of 51.35%. The EC50 values of certain isolates from Tianyang were higher than 500 μg·mL^-1 and their resistance levels were over 100 000 folds. Cymoxanil has been used for nearly 10 years in Guangxi, and dimethomorph has been used for 5-6 years. However, there was no decrease in sensitivity of P. infestans populations and the sensitivities of the pathogen were nearly normally distributed. Hence, their mean ECs0 value [cymoxanil （0.1647 ±0.0255） μg·mL^-1, dimethomorph （0.0970 ± 0.0052） μg·mL^-1 could be used as the baseline sensitivities for monitoring the field resistance development. The comparison with the floating-leaf-disk method indicates that both the techniques provided equivalent results. These studies suggested that metalaxyl can be continuously applied in Tianlin, Wuxuan, and Nanning due to the resistant isolates that have not been found, while for those areas with resistant isolate, the use of metalaxyl should be reduced or alternated, and cymoxanil or dimethomorph was recommended for controlling late blight disease of tomato.
文摘Ninety isolates collected from five different provinces and cities (Hebei, Yunan, Sichuan, Chongqing, Inner Mongolia ) during 1997 - 1998 were tested with potato clones possessed 8 dominant mono-genes R1, R3, R4, R6, R7, R9, R10, R11 and the combination of R1-R4 of the international late blight differential host. It concluded that: (1) in the 90 isolates tested 21 different races were detected, of which the 1.3.4. 7. 9. 10. 11 was very common with frequency of 32. 2%, followed by 1. 3. 4. 6. 7. 9. 10. 11 and 3.4.7. 9. 11 with frequency of 10.0%; (2) all tested resistant genes were compatible to the virulent gene of isolates of Phytophthora infestans assayed, which indicated that the virulent genes were very common in the tested population of Phytophthora infestans.
基金supported by the grant from the Agricultural Scientific Achievements Transform Foundation,China (02EFN215300561)the Ministry of Science and Technology of Yunnan Province,China (2002NG09)the Modern Agriculture Industrial Technology System in Yunnan Province,China
文摘Plant pathogenic fungi produce mycotoxins which may lead host plants to produce disease symptoms and may have a significant positive role in the course of disease development.The putative Phytophthora infestans toxins were prepared by culturing in liquid medium（60 g rye and 10% tomato juice L-1） for 1 mon at 17℃,filtering through four layers of cheesecloth and being precipitated by ammonium sulfate.The resulted putative toxin solutions were used to study the effects on 3 potato varieties（both leaf and tuber tissues）.The results show that potato leaves and tubers exhibit symptoms similar to the late blight resulted from P.infestans infection.Potato varieties reacting differentially to both the toxin dilutions and toxins produced by different P.infestans isolates suggested the presence of toxin-mediated specificities between potato and P.infestans.Potato leaf and tuber tissues have different and contrary reactions to the toxin.Toxin-mediated specificities are likely present between potato and P.infestans.
基金Supported by Agricultural Science and Technology Project of Guizhou Province in 2011([2011]3022)
文摘Abstract [ Objective ] This study aimed to investigate the phenotypic characteristics of Phytophthora infestans from Guizhou Province. The metalaxyl resistance, mating type and isozyme genotype of 292 P. infestans strains isolated from Guizhou Province were analyzed. [ Result] Metalaxyl-resistant P. infestans strains were found in different areas of Guizhou Province. Resistant, moderately resistant and susceptible strains accounted for 35.62% , 33.90% and 30.48% , re- spectively. Both mating types A1 and A2 were found, which accounted for 65.38% and 34.62%, respectively. P. infestans strains isolated from Guizhou Province mainly belonged to Gpi genotypes 100/100 and 100/100/111, accounting for 50.68% and 43.84%, respectively. [ Conclusion] This study provides the theoretical basis for the prevention and control of potato late blight in Guizhou Province.
基金supported by the Chinese Academy of Sciences,China (Grant No.CXJQ120105)
文摘Phytophthora infestans is a highly destructive plant path- ogen that causes late blight disease in plants such as potato and tomato （Fry and Goodwin, 1997）. As a typical oomycete, the primary infective propagule of P. infestans is the sporangium, which can either germinate directly or release biflagellate zoospores that encyst and germinate on the host subsequently （Grenville-Briggs et al., 2005）. Due to abundant formation of the sporangia and prolific sporulation, P. infestans can spread quickly in the host tissues and cause extensive necrosis of the infected plants （Kamoun and Smart, 2005）.
基金Supported by Natural Science Foundation of Hebei Province( C2011201003)
文摘[ Objective] The paper was to screen the antagonistic Bacillus spp. strains against Phytophthora infestans （Mont.） de Bary and analyze its lipepeptide substances. [ Methods] Using flat isolation and culture method, the bacteria that could produce Bacillus spp. were isolated from rhizosphere soil, and carried out primary and secondary screening by confrontation culture. The lipopeptide substances of Y-3 strain with better antifungal effect were carried out I-IPLC analysis. [Result] Nine strains of bacteria had certain antagonistic effects against P. infestans in primary screening, Y-1 and Y-3 strains had significant inhibition effect against the growth of P. infestans in secondary screening, with inhibition rate higher than 80% ; the crude extract of lipepeptide produced by Y-3 strain had better antagonistic effect against P. infestans, with inhibition rate higher than 90%. HPLC analysis showed that the crude extract of lipepeptide mainly contained 8 components. [ Conclusion] The lipopeptide substances produced by Y-3 strain had significant inhibition effect, which had potential application value for biological control of potato late blight.
基金Supported by Natural Science Foundation of Heilongjiang Province of China (C200622)
文摘Late blight caused by the oomycete Phytophthora infestans Montagne de Bary is a devastating disease on potato production. A total of six parameters affecting the PCR system in P. infestans were investigated based on the template DNA of the isolate HH06-23 and EST-SSR primer pair Pi08N. The results showed that the optimal annealing temperature was 63 ℃, and the optimum PCR system of EST-SSR was 25 ng template DNA, 0.5 mmol·L^-1 dNTPs, 2 μL 10×Buffer （Mg^2＋ free）, 1.75 mmol·L^-1 MgCl2, 15 pmol primer, and 1.2 U Taq DNA polymerase in total 20 μL reaction system. The PCR program was initial denaturation at 94℃ for 2 rain, followed by 35 cycles of 94℃ for 30 s, 63℃ for 30 s, and 72℃ for 30 s, then a final extension step was 72℃ for 7 min, and held at 4℃. In addition, using the optimal PCR system, a total of 20 isolates of P. infestans were used for testing the stability and polymorphism of the PCR amplification. The clarity and abundant polymorphism indicated that this system was stable and suitable for researching the genetic diversity ofP. infestans population.
基金Supported by Scientific Research Fund of Northeast Agricultural UniversityScience Foundation and Ministry of EducationReturned Overseas Students to Start-up Foundation (210150)
文摘A total of 104 isolates including two Korean isolates and three Japanese isolates of Phytophthora infestans collected from Heilongjiang and Jilin Provinces from 2006 to 2008 were used to determine their mating types,metalaxyl resistance,and RAPD genotypes.All the isolates of P.infestans collected from Heilongjiang and Jilin Provinces belonged to A 1 mating type,and no A 2 mating type was detected.Frequencies of metalaxyl resistant isolates were 94.4%,47.8% and 75.0% in 2006,2007 and 2008,respectively.Accord...
基金Supported by Heilongjiang Province Natural Science Foundation(C2016019)Cooperative Innovation System of Potato Modern Agricultural Industry Technology in Heilongjiang Province(HNWJZT201801)。
文摘The occurrence of sexual reproduction accelerates the population genetic variation of Phytophthora infestans and makes it more difficult to control.The systematic analysis of the differentiation of phenotype(mating type and metalaxyl sensitivity)and genotype(mtDNA haplotype and SSR genotype)of 65 single oospore strains of P.infestans was carried out in this article.Five test strains were isolated from Heilongjiang Province and Mongolia Autonomous Region.The experiment results showed that the isolation ratio of metalaxyl resistance(MR:HR)of single oospore strains produced through the cross of medium resistance and high resistant parents was 18:13;the isolation ratio of the metalaxyl resistance(S:MR:HR)of single oospore strains produced through the cross of sensitive and high resistant parents was 4:12:7.The progenies of single oospore strains produced through self-fertility parents with medium resistance were all of the medium resistance.The mating types A1:A2 was greater than 1:1 in single oospore strains of the progenies,which did not conform to the Mendel's law of inheritance.All single oospore strains of the progenies inherited mitochondrial DNA fragments from only one parent.Sexual recombination of single oospore strains was verified by using two pairs of SSR primers(Pi4B and Pi4G).At the locus of Pi4B and Pi4G in the cross of KS-37 and KS-25,the separation frequencies of allele were 19:12 and 14:17,respectively.They produced two new genotype strains.This study could provide a basis for formulating disease control strategies.
文摘Chagas disease is endemic in south America. One of the major preventive actions is removing the vector TI （Triatoma infestans） from household. Although households are frequently sprayed to eliminate TI, pets and domestic animals are natural storage for vector survival. This work proposes TI elimination from farm animals using IVM （ivermectin）, as a new strategy to Chagas disease control. Rhode island hens were divided into TG （treatment groups） and CG （control groups）. TG received IVM while CG received DMSO. TI used in the assay was fifth instar nymphs. Hens served as food source for TI. Blood was extracted for IVM chromatographic pharmacokinetic analysis. The pharmacokinetic models that best fitted the IVM plasma profiles were determined by means of the minimum Akaike information criterion estimation （MAICE） test. In TG nymphs mortality was 23.25% to 47.5% at 24-120 h, respectively. IVM plasma profile showed a first-order one-compartment model with a rapid absorption reaching a Cmax （maximum concentration） of 64.7 ± 15.4 ng/mL at 48 h （Troop） post-application. Our data shows that TI mortality is directly related to the plasma concentration of IVM and is up to 47.5% at 120 h. Therefore, ivermectin may have a potential effect on controlling TI vector in peri-domestic level.
基金supported by the National Natural Science Foundation of China(32170100,32470085,22274059)Science and Technology Program of Guangzhou(2024A04J5241)+1 种基金Guangdong Basic and Applied Basic Research Foundation(2023A1515012871)Open Fund of Key Laboratory of Information Traceability for Agricultural Products,Ministry of Agriculture and Rural Aff airs(2023KF04)。
文摘Phytophthora infestans,the causative agent of potato late blight,poses a destructive threat to global agricultural production.Herein,a 3D DNA scaff old is elaborately designed as DNA tracks for accelerating the walking process of the quadruped walker,further accompanied by the perylene-3,4,9,10-tetracarboxylic dianhydride(PTCDA)/CdS/TiO_(2)photoelectrode for the detection of RNA in Phytophthora infestans.Upon interaction with the target RNA,the quadruped walker was released to expeditiously walk along the 3D DNA scaff old and initiate the unfolding of hairpin 1(H1),where H1 could completely pair with the alkaline phosphatase-modified hairpin 2(AP-H2).Impressively,compared to traditional DNA track,the unique structure of the 3D DNA scaff old with equidistant binding sites and high continuity endowed the quadruped walker with a faster walking rate and better reaction efficiency.Consequently,a substantial quantity of AP-H2 was anchored,causing the hydrolysis of ascorbic acid 2-phosphate(AAP)into ascorbic acid(AA)by the immobilized AP.AA,as an active electron donor,can significantly increase the photocurrent signal.Thus,the proposed biosensor presents remarkable sensitivity in RNA detection with a detection limit down to 3.3 fM.This strategy of designing a 3D DNA scaff old as a DNA track provides a high-efficiency sensing platform and a valuable potential application for other biomarker detection.
基金provided by the National Natural Science Foundation of China (No. 32072592, 31872116 and 61872055)
文摘The yield and quality of tomatoes(Solanum lycopersicum)is seriously affected by Phytophthora infestans.The long non-coding RNA(lnc RNA)Sl-lnc RNA39896 is induced after P.infestans infection and was previously predicted to act as an endogenous target mimic(eTM)for the micro RNA Sl-miR166b,which function in stress responses.Here,we further examined the role of Sl-lncRNA39896 and Sl-mi R166b in tomato resistance to P.infestans.Sl-miR166b levels were higher in Sl-lnc RNA39896-knockout mutants than in wild-type plants,and the mutants displayed enhanced resistance to P.infestans.A six-point mutation in the region of Sl-lncRNA39896 that binds to Sl-miR166b disabled the interaction,suggesting that Sl-lnc RNA39896 acts as an e TM for Sl-mi R166b.Overexpressing Sl-miR166b yielded a similar phenotype to that produced by Sl-lncRNA39896-knockout,whereas silencing of Sl-mi R166b impaired resistance.We verified that Sl-miR166b cleaved transcripts of its target classⅢhomeodomain-leucine zipper genes Sl HDZ34and Sl HDZ45.Silencing of Sl HDZ34/45 decreased pathogen accumulation in plants infected with P.infestans.Additionally,jasmonic acid and ethylene contents were elevated following infection in the plants with enhanced resistance.Sl-lnc RNA39896is the first known lnc RNA to negatively regulate resistance to P.infestans in tomato.We propose a novel mechanism in which the lnc RNA39896–mi R166b–HDZ module modulates resistance to P.infestans.
基金supported by a grant of the Natural Sciences and Engineering Research Council of Canada (NSERC) to F. Daayf
文摘Using a subtractive hybridization （SH）/cDNA-AFLP combinational approach, differentially expressed genes involved in the potato-Phytophthora infestans interaction were identified. These included genes potentially controlling pathogenesis or avr genes in P. infestans as well as those potentially involved in potato resistance or susceptibility to this pathogen. Forty-one differentially expressed transcript, derived fragments （TDFs）, resulting from the interaction, were cloned and sequenced. Two TDFs, suggested as potential pathogenicity factors, have sequence similarity to N-succinyl diaminopimelate aminotransferase and a transcriptional regulator, TetR family gene, respectively. Two other TDFs, suggested as potential avr genes, have sequence similarity to an EST sequence from Avr41Cf.41Avr91Cf- 9 and a P. infestans avirulence-associated gene, respectively. Genes＇ expression and origin were confirmed using Southern blots, Northern blots and qRT-PCR, he., potential resistance gene DL81 was induced at 12 hpi in the moderately resistant cultivar, whereas it was down-regulated as early as 6 hpi in the susceptible cultivar. On the other hand, DL21 was induced at 6 hpi （3.38-fold） in response to the highly aggressive isolate （US8） and strongly up-regulated thereafter （25.13-fold at 120 hpi.）, whereas it was only slightly up-regulated in response to the weakly aggressive isolate US11 （3.82-fold at 96 hpi）, suggesting its potential involvement as a susceptibility gene.
