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Sample records for blast resistance gene

  1. Analysis of rice blast resistance genes by QTL mapping

    Institute of Scientific and Technical Information of China (English)

    XU Jichen; WANG Jiulin; LING Zhongzhuan; ZHU Lihuang

    2004-01-01

    Resistance to rice blast pathogen mostly shows a quantitative trait controlled by several minor genes. Its complexity and the mutable characteristic of rice blast isolates both hinder the development of the blast resistance research. The article here tried to explore the resistance gene distribution on rice chromosomes and the way of function. Totally 124 QTLs have been identified against 20 isolates using Cartographer software with a ZYQ8/JX17 DH population, which separately are at 100 loci of 72 marker intervals on 12 rice chromosomes. Of them, 16 QTLs were determined by the isolate HB-97-36-1. 82 QTLs (66.13%) are from the resistant parent alleles, ZYQ8, while 42 QTLs (33.87%) are from the susceptible parent alleles, JX17. In comparison of their positions on chromosome, most QTLs are clustered together and distributed nearby the major genes especially the regions on chromosomes 1, 2, 8, 10 and 12. Each QTL could account for the resistance variation between 3.52%-68.64%. And, a positional QTL might display the resistance to several different isolates with different contributions.

  2. QTL Mapping and Gene Cloning of Durable Resistance to Blast in Rice

    OpenAIRE

    Kazutoshi Okuno

    2015-01-01

    Rice blast, caused by Pyricularia grisea Sacc., is a destructive disease of rice in most rice growing areas around the world. Breeding efforts have been made to introduce genes for blast resistance into desirable genetic background. Resistance to rice blast is categorized two types, complete (true) and incomplete (field resistance). Complete resistance is a hypersensitive reaction, often a complete form of resistance, and is characterized by a resistant infection type. More than 20 loci for c...

  3. QTL Mapping and Gene Cloning of Durable Resistance to Blast in Rice

    Directory of Open Access Journals (Sweden)

    Kazutoshi Okuno

    2015-12-01

    Full Text Available Rice blast, caused by Pyricularia grisea Sacc., is a destructive disease of rice in most rice growing areas around the world. Breeding efforts have been made to introduce genes for blast resistance into desirable genetic background. Resistance to rice blast is categorized two types, complete (true and incomplete (field resistance. Complete resistance is a hypersensitive reaction, often a complete form of resistance, and is characterized by a resistant infection type. More than 20 loci for complete blast resistance have been identified.

  4. Molecular Screening of Blast Resistance Genes in Rice using SSR Markers

    OpenAIRE

    Singh, A.K.; Singh, P. K.; Arya, Madhuri; Singh, N K; U S Singh

    2015-01-01

    Rice Blast is the most devastating disease causing major yield losses in every year worldwide. It had been proved that using resistant rice varieties would be the most effective way to control this disease. Molecular screening and genetic diversities of major rice blast resistance genes were determined in 192 rice germplasm accessions using simple sequence repeat (SSR) markers. The genetic frequencies of the 10 major rice blast resistance genes varied from 19.79% to 54.69%. Seven accessions I...

  5. PEDIGREE AND DNA MARKER ANALYSIS OF BLAST RESISTANCE GENES IN US RICE GERMPLASM

    Science.gov (United States)

    Blast resistance genes have been effectively used in southern US rice germplasm to reduce crop losses from this serious disease threat. Historical records indicate the most common blast resistance genes in USA rice germplasm are Pi-z and Pi-ks in medium grain and Pi-kh and Pi-ta2 in long grain varie...

  6. DNA tagging of blast resistant gene(s in three Brazilian rice cultivars

    Directory of Open Access Journals (Sweden)

    S.S. Sandhu

    2003-12-01

    Full Text Available Rice blast is the most important fungal disease of rice and is caused by Pyricularia oryzae Sacc. (Telomorph Magnoporthe grisea Barr.. Seven randomly amplified polymorphic DNA (RAPD markers OPA5, OPG17, OPG18, OPG19, OPF9, OPF17 and OPF19 showed very clear polymorphism in resistant cultivar lines which differed from susceptible lines. By comparing different susceptible lines, nine DNA amplifications of seven primers (OPA5(1000, OPA5(1200, OPG17(700, OPG18(850, OPG19(500, OPG19(600, OPF9(600, OPF17(1200 and OPF19(600 were identified as dominant markers for the blast resistant gene in resistant cultivar lines. These loci facilitate the indirect scoring of blast resistant and blast susceptible genotypes. The codomine RAPDs markers will facilitate marker-assisted selection of the blast resistant gene in two blast resistant genotypes of rice (Labelle and Line 11 and will be useful in rice breeding programs.

  7. Identification of novel alleles of the rice blast resistance gene Pi54

    OpenAIRE

    Kumar Vasudevan; Wilhelm Gruissem; Bhullar, Navreet K

    2015-01-01

    Rice blast is one of the most devastating rice diseases and continuous resistance breeding is required to control the disease. The rice blast resistance gene Pi54 initially identified in an Indian cultivar confers broad-spectrum resistance in India. We explored the allelic diversity of the Pi54 gene among 885 Indian rice genotypes that were found resistant in our screening against field mixture of naturally existing M. oryzae strains as well as against five unique strains. These genotypes are...

  8. New Marker Development for the Rice Blast Resistance Gene Pi-km

    Science.gov (United States)

    The blast resistance (R) gene Pi-km protects rice against specific races of the fungal pathogen Magnaporthe oryzae. The use of blast R genes remains the most cost-effective method of disease control. To facilitate the breeding process, we developed a Pi-km specific molecular marker. For this purp...

  9. Clustering of Major Genes Conferring Blast Resistance in a Durable Resistance Rice Cultivar Gumei 2

    Institute of Scientific and Technical Information of China (English)

    WU Jian-li; CHAI Rong-yao; FAN Ye-yang; LI De-bao; ZHENG Kang-le; Hei LEUNG; ZHUANG Jie-yun

    2004-01-01

    By using 304 recombinant inbred lines derived from indica rice cross Zhong 156/Gumei 2, a linkage map consisting of 177 marker loci and covering 12 rice chromosomes was constructed and employed for mapping genes conferring blast resistance in rice. Genomic location of gene Pi25(t) conferring neck blast resistance to the Chinese isolate 92-183 (race ZC15) was verified to be located between markers A7 and RG456 on chromosome 6, with genetic distances of 1.7 cM and 1.5 cM to A7 and RG456,respectively. Leaf blast resistance of Gumei 2 to the Philippine isolate Ca89 (lineage 4) was found to be controlled by a single gene. The gene tentatively designated as Pi26(t) was located between makers B10 and R674 on chromosome 6, with genetic distances of 5.7 cM and 25.8 cM to B10 and R674 respectively. Resistant alleles at both gene loci were derived from Gumei 2,indicating an existence of resistance gene cluster in Gumei 2.

  10. Blast resistant gene on rice mutant R917 and it translation

    International Nuclear Information System (INIS)

    R917 is a new rice variety with strong blast disease resistance. The resistance genes of R917 and its parents, Chengte 232 and Xiushui 37, were analysed with blast races of Pyricularia oryzae ZB13, ZC15 and ZE3. The results showed that only one dominant gene controlled the resistance to the three blast races in R917. Allelism test indicated that the resistant gene of R917 was non-allelic with its parents. The blast resistance was tested by inoculating with 7 Japanese strains. R917 was highly resistant to the all. The allelism test also indicated that the resistant gene of R917 was non-allelic with Toride 1. The reaction with some strains between R917 and Toride 1 indicated that the blast resistant gene of R917 is different with the 14 genes that was reported in Japan. The identification of the disease resistance for the progenies of R917 crosses with XS861 showed that R917 could be used as a good material for resistance to rice blast in rice breeding

  11. Cloning of novel rice blast resistance genes from two rapidly evolving NBS-LRR gene families in rice.

    Science.gov (United States)

    Guo, Changjiang; Sun, Xiaoguang; Chen, Xiao; Yang, Sihai; Li, Jing; Wang, Long; Zhang, Xiaohui

    2016-01-01

    Most rice blast resistance genes (R-genes) encode proteins with nucleotide-binding site (NBS) and leucine-rich repeat (LRR) domains. Our previous study has shown that more rice blast R-genes can be cloned in rapidly evolving NBS-LRR gene families. In the present study, two rapidly evolving R-gene families in rice were selected for cloning a subset of genes from their paralogs in three resistant rice lines. A total of eight functional blast R-genes were identified among nine NBS-LRR genes, and some of these showed resistance to three or more blast strains. Evolutionary analysis indicated that high nucleotide diversity of coding regions served as important parameters in the determination of gene resistance. We also observed that amino-acid variants (nonsynonymous mutations, insertions, or deletions) in essential motifs of the NBS domain contribute to the blast resistance capacity of NBS-LRR genes. These results suggested that the NBS regions might also play an important role in resistance specificity determination. On the other hand, different splicing patterns of introns were commonly observed in R-genes. The results of the present study contribute to improving the effectiveness of R-gene identification by using evolutionary analysis method and acquisition of novel blast resistance genes. PMID:26530637

  12. Nucleotide Base Variation of Blast Disease Resistance Gene Pi33 in Rice Selected Broad Genetic Background

    OpenAIRE

    DWINITA WIKAN UTAMI; KALIA BARNITA; SITI YURIAH; IDA HANARIDA

    2011-01-01

    Rice is one of the most important crops for human beings, thus increasing productivity are continually persecuted. Blast disease can reduce the rate of productivity of rice cultivation. Therefore, the program of blast disease-resistant varieties needs to do effectively. One of broad-spectrum blast disease-resistant gene is Pi33. This study was aimed to identify the variation in the sequence of nucleotide bases of Pi33 gene in five interspesific lines which derived from Bio46 (IR64/Oryza rufip...

  13. Natural variation of rice blast resistance gene Pi-d2

    Science.gov (United States)

    Studying natural variation of rice resistance (R) genes in cultivated and wild rice relatives can predict resistance stability to rice blast fungus. In the present study, the protein coding regions of rice R gene Pi-d2 in 35 rice accessions of subgroups, aus (AUS), indica (IND), temperate japonica (...

  14. Rapidly evolving R genes in diverse grass species confer resistance to rice blast disease

    OpenAIRE

    Yang, Sihai; Li, Jing; Zhang, Xiaohui; Zhang, Qijun; Huang, Ju; Chen, Jian-Qun; Hartl, Daniel L.; Tian, Dacheng

    2013-01-01

    We show that the genomes of maize, sorghum, and brachypodium contain genes that, when transformed into rice, confer resistance to rice blast disease. The genes are resistance genes (R genes) that encode proteins with nucleotide-binding site (NBS) and leucine-rich repeat (LRR) domains (NBS–LRR proteins). By using criteria associated with rapid molecular evolution, we identified three rapidly evolving R-gene families in these species as well as in rice, and transformed a randomly chosen subset ...

  15. Gene interactions and genetics of blast resistance and yield attributes in rice (Oryza sativa L.)

    Indian Academy of Sciences (India)

    B. Divya; A. Biswas; S. Robin; R. Rabindran; A. John Joel

    2014-08-01

    Blast disease caused by the pathogen Pyricularia oryzae is a serious threat to rice production. Six generations viz., P1, P2, F1, F2, B1 and B2 of a cross between blast susceptible high-yielding rice cultivar ADT 43 and resistant near isogenic line (NIL) CT13432-3R, carrying four blast resistance genes Pi1, Pi2, Pi33 and Pi54 in combination were used to study the nature and magnitude of gene action for disease resistance and yield attributes. The epistatic interaction model was found adequate to explain the gene action in most of the traits. The interaction was complementary for number of productive tillers, economic yield, lesion number, infected leaf area and potential disease incidence but duplicate epistasis was observed for the remaining traits. Among the genotypes tested under epiphytotic conditions, gene pyramided lines were highly resistant to blast compared to individuals with single genes indicating that the nonallelic genes have a complementary effect when present together. The information on genetics of various contributing traits of resistance will further aid plant breeders in choosing appropriate breeding strategy for blast resistance and yield enhancement in rice.

  16. Comparative genomics and association mapping approaches for blast resistant genes in finger millet using SSRs.

    Directory of Open Access Journals (Sweden)

    B Kalyana Babu

    Full Text Available The major limiting factor for production and productivity of finger millet crop is blast disease caused by Magnaporthe grisea. Since, the genome sequence information available in finger millet crop is scarce, comparative genomics plays a very important role in identification of genes/QTLs linked to the blast resistance genes using SSR markers. In the present study, a total of 58 genic SSRs were developed for use in genetic analysis of a global collection of 190 finger millet genotypes. The 58 SSRs yielded ninety five scorable alleles and the polymorphism information content varied from 0.186 to 0.677 at an average of 0.385. The gene diversity was in the range of 0.208 to 0.726 with an average of 0.487. Association mapping for blast resistance was done using 104 SSR markers which identified four QTLs for finger blast and one QTL for neck blast resistance. The genomic marker RM262 and genic marker FMBLEST32 were linked to finger blast disease at a P value of 0.007 and explained phenotypic variance (R² of 10% and 8% respectively. The genomic marker UGEP81 was associated to finger blast at a P value of 0.009 and explained 7.5% of R². The QTLs for neck blast was associated with the genomic SSR marker UGEP18 at a P value of 0.01, which explained 11% of R². Three QTLs for blast resistance were found common by using both GLM and MLM approaches. The resistant alleles were found to be present mostly in the exotic genotypes. Among the genotypes of NW Himalayan region of India, VHC3997, VHC3996 and VHC3930 were found highly resistant, which may be effectively used as parents for developing blast resistant cultivars in the NW Himalayan region of India. The markers linked to the QTLs for blast resistance in the present study can be further used for cloning of the full length gene, fine mapping and their further use in the marker assisted breeding programmes for introgression of blast resistant alleles into locally adapted cultivars.

  17. Statistical Inference of Selection and Divergence of the Rice Blast Resistance Gene Pi-ta

    OpenAIRE

    Amei, Amei; Lee, Seonghee; Mysore, Kirankumar S.; Jia, Yulin

    2014-01-01

    The resistance gene Pi-ta has been effectively used to control rice blast disease, but some populations of cultivated and wild rice have evolved resistance. Insights into the evolutionary processes that led to this resistance during crop domestication may be inferred from the population history of domesticated and wild rice strains. In this study, we applied a recently developed statistical method, time-dependent Poisson random field model, to examine the evolution of the Pi-ta gene in cultiv...

  18. The wheat durable, multipathogen resistance gene Lr34 confers partial blast resistance in rice.

    Science.gov (United States)

    Krattinger, Simon G; Sucher, Justine; Selter, Liselotte L; Chauhan, Harsh; Zhou, Bo; Tang, Mingzhi; Upadhyaya, Narayana M; Mieulet, Delphine; Guiderdoni, Emmanuel; Weidenbach, Denise; Schaffrath, Ulrich; Lagudah, Evans S; Keller, Beat

    2016-05-01

    The wheat gene Lr34 confers durable and partial field resistance against the obligate biotrophic, pathogenic rust fungi and powdery mildew in adult wheat plants. The resistant Lr34 allele evolved after wheat domestication through two gain-of-function mutations in an ATP-binding cassette transporter gene. An Lr34-like fungal disease resistance with a similar broad-spectrum specificity and durability has not been described in other cereals. Here, we transformed the resistant Lr34 allele into the japonica rice cultivar Nipponbare. Transgenic rice plants expressing Lr34 showed increased resistance against multiple isolates of the hemibiotrophic pathogen Magnaporthe oryzae, the causal agent of rice blast disease. Host cell invasion during the biotrophic growth phase of rice blast was delayed in Lr34-expressing rice plants, resulting in smaller necrotic lesions on leaves. Lines with Lr34 also developed a typical, senescence-based leaf tip necrosis (LTN) phenotype. Development of LTN during early seedling growth had a negative impact on formation of axillary shoots and spikelets in some transgenic lines. One transgenic line developed LTN only at adult plant stage which was correlated with lower Lr34 expression levels at seedling stage. This line showed normal tiller formation and more importantly, disease resistance in this particular line was not compromised. Interestingly, Lr34 in rice is effective against a hemibiotrophic pathogen with a lifestyle and infection strategy that is different from obligate biotrophic rusts and mildew fungi. Lr34 might therefore be used as a source in rice breeding to improve broad-spectrum disease resistance against the most devastating fungal disease of rice. PMID:26471973

  19. Identification of DNA markers linked to a blast resistance gene in rice

    International Nuclear Information System (INIS)

    Identification of DNA markers closely linked to a blast (Pyricularia oryzae Cav.) resistance gene and establishment of an indirect selection method for the blast resistance gene based on linked DNA markers are reported. A pair of near isogenic lines, K80R and K79S, were developed using a local Chinese indica rice cultivar, Hong-jiao-zhan, as the resistant donor and IR24 as the recurrent parent. Ten putatitvely positive markers were identified by screening 177 mapped DNA markers. Using 143 plants composed of the F2 population of K80R/K79S, three restriction fragment length polymorphism (RFLP) markers (RG81, RG869 and RZ397) on chromosome 12 of rice were verified to be closely linked to the blast resistance gene. The resistance genotypes of each F2 resistant individual were determined by inoculation of the F3 lines. RG869 was found to be most closely linked to the resistance gene, with a genetic distance of 5.1 cM. To fine map this gene with more DNA markers, the bulk segregation analysis procedure was employed to identify the random amplified polymorphic DNA (RAPD) markers linked to the resistance gene. Six of 199 arbitrary primers were able to produce positive RAPD bands. Tight linkage between the resistance gene and the three RAPD bands, each from a different primer, was confirmed after amplification of the DNA of all the F2 individuals. The linked DNA fragments were cloned and sequenced. The results of specific amplification were in agreement with those of RAPD analysis. The half-seed RAPD analysis procedure for blast resistance detection was established. The amplified DNA patterns on the extract from the endosperm half of the mature seeds were identical to those of the total DNA from the leaves. (author). 13 refs, 3 figs

  20. A genome-wide survey reveals abundant rice blastgenes in resistant cultivars.

    Science.gov (United States)

    Zhang, Xiaohui; Yang, Sihai; Wang, Jiao; Jia, Yanxiao; Huang, Ju; Tan, Shengjun; Zhong, Yan; Wang, Ling; Gu, Longjiang; Chen, Jian-Qun; Pan, Qinghua; Bergelson, Joy; Tian, Dacheng

    2015-10-01

    Plant resistance genes (R genes) harbor tremendous allelic diversity, constituting a robust immune system effective against microbial pathogens. Nevertheless, few functional R genes have been identified for even the best-studied pathosystems. Does this limited repertoire reflect specificity, with most R genes having been defeated by former pests, or do plants harbor a rich diversity of functional R genes, the composite behavior of which is yet to be characterized? Here, we survey 332 NBS-LRR genes cloned from five resistant Oryza sativa (rice) cultivars for their ability to confer recognition of 12 rice blast isolates when transformed into susceptible cultivars. Our survey reveals that 48.5% of the 132 NBS-LRR loci tested contain functional rice blastgenes, with most R genes deriving from multi-copy clades containing especially diversified loci. Each R gene recognized, on average, 2.42 of the 12 isolates screened. The abundant R genes identified in resistant genomes provide extraordinary redundancy in the ability of host genotypes to recognize particular isolates. If the same is true for other pathogens, many extant NBS-LRR genes retain functionality. Our success at identifying rice blastgenes also validates a highly efficient cloning and screening strategy. PMID:26248689

  1. DEVELOPMENT OF MULTIPLEX DNA-MARKER SET FOR IDENTIFICATION OF RICE BLAST RESISTANCE GENES Pi -40 AND Pi-b

    OpenAIRE

    Suprun I. I.; Kovalev V. S.; Shilovskiy V. N.

    2013-01-01

    Multiplex DNA-marker set for PCR identification for rice blast resistance genes Pi-40 and Pi-b was developed in this study. Optimal primers combinations and PCR conditions allows to identify both abovementioned genes in the single PCR

  2. Identification of novel alleles of the rice blast resistance gene Pi54

    Science.gov (United States)

    Vasudevan, Kumar; Gruissem, Wilhelm; Bhullar, Navreet K.

    2015-10-01

    Rice blast is one of the most devastating rice diseases and continuous resistance breeding is required to control the disease. The rice blast resistance gene Pi54 initially identified in an Indian cultivar confers broad-spectrum resistance in India. We explored the allelic diversity of the Pi54 gene among 885 Indian rice genotypes that were found resistant in our screening against field mixture of naturally existing M. oryzae strains as well as against five unique strains. These genotypes are also annotated as rice blast resistant in the International Rice Genebank database. Sequence-based allele mining was used to amplify and clone the Pi54 allelic variants. Nine new alleles of Pi54 were identified based on the nucleotide sequence comparison to the Pi54 reference sequence as well as to already known Pi54 alleles. DNA sequence analysis of the newly identified Pi54 alleles revealed several single polymorphic sites, three double deletions and an eight base pair deletion. A SNP-rich region was found between a tyrosine kinase phosphorylation site and the nucleotide binding site (NBS) domain. Together, the newly identified Pi54 alleles expand the allelic series and are candidates for rice blast resistance breeding programs.

  3. Introgression of Blast Resistance Genes (Putative Pi-b and Pi-kh) into Elite Rice Cultivar MR219 through Marker-Assisted Selection

    OpenAIRE

    Tanweer, Fatah A.; Rafii, Mohd Y.; Sijam, Kamaruzaman; Rahim, Harun A.; Ahmed, Fahim; ASHKANI, SADEGH; Latif, Mohammad A.

    2015-01-01

    Blast is the most common biotic stress leading to the reduction of rice yield in many rice-growing areas of the world, including Malaysia. Improvement of blast resistance of rice varieties cultivated in blast endemic areas is one of the most important objectives of rice breeding programs. In this study, the marker-assisted backcrossing strategy was applied to improve the blast resistance of the most popular Malaysian rice variety MR219 by introgressing blast resistance genes from the Pongsu S...

  4. Nucleotide Base Variation of Blast Disease Resistance Gene Pi33 in Rice Selected Broad Genetic Background

    Directory of Open Access Journals (Sweden)

    DWINITA WIKAN UTAMI

    2011-09-01

    Full Text Available Rice is one of the most important crops for human beings, thus increasing productivity are continually persecuted. Blast disease can reduce the rate of productivity of rice cultivation. Therefore, the program of blast disease-resistant varieties needs to do effectively. One of broad-spectrum blast disease-resistant gene is Pi33. This study was aimed to identify the variation in the sequence of nucleotide bases of Pi33 gene in five interspesific lines which derived from Bio46 (IR64/Oryza rufipogon and CT13432 crossing. DNA of five rice lines were amplified using the spesific primer for Pi33, G1010. Amplification results purified through Exonuclease 1 and Shrimp Alkaline Phosphatase protocols. Labelling using fluorescent dyes done before sequencing nucleotide base using CEQ8000 instrument. The results showed that lines number 28 showed introgesion of the three control parent genome (subspecies of Indica, subspecies of Japonica, and O. rufipogon while the Lines number 79, 136, and 143 were identical to Indica genome. Strain number 195 was identical to Japonica genome. These broad genetic background lines promise as durable performance to attack the expansion of the dynamic nature of the pathogen to blast. The result of ortholog sequence analysis found conserved nucleotide base sequence (CAGCAGCC which involved in heterotrimeric G-protein group. This protein has role as plant receptor for recognizing pathogen elicitor in interaction of rice and blast pathogen.

  5. Tagging of blast resistance gene(s) to DNA markers and marker-assisted selection (MAS) in rice improvement

    International Nuclear Information System (INIS)

    This paper reports progress made on the tagging of blast resistance gene(s) to DNA markers and on the initiation of marker-assisted selection (MAS) for blast resistance in rice improvement. A pair of near isogenic lines, K8OR and K79S, were developed using a Chinese landrace Hong-jiao-zhan as the resistance donor. Ten putatively positive markers were identified by screening 177 mapped DNA markers. Using the F2 population of 143 plants and the derived F3 lines, three Restriction Fragment Length Polymorphism (RFLP) markers (RG81, RG869 and RZ397) on chromosome 12 of rice were identified to be closely linked to the blast resistance gene Pi-12(t). The genetic distance between Pi-12(t) and the closest marker RG869 was 5.1 cM. By employing the bulk segregant analysis (BSA) procedure, six of 199 arbitrary primers were found to produce positive Randomly Amplified Polymorphic DNA (RAPD) bands. Tight linkage between Pi-12(t) and three RAPD bands, each from a different primer, was confirmed after amplification of DNA of all F2 individuals. Two fragments were cloned and sequenced, and two sequence characterised amplified re-ion (SCAR) markers were established. In two other F3 populations, Xian-feng I/Tetep and Xian-feng, 1/Hong-jiao-zhan, the blast resistance was found to be controlled by interactions of two or more genes. One resistance gene was located in the vicinity of RG81 in both populations. Work to identify other gene(s) is currently under way. Marker assisted selection for blast resistance was initiated. Crosses were made between elite varieties and blast resistance donors to develop populations for DNA marker-assisted selection of blast resistance. In addition, 48 varieties widely used in current rice breeding programs were provided by rice breeders. DNA marker-based polymorphism among, these varieties and resistance donors were analysed to produce a database for future MAS program. (author)

  6. Understanding the coevolution of rice blast resistance gene Pi-ta and Magnaporthe oryzae avirulence gene AVR-Pita

    Science.gov (United States)

    Rice blast disease caused by the filamentous ascomycetous fungus Magnaporthe oryzae remains to be one of the most serious threats for food security globally. Using resistance (R) genes in integrated cultural practices has been the most powerful practice for rice crop protection. Genetic analysis s...

  7. Tagging microsatellite marker to a blast resistance gene in the irrigated rice cultivar Cica-8

    Directory of Open Access Journals (Sweden)

    Thiago Martins Pinheiro

    2012-09-01

    Full Text Available The rice cultivar Cica-8 exhibit differential reaction to several pathotypes of Magnaporthe oryzae. The objective of the present investigation was to determine the number of alleles involved in the expression of resistance to leaf blast and identify microsatellite markers linked to these alleles. A cross between cultivar Metica-1 and Cica-8 susceptible and resistant, respectively, to pathotype IB-1 (Py1049 was made to obtain F1, F2, BC1:1 and BC1:2 progenies. Greenhouse tests for leaf blast reaction showed that resistance is controlled by a monogenic dominant gene. For testing microsatellite markers, DNA of both resistant and susceptible parents and F1 and F2 populations was extracted. As expected for single dominant gene the F2 populations segregated at a ratio of 3:1. Of the 11 microsatellite markers tested, one marker RM 7102 was found to be closely linked to the resistant allele at a distance of 2.7 cM, in the cultivar Cica-8 to pathotype IB-1.

  8. Selection of Representative Magnaporthe oryzae Isolates and Rice Resistant Gene Types for Screening of Blast-resistant Rice Cultivars

    OpenAIRE

    Jaeduk Goh; Dong-Bum Shin; Seong-Sook Han; Byung-Ryun Kim; Se-Won Lee; Jae-Hwan Roh; Ji-Ung Jeung; Young-Chan Cho

    2013-01-01

    Rice blast is one of the most serious disease threatening stable production of rice. Breeding of resistant cultivars has been used as the most effective and useful method to controll rice blast caused by Magnaporthe oryzae. To collect rice blast isolates in fields and test their pathogenicity on new cultivars are important for establishment of new resistant cultivars breeding program of rice. Pathotypes of Korean rice blast isolates have been categorized to Korean differential rac...

  9. Molecular breeding of thermo-sensitive genic male sterile (TGMS) lines of rice for blast resistance using Pi2 gene

    OpenAIRE

    Jiang, Jiefeng; Mou, Tongmin; Yu, Huihui; Zhou, Fasong

    2015-01-01

    Background Blast disease caused by the fungal pathogen Magnaporthe oryzae is one of the big problems in rice production in China, especially for high yield hybrid varieties made from a two-line system in which thermo-sensitive genic male sterile (TGMS) lines are used. In this study, we report the introgression of a rice blast resistance gene Pi2 from VE6219 into C815S, an elite rice TGMS line, leading to the development of blast resistant TGMS lines through marker assisted selection (MAS) and...

  10. Extensive sequence variation in rice blast resistance gene Pi54 makes it broad spectrum in nature

    Directory of Open Access Journals (Sweden)

    Shallu eThakur

    2015-05-01

    Full Text Available Rice blast resistant gene, Pi54 cloned from rice line, Tetep, is effective against diverse isolates of Magnaporthe oryzae. In this study, we prospected the allelic variants of the dominant blast resistance gene from a set of 92 rice lines to determine the nucleotide diversity, pattern of its molecular evolution, phylogenetic relationships and evolutionary dynamics, and to develop allele specific markers. High quality sequences were generated for homologs of Pi54 gene. Using comparative sequence analysis, InDels of variable sizes in all the alleles were observed. Profiling of the selected sites of SNP (Single Nucleotide Polymorphism and amino acids (N sites ≥ 10 exhibited constant frequency distribution of mutational and substitutional sites between the resistance and susceptible rice lines, respectively. A total of 50 new haplotypes based on the nucleotide polymorphism was also identified. A unique haplotype (H_3 was found to be linked to all the resistant alleles isolated from indica rice lines. Unique leucine zipper and tyrosine sulfation sites were identified in the predicted Pi54 proteins. Selection signals were observed in entire coding sequence of resistance alleles, as compared to LRR domains for susceptible alleles. This is a maiden report of extensive variability of Pi54 alleles in different landraces and cultivated varieties, possibly, attributing broad-spectrum resistance to Magnaporthe oryzae. The sequence variation in two consensus region: 163 bp and 144 bp were used for the development of allele specific DNA markers. Validated markers can be used for the selection and identification of better allele(s and their introgression in commercial rice cultivars employing marker assisted selection.

  11. DEVELOPMENT OF MULTIPLEX DNA-MARKER SET FOR IDENTIFICATION OF RICE BLAST RESISTANCE GENES Pi -40 AND Pi-b

    Directory of Open Access Journals (Sweden)

    Suprun I. I.

    2013-12-01

    Full Text Available Multiplex DNA-marker set for PCR identification for rice blast resistance genes Pi-40 and Pi-b was developed in this study. Optimal primers combinations and PCR conditions allows to identify both abovementioned genes in the single PCR

  12. Characterization of resistance genes to rice blast fungus Magnaporthe oryzae in a “Green Revolution” rice variety

    Science.gov (United States)

    The indica rice variety Dee Geo Woo Gen (DGWG) was the source of the semi-dwarf gene (SD1) which played an important role in the Green Revolution. In the present study, resistance (R) genes to the U.S. race (isolate) IB54 of Magnaporthe oryzae, causal agent of rice blast disease, was investigated. T...

  13. DNA tagging of blast resistant gene(s) in three Brazilian rice cultivars

    OpenAIRE

    Sandhu S.S.; Colombo Carlos; Bastos Cândido R.; Siqueira Walter J.

    2003-01-01

    Rice blast is the most important fungal disease of rice and is caused by Pyricularia oryzae Sacc. (Telomorph Magnoporthe grisea Barr.). Seven randomly amplified polymorphic DNA (RAPD) markers OPA5, OPG17, OPG18, OPG19, OPF9, OPF17 and OPF19 showed very clear polymorphism in resistant cultivar lines which differed from susceptible lines. By comparing different susceptible lines, nine DNA amplifications of seven primers (OPA5(1000), OPA5(1200,) OPG17(700), OPG18(850), OPG19(500), OPG19(600), OP...

  14. Close linkage of a blast resistance gene, Pias(t), with a bacterial leaf blight resistance gene, Xa1-as(t), in a rice cultivar ‘Asominori’

    OpenAIRE

    Endo, Takashi; Yamaguchi, Masayuki; Kaji, Ryota; Nakagomi, Koji; Kataoka, Tomomori; Yokogami, Narifumi; Nakamura, Toshiki; Ishikawa, Goro; Yonemaru, Jun-ichi; Nishio, Takeshi

    2012-01-01

    It has long been known that a bacterial leaf blight-resistant line in rice obtained from a crossing using ‘Asominori’ as a resistant parent also has resistance to blast, but a blast resistance gene in ‘Asominori’ has not been investigated in detail. In the present study, a blast resistance gene in ‘Asominori’, tentatively named Pias(t), was revealed to be located within 162-kb region between DNA markers YX4-3 and NX4-1 on chromosome 4 and to be linked with an ‘Asominori’ allele of the bacteri...

  15. Identification of a new locus, Ptr(t), required for rice blast resistance gene Pi-ta-mediated resistance.

    Science.gov (United States)

    Jia, Yulin; Martin, Rodger

    2008-04-01

    Resistance to the blast pathogen Magnaporthe oryzae is proposed to be initiated by physical binding of a putative cytoplasmic receptor encoded by a nucleotide binding site-type resistance gene, Pi-ta, to the processed elicitor encoded by the corresponding avirulence gene AVR-Pita. Here, we report the identification of a new locus, Ptr(t), that is required for Pi-ta-mediated signal recognition. A Pi-ta-expressing susceptible mutant was identified using a genetic screen. Putative mutations at Ptr(t) do not alter recognition specificity to another resistance gene, Pi-k(s), in the Pi-ta homozygote, indicating that Ptr(t) is more likely specific to Pi-ta-mediated signal recognition. Genetic crosses of Pi-ta Ptr(t) and Pi-ta ptr(t) homozygotes suggest that Ptr(t) segregates as a single dominant nuclear gene. A ratio of 1:1 (resistant/susceptible) of a population of BC1 of Pi-ta Ptr(t) with pi-ta ptr(t) homozygotes indicates that Pi-ta and Ptr(t) are linked and cosegregate. Genotyping of mutants of pi-ta ptr(t) and Pi-ta Ptr(t) homozygotes using ten simple sequence repeat markers at the Pi-ta region determined that Pi-ta and Ptr(t) are located within a 9-megabase region and are of indica origin. Identification of Ptr(t) is a significant advancement in studying Pi-ta-mediated signal recognition and transduction. PMID:18321185

  16. Analysis of the effectiveness of the rice blast resistance gene Pi-ta

    Science.gov (United States)

    The casual agent of rice blast, Magnaporthe oryzae, continues to remain a serious threat for rice production and in general for the world food supply. The most economically and environmentally viable strategy to control this pathogen is the development of cultivars which possess major resistance gen...

  17. OsGF14b Positively Regulates Panicle Blast Resistance but Negatively Regulates Leaf Blast Resistance in Rice.

    Science.gov (United States)

    Liu, Qing; Yang, Jianyuan; Zhang, Shaohong; Zhao, Junliang; Feng, Aiqing; Yang, Tifeng; Wang, Xiaofei; Mao, Xinxue; Dong, Jingfang; Zhu, Xiaoyuan; Leung, Hei; Leach, Jan E; Liu, Bin

    2016-01-01

    Although 14-3-3 proteins have been reported to be involved in responses to biotic stresses in plants, their functions in rice blast, the most destructive disease in rice, are largely unknown. Only GF14e has been confirmed to negatively regulate leaf blast. We report that GF14b is highly expressed in seedlings and panicles during blast infection. Rice plants overexpressing GF14b show enhanced resistance to panicle blast but are susceptible to leaf blast. In contrast, GF14b-silenced plants show increased susceptibility to panicle blast but enhanced resistance to leaf blast. Yeast one-hybrid assays demonstrate that WRKY71 binds to the promoter of GF14b and modulates its expression. Overexpression of GF14b induces expression of jasmonic acid (JA) synthesis-related genes but suppresses expression of salicylic acid (SA) synthesis-related genes. In contrast, suppressed GF14b expression causes decreased expression of JA synthesis-related genes but activation of SA synthesis-related genes. These results suggest that GF14b positively regulates panicle blast resistance but negatively regulates leaf blast resistance, and that GF14b-mediated disease resistance is associated with the JA- and SA-dependent pathway. The different functions for 14-3-3 proteins in leaf and panicle blast provide new evidence that leaf and panicle blast resistance are controlled by different mechanisms. PMID:26467468

  18. Natural variation of rice blast resistant gene Pi-ta in Oryza species

    Science.gov (United States)

    The Pi-ta gene in rice is a putative NBS type cytoplasmic receptor conferring resistance to races of Magnaporthe oryzae in a gene-for-gene manner. A Functional Nucleotide Polymorphism (FNP) change resulting in an amino acid substitution of Alanine to Serine at position 918 (nucleotide G to T at posi...

  19. Quantitative trait locus analysis of resistance to panicle blast in the rice cultivar Miyazakimochi

    OpenAIRE

    Ishihara, Takeaki; Hayano-Saito, Yuriko; Oide, Shinichi; Ebana, Kaworu; La, Nghia Tuan; Hayashi, Keiko; Ashizawa, Taketo; Suzuki, Fumihiko; Koizumi, Shinzo

    2014-01-01

    Background Rice blast is a destructive disease caused by Magnaporthe oryzae, and it has a large impact on rice production worldwide. Compared with leaf blast resistance, our understanding of panicle blast resistance is limited, with only one panicle blast resistance gene, Pb1, isolated so far. The japonica cultivar Miyazakimochi shows resistance to panicle blast, yet the genetic components accounting for this resistance remain to be determined. Results In this study, we evaluated the panicle ...

  20. Identification of a New Rice Blast Resistance Gene, Pid3, by Genomewide Comparison of Paired Nucleotide-Binding Site–Leucine-Rich Repeat Genes and Their Pseudogene Alleles Between the Two Sequenced Rice Genomes

    OpenAIRE

    Shang, Junjun; Tao, Yong; Chen, Xuewei; Zou, Yan; Lei, Cailin; Wang, Jing; Li, Xiaobing; Zhao, Xianfeng; Zhang, Meijun; Lu, Zhike; Xu, Jichen; Cheng, Zhukuan; Wan, Jianmin; Zhu, Lihuang

    2009-01-01

    Rice blast, caused by Magnaporthe oryzae, is one of the most devastating diseases. The two major subspecies of Asian cultivated rice (Oryza sativa L.), indica and japonica, have shown obvious differences in rice blast resistance, but the genomic basis that underlies the difference is not clear. We performed a genomewide comparison of the major class of resistant gene family, the nucleotide-binding site–leucine-rich repeat (NBS–LRR) gene family, between 93-11 (indica) and Nipponbare (japonica)...

  1. Marker-assisted selection for the rice blast resistance gene Pi-ar in a backcross population

    Directory of Open Access Journals (Sweden)

    Leila Garcês de Araújo

    2010-01-01

    Full Text Available A doubled-haploid (DH population, obtained by anther culture of F1 plants from a cross between a highlysusceptible rice cultivar Lijiangxintuanheigu and the resistant somaclone (SC09, of the cultivar Araguaia, was used to identifyRAPD markers linked to the blast resistance gene Pi-ar. The 86 DH plants, inoculated with the race IB-9 of Magnaportheoryzae, segregated in 1:1 ratio of resistant and susceptible plants. Of the 67 primers used 31 produced DNA profiles thatdifferentiated resistant and susceptible bulks as well as the parental cultivars. The resistance gene was found linked to theprimer OPS162072 (‘AGGGGGTTCC’ at a distance of 3.6 cM. The selection efficiency of this primer was assessed in a BC3 F1population derived from another cross between a susceptible cultivar IAC 201 and SC09. The marker OPS16 showedefficiency of 86.9%, when six resistant and two susceptible plants were considered as negatives in RAPD analysis.

  2. Molecular evolution and strong selective sweep at the rice blast resistance gene Pi-ta during crop domestication

    Science.gov (United States)

    The Pi-ta gene in rice has been effectively deployed worldwide to prevent the infection by the blast fungus Magnaporthe oryzae in a gene for gene specificity. The genomic region spanning Pi-ta and six flanking genes in 157 rice accessions composed of seven Oryza species including US and Asian culti...

  3. Design of Blast Resistant Structure

    Directory of Open Access Journals (Sweden)

    C. K. Gautam

    1997-04-01

    Full Text Available A shock blast resistant structure designed, developed and experimentally evaluated by the authors is described. We structure, capable of with standing dynamic loading (12 psi and a static pressure of 1.5 m earth cover due to blast or any other explosion, also gives protection against radiation, chemical and thermal hazards. Some results and details of analysis and experimentation are presented.

  4. Selection for blast-resistant mutants in irradiated rice populations

    International Nuclear Information System (INIS)

    A newly released rice variety, Tongil, has many desirable agronomic characters and a particularly high resistance to blast disease. However, it may become susceptible in the future, since a resistant variety released for field planting often encounters the creation of new races of blast fungus. This study was undertaken to identify potential blast-resistant mutants from the population of the irradiated variety, Tongil, by inoculating these materials with induced mutant races of blast fungus which are likely to occur in the future. Blast conidia were irradiated with X-rays and the virulent mutants were identified according to their ability to infect Tongil. Seven blast-resistant mutant lines from the Pungkwang variety, selected through the uplands blast nursery test, were likewise outstanding in resistance in the field compared with the parent. Ten resistant lines from the variety Tongil, identified by artificial inoculation with the mutant race IA-67, were also selected. The results in the study of resistance inheritance showed that blast resistance was conditioned by a single dominant gene and the Tongil variety has three or more resistant genes. (author)

  5. The single functional blast resistance gene Pi54 activates a complex defence mechanism in rice.

    Science.gov (United States)

    Gupta, Santosh Kumar; Rai, Amit Kumar; Kanwar, Shamsher Singh; Chand, Duni; Singh, Nagendera Kumar; Sharma, Tilak Raj

    2012-01-01

    The Pi54 gene (Pi-k(h)) confers a high degree of resistance to diverse strains of the fungus Magnaporthe oryzae. In order to understand the genome-wide co-expression of genes in the transgenic rice plant Taipei 309 (TP) containing the Pi54 gene, microarray analysis was performed at 72 h post-inoculation of the M. oryzae strain PLP-1. A total of 1154 differentially expressing genes were identified in TP-Pi54 plants. Of these, 587 were up-regulated, whereas 567 genes were found to be down-regulated. 107 genes were found that were exclusively up-regulated and 58 genes that were down- regulated in the case of TP-Pi54. Various defence response genes, such as callose, laccase, PAL, and peroxidase, and genes related to transcription factors like NAC6, Dof zinc finger, MAD box, bZIP, and WRKY were found to be up-regulated in the transgenic line. The enzymatic activities of six plant defence response enzymes, such as peroxidase, polyphenol oxidase, phenylalanine ammonia lyase, β-glucosidase, β-1,3-glucanase, and chitinase, were found to be significantly high in TP-Pi54 at different stages of inoculation by M. oryzae. The total phenol content also increased significantly in resistant transgenic plants after pathogen inoculation. This study suggests the activation of defence response and transcription factor-related genes and a higher expression of key enzymes involved in the defence response pathway in the rice line TP-Pi54, thus leading to incompatible host-pathogen interaction. PMID:22058403

  6. Current advances on genetic resistance to rice blast disease

    Science.gov (United States)

    Rice blast disease caused by the fungal pathogen Magnaporthe oryzae is one of the most threatening fungal diseases resulting in significant annual crop losses worldwide. Blast disease has been effectively managed by a combination of resistant (R) gene deployment, application of fungicides, and suita...

  7. Inheritance patterns and identification of microsatellite markers linked to the rice blast resistance in BC2F1 population of rice breeding

    OpenAIRE

    Gous Miah; Rafii, Mohd Y.; Mohd. Razi Ismail; Adam Bin Puteh; Harun Abdul Rahim; Sadegh Ashkani; Abdul Latif

    2015-01-01

    The BC2F1 population was derived from a cross between rice variety, MR219 (susceptible to blast) and Pongsu Seribu 1 (resistant to blast). The objectives of this research were to know the inheritance pattern of blast resistance and to identify the linked markers associated with blast resistance in BC2F1 population. Sixteen microsatellite markers were found as polymorphic between the parents related to blast resistant genes (Pi-genes). Among the selected blast resistant linked markers, two mar...

  8. Studies on induction of blast-resistant mutation in rice

    International Nuclear Information System (INIS)

    The mutation frequency of blast resistance in rice and that of increased pathogenicity of blast fungi were examined, using the rice variety, Norin 8, which is susceptible to all races of blast fungi in Japan, and a fungus strain, Ina 168, which carries 6 virulent genes, respectively. Four different inoculation methods were employed for screening blast resistant mutants, i.e., spraying spore suspensions in growth chambers, in a greenhouse and in a field nursery, and injecting spore suspensions into newly developed tillers. The number of lesions and their types were used as the criteria of blast resistance. For screening the fungus mutants with increased pathogenicity, the spore suspensions of the fungi to be tested were sprayed on the seedlings of the blast resistant varieties, and when susceptible-type lesions were formed, single spores were isolated from these lesions, and the change in its pathogenicity was confirmed. When seeds were irradiated with gamma ray and treated with chemicals (EMS or EI), the frequency of the mutants with high resistance to blast was 5/4,575 and 4/5,851 respectively, in the M2 generation. The frequency of dominant blast resistant mutations following gamma-ray irradiation at the pre-embryo stage of growing plants was 3/60,101 in the M1 generation. When the spore suspensions of blast fungi were treated with X-ray, the frequency of the mutants with increased pathogenicity was about 0.5%. Thus, the mutants highly resistant against blast of rice induced by radiation or chemicals would eventually become susceptible varieties because blast fungus mutants occurred more frequently with increased pathogenicity. (Kaihara, S.)

  9. Genetic analysis of durable resistance to Magnaporthe oryzae in the rice accession Gigante Vercelli identified two blast resistance loci.

    Science.gov (United States)

    Urso, Simona; Desiderio, Francesca; Biselli, Chiara; Bagnaresi, Paolo; Crispino, Laura; Piffanelli, Pietro; Abbruscato, Pamela; Assenza, Federica; Guarnieri, Giada; Cattivelli, Luigi; Valè, Giampiero

    2016-02-01

    Rice cultivars exhibiting durable resistance to blast, the most important rice fungal disease provoking up to 30 % of rice losses, are very rare and searching for sources of such a resistance represents a priority for rice-breeding programs. To this aim we analyzed Gigante Vercelli (GV) and Vialone Nano (VN), two temperate japonica rice cultivars in Italy displaying contrasting response to blast, with GV showing a durable and broad-spectrum resistance, whereas VN being highly susceptible. An SSR-based genetic map developed using a GV × VN population segregating for blast resistance identified two blast resistance loci, localized to the long arm of chromosomes 1 and 4 explaining more than 78 % of the observed phenotypic variation for blast resistance. The pyramiding of two blast resistance QTLs was therefore involved in the observed durable resistance in GV. Mapping data were integrated with information obtained from RNA-seq expression profiling of all classes of resistance protein genes (resistance gene analogs, RGAs) and with the map position of known cloned or mapped blast resistance genes to search candidates for the GV resistant response. A co-localization of RGAs with the LOD peak or the marker interval of the chromosome 1 QTL was highlighted and a valuable tool for selecting the resistance gene during breeding programs was developed. Comparative analysis with known blast resistance genes revealed co-positional relationships between the chromosome 1 QTL with the Pi35/Pish blast resistance alleles and showed that the chromosome 4 QTL represents a newly identified blast resistance gene. The present genetic analysis has therefore allowed the identification of two blast resistance loci in the durable blast-resistant rice cultivar GV and tools for molecular selection of these resistance genes. PMID:26141566

  10. Molecular Evolution of the Rice Blast Resistance Gene Pi-ta in Invasive Weedy Rice in the USA

    OpenAIRE

    Lee, Seonghee; Jia, Yulin; Jia, Melissa; Gealy, David R.; Olsen, Kenneth M; Caicedo, Ana L.

    2011-01-01

    The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variati...

  11. Enhanced Rice Blast Resistance by CRISPR/Cas9-Targeted Mutagenesis of the ERF Transcription Factor Gene OsERF922.

    Science.gov (United States)

    Wang, Fujun; Wang, Chunlian; Liu, Piqing; Lei, Cailin; Hao, Wei; Gao, Ying; Liu, Yao-Guang; Zhao, Kaijun

    2016-01-01

    Rice blast is one of the most destructive diseases affecting rice worldwide. The adoption of host resistance has proven to be the most economical and effective approach to control rice blast. In recent years, sequence-specific nucleases (SSNs) have been demonstrated to be powerful tools for the improvement of crops via gene-specific genome editing, and CRISPR/Cas9 is thought to be the most effective SSN. Here, we report the improvement of rice blast resistance by engineering a CRISPR/Cas9 SSN (C-ERF922) targeting the OsERF922 gene in rice. Twenty-one C-ERF922-induced mutant plants (42.0%) were identified from 50 T0 transgenic plants. Sanger sequencing revealed that these plants harbored various insertion or deletion (InDel) mutations at the target site. We showed that all of the C-ERF922-induced allele mutations were transmitted to subsequent generations. Mutant plants harboring the desired gene modification but not containing the transferred DNA were obtained by segregation in the T1 and T2 generations. Six T2 homozygous mutant lines were further examined for a blast resistance phenotype and agronomic traits, such as plant height, flag leaf length and width, number of productive panicles, panicle length, number of grains per panicle, seed setting percentage and thousand seed weight. The results revealed that the number of blast lesions formed following pathogen infection was significantly decreased in all 6 mutant lines compared with wild-type plants at both the seedling and tillering stages. Furthermore, there were no significant differences between any of the 6 T2 mutant lines and the wild-type plants with regard to the agronomic traits tested. We also simultaneously targeted multiple sites within OsERF922 by using Cas9/Multi-target-sgRNAs (C-ERF922S1S2 and C-ERF922S1S2S3) to obtain plants harboring mutations at two or three sites. Our results indicate that gene modification via CRISPR/Cas9 is a useful approach for enhancing blast resistance in rice. PMID

  12. Enhanced Rice Blast Resistance by CRISPR/Cas9-Targeted Mutagenesis of the ERF Transcription Factor Gene OsERF922.

    Directory of Open Access Journals (Sweden)

    Fujun Wang

    Full Text Available Rice blast is one of the most destructive diseases affecting rice worldwide. The adoption of host resistance has proven to be the most economical and effective approach to control rice blast. In recent years, sequence-specific nucleases (SSNs have been demonstrated to be powerful tools for the improvement of crops via gene-specific genome editing, and CRISPR/Cas9 is thought to be the most effective SSN. Here, we report the improvement of rice blast resistance by engineering a CRISPR/Cas9 SSN (C-ERF922 targeting the OsERF922 gene in rice. Twenty-one C-ERF922-induced mutant plants (42.0% were identified from 50 T0 transgenic plants. Sanger sequencing revealed that these plants harbored various insertion or deletion (InDel mutations at the target site. We showed that all of the C-ERF922-induced allele mutations were transmitted to subsequent generations. Mutant plants harboring the desired gene modification but not containing the transferred DNA were obtained by segregation in the T1 and T2 generations. Six T2 homozygous mutant lines were further examined for a blast resistance phenotype and agronomic traits, such as plant height, flag leaf length and width, number of productive panicles, panicle length, number of grains per panicle, seed setting percentage and thousand seed weight. The results revealed that the number of blast lesions formed following pathogen infection was significantly decreased in all 6 mutant lines compared with wild-type plants at both the seedling and tillering stages. Furthermore, there were no significant differences between any of the 6 T2 mutant lines and the wild-type plants with regard to the agronomic traits tested. We also simultaneously targeted multiple sites within OsERF922 by using Cas9/Multi-target-sgRNAs (C-ERF922S1S2 and C-ERF922S1S2S3 to obtain plants harboring mutations at two or three sites. Our results indicate that gene modification via CRISPR/Cas9 is a useful approach for enhancing blast resistance in

  13. Enhanced Rice Blast Resistance by CRISPR/Cas9-Targeted Mutagenesis of the ERF Transcription Factor Gene OsERF922

    Science.gov (United States)

    Wang, Chunlian; Liu, Piqing; Lei, Cailin; Hao, Wei; Gao, Ying; Liu, Yao-Guang; Zhao, Kaijun

    2016-01-01

    Rice blast is one of the most destructive diseases affecting rice worldwide. The adoption of host resistance has proven to be the most economical and effective approach to control rice blast. In recent years, sequence-specific nucleases (SSNs) have been demonstrated to be powerful tools for the improvement of crops via gene-specific genome editing, and CRISPR/Cas9 is thought to be the most effective SSN. Here, we report the improvement of rice blast resistance by engineering a CRISPR/Cas9 SSN (C-ERF922) targeting the OsERF922 gene in rice. Twenty-one C-ERF922-induced mutant plants (42.0%) were identified from 50 T0 transgenic plants. Sanger sequencing revealed that these plants harbored various insertion or deletion (InDel) mutations at the target site. We showed that all of the C-ERF922-induced allele mutations were transmitted to subsequent generations. Mutant plants harboring the desired gene modification but not containing the transferred DNA were obtained by segregation in the T1 and T2 generations. Six T2 homozygous mutant lines were further examined for a blast resistance phenotype and agronomic traits, such as plant height, flag leaf length and width, number of productive panicles, panicle length, number of grains per panicle, seed setting percentage and thousand seed weight. The results revealed that the number of blast lesions formed following pathogen infection was significantly decreased in all 6 mutant lines compared with wild-type plants at both the seedling and tillering stages. Furthermore, there were no significant differences between any of the 6 T2 mutant lines and the wild-type plants with regard to the agronomic traits tested. We also simultaneously targeted multiple sites within OsERF922 by using Cas9/Multi-target-sgRNAs (C-ERF922S1S2 and C-ERF922S1S2S3) to obtain plants harboring mutations at two or three sites. Our results indicate that gene modification via CRISPR/Cas9 is a useful approach for enhancing blast resistance in rice. PMID

  14. Multiplex SSR-PCR approaches for semi-automated genotyping and characterization of loci linked to blast disease resistance genes in rice.

    Science.gov (United States)

    Ashkani, Sadegh; Rafii, Mohd Yusop; Shabanimofrad, Mahmoodreza; Foroughi, Majid; Azizia, Parisa; Akhtar, Mohd Sayeed; Sahebi, Mahbod; Harun, Abd Rahim; Nasehi, Abbas

    2015-11-01

    In the present study, 63 polymorphic microsatellite markers related to rice blast resistance genes were fluorescently labelled at the 5'-end with either 6-FAM or HEX using the G5 dye set and incorporated into a multiplex SSR-PCR for the detection of fragments using an automated system. For rice F3 families obtained from crosses between Pongsu Seribu 2 (Malaysian blast resistant cultivar) and Mahsuri (a susceptible rice cultivar), the genotypes for 13 designated multiplex SSR panels were determined. The genotyping assays were performed using a capillary-based ABIPRISM 3100 genetic analyser. The sizes of the SSRs alleles observed in the range from 79 to 324 bp. The observed marker segregation data were analysed using the Chi(2) test. A genetic linkage map covering ten chromosomes and comprising 63 polymorphic SSR markers was constructed, and the distorted loci were localised to linkage groups. The results indicated that distorted loci are presented on eight chromosomes. PMID:26318048

  15. Induced mutation for disease resistance in rice with special reference to blast, bacterial blight and tungro

    International Nuclear Information System (INIS)

    Rice varieties Ratna, Pusa 2-21, Vijaya and Pankaj have been treated with gamma rays, EMS or sodium azide to improve their resistance against blast, bacterial leaf blight or tungro virus. For blast and tungro, mutants with improved resistance were selected. Variation in reaction to bacterial leaf blight has been used in crossbreeding to accumulate genes for resistance. (author)

  16. The genetics analysis of rice mutant R917 with resistance to rice blast (pyricularia oryza)

    International Nuclear Information System (INIS)

    Rice mutant R917 with resistance to rice blast was selected by induced mutation with irradiation. The F2 segregation of R917/NF6, XS11, XS861 crosses with resistance to rice blast ZB15, ZC13, ZE3 showed that the rice blast resistance is controlled by one dominant gene. The identification of the disease resistance for the progenies of R917 crosses with XS11, XS861 showed that R917 could be used as a good material for resistance to rice blast in rice breeding

  17. Development and Identification of Novel Rice Blast Resistant Sources and Their Characterization Using Molecular Markers

    Institute of Scientific and Technical Information of China (English)

    S J S RAMA DEVI; M. S. MADHAV; Kuldeep SINGH; B UMAKANTH; B VISHALAKSHI; P RENUKA; K. VIJAY SUDHAKAR; M. S. PRASAD3; B. C. VIRAKTAMATH; V. RAVINDRA BABU

    2015-01-01

    To develop and characterize introgression lines for leaf and neck blast resistance, 326 introgression lines were developed using various accessions of six different AA genome wild species in the genetic background of elite Indian varieties like PR114 and Pusa 44 and were screened for blast resistance. Stringent phenotyping coupled with genotyping using gene based markers led to the identification of four resistant introgression lines, which showed promising resistance and do not possess any of the tested genes. Furthermore, multi-location screening confirmed the field resistance of the four introgression lines to both leaf and neck blast. Molecular characterization of these introgression lines using genome-wide simple sequence repeat markers revealed the presence of small percentage of wildOryza genome introgrssion. So these lines can be used for mapping and identification of novel leaf and neck blast resistance genes. Thus, these four introgression lines can be considered as new genetic resources for blast resistance.

  18. Natural variation of the rice blast resistance gene Pi-ta in Oryza species and its corresponding avirulence gene AVR-Pita in Magnaporthe oryzae

    Science.gov (United States)

    The Pi-ta gene prevents the infections of M. oryzae races containing the corresponding avirulence gene AVR-Pita in a gene-for-gene manner. Pi-ta is a putative NBS type major resistance gene, and can directly recognize the AVR-Pita putative metalloprotease in triggering effective resistance. We hav...

  19. 稻瘟病抗性基因在主要育种亲本中的分布研究%Research on the Distribution of Rice Blast Resistance Genes in the Main Rice Breeding Parents

    Institute of Scientific and Technical Information of China (English)

    邢鹏; 张幸; 李冬梅; 钟光荣; 李进; 胡江博; 卢代华; 马炳田

    2015-01-01

    稻瘟病是由稻瘟病菌引起的具有广泛性和毁灭性的水稻病害。目前通过抗病亲本杂交聚合培育持久广谱的稻瘟病抗性品种是水稻稻瘟病防治最经济环保的途径,而利用分子标记辅助选择技术对水稻育种亲本抗性基因分布的研究是分子辅助聚合育种的基础。本研究以36个育种亲本为实验材料,进行苗瘟和穗颈瘟鉴定,结合特异性分子标记Pid3、Pita、Pik m、Pib、Piz ,研究这些育种亲本的稻瘟病抗性基因的分布情况。同时,对恢复系材料蜀恢498的抗稻瘟病基因Pita和Pik m扩增测序并进行同源序列比对分析,初步在分子水平分析抗病基因与抗病表型的关系。%Rice blast is one of the most widespread and devastating diseases of rice which caused by fungal pathogen Magnaporthe grisea. The econmiec and friendly to control rice blast is to foster durable broad spectrum of hybrid polymeric blast by method of hybriding resistant parents. Molecular marker assisted selection technology is used to study the distribution of the resistance gene of rice breeding parent is the basis of molecular assisted breeding. In our research, 36 breeding parents as experimental materials for seedling blast and panicle blast identification, combined marker of Pid3, Pita, Pik m, Pib , Piz to study these rice blast resistance gene distribution on parental, while we cloned the blast resistance gene Pita, Pik m of the restorer line Shuhui498 and had the homologous sequence alignment analysis, preliminary analysis of the relationship between genes and disease resistance phenotype at the molecular level.

  20. Artificial induction of blast-resistant mutations in rice

    International Nuclear Information System (INIS)

    The paper describes studies on the induction of mutations in rice for resistance to blast disease and studies on the induction of changes in pathogenicity in the rice blast fungus. Treatments were done with both radiation and chemical mutagens. Frequencies in blast-resistant mutations and in increase and decrease of pathogenicity of the fungus are reported. (author). 4 refs

  1. Genetic structure and virulence diversity of Pyricularia grisea in breeding for rice blast resistance

    International Nuclear Information System (INIS)

    Rice blast caused by Pyricularia grisea Sacc. is the main production constraint in rice worldwide. Development of resistant cultivars has been the preferred means of controlling this disease; however, resistance is defeated by the pathogen shortly after cultivar release. The blast pathogen population in Colombia's rice growing areas has been grouped into six genetically different families named SRL-1 to SRL-6 using DNA fingerprinting. The spectrum of virulence of isolates within each family is highly similar, differing mainly in signel virulences. Although the six genetic families of the fungus share a high number of virulence factors, high specific interaction between some avirulence/virulence factors in the pathogen and resistance genes in the host has been observed. This specific interaction is the basis for selecting the progenitors to be included in a breeding programme aimed at obtaining more durable blast resistance. Combinations of genes showing complementary resistance to different genetic families of the fungus should exclude any compatible interaction with a blast isolate. Identification of complementary resistance genes is based on detecting those virulence factors whose combinations in individual isolates within the pathogen population have a frequency near zero. It is assumed that certain virulence combinations in the blast pathogen may confer a low fitness or have a deleterious effect on the fungus, reducing its frequency in nature. The frequency of the virulence factors to the resistance genes Pi-1 and Pi-2 present independently in two different near isogenic lines is high in the blast fungus population of genetic families SRL-5 and SRL-1, respectively. The two genes show complementary resistance that excludes all the genetic families of the fungus, and no isolate with a combination of the two virulence genes infecting both isogenic lines has been detected. Induced mutations can be a useful technique for producing rice lines with specific resistance

  2. Co-evolution of the rice blast resistance gene Pi-ta and Magnaporthe oryzae avirulence gene AVR-Pita1

    Science.gov (United States)

    The Pi-ta gene in rice provides resistance to races of Magnaporthe oryzae that contain the corresponding avirulence gene AVR-Pita1. Pi-ta encodes a predicted receptor protein with nucleotide binding site and leucine rich repeat domain (NBS-LRR) that directly recognizes the products of AVR-Pita1 insi...

  3. Induced mutations to develop sources of resistance to rice blast, Pyricularia grisea Sacc

    International Nuclear Information System (INIS)

    Rice blast caused by Pyricularia grisea is the most important disease limiting yields worldwide. The pathogen has many virulent forms or pathotypes, hence durable blast resistance is lacking. Studies on strategy to develop durable blast resistance based on defining the genetic structure of the population, using DNA-fingerprinting, and virulence diversity are described. This strategy is leading to the identification of resistance genes/sources against all isolates within a genetic family of the pathogen. Combinations of genes showing complementary resistance to different genetic families of the fungus exclude any compatible interaction with a blast isolate. Identification of complementary resistance genes is based on detecting those virulence factors whose combinations in individual isolates within the pathogen population have a frequency near zero. Identifying and combining resistance genes to which combinations of corresponding virulence genes are absent in the pathogen population should confer more durable resistance than that previously obtained. The use of induced mutations in the development of resistance was limited, since in most cases single gene changes were responsible for the induced resistance against all the pathogen population. The main objective here is to develop many mutants, each with a gene resistant to just one or a few families of the blast pathogen; and crossing them can accumulate the different resistance genes. A total of 201 Latin American commercial cultivars, including Cuban, Brazilian and Venezuelan were analyzed with different genetic families of the blast pathogen to identify potential sources of resistance to blast and identify complementary resistance sources. Characterization of the resistance of 37 mutants of the Colombian rice cultivar Oryzica 1 was conducted in collaboration with the INEA in Colombia. Results suggested that mutations for resistance to genetic families to which Oryzica 1 is susceptible were induced, although one

  4. Establishment and Application of a Set of Material System for Studying the Resistance to Blast in Rice

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-fang; LUO Wen-yong; XIAO Xin; MAO Xing-xue; LIU Yan-zhuo

    2003-01-01

    The study used Waixuan35, a blast resistant rice material adopted widely previously in South China, Yuexiangzhan, a rice variety with the largest planting area in Guangdong Province at present and with the characteristics of horizontal blast resistance and high harvest index, and Qisizhan, the earliest good eating quality variety in Guangdong Province as parent materials, and created an important material systems for studying agricultural characters such as rice blast resistance genes, their resistance mechanisms and quality by hybridization offspring single grain transfer method and DNA hybridization method, namely recombination inbred line RIL, extend recombination inbred line ERIL and transferred-mutant recombination inbred line TRIL assemblages. In RIL assemblage, various materials of resistance gene combinations for identifying rice blast pathogen strains had been identified from the material system, providing direct material evidence for gene to gene theory. Using the same control and same method, in ERIL assemblage, it was proved that there were several main resistance genes and several minor resistance genes in horizontal resistant Yuexiangzhan,providing preliminary evidences for multigene control in horizontal resistance. A set of stable material assemblage for studying future horizontal resistance had been created. A mutation material of Yuexiangzhan from horizontal resistance to vertical resistance was obtained by wild rice external DNA electric stimulation introduction, and variation in mutation assemblage was certified by SSLP. These studies and materials provided important new materials for studying rice blast resistance mechanisms, gene cloning, resistance genes especially horizontal resistance.

  5. Resistance to rice blast(Pyricularia oryzae) caused by the expression of trichosanthin gene in transgenic rice plants transferred through agrobacterium method

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The gene of trichosanthin has been transferred into rice plants through agrobacterium method.The single copy insertion and the expression of foreign gene have been proved in regenerated plants.In antifungal assay the degrees of rice blast (Pyricularia oryzae) infection of the transgenic plants expressing trichosanthin and expressing GUS gene as control have been evaluated.The differences such as the time of disease symptom observed,the number of infected plants and damaged leaves,the growth of infected plants of the two transgenic plants after being inoculated by rice blast (Pyricularia oryzae) are significant.The transgenic plants with trichosanthin gene grew faster than the plants with GUS gene,even when humidity environment was removed.The results show that the transgenic plants that expressed trichosanthin are able to delay the infection of rice blast compared with the plants as control.In addition,no damage caused by the expression of trichosanthin gene in transgenic plants has been observed.

  6. Preliminary report on the rice blast resistance of space-induced mutants derived from rice cultivar 'Taihang-68'

    International Nuclear Information System (INIS)

    To screen the blast resistance mutants, the resistance of SP1 progenies derived from rice variety Taihang-68 were evaluated after satellite flight by representative blast isolate GD0193 which had a broad pathogenic spectra, and then primary genetic analysis of resistant mutants and mapping of resistance gene, as well as resistance spectra at seedling and neck blast resistance at maturity were performed. The results showed that space-mutation was effective method to change the blast resistance of Taihang-68. The screened resistant mutants TH1 and TH2 showed that resistance to isolate GD0193 no disjunction and separation respectively, and the resistance separation ratio of TH2 indicated that its resistance was controlled by one pair of major genes, which was preliminary mapped on the long arm of chromosome 11. In blast resistance spectra and neck blast resistance, TH1 and TH2 were both enhanced remarkable compared with the wild-type at seedling and maturity, and their resistance could be inherited, the blast resistance of these two mutants were also increased comparing with several main cultivars in South China. (authors)

  7. Inheritance of blast resistance in rice to two Pyricularia grisea races, IB-1 and IB-9

    Directory of Open Access Journals (Sweden)

    Marta C. de Filippi

    1996-01-01

    Full Text Available Seven sources of resistance to the two predominant races IB-1 and IB-9 of the rice blast pathogen Pyricularia grisea were selected based on leaf blast reaction in tests conducted under controlled greenhouse conditions. Crosses involving resistant and susceptible parents were made to study the inheritance of the disease reaction for different sources of resistance. The F1 and F2 progenies of all crosses, including backcrosses to resistant and susceptible parents, were tested for reaction to leaf blast. The data showed that resistance is controlled by one to three genes that segregate independently in most of the donors. Non-allelic interaction among resistance genes, including dominant epistasis, was identified.

  8. ESTIMATION OF RICE HYBRID LINES WITH BLAST RESISTANCE GENES PI-B, PI-Z AND PI-40 FOR RESISTANCE TO RICE BLAST (PIRYCULARIA ORYZA) ISOLATES, COLLECTED IN THE KRASNODAR TERRITORY Оценка линий риса с генами PI-B, PI-Z и PI-40 на устойчивость к Краснодарской популяции возбудителя пирикуляриоза (pirycularia oryza)

    OpenAIRE

    Suprun I. I.; Kharchenko E. S.; Seraya L. I.; Kovalev V. S.

    2012-01-01

    Estimation of blast resistance of rice breeding lines, carrying resistance genes Pi-b, Pi-z and Pi-40 has been done. For phytopatological test isolates of pathogen from Krasnodar territory were used. As the results of the study Pi-40 gene showed maximal resistance to blast isolates. On the other part, rice line, carrying both genes – Pib and Pi-z showed significantly higher level of resistance with compare to standart variety Khazar

  9. [Genetic studies of blast resistance of indica variety Zhefu 802].

    Science.gov (United States)

    Wang, J L; Lei, C L; Jiang, W R; Ling, Z Z

    2000-01-01

    One indica variety, Zhefu 802, was studied for its inheritance of blast resistance by inoculation of two strains Ken54-04 and 95-t2. The B1F1 and F2 populations from cross of Zhefu 802(R) x Lijiangxintuanheigu (S) and related parents were inoculated by spray inoculation method with the two above mentioned strains to determine R:S ratio of segregating populations of this cross. The results indicated that Zhefu 802 has two dominant resistance genes to strain Ken 54-04. One of the two genes showed resistant reaction and the other is susceptible to strain 95-t2. The allelism test indicated that one gene in Zhefu 802, which showed resistant reaction to strain 95-t2, is allelic to Pi-i gene locus and non-allelic to loci of Pi-a, Pi-sh, Pi-k, Pi-z, Pi-ta, Pi-b, Pi-t. The other gene in this variety was also estimated to be different from all of the known genes. So it may be an unknown gene. But this point needs to be confirmed further. PMID:10887695

  10. Structural and functional analysis of rice blast avirulence gene AVR-Pita1 in Magnaporthe oryzae

    Science.gov (United States)

    The resistance gene Pi-ta in rice has been effectively deployed around the globe to prevent the rice blast disease. It was previously known that Pi-ta interacts with the avirulence gene AVR-Pita1 in the fungus in triggering effective resistance responses. In order to predict the stability of deploy...

  11. Rapid evolution of avirulence genes in rice blast fungus Magnaporthe oryzae

    OpenAIRE

    Huang, Ju; Si, Weina; Deng, Qiming; Li, Ping; Yang, Sihai

    2014-01-01

    Background Rice blast fungus Magnaporthe oryzae is one of the most devastating pathogens in rice. Avirulence genes in this fungus share a gene-for-gene relationship with the resistance genes in its host rice. Although numerous studies have shown that rice blast R-genes are extremely diverse and evolve rapidly in their host populations, little is known about the evolutionary patterns of the Avr-genes in the pathogens. Results Here, six well-characterized Avr-genes and seven randomly selected n...

  12. Selection for blast resistant mutants in radiation irradiated rice populations. Part of a coordinated programme on induced mutations for disease resistance in crop plants

    International Nuclear Information System (INIS)

    A newly released rice variety, Tongil, has many desirable agronomic characters and a particularly high resistance to blast disease. However, it may become susceptible in the future, since a resistant variety released for field planting often encounters the creation of new races of blast fungus. This study was undertaken to identify potential blast-resistant mutants from the population of the irradiated variety, Tongil, by inoculating these materials with induced mutant races of blast fungus which are likely to occur in the future. Blast conidia were irradiated with X-rays and the virulent mutants were identified according to their ability to infect Tongil. Seven blast-resistant mutant lines from the Pungkwang variety, selected through the uplands blast nursery test, were likewise outstanding in resistance in the field compared with the parent. Ten resistant lines from the variety Tongil, identified by artificial inoculation with the mutant race IA-67, were also selected. The results in the study of resistance inheritance showed that blast resistance was conditioned by a single dominant gene and the Tongil variety has three or more resistant genes

  13. Large scale germplasm screening for identification of novel rice blast resistance sources

    OpenAIRE

    Vasudevan, Kumar; Vera Cruz, Casiana M.; Gruissem, Wilhelm; Bhullar, Navreet K

    2014-01-01

    Rice is a major cereal crop that contributes significantly to global food security. Biotic stresses, including the rice blast fungus, cause severe yield losses that significantly impair rice production worldwide. The rapid genetic evolution of the fungus often overcomes the resistance conferred by major genes after a few years of intensive agricultural use. Therefore, resistance breeding requires continuous efforts of enriching the reservoir of resistance genes/alleles to effectively tackle t...

  14. Blast resistance of CC-NB-LRR protein Pb1 is mediated by WRKY45 through protein–protein interaction

    OpenAIRE

    Inoue, Haruhiko; Hayashi, Nagao; Matsushita, Akane; Xinqiong, Liu; Nakayama, Akira; Sugano, Shoji; Jiang, Chang-Jie; Takatsuji, Hiroshi

    2013-01-01

    Panicle blast 1 (Pb1) is a panicle blast resistance gene derived from the indica rice cultivar “Modan.” Pb1 encodes a coiled-coil–nucleotide-binding site–leucine-rich repeat (CC-NB-LRR) protein and confers durable, broad-spectrum resistance to Magnaporthe oryzae races. Here, we investigated the molecular mechanisms underlying Pb1-mediated blast resistance. The Pb1 protein interacted with WRKY45, a transcription factor involved in induced resistance via the salicylic acid signaling pathway tha...

  15. Dissection of the genetic architecture of rice resistance to the blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Kang, Houxiang; Wang, Yue; Peng, Shasha; Zhang, Yanli; Xiao, Yinghui; Wang, Dan; Qu, Shaohong; Li, Zhiqiang; Yan, Shuangyong; Wang, Zhilong; Liu, Wende; Ning, Yuese; Korniliev, Pavel; Leung, Hei; Mezey, Jason; McCouch, Susan R; Wang, Guo-Liang

    2016-08-01

    Resistance in rice cultivars to the rice blast fungus Magnaporthe oryzae is complex and is controlled by both major genes and quantitative trait loci (QTLs). We undertook a genome-wide association study (GWAS) using the rice diversity panel 1 (RDP1) that was genotyped using a high-density (700 000 single nucleotide polymorphisms) array and inoculated with five diverse M. oryzae isolates. We identified 97 loci associated with blast resistance (LABRs). Among them, 82 were new regions and 15 co-localized with known blast resistance loci. The top 72 LABRs explained up to 98% of the phenotypic variation. The candidate genes in the LABRs encode nucleotide-binding site leucine-rich repeat (NBS-LRR) resistance proteins, receptor-like protein kinases, transcription factors and defence-related proteins. Among them, LABR_64 was strongly associated with resistance to all five isolates. We analysed the function of candidate genes underlying LABR_64 using RNA interference (RNAi) technology and identified two new resistance alleles at the Pi5 locus. We demonstrate an efficient strategy for rapid allele discovery using the power of GWAS, coupled with RNAi technology, for the dissection of complex blast resistance in rice. PMID:26574735

  16. Development of transgenic finger millet (Eleusine coracana (L.) Gaertn.) resistant to leaf blast disease

    Indian Academy of Sciences (India)

    S Ignacimuthu; S Antony Ceasar

    2012-03-01

    Finger millet plants conferring resistance to leaf blast disease have been developed by inserting a rice chitinase (chi11) gene through Agrobacterium-mediated transformation. Plasmid pHyg-Chi.11 harbouring the rice chitinase gene under the control of maize ubiquitin promoter was introduced into finger millet using Agrobacterium strain LBA4404 (pSB1). Transformed plants were selected and regenerated on hygromycin-supplemented medium. Transient expression of transgene was confirmed by GUS histochemical staining. The incorporation of rice chitinase gene in R0 and R1 progenies was confirmed by PCR and Southern blot analyses. Expression of chitinase gene in finger millet was confirmed by Western blot analysis with a barley chitinase antibody. A leaf blast assay was also performed by challenging the transgenic plants with spores of Pyricularia grisea. The frequency of transient expression was 16.3% to 19.3%. Stable frequency was 3.5% to 3.9%. Southern blot analysis confirmed the integration of 3.1 kb chitinase gene. Western blot analysis detected the presence of 35 kDa chitinase enzyme. Chitinase activity ranged from 19.4 to 24.8. In segregation analysis, the transgenic R1 lines produced three resistant and one sensitive for hygromycin, confirming the normal Mendelian pattern of transgene segregation. Transgenic plants showed high level of resistance to leaf blast disease compared to control plants. This is the first study reporting the introduction of rice chitinase gene into finger millet for leaf blast resistance.

  17. Molecular Breeding Strategy and Challenges Towards Improvement of Blast Disease Resistance in Rice Crop.

    Science.gov (United States)

    Ashkani, Sadegh; Rafii, Mohd Y; Shabanimofrad, Mahmoodreza; Miah, Gous; Sahebi, Mahbod; Azizi, Parisa; Tanweer, Fatah A; Akhtar, Mohd Sayeed; Nasehi, Abbas

    2015-01-01

    Rice is a staple and most important security food crop consumed by almost half of the world's population. More rice production is needed due to the rapid population growth in the world. Rice blast caused by the fungus, Magnaporthe oryzae is one of the most destructive diseases of this crop in different part of the world. Breakdown of blast resistance is the major cause of yield instability in several rice growing areas. There is a need to develop strategies providing long-lasting disease resistance against a broad spectrum of pathogens, giving protection for a long time over a broad geographic area, promising for sustainable rice production in the future. So far, molecular breeding approaches involving DNA markers, such as QTL mapping, marker-aided selection, gene pyramiding, allele mining and genetic transformation have been used to develop new resistant rice cultivars. Such techniques now are used as a low-cost, high-throughput alternative to conventional methods allowing rapid introgression of disease resistance genes into susceptible varieties as well as the incorporation of multiple genes into individual lines for more durable blast resistance. The paper briefly reviewed the progress of studies on this aspect to provide the interest information for rice disease resistance breeding. This review includes examples of how advanced molecular method have been used in breeding programs for improving blast resistance. New information and knowledge gained from previous research on the recent strategy and challenges towards improvement of blast disease such as pyramiding disease resistance gene for creating new rice varieties with high resistance against multiple diseases will undoubtedly provide new insights into the rice disease control. PMID:26635817

  18. Molecular Breeding Strategy and Challenges toward Improvement of Blast Disease Resistance in Rice Crops

    Directory of Open Access Journals (Sweden)

    Sadegh eAshkani

    2015-11-01

    Full Text Available Rice is a staple and most important security food crop consumed by almost half of the world’s population. More rice production is needed due to the rapid population growth in the world. Rice blast caused by the fungus, Magnaporthe oryzae is one of the most destructive diseases of this crop in different part of the world. Breakdown of blast resistance is the major cause of yield instability in several rice growing areas. There is a need to develop strategies providing long-lasting disease resistance against a broad spectrum of pathogens, giving protection for a long time over a broad geographic area, promising for sustainable rice production in the future. So far, molecular breeding approaches involving DNA markers, such as QTL mapping, marker-aided selection, gene pyramiding, allele mining and genetic transformation have been used to develop new resistant rice cultivars. Such techniques now are used as a low-cost, high-throughput alternative to conventional methods allowing rapid introgression of disease resistance genes into susceptible varieties as well as the incorporation of multiple genes into individual lines for more durable blast resistance. The paper briefly reviewed the progress of studies on this aspect to provide the interest information for rice disease resistance breeding. This review includes examples of how advanced molecular method have been used in breeding programs for improve blast resistance. New information and knowledge gained from previous research on the recent strategy and challenges toward improvement of blast disease such as pyramiding disease resistance gene for creating new rice varieties with high resistance against multiple diseases will undoubtedly provide new insights into the rice disease control.

  19. Biochemical Characterization of Rice Somaclones Resistant to Blast

    OpenAIRE

    Antar N. El-Banna; Ismael A. Khatab

    2012-01-01

    The aim of the present study was to produce rice somaclones resistant to P. oryza that could be useful to improve rice plants against blast disease and use them in the future breeding programs. In addition, to detect biochemical changes among somaclones and their original cultivars. Mature embryo-derived calli of the three susceptible rice varieties, Sakha 101, Sakha 104 and Riho were stressed with different concentrations of fungal toxin filtrate. Blast-resistant lines of rice were developed...

  20. Blast resistance of space-induced variants derived from rice cultivar Hanghui 7

    International Nuclear Information System (INIS)

    To screen the resistance lines to rice blast, the blast resistance of SP3 and SP4 progenies derived from rice variety Hanghui 7 were evaluated after satellite flight, and the genomic DNA polymorphism of the resistant variants selected from SP3 was compared with the wild type by microsatellite markers. The results indicated that the SP3 Variant line H24, which was selected from the 250 space-induced lines ( SP3) with excellent agronomic and economical characters, showed resistance segregation (119R : 108S) against blast isolate GD3286. It was demonstrated that the resistance of H24 might be controlled by two dominant and complementary resistance genes. The resistance of H24 was still segregated in SP4, but the resistance spectrum of H24 was 84. 4% in SP5, much higher than the wild type, 40. 6%, and H24 especially showed resistant against some blast isolates of broad pathogenic spectrum or specialized pathogenicity; further more, the DNA polymorphism wasn't detected between H24 and its wild type by 229 SSR (simple sequence repeat) markers covering the rice genome equally. (authors)

  1. Identification and QTL mapping of blast resistance in wild Oryza species

    Science.gov (United States)

    Leaf blast disease of rice (Oryza sativa L.) caused by Magnaporthe oryzae B. Couch is one of the most devastating rice fungal diseases worldwide. Wild relatives of rice (Oryza spp.) may contain novel genes for biotic and abiotic stress resistance lost during domestication. A collection of 67 wild ...

  2. Chloroplast-Expressed MSI-99 in Tobacco Improves Disease Resistance and Displays Inhibitory Effect against Rice Blast Fungus

    OpenAIRE

    Yun-Peng Wang; Zheng-Yi Wei; Yu-Ying Zhang; Chun-Jing Lin; Xiao-Fang Zhong; Yue-Lin Wang; Jing-Yong Ma; Jian Ma; Shao-Chen Xing

    2015-01-01

    Rice blast is a major destructive fungal disease that poses a serious threat to rice production and the improvement of blast resistance is critical to rice breeding. The antimicrobial peptide MSI-99 has been suggested as an antimicrobial peptide conferring resistance to bacterial and fungal diseases. Here, a vector harboring the MSI-99 gene was constructed and introduced into the tobacco chloroplast genome via particle bombardment. Transformed plants were obtained and verified to be homoplast...

  3. Study on Blast Pressure Resistance of Foamed Concrete Material

    Directory of Open Access Journals (Sweden)

    A.M. Ahmad Zaidi

    2009-12-01

    Full Text Available Great demand exist for more efficient design to protect personals and critical components against explosion or blast wave, generated both accidentally and deliberately, in various blast scenarios in both civilian and military activities. Concrete is a common material used in protective design of structures. Recently, the demands on producing the lighter concrete material have become interest in concrete research. Foamed concrete is a possible alternative of lightweight concrete for producing intermediate strength capabilities with excellent thermal insulation, freeze-thaw resistance, high-impact resistance and good shock absorption. This paper explores the role and development of Blast Pressure Resistant Materials (BPRM’s on foamed concrete. The explosive tests were conducted to determine the blast mitigating properties. The results show that when the foamed concrete density is increases the blast energy absorption capability will be decreases due to reduce of cavity volume. This is suggested that cavity plays an important role to dissipate and absorb the shock energy of the blast.

  4. Screening and breeding of rice-blast resistant mutant variety

    International Nuclear Information System (INIS)

    A rice variety, Shengxianggeng No.4 bred with irradiation of soft X-rays was characterized by short stem, high yield, good quality with special scent and high resistance to rice blast. This new variety showed a high resistance to 87 tested pathogen strains

  5. New insight for two major rice blast R genes: Pi-ta and Pi-km

    Science.gov (United States)

    In rice breeding programs across the world, the introgression of major resistance (R) genes remains the most cost-effective method to control blast epidemics caused by the fungal pathogen Magnaporthe oryzae. During the last two years, we have examined two loci, on chromosome 12 and 11, which harbor ...

  6. Genome-Wide Association of Rice Blast Disease Resistance and Yield-Related Components of Rice.

    Science.gov (United States)

    Wang, Xueyan; Jia, Melissa H; Ghai, Pooja; Lee, Fleet N; Jia, Yulin

    2015-12-01

    Robust disease resistance may require an expenditure of energy that may limit crop yield potential. In the present study, a subset of a United States Department of Agriculture rice core collection consisting of 151 accessions was selected using a major blast resistance (R) gene, Pi-ta, marker and was genotyped with 156 simple sequence repeat (SSR) markers. Disease reactions to Magnaporthe oryzae, the causal agent of rice blast disease, were evaluated under greenhouse and field conditions, and heading date, plant height, paddy and brown seed weight in two field environments were analyzed, using an association mapping approach. A total of 21 SSR markers distributed among rice chromosomes 2 to 12 were associated with blast resistance, and 16 SSR markers were associated with seed weight, heading date, and plant height. Most noticeably, shorter plants were significantly correlated with resistance to blast, rice genomes with Pi-ta were associated with lighter seed weights, and the susceptible alleles of RM171 and RM6544 were associated with heavier seed weight. These findings unraveled a complex relationship between disease resistance and yield-related components. PMID:26284908

  7. Molecular progress on the mapping and cloning of functional genes for blast disease in rice (Oryza sativa L.): current status and future considerations.

    Science.gov (United States)

    Ashkani, S; Rafii, M Y; Shabanimofrad, M; Ghasemzadeh, A; Ravanfar, S A; Latif, M A

    2016-01-01

    Rice blast disease, which is caused by the fungal pathogen Magnaporthe oryzae, is a recurring problem in all rice-growing regions of the world. The use of resistance (R) genes in rice improvement breeding programmes has been considered to be one of the best options for crop protection and blast management. Alternatively, quantitative resistance conferred by quantitative trait loci (QTLs) is also a valuable resource for the improvement of rice disease resistance. In the past, intensive efforts have been made to identify major R-genes as well as QTLs for blast disease using molecular techniques. A review of bibliographic references shows over 100 blast resistance genes and a larger number of QTLs (∼500) that were mapped to the rice genome. Of the blast resistance genes, identified in different genotypes of rice, ∼22 have been cloned and characterized at the molecular level. In this review, we have summarized the reported rice blast resistance genes and QTLs for utilization in future molecular breeding programmes to introgress high-degree resistance or to pyramid R-genes in commercial cultivars that are susceptible to M. oryzae. The goal of this review is to provide an overview of the significant studies in order to update our understanding of the molecular progress on rice and M. oryzae. This information will assist rice breeders to improve the resistance to rice blast using marker-assisted selection which continues to be a priority for rice-breeding programmes. PMID:25394538

  8. Studies on induced resistance to blast in rice

    International Nuclear Information System (INIS)

    Eleven rice varieties were treated with 60Co gamma ray, laser and other mutagens. 154 mutants with different characters were developed. 154 mutants and their parents have been inoculated with blast (Piricularia oryzae) races. It was found that the mutants of disease-resistance could be produced. The disease-resistant mutants with various better cheracters were selected. The frequencies of mutation in disease-resistance are different with different parental varieties. After inoculation with 13 blast physiological races, the results showed that the spectrum of resistance of mutants, other characters were changed, when one character was changed. In order to get a veriety with higher yield and disease-resistance, it is important to take account of other economic charaters

  9. Inheritance patterns and identification of microsatellite markers linked to the rice blast resistance in BC2F1 population of rice breeding

    Directory of Open Access Journals (Sweden)

    Gous Miah

    2015-03-01

    Full Text Available The BC2F1 population was derived from a cross between rice variety, MR219 (susceptible to blast and Pongsu Seribu 1 (resistant to blast. The objectives of this research were to know the inheritance pattern of blast resistance and to identify the linked markers associated with blast resistance in BC2F1 population. Sixteen microsatellite markers were found as polymorphic between the parents related to blast resistant genes (Pi-genes. Among the selected blast resistant linked markers, two markers RM6836 and RM8225 showed expected testcross ratio (1:1 for single-gene model in the BC2F1 population with the association between resistant and susceptible progeny. A total of 333-BC2F1 plants were challenged with the most virulent pathotype P7.2 of Magnaporthe oryzae. Chi-square (χ2 analysis for phenotypic segregation in single-gene model showed goodness of fit (P = 0.4463 to the expected segregation ratio (1:1. In marker segregation analysis, two polymorphic markers (RM6836 and RM8225 clearly showed goodness of fit to the expected segregation testcross ratio (1:1 for the single-gene model. The marker RM8225 and RM6836 showed significant R2 values higher than 10 for the trait of the blast lesions degree (BLD. The positions of RM6836 and RM8225 markers on rice chromosome 6 and the distance between these two markers is 0.2 cM. We conclude that single dominant gene control the blast resistance in Pongsu Seribu 1 located on chromosome 6, which is linked to RM8225 and RM6836 microsatellite markers. This information could be useful in marker-assisted selection for blast resistance in rice breeding involving Pongsu Seribu 1.

  10. TNO-PML developments of blast resistant doors and walls

    NARCIS (Netherlands)

    Erkel, A.G.; Luyten, J.M.; Galle, L.F.

    2002-01-01

    This paper will address the ongoing developments on blast resistant light or moderate weight steel structures at the Prins Maurits Laboratory of the Netherlands Organisation for Applied Scientific Research (TNO-PML) for the Royal Netherlands Navy (RNLN) and other parties. Five structural products wi

  11. Blast-Resistant Improvement of Sandwich Armor Structure with Aluminum Foam Composite

    OpenAIRE

    Shu Yang; Chang Qi

    2013-01-01

    Sandwich armor structures with aluminum foam can be utilized to protect a military vehicle from harmful blast load such as a landmine explosion. In this paper, a system-level dynamic finite element model is developed to simulate the blast event and to evaluate the blast-resistant performance of the sandwich armor structure. It is found that a sandwich armor structure with only aluminum foam is capable of mitigating crew injuries under a moderate blast load. However, a severe blast load causes...

  12. Impact and Blast Resistance of Sandwich Plates

    Science.gov (United States)

    Dvorak, George J.; Bahei-El-Din, Yehia A.; Suvorov, Alexander P.

    Response of conventional and modified sandwich plate designs is examined under static load, impact by a rigid cylindrical or flat indenter, and during and after an exponential pressure impulse lasting for 0.05 ms, at peak pressure of 100 MPa, simulating a nearby explosion. The conventional sandwich design consists of thin outer (loaded side) and inner facesheets made of carbon/epoxy fibrous laminates, separated by a thick layer of structural foam core. In the three modified designs, one or two thin ductile interlayers are inserted between the outer facesheet and the foam core. Materials selected for the interlayers are a hyperelas-tic rate-independent polyurethane;a compression strain and strain rate dependent, elastic-plastic polyurea;and an elastomeric foam. ABAQUS and LS-Dyna software were used in various response simulations. Performance comparisons between the enhanced and conventional designs show that the modified designs provide much better protection against different damage modes under both load regimes. After impact, local facesheet deflection, core compression, and energy release rate of delamination cracks, which may extend on hidden interfaces between facesheet and core, are all reduced. Under blast or impulse loads, reductions have been observed in the extent of core crushing, facesheet delaminations and vibration amplitudes, and in overall deflections. Similar reductions were found in the kinetic energy and in the stored and dissipated strain energy. Although strain rates as high as 10-4/s1 are produced by the blast pressure, peak strains in the interlayers were too low to raise the flow stress in the polyurea to that in the polyurethane, where a possible rate-dependent response was neglected. Therefore, stiff polyurethane or hard rubber interlayers materials should be used for protection of sandwich plate foam cores against both impact and blast-induced damage.

  13. OsGF14e positively regulates panicle blast resistance in rice.

    Science.gov (United States)

    Liu, Qing; Yang, Jianyuan; Zhang, Shaohong; Zhao, Junliang; Feng, Aiqing; Yang, Tifeng; Wang, Xiaofei; Mao, Xingxue; Dong, Jingfang; Zhu, Xiaoyuan; Leung, Hei; Leach, Jan E; Liu, Bin

    2016-02-26

    Though GF14e has been reported to negatively regulate bacterial blight and sheath blight resistance in rice, its effect on panicle blast, the most destructive disease in rice is still unknown. In the present study, we identified that GF14e was highly expressed in panicles and was induced in panicles infected by blast pathogen. Overexpression of GF14e enhances resistance to panicle blast whereas silencing GF14e results in increased susceptibility to panicle blast, suggesting that GF14e plays a positive role in quantitative panicle blast resistance in rice. Our results also demonstrate that GF14e is regulated by WRKY71 and GF14e-mediated panicle blast resistance is related to activation of SA-dependent pathway and suppression of JA-dependent pathway. The functional confirmation of GF14e in panicle blast resistance makes it to be a promising target in molecular rice breeding. PMID:26851365

  14. 分子标记辅助选择Pi25基因选育抗稻瘟病三系不育系%Breeding Blast-resistant Male Sterile Line of Three Line Hybrid Rice by Pi25 Gene Marker Assisted Selection

    Institute of Scientific and Technical Information of China (English)

    涂诗航; 周鹏; 郑轶; 董瑞霞; 张水金; 黄庭旭; 郑家团

    2015-01-01

    稻瘟病是水稻最具毁灭性的病害之一,选育抗稻瘟病三系不育系,是选育抗稻瘟病品种的有效途径之一。本研究以携带抗稻瘟病基因Pi25的材料BL47为抗性供体亲本、福稻B为受体亲本,利用分子标记辅助选择技术和常规育种方法,从F2代起利用分子标记Si13070C检测Pi25基因,从F3代起结合稻瘟病重发病区苗瘟鉴定,从BC1代起对不育系植株进行花粉育性鉴定,筛选出5份具有中抗以上水平的候选不育系,其中不育系CP4A具有良好的不育性和开花习性,所配组合表现出良好的农艺性状。结果表明,利用分子标记Si13070C检测Pi25基因并结合田间苗瘟鉴定在选育抗性育种材料上是有效的。%The rice blast was known as one of the most crushing diseases in rice production. One of effective ways to develop blast-resistant hybrid rice combination should be through breeding blast-resistant sterile line. In this study, five rice candidate sterile lines that have resistance or moderate resistance to rice blast were selected through the approaches of marker assisted selection and conventional breeding methods by using BL-47 as the donor parent that carries rice blast resistant gene Pi25 and Fudao B as the receptor parent. From the beginning of F2, molecular marker Si13070C was used to detect gene Pi25;while from the beginning of F3, we began to identify seedling blast in rice blast endemic area, and from the beginning of BC1 we set about identifying pollen fertility of sterile line plants. Stigma exsertion rate of these candidate sterile lines was investigated. The results indicated that CP4A should be highly stable in sterility and own good flowering characteristics. And the hybrids derived from CP4A displayed elite agronomic characters. In conclusion, it would be an effective breeding process to develop blast-resistant materials by using molecular marker Si13070C to detect gene Pi25 and combined with identifying

  15. Development of blast resistant somaclones of the upland rice cultivar araguaia

    OpenAIRE

    ARAÚJO LEILA GARCÊS DE; PRABHU ANNE SITARAMA; FREIRE ADELSON DE BARROS

    2000-01-01

    The degree of blast resistance of upland rice (Oryza sativa L.) cultivar Araguaia has decreased over time causing significant yield losses. The major objective of this study was to obtain blast (Pyricularia grisea) resistant somaclones, adapting greenhouse and field selection procedures. Rice blast resistance and agronomic traits were assessed in R2 to R6 generations derived from regenerant plants (R1) from immature panicles of Araguaia. The evaluation and selection procedures include testing...

  16. Blast resistance of cracked steel structures repaired with CFRP composite patch

    OpenAIRE

    Pereira, João M.; Ghasemnejad, H.; Wen, J. X.; Lourenço, Paulo B.; Tam, V. H. Y.

    2010-01-01

    In this paper the blast resistance of cracked steel structures repaired with fibre-reinforced polymer (FRP) composite patch are investigated. The switch box which has been subjected to blast loading is chosen for a detailed study. For impulsively loaded structures, the structural damage and response depends on the impulse rather than the pressure pulse. In this regard, the blast wave is modelled as a uniform rectangular pressure pulse distributed over the sides of the switch box. The blast be...

  17. Study on the induction and selection of rice mutant R917 for blast disease (Piricularia oryzae) resistance

    International Nuclear Information System (INIS)

    Rice F0 seeds were treated with 10 krad of 60Co γ-rays, and blast resistance mutant R917 was selected in the following generations. The blast resistance was tested by inoculating the mutant with 138 strains of Piricularia oryzae artificially from nine blast regions in Zhejiang Province, scale of blast resistance was only 0.89 and 1.0 in 1991 and 1992 respectively. The rice mutant R917 was resistant to 136 blast fungus strains. The rate of blast resistance for R917 was higher than that of its parents. The mutant is likely to be used in rice breeding for variety improvement

  18. Erosion-Resistant Water-Blast Nozzle

    Science.gov (United States)

    Roberts, Marion L.; Rice, R. M.; Cosby, S. A.

    1988-01-01

    Design of nozzle reduces erosion of orifice by turbulent high-pressure water flowing through it. Improved performance and resistance to erosion achieved by giving interior nozzle surface long, gradual convergence before exit orifice abrupt divergence after orifice and by machining surface to smooth finish.

  19. RICE PI-TA GENE IS CLOSELY LINKED WITH RESISTANCE TO THE MAJOR PATHOTYPES OF THE RICE BLAST FUNGUS IN THE U.S.

    Science.gov (United States)

    The Pi-ta gene, allelic to Pi-ta2, in rice is effective in preventing the infection of Magnaporthe grisea isolates containing the corresponding avirulence gene AVR-Pita. Pi-ta encodes a putative cytoplasmic receptor that appears to bind to a predicted processed AVR-Pita to elicit a defense response...

  20. Structural and functional analysis of the avirulence gene AVR-Pita1 of the rice blast fungus in isolates of Magnaporthe oryzae worldwide

    Science.gov (United States)

    The avirulence gene AVR-Pita1 of the rice blast fungus triggers race-specific resistance when races of Magnaporthe oryzae that contain AVR-Pita1 infect rice cultivars that contain the resistance gene Pi-ta. In the present study, a panel of 221 isolates from the US, China, Colombia, Egypt, India and ...

  1. Differential Gene Expression Reflects Morphological Characteristics and Physiological Processes in Rice Immunity against Blast Pathogen Magnaporthe oryzae.

    Science.gov (United States)

    Azizi, Parisa; Rafii, Mohd Y; Mahmood, Maziah; Abdullah, Siti N A; Hanafi, Mohamed M; Nejat, Naghmeh; Latif, Muhammad A; Sahebi, Mahbod

    2015-01-01

    The rice blast fungus Magnaporthe oryzae is a serious pathogen that jeopardises the world's most important food-security crop. Ten common Malaysian rice varieties were examined for their morphological, physiological and genomic responses to this rice blast pathogen. qPCR quantification was used to assess the growth of the pathogen population in resistant and susceptible rice varieties. The chlorophyll content and photosynthesis were also measured to further understand the disruptive effects that M. oryzae has on infected plants of these varieties. Real-time PCR was used to explore the differential expression of eight blast resistance genes among the ten local varieties. Blast disease has destructive effects on the growth of rice, and the findings of our study provide evidence that the Pikh, Pi9, Pi21, and Osw45 genes are involved in defence responses in the leaves of Malaysian rice at 31 h after inoculation with M. oryzae pathotype P7.2. Both the chlorophyll content and photosynthesis were reduced, but the levels of Pikh gene expression remained constant in susceptible varieties, with a developed pathogen population and mild or severe symptoms. The Pi9, Pi21, and Osw45 genes, however, were simultaneously upregulated in infected rice plants. Therefore, the presence of the Pikh, Pi9, Pi21, and Osw45 genes in the germplasm is useful for improving the resistance of rice varieties. PMID:26001124

  2. Inheritance of blast resistance in rice to two Pyricularia grisea races, IB-1 and IB-9

    OpenAIRE

    MARTA C. FILIPPI; Prabhu, A.S.

    1996-01-01

    Seven sources of resistance to the two predominant races IB-1 and IB-9 of the rice blast pathogen Pyricularia grisea were selected based on leaf blast reaction in tests conducted under controlled greenhouse conditions. Crosses involving resistant and susceptible parents were made to study the inheritance of the disease reaction for different sources of resistance. The F1 and F2 progenies of all crosses, including backcrosses to resistant and susceptible parents, were tested for reaction to le...

  3. Inheritance of Blast Resistance (Pyricularia grisea Sacc.) on Interspecific Crossing between IR64 and Oryza rufipogon Griff

    OpenAIRE

    DWINITA WIKAN UTAMI; HAJRIAL ASWIDINNOOR; SUGIONO MOELJOPAWIRO; IDA HANARIDA; REFLINUR

    2006-01-01

    Blast disease affected by Pyricularia grisea causes high percentage of yield losses in rice production. The improvement of durable Blast resistance is difficult due to the complexity of the inheritance of this trait. This study was conducted to evaluate the genetic control and inheritance of Blast resistance trait in interspesific population between IR 64 (accepted Indonesian rice type, medium resistant to Indonesian Blast pathogen) and Oryza rufipogon (AA genome; acc. No.IRGC#105491; donor f...

  4. Blast-Resistant Improvement of Sandwich Armor Structure with Aluminum Foam Composite

    Directory of Open Access Journals (Sweden)

    Shu Yang

    2013-01-01

    Full Text Available Sandwich armor structures with aluminum foam can be utilized to protect a military vehicle from harmful blast load such as a landmine explosion. In this paper, a system-level dynamic finite element model is developed to simulate the blast event and to evaluate the blast-resistant performance of the sandwich armor structure. It is found that a sandwich armor structure with only aluminum foam is capable of mitigating crew injuries under a moderate blast load. However, a severe blast load causes force enhancement and results in much worse crew injury. An isolating layer between the aluminum foam and the vehicle floor is introduced to remediate this drawback. The results show that the blast-resistant capability of the innovative sandwich armor structure with the isolating layer increases remarkably.

  5. Enhancing blast disease resistance by overexpression of the calcium-dependent protein kinase OsCPK4 in rice.

    Science.gov (United States)

    Bundó, Mireia; Coca, María

    2016-06-01

    Rice is the most important staple food for more than half of the human population, and blast disease is the most serious disease affecting global rice production. In this work, the isoform OsCPK4 of the rice calcium-dependent protein kinase family is reported as a regulator of rice immunity to blast fungal infection. It shows that overexpression of OsCPK4 gene in rice plants enhances resistance to blast disease by preventing fungal penetration. The constitutive accumulation of OsCPK4 protein prepares rice plants for a rapid and potentiated defence response, including the production of reactive oxygen species, callose deposition and defence gene expression. OsCPK4 overexpression leads also to constitutive increased content of the glycosylated salicylic acid hormone in leaves without compromising rice yield. Given that OsCPK4 overexpression was known to confer also salt and drought tolerance in rice, the results reported in this article demonstrate that OsCPK4 acts as a convergence component that positively modulates both biotic and abiotic signalling pathways. Altogether, our findings indicate that OsCPK4 is a potential molecular target to improve not only abiotic stress tolerance, but also blast disease resistance of rice crops. PMID:26578239

  6. Transcriptional Profiling of Rice Early Response to Magnaporthe oryzae Identified OsWRKYs as Important Regulators in Rice Blast Resistance

    OpenAIRE

    WEI, Tong; Ou, Bin; Li, Jinbin; Zhao, Yang; Guo, Dongshu; Zhu, Youyong; Chen, Zhangliang; Gu, Hongya; Li, Chengyun; Qin, Genji; Qu, Li-Jia

    2013-01-01

    Rice blast disease is a major threat to rice production worldwide, but the mechanisms underlying rice resistance to the causal agent Magnaporthe oryzae remain elusive. Therefore, we carried out a transcriptome study on rice early defense response to M. oryzae. We found that the transcriptional profiles of rice compatible and incompatible interactions with M. oryzae were mostly similar, with genes regulated more prominently in the incompatible interactions. The functional analysis showed that ...

  7. Chloroplast-Expressed MSI-99 in Tobacco Improves Disease Resistance and Displays Inhibitory Effect against Rice Blast Fungus

    Directory of Open Access Journals (Sweden)

    Yun-Peng Wang

    2015-03-01

    Full Text Available Rice blast is a major destructive fungal disease that poses a serious threat to rice production and the improvement of blast resistance is critical to rice breeding. The antimicrobial peptide MSI-99 has been suggested as an antimicrobial peptide conferring resistance to bacterial and fungal diseases. Here, a vector harboring the MSI-99 gene was constructed and introduced into the tobacco chloroplast genome via particle bombardment. Transformed plants were obtained and verified to be homoplastomic by PCR and Southern hybridization. In planta assays demonstrated that the transgenic tobacco plants displayed an enhanced resistance to the fungal disease. The evaluation of the antimicrobial activity revealed that the crude protein extracts from the transgenic plants manifested an antimicrobial activity against E. coli, even after incubation at 120 °C for 20 min, indicating significant heat stability of MSI-99. More importantly, the MSI-99-containing protein extracts were firstly proved in vitro and in vivo to display significant suppressive effects on two rice blast isolates. These findings provide a strong basis for the development of new biopesticides to combat rice blast.

  8. Wheat Blast and Fusarium Head Blight Display Contrasting Interaction Patterns on Ears of Wheat Genotypes Differing in Resistance.

    Science.gov (United States)

    Ha, Xia; Koopmann, Birger; von Tiedemann, Andreas

    2016-03-01

    The interaction of wheat with two ear pathogens, Magnaporthe wheat blast (MWB) and Fusarium graminearum (Fusarium head blight, FHB), was studied on the phenotypic, histological, and gene expression level. Most of the 27 wheat cultivars inoculated with MWB and F. graminearum displayed inverse disease responses to blast and FHB infection. Two cultivars, Milan and Sumai 3, were selected expressing converse disease phenotypes to blast (Milan, R)/(Sumai 3, S) and FHB (Milan, S)/(Sumai 3, R). Confocal laser scanning microscopy revealed early (12 h postinoculation) colonization of the spikelets by MWB similarly on both cultivars, while F. graminearum infected anthers of the susceptible cultivar earlier. Both pathogens grew much faster in the rachilla of susceptible than resistant cultivars, indicating that resistance is mainly expressed in this part connecting the spikelet with the rachis. In general, O2(-) and H2O2 levels were unrelated to disease expression in the four studied interactions. The differential disease phenotypes, fungal spread in the rachis, and colonization patterns in the spikelets were confirmed by distinct gene expression patterns. Among the eight genes analyzed, seven were more strongly induced by FHB than by blast. Genes for chitinase (Chi2), β-1,3-glucanase (PR2), a plant defensin homolog (PRPI), and peroxidase (Pox2) were strongly upregulated in Milan in response to both pathogens, while PR2 and PR5 (thaumatin-like protein) were transiently triggered by MWB on both cultivars. Upregulation of cinnamoyl-CoA reductase (CCR), cytochrome P450 (CYP709C1), and UDP-glycosyl transferase (UGT) were more prominent in ears infected with F. graminearum, while upregulation of UGT was higher in Sumai 3 when infected with either pathogen. Cultivar resistance to FHB was reflected by clearly higher expression levels of UGT and CYP709C1 in Sumai 3. The differential responses of wheat to the two ear pathogens demonstrated in this study makes it unlikely that common

  9. Tracing QTLs for Leaf Blast Resistance and Agronomic Performance of Finger Millet (Eleusine coracana (L.) Gaertn.) Genotypes through Association Mapping and in silico Comparative Genomics Analyses

    Science.gov (United States)

    Ramakrishnan, M.; Antony Ceasar, S.; Duraipandiyan, V.; Vinod, K. K.; Kalpana, Krishnan; Al-Dhabi, N. A.; Ignacimuthu, S.

    2016-01-01

    Finger millet is one of the small millets with high nutritive value. This crop is vulnerable to blast disease caused by Pyricularia grisea, which occurs annually during rainy and winter seasons. Leaf blast occurs at early crop stage and is highly damaging. Mapping of resistance genes and other quantitative trait loci (QTLs) for agronomic performance can be of great use for improving finger millet genotypes. Evaluation of one hundred and twenty-eight finger millet genotypes in natural field conditions revealed that leaf blast caused severe setback on agronomic performance for susceptible genotypes, most significant traits being plant height and root length. Plant height was reduced under disease severity while root length was increased. Among the genotypes, IE4795 showed superior response in terms of both disease resistance and better agronomic performance. A total of seven unambiguous QTLs were found to be associated with various agronomic traits including leaf blast resistance by association mapping analysis. The markers, UGEP101 and UGEP95, were strongly associated with blast resistance. UGEP98 was associated with tiller number and UGEP9 was associated with root length and seed yield. Cross species validation of markers revealed that 12 candidate genes were associated with 8 QTLs in the genomes of grass species such as rice, foxtail millet, maize, Brachypodium stacei, B. distachyon, Panicum hallii and switchgrass. Several candidate genes were found proximal to orthologous sequences of the identified QTLs such as 1,4-β-glucanase for leaf blast resistance, cytokinin dehydrogenase (CKX) for tiller production, calmodulin (CaM) binding protein for seed yield and pectin methylesterase inhibitor (PMEI) for root growth and development. Most of these QTLs and their putatively associated candidate genes are reported for first time in finger millet. On validation, these novel QTLs may be utilized in future for marker assisted breeding for the development of fungal

  10. Determination of resistance spectra of the Pi-ta and Pi-k genes to US races of Magnaporthe oryzae causing rice blast in a recombinant inbred line population

    Science.gov (United States)

    Resistance (R) genes to ten common races of Magnaporthe oryzae were mapped using an F10 recombinant inbred line population of a cross of a tropical japonica cultivar Katy with a breeding line RU9101001. Katy was found to confer resistance to all common races IA-45, IB-1, IB-45, IB-49, IB-54, IC-17,...

  11. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Mahadtanapuk, S. [School of Agriculture and Natural Resources, University of Phayao, Phayao 56000 (Thailand); Teraarusiri, W. [Central Laboratory, University of Phayao, Phayao 56000 (Thailand); Phanchaisri, B. [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@frnf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Anuntalabhochai, S., E-mail: burinka@hotmail.com [Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2013-07-15

    Highlights: •N-ion beam bombarded Thai jasmine rice seeds to induce mutation. •Mutants with blast-disease resistance and high yield were screened. •Gene involved in the blast-disease resistance was analyzed. •The gene responsible for the resistance was linked to Spotted leaf protein 11. -- Abstract: Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60–80 keV to a beam fluence range of 2 × 10{sup 16}–2 × 10{sup 17} ions/cm{sup 2}. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 10{sup 6} spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11)

  12. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    International Nuclear Information System (INIS)

    Highlights: •N-ion beam bombarded Thai jasmine rice seeds to induce mutation. •Mutants with blast-disease resistance and high yield were screened. •Gene involved in the blast-disease resistance was analyzed. •The gene responsible for the resistance was linked to Spotted leaf protein 11. -- Abstract: Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60–80 keV to a beam fluence range of 2 × 1016–2 × 1017 ions/cm2. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 106 spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11)

  13. Unique features of the rice blast resistance Pish locus revealed by large scale retrotransposon-tagging

    Directory of Open Access Journals (Sweden)

    Takahashi Akira

    2010-08-01

    Full Text Available Abstract Background R gene-mediated resistance is one of the most effective mechanisms of immunity against pathogens in plants. To date some components that regulate the primary steps of plant immunity have been isolated, however, the molecular dissection of defense signaling downstream of the R proteins remains to be completed. In addition, R genes are known to be highly variable, however, the molecular mechanisms responsible for this variability remain obscure. Results To identify novel factors required for R gene-mediated resistance in rice, we used rice insertional mutant lines, induced by the endogenous retrotransposon Tos17, in a genetic screening involving the rice blast fungus Magnaporthe oryzae. We inoculated 41,119 mutant lines with the fungus using a high throughput procedure, and identified 86 mutant lines with diminished resistance. A genome analysis revealed that 72 of the 86 lines contained mutations in a gene encoding a nucleotide binding site (NBS and leucine rich repeat (LRR domain-containing (NBS-LRR protein. A genetic complementation analysis and a pathogenesis assay demonstrated that this NBS-LRR gene encodes Pish, which confers resistance against races of M. oryzae containing avrPish. The other 14 lines have intact copies of the Pish gene, suggesting that they may contain mutations in the signaling components downstream of Pish. The genome analysis indicated that Pish and its neighboring three NBS-LRR genes are high similar to one another and are tandemly located. An in silico analysis of a Tos17 flanking sequence database revealed that this region is a "hot spot" for insertion. Intriguingly, the insertion sites are not distributed evenly among these four NBS-LRR genes, despite their similarity at the sequence and expression levels. Conclusions In this work we isolated the R gene Pish, and identified several other mutants involved in the signal transduction required for Pish-mediated resistance. These results indicate that

  14. Diversity of the Rice Blast Pathogen Populations in Ghana and Strategies for Resistance Management

    OpenAIRE

    S.K. Nutsugah; J.K. Twumasi; J. Chipili; Y. Sere; S. Sreenivasaprasad

    2008-01-01

    The present study describes the outputs of a collaborative research programme funded by the UK`s Department for International Development-Crop Protection Program to investigate the genetic (lineages) and pathogenic (pathotypes) diversity of the blast fungus populations and characterize the key sites suitable for resistance screening. Seventy-one Magnaporthe grisae isolates were collected from seven regions where rice is grown, representing blast populations in Ghana. Following molecular chara...

  15. A Review of Microsatellite Markers and Their Applications in Rice Breeding Programs to Improve Blast Disease Resistance

    Directory of Open Access Journals (Sweden)

    Mohammad Abdul Latif

    2013-11-01

    Full Text Available Over the last few decades, the use of molecular markers has played an increasing role in rice breeding and genetics. Of the different types of molecular markers, microsatellites have been utilized most extensively, because they can be readily amplified by PCR and the large amount of allelic variation at each locus. Microsatellites are also known as simple sequence repeats (SSR, and they are typically composed of 1–6 nucleotide repeats. These markers are abundant, distributed throughout the genome and are highly polymorphic compared with other genetic markers, as well as being species-specific and co-dominant. For these reasons, they have become increasingly important genetic markers in rice breeding programs. The evolution of new biotypes of pests and diseases as well as the pressures of climate change pose serious challenges to rice breeders, who would like to increase rice production by introducing resistance to multiple biotic and abiotic stresses. Recent advances in rice genomics have now made it possible to identify and map a number of genes through linkage to existing DNA markers. Among the more noteworthy examples of genes that have been tightly linked to molecular markers in rice are those that confer resistance or tolerance to blast. Therefore, in combination with conventional breeding approaches, marker-assisted selection (MAS can be used to monitor the presence or lack of these genes in breeding populations. For example, marker-assisted backcross breeding has been used to integrate important genes with significant biological effects into a number of commonly grown rice varieties. The use of cost-effective, finely mapped microsatellite markers and MAS strategies should provide opportunities for breeders to develop high-yield, blast resistance rice cultivars. The aim of this review is to summarize the current knowledge concerning the linkage of microsatellite markers to rice blast resistance genes, as well as to explore the use of MAS

  16. Understanding the molecular mechanisms of rice blast resistance using rice mutants

    International Nuclear Information System (INIS)

    Induced mutation can be useful for studying resistance gene controlled plant immunity. Resulting knowledge should benefit the development of strategies for crop protection. The Pi-ta gene in rice has been effectively deployed for preventing rice blast disease-the most devastating disease of rice worldwide. Pi-ta was introgressed into diverse cultivars in the US and Japan from landrace indica varieties, Tetep and Taducan, respectively. Pi-ta was predicted to be a cytoplasmic receptor that directly binds to the elicitor produced by the pathogen avirulence gene AVR-Pita for initiating resistance. Alanine located at position 918 of the Pi-ta protein in the region predicted to be involved in ligand binding has been shown to determine the binding specificity. Here I report the identification of a second gene, Ptr(t), required by Pi-ta for resistance. Katy, a tropical japonica cultivar from the US, expressing resistance conditioned by Pi-ta and Pi-ks to the common races of M. oryzae, IB1, IB45, IB49, IB54, IC17, IH1, IE1, and IG1 was treated with fast neutrons. Five susceptible M2 mutants were identified by screening seedlings derived from 10,000 M1 plants. Among them a stable mutant M2354 was found susceptible to IB1, IB45, IB49, IC17, IH1, IE1, and IG1 conditioned by Pi-ta and resistant to IB54 conditioned by Pi-ks. The DNA sequences of the Pi-ta gene in M2354 was found unchanged based on PCR-sequencing. Expression of Pi-ta in M2354 was also found identical to that of the mother parent examined by qRT-PCR and real time RT-PCR. Thus, mutations in M2354 likely occurred at a new locus specific to Pi-ta-mediated resistance. Genetic analysis and genotyping the Pi-taptr(t), Pi-taPtr(t), pitaptr( t) homozygotes revealed that Pi-ta and Ptr(t) co-segregate and are located within a 9 megabase genomic region on chromosome 12. These findings provide a starting point to isolate Ptr(t) and dissect the Pi-ta mediated signaling pathways leading to resistance. (author)

  17. CREATION OF RICE BREEDING LINES, CARRYING BROAD SPECTRUM BLAST RESISTANCE GENE Pi-40 USING DNA-MARKERS METHODS Создание селекционных форм риса, несущих ген широкого спектра устойчивости к пирикуляриозу Pi-40, с использованием методов ДНК-маркирования

    Directory of Open Access Journals (Sweden)

    Suprun I. I.

    2013-02-01

    Full Text Available The results of development of rice breeding lines, carrying the wide range resistance gene to rice blast disease - Pi-40. For identification of the dominant allele of the gene the DNA - marker analysis was used. With co-dominant DNA markers plants from inbred populations that carry a dominant allele of this gene in the homozygous state were selected

  18. Studies on the Impact of Explosion on Blast Resistant Stiffened Door Structures

    Science.gov (United States)

    Veeredhi, Lakshmi Shireen Banu; Ramana Rao, N. V.

    2015-01-01

    The objective of this work is to study the extent of damage that is likely to be caused by a blast load on stiffened steel plate (door structure) designed to withstand blast load using computational methods. In this paper, panels with three types of reinforcements namely T, I and HAT shaped stiffeners are considered. The thickness of these stiffeners is varied to study the extent of increase in the resistance against the damage due to blast load. Special emphasis is given to evaluate mid-point displacements. The finite element package ABAQUS is employed for modeling the cover plate, with three different stiffeners separately having constant height and different thickness. The boundary conditions are assumed to be fixed on all sides and the computational domain is meshed using the S4R type shell element. For the response calculations, the weight of TNT (explosive) applied is varied from 100 to 500 kg with an increment of 100 kg. The blast response of stiffened doors with three different stiffeners subjected to constant blast load was examined systematically. The results of blast load analysis of stiffened door structure for stress, mid-point displacements for T, I and HAT stiffeners were compared against each other. It is found that the blast door structures with HAT stiffener performs better in this application.

  19. Main agronomic traits and resistance to rice blast of space-induced mutant lines of Zhong-er-ruan-zhan

    International Nuclear Information System (INIS)

    The main agronomic traits and resistance to rice blast of 34 space-induced lines from an elite rice cultivar, Zhong-er-ruan-zhan were evaluated at their SP4. The resistance to blast of the mutant lines had been tested by two blast isolates previously. It was found that the mutant lines showed significant difference in plant height, effective panicles, panicle length and grains per panicle etc. from their parent. The range of variation in 1000-grain weight the largest, followed by the seed-setting rate, and that of effective panicles was the least among all the traits. Except for the line Z34, 33 mutant lines had broader resistance spectra than the wild-type based on the test with 38 different blast isolates, and all the 33 lines were also resistant to the panicle blast in the field. The result confirmed that selection for resistant to blast in lower generations was reliable. Taking account of agronomic traits and blast resistance, promising lines with resistance to blast and good agronomic characters could be selected from those mutant lines. Therefore, the elite rice germplasm with enhanced disease resistance can be produced. (authors)

  20. Obtaining transgenic rice resistant to rice fungal blast disease by controlled cell death strategy

    Institute of Scientific and Technical Information of China (English)

    MAO Shengji; GU Hongya; QU Lijia; CHEN Zhangliang

    2003-01-01

    The strategy of the two-component system, composed of Barnase and Barstar which encode RNase and a specific inhibitor to the RNase respectively, is adopted to obtain transgenic rice resistant to rice fungal blast disease. In this study, two chimeric promoters, induced by rice blast fungus pathogen (Magnaporthe grisea), are fused with Barnase respectively to construct two plant expression vectors, pWBNBS and pPBNBS together with the Barstar driven by CaMV 35S promoter. The resistance of the transgenic rice lines to rice blast fungus disease and rice blight disease are evaluated. The results show that (1) the expression of Barnase is induced in rice leaves when inoculated with the spores of Magnaporthe grisea; (2) the induced expression level of Barnase surpasses the level of Barstar, which elicits a similar hypersensitive response (HR) in the leaves, and the transgenic plant shows high resistance to the rice fungal blast disease; and (3) transgenic rice plants also show obvious resistance to rice bacterial blight disease. Taken together, these results suggest that the transgenic rice plants harboring this two-component system acquire relatively broad spectrum resistance against pathogens, especially high resistance to rice fungal pathogen.

  1. Constitutive expression of McCHIT1-PAT enhances resistance to rice blast and herbicide, but does not affect grain yield in transgenic glutinous rice.

    Science.gov (United States)

    Zeng, Xiao-Fang; Li, Lei; Li, Jian-Rong; Zhao, De-Gang

    2016-01-01

    To produce new rice blast- and herbicide-resistant transgenic rice lines, the McCHIT1 gene encoding the class I chitinase from Momordica charantia and the herbicide resistance gene PAT were introduced into Lailong (Oryza sativa L. ssp. Japonica), a glutinous local rice variety from Guizhou Province, People's Republic of China. Transgenic lines were identified by ß-glucuronidase (GUS) histochemical staining, PCR, and Southern blot analyses. Agronomic traits, resistance to rice blast and herbicide, chitinase activities, and transcript levels of McCHIT1 were assessed in the T2 progeny of three transgenic lines (L1, L8, and L10). The results showed that the introduction of McCHIT1-PAT into Lailong significantly enhanced herbicide and blast resistance. After infection with the blast fungus Magnaporthe oryzae, all of the T2 progeny exhibited less severe lesion symptoms than those of wild type. The disease indices were 100% for wild type, 65.66% for T2 transgenic line L1, 59.69% for T2 transgenic line L8, and 79.80% for T2 transgenic line L10. Transgenic lines expressing McCHIT1-PAT did not show a significant difference from wild type in terms of malondialdehyde (MDA) content, polyphenol oxidase (PPO) activity, and superoxide dismutase (SOD) activity in the leaves. However, after inoculation with M. oryzae, transgenic plants showed significantly higher SOD and PPO activities and lower MDA contents in leaves, compared with those in wild-type leaves. The transgenic and the wild-type plants did not show significant differences in grain yield parameters including plant height, panicles per plant, seeds per panicle, and 1000-grain weight. Therefore, the transgenic plants showed increased herbicide and blast resistance, with no yield penalty. PMID:25639923

  2. Study on induction and selection of mutants for blast disease (Piricula oryzae) resistance

    International Nuclear Information System (INIS)

    The rice seeds of varieties Zhejiang 66, R8617 which were blast disease susceptible were treated by 15, 25, 35 krad 60Co-γ rays, and the disease resistant rice plants were selected in M2 generation with natural induced inoculation. The disease resistant plants selected from M2 were inoculated artificialy. 30, 34, 36 of variant plants were selected in the M2 generation and their mutation rate were 0.016, 0.0190, 0.316 percent respectively. The resistance for most of mutants can be hereditary. The disease resistance mutants from same parents with same treatment showed different resistance

  3. A Novel Blasted and Grooved Low Profile Pedicle Screw Able to Resist High Compression Bending Loads

    OpenAIRE

    Kuh, Sung-Uk; Kim, Young-Sung; Choi, Hong-June; Kim, Kyung-Hyun; Park, Jeong-Yoon; Jeong, Hyun-Yong; Chin, Dong-Kyu; Kim, Keun-Su; Yoon, Young-Sul; Lee, Yoon-Chul; Cho, Yong-Eun

    2012-01-01

    Objective Polyaxial pedicle screws are a safe, useful adjunct to transpedicular fixation. However, the large screw head size can cause soft tissue irritation, high rod positioning, and facet joint injury. However, the mechanical resistance provided by small and low profile pedicle screws is very limited. We therefore developed a novel, low profile pedicle screw using grooving and blasting treatment that is able to resist a high compression bending load. Methods We evaluated the compression be...

  4. Molecular Breeding Strategy and Challenges Towards Improvement of Blast Disease Resistance in Rice Crop

    OpenAIRE

    Ashkani, Sadegh; Mohd Y. Rafii; Shabanimofrad, Mahmoodreza; Miah, Gous; Sahebi, Mahbod; Azizi, Parisa; Tanweer, Fatah A.; Akhtar, Mohd Sayeed; Nasehi, Abbas

    2015-01-01

    Rice is a staple and most important security food crop consumed by almost half of the world’s population. More rice production is needed due to the rapid population growth in the world. Rice blast caused by the fungus, Magnaporthe oryzae is one of the most destructive diseases of this crop in different part of the world. Breakdown of blast resistance is the major cause of yield instability in several rice growing areas. There is a need to develop strategies providing long-lasting disease resi...

  5. Improving Blast Resistance of a Thermo-Sensitive Genic Male Sterile Rice Line GD-8S by Molecular Marker-Assisted Selection

    Institute of Scientific and Technical Information of China (English)

    LIU Wu-ge; LIU Yi-bai; JIN Su-juan; ZHU Xiao-yuan; WANG Feng; LI Jin-hua; LIU Zhen-rong; LIAO Yi-long; ZHU Man-shan; HUANG Hui-jun

    2008-01-01

    The broad-spectrum blast resistance gene Pi-1, from donor line BL122, was introduced into a thermo-sensitive genic male sterile rice line GD-8S, which possessed good grain quality but high susceptibility to rice blast, by using backcross breeding and molecular marker-assisted selection. Five elite improved male sterile lines, RGD8S-1, RGD8S-2, RGD8S-3, RGD8S-4 and RGD8S-5, were selected based on the results of molecular marker analysis, spikelet sterility, recovery rate of genetic background and agronomic traits. Thirty-three representative blast isolates collected from Guangdong Province,China were used to inoculate the improved lines and the original line GD-8S artificially. The resistance frequencies of the improved lines ranged from 76.47% to 100%, much higher than that of the original line GD-8S (9.09%). On the agronomic characters, there were no significant differences between the improved lines and GD-8S except for flag leaf length and panicle number per plant. The improved lines could be used for breeding hybrid rice with high blast resistance.

  6. Screening of resistant mutant induced by γ-rays irradiation to rice blast

    International Nuclear Information System (INIS)

    Rice seeds were irradiated with 60Co γ-rays to induce mutants, which resistant to rice blast were screened in subculture medium and differentiation medium under mix toxin from dominant strains of pyricularia grisea in Heilongjiang. The results indicated that the inductivity of callus of mature rice embryo by irradiation was very low and the browning rate of callus was very high. However, the resistance rate of resistant regenerating plants was obviously higher, which indicated the resistant breeding by irradiation and biotechnology had a great potential and a better prospect. (authors)

  7. Aspergillus flavus Blast2GO gene ontology database: elevated growth temperature alters amino acid metabolism

    Science.gov (United States)

    The availability of a representative gene ontology (GO) database is a prerequisite for a successful functional genomics study. Using online Blast2GO resources we constructed a GO database of Aspergillus flavus. Of the predicted total 13,485 A. flavus genes 8,987 were annotated with GO terms. The mea...

  8. Gene Ontology annotation of the rice blast fungus, Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Deng Jixin

    2009-02-01

    Full Text Available Abstract Background Magnaporthe oryzae, the causal agent of blast disease of rice, is the most destructive disease of rice worldwide. The genome of this fungal pathogen has been sequenced and an automated annotation has recently been updated to Version 6 http://www.broad.mit.edu/annotation/genome/magnaporthe_grisea/MultiDownloads.html. However, a comprehensive manual curation remains to be performed. Gene Ontology (GO annotation is a valuable means of assigning functional information using standardized vocabulary. We report an overview of the GO annotation for Version 5 of M. oryzae genome assembly. Methods A similarity-based (i.e., computational GO annotation with manual review was conducted, which was then integrated with a literature-based GO annotation with computational assistance. For similarity-based GO annotation a stringent reciprocal best hits method was used to identify similarity between predicted proteins of M. oryzae and GO proteins from multiple organisms with published associations to GO terms. Significant alignment pairs were manually reviewed. Functional assignments were further cross-validated with manually reviewed data, conserved domains, or data determined by wet lab experiments. Additionally, biological appropriateness of the functional assignments was manually checked. Results In total, 6,286 proteins received GO term assignment via the homology-based annotation, including 2,870 hypothetical proteins. Literature-based experimental evidence, such as microarray, MPSS, T-DNA insertion mutation, or gene knockout mutation, resulted in 2,810 proteins being annotated with GO terms. Of these, 1,673 proteins were annotated with new terms developed for Plant-Associated Microbe Gene Ontology (PAMGO. In addition, 67 experiment-determined secreted proteins were annotated with PAMGO terms. Integration of the two data sets resulted in 7,412 proteins (57% being annotated with 1,957 distinct and specific GO terms. Unannotated proteins

  9. Durable resistance to Puccinia triticina by accumulation of resistance genes

    Directory of Open Access Journals (Sweden)

    Bošković Jelena

    2009-01-01

    Full Text Available The individual use of single race-specific resistance genes with major phenotypic effects has rarely provided lasting resistance. However, breeding and combining or pyramiding of resistance genes into individual cultivars has had considerable success, particularly in situations in which the pathogen does not reproduce sexually, as in the case of wheat leaf rust pathogen. In European-Mediterranean region perfomed international investigations of wheat leaf rust proved that breeding of new lines of wheat resistant to Puccinia triticina Eriks. for differentiation of pathogen population, as well as for sources of durable resistance is necessary. Breeding of such resistant lines has proved necessary due to the unsatisfatory survey results of these regions on standard isogenic Lr lines. It has become clear that these regions needed new, more efficient differential resistance genes, as well as sources of resistance. In the beginning, after extensive screening tests of several International Rust Nurseries, 18 donors of resistance had been selected as crosses with recurrent parents' varieties Princ and Starke. These hybrid lines had been comparatively tested with twenty six Lr single gene lines using twenty especially virulent cultures of P. triticina in order to check the presence of these known Lr genes in our hybrid lines. Considerable influence of recurrent parent to the number of resistant genes in used donors was demonstrated. On the other hand, considerable influence of the pathogen culture was established to the number of resistance genes in used donors. In order to enhance resistance and pyramiding genes in these hybrids, the most interesting selected eight lines have been crossed with only effective isogenic ones, containing the strong genes Lr9, Lr19 and Lr24. On the basis of different segregation rations of all crossing combinations it was proved that no one of resistant donors contained the applied strong resistant genes. It means that our

  10. "Rice blast disease in Republic of Macedonia and Peoples Republic of China, sources for resistance and material for selection"

    OpenAIRE

    Karov, Ilija

    2006-01-01

    Rice (Oryza sativa) is a major crop in Macedonia. The most important rice disease is rice blast caused by Pyricularia grisea. One of the most effective means of controlling rice blast disease is the development and use of resistant rice cultivars. R. Macedonia is planning to examine vertical and horizontal resistance to Pyricularia grisea in several rice varieties from Europe and People’s Republic of China. During the first year of the project we expect to identify the pathotypes of Py...

  11. Improvement of Basmati rice varieties for resistance to blast and bacterial blight diseases using marker assisted backcross breeding.

    Science.gov (United States)

    Ellur, Ranjith K; Khanna, Apurva; Yadav, Ashutosh; Pathania, Sandeep; Rajashekara, H; Singh, Vikas K; Gopala Krishnan, S; Bhowmick, Prolay K; Nagarajan, M; Vinod, K K; Prakash, G; Mondal, Kalyan K; Singh, Nagendra K; Vinod Prabhu, K; Singh, Ashok K

    2016-01-01

    Marker assisted backcross breeding was employed to incorporate the blast resistance genes, Pi2 and Pi54 and bacterial blight (BB) resistance genes xa13 and Xa21 into the genetic background of Pusa Basmati 1121 (PB1121) and Pusa Basmati 6. Foreground selection for target gene(s) was followed by arduous phenotypic and background selection which fast-tracked the recovery of recurrent parent genome (RPG) to an extent of 95.8% in one of the near-isogenic lines (NILs) namely, Pusa 1728-23-33-31-56, which also showed high degree of resemblance to recurrent parent, PB6 in phenotype. The phenotypic selection prior to background selection provided an additional opportunity for identifying the novel recombinants viz., Pusa 1884-9-12-14 and Pusa 1884-3-9-175, superior to parental lines in terms of early maturity, higher yield and improved quality parameters. There was no significant difference between the RPG recovery estimated based on SSR or SNP markers, however, the panel of SNPs markers was considered as the better choice for background selection as it provided better genome coverage and included SNPs in the genic regions. Multi-location evaluation of NILs depicted their stable and high mean performance in comparison to the respective recurrent parents. The Pi2+Pi54 carrying NILs were effective in combating a pan-India panel of Magnaporthe oryzae isolates with high level of field resistance in northern, eastern and southern parts of India. Alongside, the PB1121-NILs and PB6-NILs carrying BB resistance genes xa13+Xa21 were resistant against Xanthomonas oryzae pv. oryzae races of north-western, southern and eastern parts of the country. Three of NILs developed in this study, have been promoted to final stage of testing during the ​Kharif 2015 in the Indian National Basmati Trial. PMID:26566849

  12. The evolution of resistance gene in plants

    Institute of Scientific and Technical Information of China (English)

    BEN Haiyan; LIU Xuemin; LI Lijun; LIU Li

    2007-01-01

    Resistance genes enable plants to fight against plant pathogens. Plant resistance genes (R gene) are organized complexly in genome. Some resistance gene sequence data enable an insight into R gene structure and gene evolution. Some sites like Leucine-Rich Repeat (LRR) are of specific interest since homologous recombination can happen. Crossing over, transposon insertion and excision and mutation can produce new specificity. Three models explaining R gene evolution were discussed. More information needed for dissection of R gene evolution though some step can be inferred from genetic and sequence analysis.

  13. Breeding of the early season indica rice variety Fu 501 with high yield and blast resistance

    International Nuclear Information System (INIS)

    Fu 501, an early season indica rice variety, was developed through the pedigree breeding method by irradiating F1 and M6F6 dry seeds of Z96-12 × Z95-03 using 80 Gy and 300 Gy 60Co γ-rays, respectively. The variety has high and stabilizing grain yield, adaptable growth duration, resistance to rice blast and wide adaptability, and it was registered and released in Zhejiang Province in Feb., 2011. (authors)

  14. Development of Thermal Shock Resistant and Low Creep Bricks for Hot Blast Stove

    Institute of Scientific and Technical Information of China (English)

    LIN Binyin; LIU Jiehua; ZHOU Ningsheng; ZHANG Jianwu

    2005-01-01

    The paper describes the development of brick series with high thermal shock resistance and low creep rate for hot blast stove, including research target and research plan on the basis of analysis on how to enhance the thermal shock resistance and to lower creep rate of the bricks. Efforts have been made on the selection of starting materials such as corundum, mullite, andalusite and sillimanite etc. , together with some measures taken on multi-grade formulation, homogenizing of the matrix of bricks and addition of some special additives. The results indicated that the bricks were with characteristics such as higher thermal shock resistance of > 30 cycles under quenching in water from 1000℃, and creep rate of 0. 2 under 1400℃ for 20 ~50hrs with load of 0. 2MPa. Now a series of products of this kind have been developed and produced. The application of the products in Wuhan Iron and Steel Co. showed very prospective results.Now most of domestic large sized blast furnaces say ≥1000m3, including those of Baoshan Iron and Steel Co. , have selected the series products made by Gongyi No. 5 Refractories Head Factory(GYWN) for their hot blast stoves.

  15. Effect of Surface Contaminants Remained on the Blasted Surface on Epoxy Coating Performance and Corrosion Resistance

    International Nuclear Information System (INIS)

    One of the critical issues in the coating specification is the allowable limit of surface contaminant(s) - such as soluble salt(s), grit dust, and rust - after grit blasting. Yet, there is no universally accepted data supporting the relationship between the long-term coating performance and the amount of various surface contaminants allowed after grit blasting. In this study, it was attempted to prepare epoxy coatings applied on grit-blasted steel substrate dosed with controlled amount of surface contaminants - such as soluble salt(s), grit dust, and rust. Then, coating samples were subjected to 4,200 hours of cyclic test(NORSOK M-501), which were then evaluated in terms of resistance to rust creepage, blistering, chalking, rusting, cracking and adhesion strength. Additional investigations on the possible damage at the paint/steel interface were carried out using an Electrochemical Impedance Spectroscopy(EIS) and observations of under-film-corrosion. Test results suggested that the current industrial specifications were well matched with the allowable degree of rust, whereas the allowable amount of soluble salt and grit dust after grit blasting showed a certain deviation from the specifications currently employed for fabrication of marine vessels and offshore facilities

  16. Exosomes Secreted by Apoptosis-Resistant Acute Myeloid Leukemia (AML) Blasts Harbor Regulatory Network Proteins Potentially Involved in Antagonism of Apoptosis.

    Science.gov (United States)

    Wojtuszkiewicz, Anna; Schuurhuis, Gerrit J; Kessler, Floortje L; Piersma, Sander R; Knol, Jaco C; Pham, Thang V; Jansen, Gerrit; Musters, René J P; van Meerloo, Johan; Assaraf, Yehuda G; Kaspers, Gertjan J L; Zweegman, Sonja; Cloos, Jacqueline; Jimenez, Connie R

    2016-04-01

    Expression of apoptosis-regulating proteins (B-cell CLL/lymphoma 2 - BCL-2, Myeloid Cell Leukemia 1 - MCL-1, BCL-2 like 1 - BCL-X and BCL-2-associated X protein - BAX) in acute myeloid leukemia (AML) blasts at diagnosis is associated with disease-free survival. We previously found that the initially high apoptosis-resistance of AML cells decreased after therapy, while regaining high levels at relapse. Herein, we further explored this aspect of dynamic apoptosis regulation in AML. First, we showed that the intraindividualex vivoapoptosis-related profiles of normal lymphocytes and AML blasts within the bone marrow of AML patients were highly correlated. The expression values of apoptosis-regulating proteins were far beyond healthy control lymphocytes, which implicates the influence of microenvironmental factors. Second, we demonstrated that apoptosis-resistant primary AML blasts, as opposed to apoptosis-sensitive cells, were able to up-regulate BCL-2 expression in sensitive AML blasts in contact cultures (p= 0.0067 andp= 1.0, respectively). Using secretome proteomics, we identified novel proteins possibly engaged in apoptosis regulation. Intriguingly, this analysis revealed that major functional protein clusters engaged in global gene regulation, including mRNA splicing, protein translation, and chromatin remodeling, were more abundant (p= 4.01E-06) in secretomes of apoptosis-resistant AML. These findings were confirmed by subsequent extracellular vesicle proteomics. Finally, confocal-microscopy-based colocalization studies show that splicing factors-containing vesicles secreted by high AAI cells are taken up by low AAI cells. The current results constitute the first comprehensive analysis of proteins released by apoptosis-resistant and sensitive primary AML cells. Together, the data point to vesicle-mediated release of global gene regulatory protein clusters as a plausible novel mechanism of induction of apoptosis resistance. Deciphering the modes of communication

  17. Transgenic Cotton and Disease Resistance Genes

    Institute of Scientific and Technical Information of China (English)

    RAJASEKARAN; Kanniah

    2008-01-01

    Success in conventional breeding for resistance to mycotoxin-producing or other phytopathogenic fungi is dependent on the availability of resistance gene(s) in the germplasm.Even when it is available,breeding for disease-resistant crops is very time consuming,especially in perennial crops such as

  18. Transgenic rice plants expressing the antifungal AFP protein from Aspergillus giganteus show enhanced resistance to the rice blast fungus Magnaporthe grisea.

    Science.gov (United States)

    Coca, María; Bortolotti, Cristina; Rufat, Mar; Peñas, Gisela; Eritja, Ramón; Tharreau, Didier; del Pozo, Alvaro Martinez; Messeguer, Joaquima; San Segundo, Blanca

    2004-01-01

    The Aspergillus giganteus antifungal protein (AFP), encoded by the afp gene, has been reported to possess in vitro antifungal activity against various economically important fungal pathogens, including the rice blast fungus Magnaporthe grisea. In this study, transgenic rice ( Oryza sativa ) constitutively expressing the afp gene was generated by Agrobacterium -mediated transformation. Two different DNA constructs containing either the afp cDNA sequence from Aspergillus or a chemically synthesized codon-optimized afp gene were introduced into rice plants. In both cases, the DNA region encoding the signal sequence from the tobacco AP24 gene was N-terminally fused to the coding sequence of the mature AFP protein. Transgenic rice plants showed stable integration and inheritance of the transgene. No effect on plant morphology was observed in the afp -expressing rice lines. The inhibitory activity of protein extracts prepared from leaves of afp plants on the in vitro growth of M. grisea indicated that the AFP protein produced by the trangenic rice plants was biologically active. Several of the T(2) homozygous afp lines were challenged with M. grisea in a detached leaf infection assay. Transformants exhibited resistance to rice blast at various levels. Altogether, the results presented here indicate that AFP can be functionally expressed in rice plants for protection against the rice blast fungus M. grisea. PMID:15159626

  19. An automated annotation tool for genomic DNA sequences using GeneScan and BLAST

    Indian Academy of Sciences (India)

    Andrew M. Lynn; Chakresh Kumar Jain; K. Kosalai; Pranjan Barman; Nupur Thakur; Harish Batra; Alok Bhattacharya

    2001-04-01

    Genomic sequence data are often available well before the annotated sequence is published. We present a method for analysis of genomic DNA to identify coding sequences using the GeneScan algorithm and characterize these resultant sequences by BLAST. The routines are used to develop a system for automated annotation of genome DNA sequences.

  20. Histochemical aspects of wheat resistance to leaf blast mediated by silicon

    Directory of Open Access Journals (Sweden)

    Washington Luís da Silva

    2015-08-01

    Full Text Available Blast, caused by Pyricularia oryzae, has become a significant disease threat to wheat (Triticum aestivum L. in Brazil. This study aimed to investigate at the histochemical level if silicon (Si could enhance the production of flavonoids in the leaves of wheat plants in response to P. oryzae infection. Plants from the Aliança cultivar, which are susceptible to blast, were grown in hydroponic cultures containing 0 (-Si or 2 mM of Si (+Si and inoculated by spraying a conidial suspension of P. oryzae (1 × 105 conidia mL−1 on all adaxial leaf surfaces of plants at 60 days after emergence (growth stage 65. The fourth and fifth leaves of each plant were used to evaluate blast severity at 24, 36, 48, 72 and 96 h after inoculation (hai. At 96 hai, leaves were collected from plants to determine the foliar Si concentration. For cytological observations, leaf samples were randomly collected from the fourth and fifth leaves of each plant at 72 hai. The foliar Si concentration was higher in +Si plants (36 g kg−1 in comparison to -Si plants (2.6 g kg−1. This increased Si concentration was correlated with reduced fungal growth inside the epidermal cells and the development of blast symptoms on leaves. Strong fluorescence, which is an indication of the presence of flavonoids, was detected in the leaf cells of +Si plants using Neu’s and Wilson's reagents. A novel item of evidence is that, at the histochemical level, Si is involved in the potentiation of the biosynthetic pathway of flavonoids that increases wheat resistance to blast.

  1. A set of vectors for introduction of antibiotic resistance genes by in vitro Cre-mediated recombination

    OpenAIRE

    Vassetzky Yegor S; Dmitriev Petr V

    2008-01-01

    Abstract Background Introduction of new antibiotic resistance genes in the plasmids of interest is a frequent task in molecular cloning practice. Classical approaches involving digestion with restriction endonucleases and ligation are time-consuming. Findings We have created a set of insertion vectors (pINS) carrying genes that provide resistance to various antibiotics (puromycin, blasticidin and G418) and containing a loxP site. Each vector (pINS-Puro, pINS-Blast or pINS-Neo) contains either...

  2. Quantitative trait loci for rice blast resistance detected in a local rice breeding population by genome-wide association mapping.

    Science.gov (United States)

    Shinada, Hiroshi; Yamamoto, Toshio; Sato, Hirokazu; Yamamoto, Eiji; Hori, Kiyosumi; Yonemaru, Junichi; Sato, Takashi; Fujino, Kenji

    2015-12-01

    Plant breeding programs aim to develop cultivars with high adaptability to the specific conditions in a local region. As a result, unique genes and gene combinations have been accumulated in local elite breeding populations during the long history of plant breeding. Genetic analyses on such genes and combinations may be useful for developing new cultivars with more-desirable agronomic traits. Here, we attempted to detect quantitative trait loci (QTL) for rice blast resistance (BR) using a local breeding rice population from Hokkaido, Japan. Using genotyping data on single nucleotide polymorphisms and simple sequence repeat markers distributed throughout the whole genomic region, we detected genetic regions associated with phenotypic variation in BR by a genome-wide association mapping study (GWAS). An additional association analysis using other breeding cultivars verified the effect and inheritance of the associated region. Furthermore, the existence of a gene for BR in the associated region was confirmed by QTL mapping. The results from these studies enabled us to estimate potential of the Hokkaido rice population as a gene pool for improving BR. The results of this study could be useful for developing novel cultivars with vigorous BR in rice breeding programs. PMID:26719741

  3. Differences in phytoalexin response among rice cultivars of different resistance to blast

    International Nuclear Information System (INIS)

    he production of both flavonoid and diterpenoid phytoalexins after induction by UV irradiation was studied in five rice genotypes of different susceptibility to the rice blast fungus Pyricularia oryzae. Consistent qualitative and quatitative differences were found between the rice cultivars in the phytoalexins produced, and there was a strong correlation between the accumulation of the phytoalexins, sakuranetin, momilactone A and oryzalexin S, and rice resistance to blast. Production of phytoalexins was also investigated in rice genotype Tetep after inoculation with an incompatible race of P. oryzae. Similar levels of sakuranetin and oryzalexin E were formed 3 days after both inoculation and UV irradiation of the leaves, but there were different levels of momilactone A and the other oryzalexins. Although a given rice genotype may respond quite differently in its production of phytoalexins depending on whether it has been irradiated or inoculated with a fungus, and in the latter case on whether a compatible race of the pathogen has been used, the present results indicate that genetic differences in phytoalexin response between rice cultivars are likely to play an important role among the many factors that determine differences in blast resistance between different rice genotypes. (author)

  4. GeneCAT--novel webtools that combine BLAST and co-expression analyses

    DEFF Research Database (Denmark)

    Mutwil, Marek; Obro, Jens; Willats, William G T;

    2008-01-01

    The gene co-expression analysis toolbox (GeneCAT) introduces several novel microarray data analyzing tools. First, the multigene co-expression analysis, combined with co-expressed gene networks, provides a more powerful data mining technique than standard, single-gene co-expression analysis. Second......, the high-throughput Map-O-Matic tool matches co-expression pattern of multiple query genes to genes present in user-defined subdatabases, and can therefore be used for gene mapping in forward genetic screens. Third, Rosetta combines co-expression analysis with BLAST and can be used to find 'true' gene...... orthologs in the plant model organisms Arabidopsis thaliana and Hordeum vulgare (Barley). GeneCAT is equipped with expression data for the model plant A. thaliana, and first to introduce co-expression mining tools for the monocot Barley. GeneCAT is available at http://genecat.mpg.de....

  5. Benchmarking of methods for identification of antimicrobial resistance genes in bacterial whole genome data

    DEFF Research Database (Denmark)

    Clausen, Philip T. L. C.; Zankari, Ea; Aarestrup, Frank Møller;

    2016-01-01

    two different methods in current use for identification of antibiotic resistance genes in bacterial WGS data. A novel method, KmerResistance, which examines the co-occurrence of k-mers between the WGS data and a database of resistance genes, was developed. The performance of this method was compared...... with two previously described methods; ResFinder and SRST2, which use an assembly/BLAST method and BWA, respectively, using two datasets with a total of 339 isolates, covering five species, originating from the Oxford University Hospitals NHS Trust and Danish pig farms. The predicted resistance was...... compared with the observed phenotypes for all isolates. To challenge further the sensitivity of the in silico methods, the datasets were also down-sampled to 1% of the reads and reanalysed. The best results were obtained by identification of resistance genes by mapping directly against the raw reads. This...

  6. Identification of acquired antimicrobial resistance genes

    DEFF Research Database (Denmark)

    Zankari, Ea; Hasman, Henrik; Cosentino, Salvatore;

    2012-01-01

    ObjectivesIdentification of antimicrobial resistance genes is important for understanding the underlying mechanisms and the epidemiology of antimicrobial resistance. As the costs of whole-genome sequencing (WGS) continue to decline, it becomes increasingly available in routine diagnostic...... antimicrobial resistance genes in whole-genome data. As input, the method can use both pre-assembled, complete or partial genomes, and short sequence reads from four different sequencing platforms. The method was evaluated on 1862 GenBank files containing 1411 different resistance genes, as well as on 23 de......-novo-sequenced isolates.ResultsWhen testing the 1862 GenBank files, the method identified the resistance genes with an ID = 100% (100% identity) to the genes in ResFinder. Agreement between in silico predictions and phenotypic testing was found when the method was further tested on 23 isolates of five different bacterial...

  7. ROLE OF UNDERGROUND STRUCTURE DEFORMATION VELOCITY IN THE ANALYSIS OF BLAST-RESISTANT STRUCTURES

    Institute of Scientific and Technical Information of China (English)

    赵晓兵; 方秦

    2002-01-01

    The structural deformation velocity plays a significant role in the dynamic calculation of underground blast-resistant structures. The motion differentiating equation of a structure system taking into account the role of deformation velocity of the structure will truthfully describe the actual situation of structural vibration. With the one-dimensional plane wave theory, the expression of load on the structural periphery is developed, and the generalized variation principle for the dynamic analysis of underground arched-bar structures is given. At the same time, the results of the numerical calculation are compared.

  8. Transgenic Cotton and Disease Resistance Genes

    Institute of Scientific and Technical Information of China (English)

    RAJASEKARAN Kanniah

    2008-01-01

    @@ Success in conventional breeding for resistance to mycotoxin-producing or other phytopathogenic fungi is dependent on the availability of resistance gene(s) in the germplasm.Even when it is available,breeding for disease-resistant crops is very time consuming,especially in perennial crops such as tree nut crops,and does not lend itself ready to combat the evolution of new virulent fungal races.

  9. Comportamento de somaclones de arroz derivados de híbridos da geração F1 para resistência à brusone Performance of rice somaclones derived from F1 hybrids to blast resistance

    Directory of Open Access Journals (Sweden)

    Leila Garcês de Araújo

    2002-05-01

    Full Text Available A indução de variabilidade genética em relação à resistência à brusone, utilizando cultura de tecidos como material, constitui uma das alternativas para a obtenção de novas fontes de genes de resistência. O objetivo deste estudo foi aumentar a freqüência de variantes usando como explante panículas imaturas da geração F1 de cruzamentos envolvendo fontes altamente suscetíveis e moderadamente resistentes à brusone como parentais. Somaclones de arroz derivados de plantas F1 dos cruzamentos Bluebelle/Araguaia e Maratelli/Basmati-370 foram avaliados, nas gerações avançadas, quanto à resistência à brusone e a algumas características agronômicas. Nos testes de inoculações em casa de vegetação, todos os somaclones, de ambos os cruzamentos, na geração R4, apresentaram alto grau de resistência aos patótipos IB-1 e IB-9. Alguns dos somaclones mantiveram-se resistentes na geração R5, em avaliações realizadas com alta pressão de brusone. No campo, os somaclones R5 e R6 mostraram alta freqüência de variação quanto à resistência à doença, altura da planta, produtividade, peso e tipo de grãos. Dois somaclones derivados do cruzamento Bluebelle/Araguaia e 31 somaclones derivados do cruzamento Maratelli/Basmati-370 foram identificados como novas fontes de resistência à brusone, e podem ser utilizados no programa de melhoramento de arroz irrigado.The induction of genetic variability, in relation to blast resistance, using tissue culture as a tool, constitutes one of the alternatives for obtaining novel resistance gene sources. The objective of this study was to increase the frequency of variants using immature panicles as explant from the F1 plants of crosses involving susceptible and moderately blast resistant sources as parents. Somaclones of rice derived from F1 plants of the crosses Bluebelle/Araguaia and Maratelli/Basmati-370 were assessed in advanced generations for blast resistance and some agronomic

  10. Rice Blast Resistance Breeding in Heilongjiang Province%黑龙江省抗稻瘟病育种

    Institute of Scientific and Technical Information of China (English)

    王敬国; 邹德堂; 赵宏伟; 刘化龙; 孙健

    2013-01-01

    This review summarizes the research and practice about the collection and identification of resistant source, analysis of resistance genes, methods of evaluating resistance, race type and resistant varieties breeding in Heilongjiang Province after liberation. This review thinks that lack of knowledge about the genetic basic of resistant varieties is the major reason of blast resistance breeding in Heilongjiang Province at present; specific molecular markers should be emphasis on the fine identification of the genetic basic for resistant varieties in the future; according to the backbone parents of the rice varieties in Heilongjiang Province, three developed specific molecular markers of Pi-b, Pi-ta and Pi-t gene should be fully used, and more attention should focus on the development and utilization of specific molecular markers linked to the Pi-a, Pi-z and Pi-k gene. Difficulties of development in the specific molecular markers and several problems need to be noticed were also discussed in this study.%综述了建国后黑龙江省在抗源搜集与鉴定、抗性基因分析、抗性鉴定方法、生理小种、抗病品种选育等方面的研究与实践。缺少品种抗性遗传基础研究是限制现阶段黑龙江省抗稻瘟病育种开展的重要因素;特异性分子标记可以在开展品种抗性遗传基础研究中发挥重要作用;根据黑龙江省水稻品种骨干亲本来源,在充分利用已开发的Pi-b、Pi-ta和Pi-t这3个基因特异性分子标记的同时,还需密切关注Pi-a、Pi-z和Pi-k等基因特异性分子标记的开发与利用,进而探讨了特异性分子标记开发过程中的难点和需要注意的问题。

  11. 稻瘟病抗病基因Pi-kh功能标记的开发及江苏粳稻品种中Pi-kh的变异%Development of a Functional Marker for Rice Blast Resistance Gene Pi-kh and Natural Variation at Pi-kh Locus in japonica Rice in Jiangsu Province,China

    Institute of Scientific and Technical Information of China (English)

    王军; 杨杰; 朱金燕; 范方军; 李文奇; 王芳权; 黄转运; 仲维功

    2014-01-01

    稻瘟病抗病基因Pi-k h是对稻瘟病菌具有广谱抗性的一个重要基因.根据 Pi-k h 感病基因和抗病基因序列存在143bp 插入的特征,设计了 InDel 标记 FM143.Tetep具有抗病基因Pi-kh ,分子标记 FM143 PCR 扩增带型为非插入带型,而不携带Pi-kh的材料的带型为插入带型.利用该标记对Tetep与宁9108的 F2群体进行分析,结果表明该标记能准确区分Pi-kh、Pi-kh纯合及杂合基因型,标记基因型符合1∶2∶1比例,没有发生偏分离现象.利用该标记对65份江苏省历年来大面积推广的粳稻品种和64份粳稻品系进行检测,筛选出具有非插入带型的粳稻品种19份、粳稻品系22份.进一步对江苏省粳稻品种中Pi-k h位点进行测序,发现江苏粳稻品种(系)Pi-k h基因座位与 Tetep 和已经登录的Pi-k h序列相比在102 bp处存在一个单碱基的变异(由 G突变为C),使得谷氨酸变异为天门冬氨酸,且该变异高度保守.将江苏省粳稻品种中发现的Pi-k h位点的等位基因暂定名为Pi-kh JSJ .%Pi-kh is a vital non race-specific resistance gene for rice blast.In this study,one InDel marker,FM143 was developed based on the 143 bp insertion between the susceptible and resistant Pi-kh alleles.Previous studies showed that Tetep carried resistant Pi-kh allele and had the none-insertion genotype for PCR by FM143.F2 population,derived from Tetep and Ning 9108,were detected by marker FM143 and the result indicated that FM143 could effectively identify Pi-kh/Pi-kh ,Pi-kh/pi-kh and pi-kh/pi-kh genotypes with the expected segregation ratio 1∶2∶1.Sixty-five japonica varieties widely grown in Jiangsu Province over years and sixty-four japonica lines were genotyped by FM143. Among them,19 japonica varieties and 22 japonica lines showed none-insertion genotype.Further sequencing at the target Pi-kh locus for these none-insertion genotype showed that there was one highly conserved single-base mutation (G

  12. Differential Gene Expression Reflects Morphological Characteristics and Physiological Processes in Rice Immunity against Blast Pathogen Magnaporthe oryzae

    OpenAIRE

    Azizi, Parisa; Rafii, Mohd Y.; Mahmood, Maziah; Abdullah, Siti N. A.; Hanafi, Mohamed M.; Nejat, Naghmeh; Latif, Muhammad A.; Sahebi, Mahbod

    2015-01-01

    The rice blast fungus Magnaporthe oryzae is a serious pathogen that jeopardises the world’s most important food-security crop. Ten common Malaysian rice varieties were examined for their morphological, physiological and genomic responses to this rice blast pathogen. qPCR quantification was used to assess the growth of the pathogen population in resistant and susceptible rice varieties. The chlorophyll content and photosynthesis were also measured to further understand the disruptive effects t...

  13. Enhancing disease resistances of Super Hybrid Rice with four antifungal genes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A plant expression vector harboring four antifungal genes was delivered into the embryogenic calli of ‘9311’, an indica restorer line of Super Hybrid Rice, via modified biolistic particle bombardment. Southern blot analysis indicated that in the regenerated hygromycin-resistant plants, all the four anti-fungal genes, including RCH10, RAC22, β-Glu and B-RIP, were integrated into the genome of ‘9311’, co-transmitted altogether with the marker gene hpt in a Mendelian pattern. Some transgenic R1 and R2 progenies, with all transgenes displaying a normal expression level in the Northern blot analysis, showed high resistance to Magnaporthe grisea when tested in the typical blast nurseries located in Yanxi and Sanya respectively. Furthermore, transgenic F1 plants, resulting from a cross of R2 homo-zygous lines with high resistance to rice blast with the non-transgenic male sterile line Peiai 64S, showed not only high resistance to M. grisea but also enhanced resistance to rice false smut (a disease caused by Ustilaginoidea virens) and rice kernel smut (another disease caused by Tilletia barclayana).

  14. Induction of resistance to blast disease (Pyricularia oryzae) in the high yielding variety, Ratna (IR8xTKM6)

    International Nuclear Information System (INIS)

    The high yielding variety, Ratna (IR8 x TKM6), susceptible to blast disease (Pyricularia oryzae Cav.), was taken up for induction of resistance to the disease through EMS treatment. The seeds of individual M1 plants were harvested and grown as M2 generation in a ''uniform blast nursery''. The scoring and classification of blast reaction was done according to the method described by Padmanabhan and Ganguly. The seeds of ''resistant'' selections and ''susceptible'' selections were harvested, grown and tested again in the ''uniform blast nursery'' for M3, M4 and M5 generations. Ratna (untreated) developed 'B', 'C', and 'D' type of spots whereas the EMS-treated populations in all generations, i.e. M2-M4, developed 'O', 'A' and 'E' types of spot, in addition to 'B', 'C' and 'D' types, in both resistant and susceptible selections. This indicated that the chemical mutagen EMS induced variability in both negative and positive directions. In M5 generation, 50 out of 1500 originally selected lines were found to be breeding true for disease resistance. Some mutants retain the grain characters of Ratna, and the high yield. The mutagen treatment also induced variability in grain characters. Ratna has a long slender grain. Some mutants have medium slender, short bold or long bold grain. (author)

  15. Analysis of the Resistance Gene Analogue for Rice Cultivars in Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    SUN Yan; WANG Yun-yue; HE Yue-qiu; FAN Jing-hua; CHEN Jian-bin; ZHU You-yong

    2002-01-01

    Genetic diversity of commercial and local rice cultivars in Yunnan Province was studied using the resistance gene analogue (RGA) based on resistance gene conserved sequences. The RGA analysis of 137cultivars was conducted by PCR amplification using three primers, i.e. S1/AS3, XLRR for/XLRR rev, and Pto-kin1/Pto-kin2, respectively. The results showed that both Indica and Japonica cultivars were genetically highly diverse. All cultivars were divided into 3 lineages according to the DNA band data at 96% dissimilarity,and into 20 lineages at 60% dissimilarity. The lineages were related to their genetic background and blast disease resistance with only a few exceptions. The RGA data can be useful in rice production by mixed-planting of different cultivars in the field and breeding of resistance cultivars by selecting different parental cultivars with great genetic diversity.

  16. Evolutionary dynamics and structure of the rice blast resistance locus Pi-ta in wild, cultivated, and US weedy rice

    Science.gov (United States)

    The Pi-ta gene in rice has been used to control rice blast pathogen, Magnaporthe oryza, in rice growing areas worldwide for decades. To understand the evolutionary process and natural selection of Pi-ta during rice domestication, we first examined sequences of the genomic region of Pi-ta in geograph...

  17. Evaluation of Resistance of Rice to Leaf and Panicle Blast in Mazandaran Province

    OpenAIRE

    M.J. Javan. Nikkhah; M. Okhovat; A. Moumeni; M. Amanzadeh; V. Khosravi

    2008-01-01

      Blast, caused by Magnaprthe grisea, is often an important fungal disease in the production of rice in temperate and tropical areas including Iran. To determine reaction of rice cultivars against blast disease, 40 rice genotypes from Iran and other sources from Asia were selected. Four blast isolates from different races were used to test all rice genotypes in different greenhouse tests. In blast nursery, experiments were conducted in a Randomized Complete Block Design (RCBD) with three repl...

  18. Metagenomic profiling of antibiotic resistance genes and mobile genetic elements in a tannery wastewater treatment plant.

    Directory of Open Access Journals (Sweden)

    Zhu Wang

    Full Text Available Antibiotics are often used to prevent sickness and improve production in animal agriculture, and the residues in animal bodies may enter tannery wastewater during leather production. This study aimed to use Illumina high-throughput sequencing to investigate the occurrence, diversity and abundance of antibiotic resistance genes (ARGs and mobile genetic elements (MGEs in aerobic and anaerobic sludge of a full-scale tannery wastewater treatment plant (WWTP. Metagenomic analysis showed that Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria dominated in the WWTP, but the relative abundance of archaea in anaerobic sludge was higher than in aerobic sludge. Sequencing reads from aerobic and anaerobic sludge revealed differences in the abundance of functional genes between both microbial communities. Genes coding for antibiotic resistance were identified in both communities. BLAST analysis against Antibiotic Resistance Genes Database (ARDB further revealed that aerobic and anaerobic sludge contained various ARGs with high abundance, among which sulfonamide resistance gene sul1 had the highest abundance, occupying over 20% of the total ARGs reads. Tetracycline resistance genes (tet were highly rich in the anaerobic sludge, among which tet33 had the highest abundance, but was absent in aerobic sludge. Over 70 types of insertion sequences were detected in each sludge sample, and class 1 integrase genes were prevalent in the WWTP. The results highlighted prevalence of ARGs and MGEs in tannery WWTPs, which may deserve more public health concerns.

  19. Transcriptomic Analysis and the Expression of Disease-Resistant Genes in Oryza meyeriana under Native Condition.

    Directory of Open Access Journals (Sweden)

    Bin He

    Full Text Available Oryza meyeriana (O. meyeriana, with a GG genome type (2n = 24, accumulated plentiful excellent characteristics with respect to resistance to many diseases such as rice shade and blast, even immunity to bacterial blight. It is very important to know if the diseases-resistant genes exist and express in this wild rice under native conditions. However, limited genomic or transcriptomic data of O. meyeriana are currently available. In this study, we present the first comprehensive characterization of the O. meyeriana transcriptome using RNA-seq and obtained 185,323 contigs with an average length of 1,692 bp and an N50 of 2,391 bp. Through differential expression analysis, it was found that there were most tissue-specifically expressed genes in roots, and next to stems and leaves. By similarity search against protein databases, 146,450 had at least a significant alignment to existed gene models. Comparison with the Oryza sativa (japonica-type Nipponbare and indica-type 93-11 genomes revealed that 13% of the O. meyeriana contigs had not been detected in O. sativa. Many diseases-resistant genes, such as bacterial blight resistant, blast resistant, rust resistant, fusarium resistant, cyst nematode resistant and downy mildew gene, were mined from the transcriptomic database. There are two kinds of rice bacterial blight-resistant genes (Xa1 and Xa26 differentially or specifically expressed in O. meyeriana. The 4 Xa1 contigs were all only expressed in root, while three of Xa26 contigs have the highest expression level in leaves, two of Xa26 contigs have the highest expression profile in stems and one of Xa26 contigs was expressed dominantly in roots. The transcriptomic database of O. meyeriana has been constructed and many diseases-resistant genes were found to express under native condition, which provides a foundation for future discovery of a number of novel genes and provides a basis for studying the molecular mechanisms associated with disease

  20. Tetracycline resistance genes acquired at birth.

    Science.gov (United States)

    Alicea-Serrano, Angela M; Contreras, Mónica; Magris, Magda; Hidalgo, Glida; Dominguez-Bello, Maria G

    2013-06-01

    Newborns acquire their first microbiota at birth. Maternal vaginal or skin bacteria colonize newborns delivered vaginally or by C-section, respectively (Dominguez-Bello et al. 2010 #884). We aimed to determine differences in the presence of four tetracycline (tet) resistance genes, in the microbes of ten newborns and in the mouth and vagina of their mothers, at the time of birth. DNA was amplified by PCR with primers specific for [tet(M), tet(O), tet(Q), and tet(W)]. Maternal vaginas harbored all four tet resistance genes, but most commonly tet(M) and tet(O) (63 and 38 %, respectively). Genes coding for tet resistance differed by birth mode, with 50 % of vaginally delivered babies had tet(M) and tet(O) and 16 and 13 % of infants born by C-section had tet(O) and tet(W), respectively. Newborns acquire antibiotic resistance genes at birth, and the resistance gene profile varies by mode of delivery. PMID:23483141

  1. Structural and functional analysis of the rice blast fungus avirulence gene AVR-Pita

    Science.gov (United States)

    The AVR-Pita gene in Magnaporthe oryzae determines efficacy of resistance stability provided by a major effective resistance gene Pi-ta in rice. AVR-Pita encodes a predicted secreted metalloprotease that appears to interact with the Pi-ta protein, a cytoplamic NBS-LRR protein directly in triggering...

  2. [Genetic analysis of blast resistance in japonica rice landrace heikezijing from Taihu region].

    Science.gov (United States)

    Wang, Jian-Fei; He, Xin-Jian; Zhang, Hong-Sheng; Chen, Zhi-Yi

    2002-09-01

    Japonica rice landrace Heikezijing (HKZJ) from Taihu region is highly resistant to several Chinese and Japanese differential strains of Magnaporthe grisea. The F1, F2 and RIL populations from the cross between the resistant variety Heikezijing and the susceptible variety Lijiangxintuanheigu (LJXTHG) were inoculated by spray with two strains of Ken 54-04 and Hoku 1 in seedling stages. Based on the R:S ratios of segregation in F1, F2 and RIL populations it was showed that there were two independent dominant genes in Heikezijing in responsible for resistance to strain Ken 54-04 and one dominant R gene to strain Hoku 1 which is the same to one of the two genes resistant to Ken 54-04. The allelic test indicated that the gene with resistance to both Hoku 1 and Ken 54-04 is non-allelic to loci of Pi-k, Pi-z, Pi-ta, Pi-b and Pi-t, also neither Pi-i nor Pi-a gene. It is necessary to confirm whether it is an unknown gene. PMID:12561228

  3. Multiple translocation of the AVR-Pita effector gene among chromosomes of the rice blast fungus Magnaporthe oryzae and related species.

    Directory of Open Access Journals (Sweden)

    Izumi Chuma

    2011-07-01

    Full Text Available Magnaporthe oryzae is the causal agent of rice blast disease, a devastating problem worldwide. This fungus has caused breakdown of resistance conferred by newly developed commercial cultivars. To address how the rice blast fungus adapts itself to new resistance genes so quickly, we examined chromosomal locations of AVR-Pita, a subtelomeric gene family corresponding to the Pita resistance gene, in various isolates of M. oryzae (including wheat and millet pathogens and its related species. We found that AVR-Pita (AVR-Pita1 and AVR-Pita2 is highly variable in its genome location, occurring in chromosomes 1, 3, 4, 5, 6, 7, and supernumerary chromosomes, particularly in rice-infecting isolates. When expressed in M. oryzae, most of the AVR-Pita homologs could elicit Pita-mediated resistance, even those from non-rice isolates. AVR-Pita was flanked by a retrotransposon, which presumably contributed to its multiple translocation across the genome. On the other hand, family member AVR-Pita3, which lacks avirulence activity, was stably located on chromosome 7 in a vast majority of isolates. These results suggest that the diversification in genome location of AVR-Pita in the rice isolates is a consequence of recognition by Pita in rice. We propose a model that the multiple translocation of AVR-Pita may be associated with its frequent loss and recovery mediated by its transfer among individuals in asexual populations. This model implies that the high mobility of AVR-Pita is a key mechanism accounting for the rapid adaptation toward Pita. Dynamic adaptation of some fungal plant pathogens may be achieved by deletion and recovery of avirulence genes using a population as a unit of adaptation.

  4. Rice OsVAMP714, a membrane-trafficking protein localized to the chloroplast and vacuolar membrane, is involved in resistance to rice blast disease.

    Science.gov (United States)

    Sugano, Shoji; Hayashi, Nagao; Kawagoe, Yasushi; Mochizuki, Susumu; Inoue, Haruhiko; Mori, Masaki; Nishizawa, Yoko; Jiang, Chang-Jie; Matsui, Minami; Takatsuji, Hiroshi

    2016-05-01

    Membrane trafficking plays pivotal roles in many cellular processes including plant immunity. Here, we report the characterization of OsVAMP714, an intracellular SNARE protein, focusing on its role in resistance to rice blast disease caused by the fungal pathogen Magnaporthe oryzae. Disease resistance tests using OsVAMP714 knockdown and overexpressing rice plants demonstrated the involvement of OsVAMP714 in blast resistance. The overexpression of OsVAMP7111, whose product is highly homologous to OsVAMP714, did not enhance blast resistance to rice, implying a potential specificity of OsVAMP714 to blast resistance. OsVAMP714 was localized to the chloroplast in mesophyll cells and to the cellular periphery in epidermal cells of transgenic rice plant leaves. We showed that chloroplast localization is critical for the normal OsVAMP714 functioning in blast resistance by analyzing the rice plants overexpressing OsVAMP714 mutants whose products did not localize in the chloroplast. We also found that OsVAMP714 was located in the vacuolar membrane surrounding the invasive hyphae of M. oryzae. Furthermore, we showed that OsVAMP714 overexpression promotes leaf sheath elongation and that the first 19 amino acids, which are highly conserved between animal and plant VAMP7 proteins, are crucial for normal rice plant growths. Our studies imply that the OsVAMP714-mediated trafficking pathway plays an important role in rice blast resistance as well as in the vegetative growth of rice. PMID:26879413

  5. Metagenomic analysis of cadmium and copper resistance genes in activated sludge of a tannery wastewater treatment plant.

    Science.gov (United States)

    Jia, Shuyu; Wang, Zhu; Zhang, Xu-Xiang; Liu, Bo; Li, Weixin; Cheng, Shupei

    2013-04-01

    In order to comprehensively characterize the copper and cadmium resistance in activated sludge of a tannery wastewater treatment plant, a resistance protein database of the two heavy metals was manually created by retrieving annotated sequences and related information from the public databases and published literatures. The metagenomic DNA was extracted from the activated sludge for Illumina high-throughput sequencing, and the obtained 11,973,394 clean reads (1.61 Gb) were compared against the established databases using BLAST tool. Annotations of the BLAST hits showed that 222 reads (0.019 per thousand) and 197 reads (0.016 per thousand) were identified as copper and cadmium resistance genes, respectively. Among the identified cadmium resistance genes, czcA encoding cobalt-zinc-cadmium resistance protein had the highest abundance (83 reads, 0.0069 per thousand), which was further confirmed by annotation of the open reading frames predicted with the assembly contigs. Among the copper resistance genes, copA (66 reads, 0.0055 per thousand) was most abundant, followed by copK and cusR. Alignment against the Clusters of Orthologous Groups (COG) database also suggested that 87.26% of the matched reads were grouped in COG0474 (cation transport ATPase). This study may be practically helpful for exploring various functional genes in the environment using high-throughput sequencing and bioinformatics methods. PMID:24620608

  6. Induction of resistance to blast disease in an elite rice cultivar 'IR 50'

    International Nuclear Information System (INIS)

    Full text: One of the most promising techniques for producing disease resistant forms of plants is the use of mutagenic agents. It has been demonstrated by several workers that genetic variability for several desired characters can be induced successfully through mutations and its practical value in plant improvement programmes has been well established. The main advantage of mutation breeding is the possibility of improving one or two characters without changing the rest of the genotype. The elite cultivar, 'IR 50' (IR 2153-14-1-6-2/IR 28//IR 36) was developed at IRRI, Los Banos, The Philippines and was released in India for the State of Tamil Nadu in 1982. It is highly responsive to fertilizer, records high yields and possesses good grain characters. It matured in just more than 100 days and was ideal for both samba and navarai seasons in Tamil Nadu. But, the cultivar was shown to be highly susceptible to blast (causative organism Magnaportha grisea) causing extensive losses year after year. With the objective of developing high yielding, blast tolerant mutant lines from IR 50, the mutation approach was adopted and both physical (gamma-rays from 60Co) and chemical mutagens (EMS - ethyl methanesulphonate and sodium azide) were employed on dry seeds. The M1 generation was grown in closely spaced plants. One hundred and sixty-eight derived families were grown in M2. In M3 generation, 128 M3 families were further selected for evaluation in M4 and M5. Based on evaluation of yield and other attributes, a total of 85 mutants were finally selected and evaluated for their stability. In selection of the mutants, it was ensured that all the selected mutants resemble the parent for both agronomic and quality characteristics. The evaluation of these mutant lines for the level of tolerance to blast disease was conducted at CRRI over a number of years under both artificial and natural conditions. These mutant lines showed varied levels of tolerance to blast in comparison to

  7. Induction of resistance to blast disease (Pyricularia oryzae Cav.) in the high yielding variety, Ratna (IR 8 x TKM 6)

    International Nuclear Information System (INIS)

    The popular high yielding variety, Ratna (IR 8 x TKM 6), with a duration of 110 days, is susceptible to blast disease, (Pyricularia oryzae). Dehusked seeds of Ratna were pre-soaked in distilled water for 4 hours and then subjected to 0.1% and 0.2% EMS for 6 hours. The percentage of germination was lower in 0.2% EMS but survival higher. Seedlings of M1 were raised in pots and panicles of individual plants were harvested separately for M2 generation. The seeds of M2 generation were grown in ''Uniform Blast Nursery'' for observing blast disease reaction. Seeds of resistant plants were harvested and grown in M3 generation. Some susceptible plants were also carried forward to M3 generation. Ratna control (untreated) developed ''B'', ''C'' and ''D'' type spots. The EMS treated population (8000 plants) developed in addtion, ''O'', ''A'' as well as ''E'' type spots, showing a wider range of variability than the untreated control regarding resistance and susceptibility. Three hundred resistant plants (with ''O, ''A'' and ''B'' type of spots) from M2 were carried forward to M3 generation. These also segregated giving a range of reaction from 0-E spots as in the case of M2. The population of resistant plants was higher in M3 (31.65%) than in M2 (23.6%). The progenies of a few plants (50 plants) found susceptible in M2 also segregated in M3 towards resistance, but the percentage of resistant plants was low (7.6%)

  8. BREEDING FOR DURABLE RESISTANCE TO RICE BLAST DISEASE-DREAM OR REALITY? J.M. BONMAN (1) & H. LEUNG (2). (1) USDA-ARS, SMALL GRAINS & POTATO GERMPLASM RESEARCH UNIT, ABERDEEN, ID;(2)INTL RICE RES INSTITUTE, MANILA, PHILLIPINES

    Science.gov (United States)

    Rice cultivars with durable resistance to blast disease have been identified in certain production environments. In cultivars such as IR36, durability is associated with partial resistance that is quantitatively inherited. Selecting for such resistance has reduced the impact of rice blast in tropi...

  9. High-resolution mapping, cloning and molecular characterization of the Pi-k ( h ) gene of rice, which confers resistance to Magnaporthe grisea.

    Science.gov (United States)

    Sharma, T R; Madhav, M S; Singh, B K; Shanker, P; Jana, T K; Dalal, V; Pandit, A; Singh, A; Gaikwad, K; Upreti, H C; Singh, N K

    2005-12-01

    In order to understand the molecular mechanisms involved in the gene-for-gene type of pathogen resistance, high-resolution genetic and physical mapping of resistance loci is required to facilitate map-based cloning of resistance genes. Here, we report the molecular mapping and cloning of a dominant gene (Pi-k ( h )) present in the rice line Tetep, which is associated with resistance to rice blast disease caused by Magnaporthe grisea. This gene is effective against M. grisea populations prevalent in the Northwestern Himalayan region of India. Using 178 sequence tagged microsatellite, sequence-tagged site, expressed sequence tag and simple sequence repeat (SSR) markers to genotype a population of 208 F(2) individuals, we mapped the Pi-k ( h ) gene between two SSR markers (TRS26 and TRS33) which are 0.7 and 0.5 cM away, respectively, and can be used in marker-assisted-selection for blast-resistant rice cultivars. We used the markers to identify the homologous region in the genomic sequence of Oryza sativa cv. Nipponbare, and a physical map consisting of two overlapping bacterial artificial chromosome and P1 artificial chromosome clones was assembled, spanning a region of 143,537 bp on the long arm of chromosome 11. Using bioinformatic analyses, we then identified a candidate blast-resistance gene in the region, and cloned the homologous sequence from Tetep. The putative Pi-k ( h ) gene cloned from Tetep is 1.5 kbp long with a single ORF, and belongs to the nucleotide binding site-leucine rich repeat class of disease resistance genes. Structural and expression analysis of the Pi-k ( h ) gene revealed that its expression is pathogen inducible. PMID:16228246

  10. Enhancing rice resistance to fungal pathogens by transformation with cell wall degrading enzyme genes from Trichoderma atroviride

    Institute of Scientific and Technical Information of China (English)

    刘梅; 孙宗修; 朱洁; 徐同; HARMANGaryE; LORITOMatteo

    2004-01-01

    Three genes encoding for fungal cell wall degrading enzymes (CWDEs), ech42, nag70 and gluc78 from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possible combinations and transformed to rice plants. More than 1800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. The ech42 gene encoding for an endochitinase increased resistance to sheath blight caused by Rhizoctonia solani, while the exochitinase-encoding gene, nag70, had lesser effect. The expression level of endochitinase but exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the effect of endochitinase on disease resistance when the two genes co-expressed in transgenics. Resistance to Magnaporthe grisea was found in all kinds of regenerated plants including that with single gluc78. A few lines expressing either ech42 or nag70 gene were immune to the disease. Transgenic plants are being tested to further evaluate disease resistance at field level. This is the first report of multiple of expression of genes encoding CWDEs from Trichoderma atroviride that result in resistance to blast and sheath blight in rice.

  11. Antibiotic Resistance in Wastewater : Methicillin-resistant Staphylococcus aureus (MRSA)and antibiotic resistance genes

    OpenAIRE

    Börjesson, Stefan

    2009-01-01

    A large part of the antibiotics consumed ends up in wastewater, and in the wastewater the antibiotics may exert selective pressure for or maintain resistance among microorganisms. Antibiotic resistant bacteria and genes encoding antibiotic resistance are commonly detected in wastewater, often at higher rates and concentrations compared to surface water. Wastewater can also provide favourable conditions for the growth of a diverse bacterial community, which constitutes a basis for the selectio...

  12. A set of vectors for introduction of antibiotic resistance genes by in vitro Cre-mediated recombination

    Directory of Open Access Journals (Sweden)

    Vassetzky Yegor S

    2008-12-01

    Full Text Available Abstract Background Introduction of new antibiotic resistance genes in the plasmids of interest is a frequent task in molecular cloning practice. Classical approaches involving digestion with restriction endonucleases and ligation are time-consuming. Findings We have created a set of insertion vectors (pINS carrying genes that provide resistance to various antibiotics (puromycin, blasticidin and G418 and containing a loxP site. Each vector (pINS-Puro, pINS-Blast or pINS-Neo contains either a chloramphenicol or a kanamycin resistance gene and is unable to replicate in most E. coli strains as it contains a conditional R6Kγ replication origin. Introduction of the antibiotic resistance genes into the vector of interest is achieved by Cre-mediated recombination between the replication-incompetent pINS and a replication-competent target vector. The recombination mix is then transformed into E. coli and selected by the resistance marker (kanamycin or chloramphenicol present in pINS, which allows to recover the recombinant plasmids with 100% efficiency. Conclusion Here we propose a simple strategy that allows to introduce various antibiotic-resistance genes into any plasmid containing a replication origin, an ampicillin resistance gene and a loxP site.

  13. Multiple Dissipative Devices for Blast-Resisting Cable-Supported Glazing Façades

    OpenAIRE

    Claudio Amadio; Chiara Bedon

    2013-01-01

    The paper analyzes the structural response of a high-level air blast loaded cable-supported façade. Since the glass panels and the cables present a typical brittle behavior and are subjected to elevated tensile stresses when a high-level explosion occurs, multiple dissipative devices are simultaneously introduced in the conventional glazing system to mitigate the maximum effects of the design blast wave. Dynamic analyses are performed using a sophisticated FE-model to describe accurately the ...

  14. Analysis of plasmid genes by phylogenetic profiling and visualization of homology relationships using Blast2Network

    Directory of Open Access Journals (Sweden)

    Bazzicalupo Marco

    2008-12-01

    Full Text Available Abstract Background Phylogenetic methods are well-established bioinformatic tools for sequence analysis, allowing to describe the non-independencies of sequences because of their common ancestor. However, the evolutionary profiles of bacterial genes are often complicated by hidden paralogy and extensive and/or (multiple horizontal gene transfer (HGT events which make bifurcating trees often inappropriate. In this context, plasmid sequences are paradigms of network-like relationships characterizing the evolution of prokaryotes. Actually, they can be transferred among different organisms allowing the dissemination of novel functions, thus playing a pivotal role in prokaryotic evolution. However, the study of their evolutionary dynamics is complicated by the absence of universally shared genes, a prerequisite for phylogenetic analyses. Results To overcome such limitations we developed a bioinformatic package, named Blast2Network (B2N, allowing the automatic phylogenetic profiling and the visualization of homology relationships in a large number of plasmid sequences. The software was applied to the study of 47 completely sequenced plasmids coming from Escherichia, Salmonella and Shigella spps. Conclusion The tools implemented by B2N allow to describe and visualize in a new way some of the evolutionary features of plasmid molecules of Enterobacteriaceae; in particular it helped to shed some light on the complex history of Escherichia, Salmonella and Shigella plasmids and to focus on possible roles of unannotated proteins. The proposed methodology is general enough to be used for comparative genomic analyses of bacteria.

  15. Candidate Gene Identification with SNP Marker-Based Fine Mapping of Anthracnose Resistance Gene Co-4 in Common Bean.

    Directory of Open Access Journals (Sweden)

    Andrew J Burt

    Full Text Available Anthracnose, caused by Colletotrichum lindemuthianum, is an important fungal disease of common bean (Phaseolus vulgaris. Alleles at the Co-4 locus confer resistance to a number of races of C. lindemuthianum. A population of 94 F4:5 recombinant inbred lines of a cross between resistant black bean genotype B09197 and susceptible navy bean cultivar Nautica was used to identify markers associated with resistance in bean chromosome 8 (Pv08 where Co-4 is localized. Three SCAR markers with known linkage to Co-4 and a panel of single nucleotide markers were used for genotyping. A refined physical region on Pv08 with significant association with anthracnose resistance identified by markers was used in BLAST searches with the genomic sequence of common bean accession G19833. Thirty two unique annotated candidate genes were identified that spanned a physical region of 936.46 kb. A majority of the annotated genes identified had functional similarity to leucine rich repeats/receptor like kinase domains. Three annotated genes had similarity to 1, 3-β-glucanase domains. There were sequence similarities between some of the annotated genes found in the study and the genes associated with phosphoinositide-specific phosphilipases C associated with Co-x and the COK-4 loci found in previous studies. It is possible that the Co-4 locus is structured as a group of genes with functional domains dominated by protein tyrosine kinase along with leucine rich repeats/nucleotide binding site, phosphilipases C as well as β-glucanases.

  16. Coincidence in map positions between pathogen-induced defense-responsive genes and quantitative resistance loci in rice

    Institute of Scientific and Technical Information of China (English)

    XIONG; Min(熊敏); WANG; Shiping(王石平); ZHANG; Qifa(张启发)

    2002-01-01

    Quantitative disease resistance conferred by quantitative trait loci (QTLs) is presumably of wider spectrum and durable. Forty-four cDNA clones, representing 44 defense-responsive genes, were fine mapped to 56 loci distributed on 9 of the 12 rice chromosomes. The locations of 32 loci detected by 27 cDNA clones were associated with previously identified resistance QTLs for different rice diseases, including blast, bacterial blight, sheath blight and yellow mottle virus. The loci detected by the same multiple-copy cDNA clones were frequently located on similar locations of different chromosomes. Some of the multiple loci detected by the same clones were all associated with resistance QTLs. These results suggest that some of the genes may be important components in regulation of defense responses against pathogen invasion and they may be the candidates for studying the mechanism of quantitative disease resistance in rice.

  17. Detection of the common resistance genes in Gram-negative bacteria using gene chip technology

    OpenAIRE

    Ting, C.; A Jun; Z Shun

    2013-01-01

    Objective: To design a resistance gene detection chip that could, in parallel, detect common clinical drug resistance genes of Gram-negative bacteria. Materials and Methods: Seventy clinically significant Gram-negative bacilli (Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae, Pseudomonas aeruginosa, Acinetobacter baumannii) were collected. According to the known resistance gene sequences, we designed and synthesized primers and probes, which were used to prepare resistance gene ...

  18. Histochemical aspects of wheat resistance to leaf blast mediated by silicon

    OpenAIRE

    Washington Luís da Silva; Maria Fernanda Antunes Cruz; Alessandro Antônio Fortunato; Fabrício Ávila Rodrigues

    2015-01-01

    Blast, caused by Pyricularia oryzae, has become a significant disease threat to wheat (Triticum aestivum L.) in Brazil. This study aimed to investigate at the histochemical level if silicon (Si) could enhance the production of flavonoids in the leaves of wheat plants in response to P. oryzae infection. Plants from the Aliança cultivar, which are susceptible to blast, were grown in hydroponic cultures containing 0 (-Si) or 2 mM of Si (+Si) and inoculated by spraying a conidial suspension of P....

  19. Major gene for field stem rust resistance co-locates with resistance gene Sr12 in "Thatcher" wheat

    Science.gov (United States)

    Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effecting stem rust resistance genes. "Thatcher" wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was ...

  20. Functional study of the novel multidrug resistance gene HA117 and its comparison to multidrug resistance gene 1

    OpenAIRE

    Chen Tingfu; Guo Zhenhua; Liang Rui; Guo Yuxia; Xu Youhua; Jin Xianqing; Zhao Lihua; Sun Yanhui; Ding Xionghui

    2010-01-01

    Abstract Background The novel gene HA117 is a multidrug resistance (MDR) gene expressed by all-trans retinoic acid-resistant HL-60 cells. In the present study, we compared the multidrug resistance of the HA117 with that of the classical multidrug resistance gene 1 (MDR1) in breast cancer cell line 4T1. Methods Transduction of the breast cancer cell line 4T1 with adenoviral vectors encoding the HA117 gene and the green fluorescence protein gene (GFP) (Ad-GFP-HA117), the MDR1 and GFP (Ad-GFP-MD...

  1. Transcriptomic analyses of space-induced rice mutants with enhanced susceptibility to rice blast

    Science.gov (United States)

    Cheng, Zhenlong; Liu, Ming; Zhang, Meng; Hang, Xiaoming; Lei, Cailin; Sun, Yeqing

    Mutagenic factors of the space environment influence organisms in different aspects. To elucidate the transcriptomic effects of space flight, a space flight-induced rice mutant, 972-4, and its on-ground control, 972ck, were inoculated with rice blast pathogens. Compared to the control, the mutant exhibited reduced resistance to the rice blast pathogen CH45. Microarray technique was employed to analyze affected genes and revealed that 481 genes were expressed at higher levels in the mutant strain and 188 genes were expressed at higher levels in the control strain under normal growth conditions, indicating that transcriptomic changes of rice seeds are induced by the space environment. After inoculation with the rice blast pathogen CH45, however, 2680 genes were differentially expressed in 972ck and 1863 genes were differentially expressed in 972-4. In addition, disease evaluation indicated that the control strain 972ck is more resistant to the rice blast pathogen CH45 than mutant strain 972-4. In addition, genes in both strains that were co-regulated after blast inoculation account for only 36.8% and 53.3% of the genes expressed in 972ck and 972-4, respectively. A large percentage of blast-regulated genes were not consistently expressed in 972-4 and 972ck, and the mutant and control strains exhibit different gene expression patterns after blast inoculation. Interestingly, 84 genes constitutively expressed higher in 972ck were up-regulated by blast inoculation, and 105 genes that were expressed at constitutively higher levels in 972-4 were down-regulated by blast inoculation. Of the differentially expressed, 7 encoded genes associated with pathogen resistance. Taken together, our results suggest that gene expression patterns are different between a space flight-induced rice mutant and its on-ground control, and the differential expression of resistance genes may be a potential mechanism that modulates the resistance of 972-4 to rice blast. Our results also suggest

  2. Detection of the common resistance genes in Gram-negative bacteria using gene chip technology

    Directory of Open Access Journals (Sweden)

    C Ting

    2013-01-01

    Full Text Available Objective: To design a resistance gene detection chip that could, in parallel, detect common clinical drug resistance genes of Gram-negative bacteria. Materials and Methods: Seventy clinically significant Gram-negative bacilli (Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae, Pseudomonas aeruginosa, Acinetobacter baumannii were collected. According to the known resistance gene sequences, we designed and synthesized primers and probes, which were used to prepare resistance gene detection chips, and finally we hybridized and scanned the gene detection chips. Results: The results between the gene chip and polymerase chain reaction (PCR were compared. The rate was consistently 100% in the eight kinds of resistance genes tested (TEM, SHV, CTX-M, DHA, CIT, VIM, KPC, OXA-23. One strain of Pseudomonas aeruginosa had the IMP, but it was not found by gene chip. Conclusion: The design of Gram-negative bacteria-resistant gene detection chip had better application value.

  3. Preformed expression of defense is a hallmark of partial resistance to rice blast fungal pathogen Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Tharreau D

    2010-09-01

    Full Text Available Abstract Background Partial resistance to plant pathogens is extensively used in breeding programs since it could contribute to resistance durability. Partial resistance often builds up during plant development and confers quantitative and usually broad-spectrum resistance. However, very little is known on the mechanisms underlying partial resistance. Partial resistance is often explained by poorly effective induction of plant defense systems. By exploring rice natural diversity, we asked whether expression of defense systems before infection could explain partial resistance towards the major fungal pathogen Magnaporthe oryzae. The constitutive expression of 21 defense-related genes belonging to the defense system was monitored in 23 randomly sampled rice cultivars for which partial resistance was measured. Results We identified a strong correlation between the expression of defense-related genes before infection and partial resistance. Only a weak correlation was found between the induction of defense genes and partial resistance. Increasing constitutive expression of defense-related genes also correlated with the establishment of partial resistance during plant development. Some rice genetic sub-groups displayed a particular pattern of constitutive expression, suggesting a strong natural polymorphism for constitutive expression of defense. Constitutive levels of hormones like salicylic acid and ethylene cannot explain constitutive expression of defense. We could identify an area of the genome that contributes to explain both preformed defense and partial resistance. Conclusion These results indicate that constitutive expression of defense-related genes is likely responsible for a large part of partial resistance in rice. The finding of this preformed defense system should help guide future breeding programs and open the possibility to identify the molecular mechanisms behind partial resistance.

  4. Occurrence of integrons and resistance genes among sulphonamide-resistant Shigella spp. from Brazil

    DEFF Research Database (Denmark)

    Peirano, G.; Agersø, Yvonne; Aarestrup, Frank Møller;

    2005-01-01

    2214 bp harbouring a gene cassette array conferring resistance to trimethoprim, streptothricin and spectinomycin/streptomycin. The genes coding for resistance to chloramphenicol (catA1), tetracycline [tet(A) and tet(B)] and ampicillin (bla(OXA) and bla(TEM)), were detected in resistant strains...

  5. Identification of genes contributing to quantitative disease resistance in rice

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Despite the importance of quantitative disease resistance during a plant’s life, little is known about the molecular basis of this type of host-pathogen interaction, because most of the genes underlying resistance quantitative trait loci (QTLs) are unknown. To identify genes contributing to resistance QTLs in rice, we analyzed the colocalization of a set of characterized rice defense-responsive genes and resistance QTLs against different pathogens. We also examined the expression patterns of these genes in response to pathogen infection in the parents of the mapping populations, based on the strategy of validation and functional analysis of the QTLs. The results suggest that defense-responsive genes are important resources of resistance QTLs in rice. OsWRKY45-1 is the gene contributing to a major resistance QTL.NRR,OsGH3-1,and OsGLP members on chromosome 8 contribute alone or collectively to different minor resistance QTLs. These genes function in a basal resistance pathway or in major disease resistance gene-mediated race-specific pathways.

  6. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    Science.gov (United States)

    Mahadtanapuk, S.; Teraarusiri, W.; Phanchaisri, B.; Yu, L. D.; Anuntalabhochai, S.

    2013-07-01

    Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60-80 keV to a beam fluence range of 2 × 1016-2 × 1017 ions/cm2. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 106 spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11).

  7. Molecular markers for leaf rust resistance genes in wheat.

    Science.gov (United States)

    Chełkowski, J; Stepień, L

    2001-01-01

    Over 100 genes of resistance to rust fungi: Puccinia recondita f. sp. tritici, (47 Lr - leaf rust genes), P. striiformis (18 Yr - yellow rust genes) and P. graminis f. sp. tritici (41 Sr - stripe rust genes) have been identified in wheat (Triticum aestivum L.) and its wild relatives according to recent papers. Sixteen Lr resistance genes have been mapped using restriction fragments length polymorphism (RFLP) markers on wheat chromosomes. More than ten Lr genes can be identified in breeding materials by sequence tagged site (STS) specific markers. Gene Lrk 10, closely linked to gene Lr 10, has been cloned and its function recognized. Available markers are presented in this review. The STS, cleaved amplified polymorphic sequence (CAPS) and sequence characterized amplified regions (SCAR) markers found in the literature should be verified using Triticum spp. with different genetic background. Simple sequence repeats (SSR) markers for Lr resistance genes are now also available. PMID:14564046

  8. Horizontal gene transfer—emerging multidrug resistance in hospital bacteria

    Institute of Scientific and Technical Information of China (English)

    SenkaDZIDIC; VladimirBEDEKOVIC

    2003-01-01

    The frequency and spectrum of antibiotic resistant infections have increased worldwide during the past few decades. This increase has been attributed to a combination of microbial characteristics, the selective pressure of antimicrobial use, and social and technical changes that enhance the transmission of resistant organisms. The resistance is acquired by mutational changer or by the acquisition of resistance-encoding genetic material which is transfered from another bacteria. The spread of antibiotic resistance genes may be causally related to the overuse of antibiotics in human health care and in animal feeds, increased use of invasive devices and procedures, a greater number of susceptible hosts, and lapses in infection control practices leading to increased transmission of resistant organisms. The resistance gene sequences are integrated by recombination into several classes of naturally occurring gene expression cassettes and disseminated within the microbial population by horizontal gene transfer mechanisms: transformation, conjugation or transduction. In the hospital, widespread use of antimicrobials in the intensive care units (ICU) and for immunocompromised patients has resulted in the selection of multidrug-resistant organisms. Methicilin-resistant Staphylococci, vancomycin resistant Enterococci and extended-spectrum betalactamase(ESBL) producing Gram negative bacilli are identified as major phoblem in nosocomial infections. Recent surveillance studies have demonstrated trend towares more seriously ill patients suffering from multidrug-resistant nosocomial infections. Emergence of multiresistant bacteria and spread of resistance genes should enforce the aplication of strict prevention strategies, including changes in antibiotic treatment regimens, hygiene measures, infection prevention and control of horizontal nosocomial transmission of organisms.

  9. Adenovirus-mediated human β-nerve growth factor gene transfer has a protective effect on cochlear spiral ganglion after blast exposure

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective: To study whether adenovirus-mediated human β-nerve growth factor (Ad-hNGFβ) gene has any protective effect on blast hearing impairment. Methods:Deafness was induced by blast exposure (172. 0 dB) in 30 healthy guinea pigs. On day 7 of blast exposure, Ad-hNGFβ was infused into the perilymphatic space of 20 animals as the study group (hNGFβ group), and artificial perilymph fluid (APF) was infused into the perilymphatic space of the other 10 animals as the control group. At weeks 1, 4 and 8 after blast exposure, the animals were sacrificed and the cochleae were removed for immunohis-tochemical and HE stainings. Results: Expression of Ad-hNGFβ protein was detected in each turn of the cochlea at the 1st week, with almost equal intensity in all turns. At the 4th week, the reactive intensity of the expression of Ad-hNGFβ protein decreased. At the 8th week, no expression was detectable. The results of HE staining showed that the amount of spiral ganglions in hNGFβ group was significantly greater than that of the control group at week 4 (F<0. 01). Conclusion: Ad-hNGFβ can be expressed at a high level and for a relatively long period in the blast impaired cochlea, suggesting that Ad-hNGFβ has a protective effect on cochlear spiral ganglion cells after blast exposure and the efficient gene transfer into cochlea had been achieved without toxicity.

  10. Gene-Drug Interactions and the Evolution of Antibiotic Resistance

    OpenAIRE

    Palmer, Adam Christopher

    2012-01-01

    The evolution of antibiotic resistance is shaped by interactions between genes, the chemical environment, and an antibiotic's mechanism of action. This thesis explores these interactions with experiments, theory, and analysis, seeking a mechanistic understanding of how different interactions between genes and drugs can enhance or constrain the evolution of antibiotic resistance. Chapter 1 investigates the effects of the chemical decay of an antibiotic. Tetracycline resistant and sensitive bac...

  11. Studies on the corrosion resistance of reinforced steel in concrete with ground granulated blast-furnace slag--An overview.

    Science.gov (United States)

    Song, Ha-Won; Saraswathy, Velu

    2006-11-16

    The partial replacement of clinker, the main constituent of ordinary Portland cement by pozzolanic or latent hydraulic industrial by-products such as ground granulated blast furnace slag (GGBFS), effectively lowers the cost of cement by saving energy in the production process. It also reduces CO2 emissions from the cement plant and offers a low priced solution to the environmental problem of depositing industrial wastes. The utilization of GGBFS as partial replacement of Portland cement takes advantage of economic, technical and environmental benefits of this material. Recently offshore, coastal and marine concrete structures were constructed using GGBFS concrete because high volume of GGBFS can contribute to the reduction of chloride ingress. In this paper, the influence of using GGBFS in reinforced concrete structures from the durability aspects such as chloride ingress and corrosion resistance, long term durability, microstructure and porosity of GGBFS concrete has been reviewed and discussed. PMID:16930831

  12. Amplification of a Gene Related to Mammalian mdr Genes in Drug-Resistant Plasmodium falciparum

    Science.gov (United States)

    Wilson, Craig M.; Serrano, Adelfa E.; Wasley, Annemarie; Bogenschutz, Michael P.; Shankar, Anuraj H.; Wirth, Dyann F.

    1989-06-01

    The malaria parasite Plasmodium falciparum contains at least two genes related to the mammalian multiple drug resistance genes, and at least one of the P. falciparum genes is expressed at a higher level and is present in higher copy number in a strain that is resistant to multiple drugs than in a strain that is sensitive to the drugs.

  13. Plasmid encoded antibiotic resistance: acquisition and transfer of antibiotic resistance genes in bacteria.

    Science.gov (United States)

    Bennett, P M

    2008-03-01

    Bacteria have existed on Earth for three billion years or so and have become adept at protecting themselves against toxic chemicals. Antibiotics have been in clinical use for a little more than 6 decades. That antibiotic resistance is now a major clinical problem all over the world attests to the success and speed of bacterial adaptation. Mechanisms of antibiotic resistance in bacteria are varied and include target protection, target substitution, antibiotic detoxification and block of intracellular antibiotic accumulation. Acquisition of genes needed to elaborate the various mechanisms is greatly aided by a variety of promiscuous gene transfer systems, such as bacterial conjugative plasmids, transposable elements and integron systems, that move genes from one DNA system to another and from one bacterial cell to another, not necessarily one related to the gene donor. Bacterial plasmids serve as the scaffold on which are assembled arrays of antibiotic resistance genes, by transposition (transposable elements and ISCR mediated transposition) and site-specific recombination mechanisms (integron gene cassettes).The evidence suggests that antibiotic resistance genes in human bacterial pathogens originate from a multitude of bacterial sources, indicating that the genomes of all bacteria can be considered as a single global gene pool into which most, if not all, bacteria can dip for genes necessary for survival. In terms of antibiotic resistance, plasmids serve a central role, as the vehicles for resistance gene capture and their subsequent dissemination. These various aspects of bacterial resistance to antibiotics will be explored in this presentation. PMID:18193080

  14. Determination of rust resistance genes in pakistani bread wheats

    International Nuclear Information System (INIS)

    Stripe and leaf rusts are the major constraints to bread wheat production in Pakistan. Molecular markers were used to investigate the presence of leaf rust and stripe rust resistance gene cluster Lr34/Yr18 and stem rust resistance gene Sr2 in 52 Pakistani bread wheat cultivars/lines. PCR amplification of DNA fragments using DNA marker csLV-34 showed that 13 of the studied cultivars/lines, namely 03FJ26, NR 337, NR 339, NR 347, NR 350, Manthar, Margalla 99, Iqbal 2000, Saleem 2000, Wafaq 2001, Marwat 2001, Pirsabak 2004 and Fareed 2006 carry leaf rust and stripe rust resistance genes Lr34/Yr18. Stem rust resistance gene Sr2 was observed in 36 Pakistani spring wheat cultivars/lines using stm560.3tgag marker. The slow rusting gene Sr2 needs to be combined with additional stem rust resistance genes to establish durable resistance against Ug99 in modern wheat cultivars. Low frequency of Lr34/Yr18 was found in Pakistani wheats. This gene cluster needs to be incorporated into Pakistani wheats for durable rust resistance. (author)

  15. Novel aerobic tetracycline resistance gene that chemically modifies tetracycline.

    OpenAIRE

    Speer, B S; Salyers, A A

    1989-01-01

    A tetracycline resistance gene that was found originally on the Bacteroides plasmid pBF4 confers resistance on Escherichia coli but only when cells are growing aerobically. When E. coli EM24 carrying this aerobic tetracycline resistance (*Tcr) gene is grown in medium containing tetracycline, the resulting spent medium is no longer toxic to tetracycline-sensitive (Tcs) E. coli EM24 (B.S. Speer and A.A. Salyers, J. Bacteriol. 170: 1423-1429, 1988). To determine whether the *Tcr gene product mod...

  16. Design of Cellular Composite Sandwich Panels for Maximum Blast Resistance Via Energy Absorption

    Science.gov (United States)

    McConnell, Jennifer Righman; Su, Hong

    2016-06-01

    This paper presents a design methodology for optimizing the energy absorption under blast loads of cellular composite sandwich panels. A combination of dynamic finite element analysis (FEA) and simplified analytical modeling techniques are used. The analytical modeling calculates both the loading effects and structural response resulting from user-input charge sizes and standoff distances and offers the advantage of expediting iterative design processes. The FEA and the analytical model results are compared and contrasted then used to compare the energy response of various cellular composite sandwich panels under blast loads, where various core shapes and dimensions are the focus. As a result, it is concluded that the optimum shape consists of vertically-oriented webs while the optimum dimensions can be generally described as those which cause the most inelasticity without failure of the webs. These dimensions are also specifically quantified for select situations. This guidance is employed, along with the analytical method developed by the authors and considerations of the influences of material properties, to suggest a general design procedure that is a simple yet sufficiently accurate method for design. The suggested design approach is also demonstrated through a design example.

  17. Multiple Dissipative Devices for Blast-Resisting Cable-Supported Glazing Façades

    Directory of Open Access Journals (Sweden)

    Claudio Amadio

    2013-01-01

    Full Text Available The paper analyzes the structural response of a high-level air blast loaded cable-supported façade. Since the glass panels and the cables present a typical brittle behavior and are subjected to elevated tensile stresses when a high-level explosion occurs, multiple dissipative devices are simultaneously introduced in the conventional glazing system to mitigate the maximum effects of the design blast wave. Dynamic analyses are performed using a sophisticated FE-model to describe accurately the response of the façade equipped by dissipative devices. Based on numerical results of previous contributions, viscoelastic spider connectors (VESCs are introduced in the points of connection between glass panels and pretensioned cables, to replace “rigid” spider connectors commonly used in practice. At the same time, rigid-plastic frictional devices (RPDs are installed at the top of the bearing cables to mitigate furthermore the bracing system. As a result, due to the combined use of VESCs and RPDs opportunely calibrated, the maximum tensile stresses in the glass panels and in the cables appear strongly reduced. In addition, the proposed devices do not trouble the aesthetics of such transparent structural systems. At last, simple design rules are presented to predict the response of cable-supported façades subjected to high-level dynamic loads and to preliminary estimate the mechanical parameters of combined VESCs and RPDs.

  18. Design of Cellular Composite Sandwich Panels for Maximum Blast Resistance Via Energy Absorption

    Science.gov (United States)

    McConnell, Jennifer Righman; Su, Hong

    2015-10-01

    This paper presents a design methodology for optimizing the energy absorption under blast loads of cellular composite sandwich panels. A combination of dynamic finite element analysis (FEA) and simplified analytical modeling techniques are used. The analytical modeling calculates both the loading effects and structural response resulting from user-input charge sizes and standoff distances and offers the advantage of expediting iterative design processes. The FEA and the analytical model results are compared and contrasted then used to compare the energy response of various cellular composite sandwich panels under blast loads, where various core shapes and dimensions are the focus. As a result, it is concluded that the optimum shape consists of vertically-oriented webs while the optimum dimensions can be generally described as those which cause the most inelasticity without failure of the webs. These dimensions are also specifically quantified for select situations. This guidance is employed, along with the analytical method developed by the authors and considerations of the influences of material properties, to suggest a general design procedure that is a simple yet sufficiently accurate method for design. The suggested design approach is also demonstrated through a design example.

  19. The Preliminary Screening of Rice Blast Resistance on the Restorer Lines of High Quality Hybrid Rice%优质杂交稻恢复系稻瘟病抗性初步评价

    Institute of Scientific and Technical Information of China (English)

    卢礼斌; 叶宁; 郑向华; 何琴; 杨德卫; 刘成德; 蒋家焕; 叶新福

    2011-01-01

    The rice blast is the worldwide basis plant disease which is harms the paddy rice seriously "three big plant diseases". The practice indicated that the anti-rice blast r-line resources' excavation use research, to breeds selectively the high production, high quality, the anti-rice blast hybrid rice combination to have the vital significance. The natural identification of Shanghang Fujian to a representative of the 162 seedlings in field blast materials, leaf blast and panicle blast incidence survey, overall performance of Shanghang Fujian for the identificcation of resistance in more than 62 anti-material recovery system indoor seedling identification of different strains, 27 high resistance to the blast resistance of rice restorer lines with high generation of materials. Survey results showed that the seedling blast, leaf blast and panicle blast incidence rate was 3.01%,12.42% and 26.21%, seedling blast and leaf blast, seedling blast and neck blast, leaf blast and panicle blast incidence correlation 0.69, 0.67 and 0.78, respectively, had reached a significant level. Panicle blast incidence was significantly greater than the seedling blast and leaf blast and panicle blast incidence at different times higher. Grade 4-5 plague vaccine, later identified neck blast is likely to be susceptible or highly susceptible.In this study, identification of panicle blast to susceptible or highly susceptible, seedlings or leaf blast identified generally susceptible or high feeling.%稻瘟病是危害水稻最严重的"三大病害"之一,属世界性病害,抗稻瘟病恢复系资源的挖掘利用研究,对选育高产、优质、抗稻瘟病的杂交稻组合具有重要的意义.在福建省上杭茶地稻瘟病自然鉴定点对162份有代表性的材料进行田间苗瘟、叶瘟和穗颈瘟发病率调查,茶地抗性鉴定综合表现为中抗以上的62份恢复系材料进行室内不同菌株的苗期鉴定,得到27份高抗至中抗稻瘟病水稻恢复系高代

  20. EXPRESSION AND CLINICAL SIGNIFICANCE OF MULTIDRUG RESISTANCE GENE AND MULTIDRUG RESISTANCE-ASSOCIATED PROTEIN GENE IN ACUTE LEUKEMIA

    Institute of Scientific and Technical Information of China (English)

    LAI Yong-rong; MA Jie; LU Yu-ying; NU Wei-lin; XIANG Zhi-fu

    1999-01-01

    Objective: To evaluate the expression and clinical significance of multidrug resistance gene (mdr1) and multidrug resistance-associated protein (MRP) gene in acute leukemia. Methods: The expression of mdr1 and MRP assay in 55 patients with acute leukemia (AL) by reverse transcription polymerase chain reaction (RT-PCR).Results: The mdr1 and MRP gene expression levels in the relapsed AL and the blastic plastic phases of CML were significantly higher than those in the newly diagnostic AL and controls. The mdr1 and MRP gene expression levels in the clinical drug-resistant group were significantly higher than those in the non-drug-resistant group. The complete remission (CR) rate in patients with high mdr1 expression (14.3%) was significantly lower than that with low mdr1 expression (57.5%); similarly the CR rate in patients with high MRP level was also lower than that with low MRP level. Using both high expression of mdr1 and MRP gene as the indicator for evaluating multidrug resistance (MDR),the positive predictive value and accuracy increased in comparison with single gene high expression. Conclusion:Elevated level of mdr1 or MRP gene expression might be unfavorable prognostic factors for AL patient and may be used as an important index for predicting drug-resistance and relapse in AL patient. Measuring both mdr1 and MRP gene expression would increase accuracy and sensibility of evaluating MDR in acute leukemia.

  1. Genes for resistance to zucchini yellow mosaic in tropical pumpkin.

    Science.gov (United States)

    Pachner, Martin; Paris, Harry S; Lelley, Tamas

    2011-01-01

    Four cultigens of Cucurbita moschata resistant to zucchini yellow mosaic virus were crossed with the susceptible 'Waltham Butternut' and with each other in order to clarify the mode of inheritance of resistance and relationships among the genes involved. Five loci were segregating, with genes for resistance Zym-0 and Zym-4 carried by 'Nigerian Local' and one of them also carried by 'Nicklow's Delight,' Zym-1 carried by 'Menina,' and zym-6 carried by 'Soler.' A recessive gene carried by 'Waltham Butternut,' zym-5, is complementary with the dominant Zym-4 of 'Nigerian Local,' that is, the resistance conferred by Zym-4 is only expressed in zym-5/zym-5 individuals. Gene zym-6 appears to be linked to either Zym-0 or Zym-4, and it is also possible that Zym-1 is linked to one of them as well. PMID:21493595

  2. Differential Expression of Salinity Resistance Gene on Cotton

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Salinity resistance and differential gene expression associated with salinity in cotton germplasm were studied,because of the large scale area of salinity in China,and its significant negative effects on

  3. [SSR mapping of stripe rust resistance gene from Ae. tauschii].

    Science.gov (United States)

    Zhang, Hai-Quan; Jia, Ji-Zeng; Yang, Hong; Zhang, Bao-Shi

    2008-04-01

    A dominant wheat stripe rust resistance gene, temporarily designated as YrY201, was identified in an accession Y201 of Aegilops tauschii. By bulk segregation analysis, three microsatellite markers Xgwm273b, Xgwm37 and Wmc14 were found to be linked to YrY201 with genetic distance of 11.5, 5.8 and 10.9 cM , respectively. According to the locations of the linked markers, the resistance gene was located on chromosome 7DL. Based on the chromosomal location and the resistance pattern of the gene, we proposed that YrY201 was a novel stripe rust resistance gene, and could be selected by marker-assisted selection. PMID:18424421

  4. Prevalence of antimicrobial resistance and resistance genes in faecal Escherichia coli isolates recovered from healthy pets.

    Science.gov (United States)

    Costa, Daniela; Poeta, Patricia; Sáenz, Yolanda; Coelho, Ana Cláudia; Matos, Manuela; Vinué, Laura; Rodrigues, Jorge; Torres, Carmen

    2008-02-01

    Faecal samples of healthy dogs (n=39) and cats (n=36) obtained in Northern Portugal were seeded on Levine agar plates, and two Escherichia coli isolates per sample were recovered (78 of dogs and 66 of cats). The susceptibility to 16 antimicrobial agents was tested in this series of 144 E. coli isolates. Almost 20% of them showed tetracycline resistance and 12 and 15% presented ampicillin or streptomycin resistance, respectively. The percentage of resistance to the other antimicrobial agents was in all cases below 4%, and no resistant isolates were detected for ceftazidime, imipenem, cefoxitin or amikacin. Two isolates (from one dog) showed cefotaxime-resistance and harboured both the CTX-M-1 and OXA-30 beta-lactamases. A bla(TEM) gene was detected in 12 of 17 ampicillin-resistant isolates, the aac(3)-II gene in the three gentamicin-resistant isolates, aadA in 7 of 22 streptomycin-resistant isolates, and tet(A) and/or tet(B) gene in all 28 tetracycline-resistant isolates. The gene encoding class 1 integrase was detected in six E. coli isolates, including the four trimethoprim-sulfamethoxazole-resistant isolates and those two harbouring CTX-M-1 and OXA-30 beta-lactamases; different gene cassette arrangements were identified: dfrA1+aadA1 (two isolates), dfrA12+orfF+aadA2 (two isolates) and bla(OXA30)+aadA1 (two isolates). One amino acid change in GyrA protein (Ser83Leu or Asp87Tyr) was detected in four nalidixic acid-resistant and ciprofloxacin-susceptible isolates and two amino acid changes in GyrA (Ser83Leu+Asp87Asn) and one in ParC (Ser80Ile) were identified in one nalidixic acid- and ciprofloxacin-resistant isolate. Faecal E. coli isolates of healthy pets could be a reservoir of antimicrobial resistance genes. PMID:17870255

  5. Novel metal resistance genes from microorganisms: a functional metagenomic approach.

    Science.gov (United States)

    González-Pastor, José E; Mirete, Salvador

    2010-01-01

    Most of the known metal resistance mechanisms are based on studies of cultured microorganisms, and the abundant uncultured fraction could be an important source of genes responsible for uncharacterized resistance mechanisms. A functional metagenomic approach was selected to recover metal resistance genes from the rhizosphere microbial community of an acid-mine drainage (AMD)-adapted plant, Erica andevalensis, from Rio Tinto, Spain. A total of 13 nickel resistant clones were isolated and analyzed, encoding hypothetical or conserved hypothetical proteins of uncertain functions, or well-characterized proteins, but not previously reported to be related to nickel resistance. The resistance clones were classified into two groups according to their nickel accumulation properties: those preventing or those favoring metal accumulation. Two clones encoding putative ABC transporter components and a serine O-acetyltransferase were found as representatives of each group, respectively. PMID:20830571

  6. Characterization of Fosfomycin Resistance Gene, fosB, in Methicillin-Resistant Staphylococcus aureus Isolates

    Science.gov (United States)

    Chen, Chunhui; Guo, Yan; Ma, Ying; Yang, Yang; Hu, Fupin; Xu, Xiaogang; Wang, Minggui

    2016-01-01

    To investigate the prevalence, location and genetic environments of fosfomycin-resistance (fos) genes in methicillin-resistant Staphylococcus aureus (MRSA) clinical strains, 67 fosfomycin-resistant MRSA strains were isolated from the blood and cerebrospinal fluid samples at a teaching hospital in Shanghai. The presence of fos genes in these clinical strains was detected by PCR and sequencing. The locations of fos genes were determined by Southern blotting and genetic environments were analyzed by primer walking sequencing. Multiple locus sequence typing (MLST) was used to characterize genetic diversity. Conjugation was performed to evaluate the transferability of fos genes. Among 67 fosfomycin-resistant MRSA strains, nine high level fosfomycin resistant strains (≥128 μg/ml) were fosB-positive. Three new subtypes of fosB, designated as fosB4, fosB5, and fosB6, were identified. fosB1, fosB4 or fosB6 genes were located on small plasmids (ca. 2.5 kb) and flanked by an analogous replication gene (rep). Differently, the fosB5 gene was surrounded by a shorter rep gene and two copies of a transposon gene (tnp) that shared high identity with the IS257-like transposon. Four MLST types were found among the nine fosB-positive strains. Transconjugants with the fosB genes were resistant to fosfomycin with MIC 64 or 128 μg/ml. In conclusion, different subtypes and genetic environment of fosB genes indicate that gene heterogeneity for fosfomycin resistance in MRSA isolates. PMID:27144405

  7. Characterization of Fosfomycin Resistance Gene, fosB, in Methicillin-Resistant Staphylococcus aureus Isolates.

    Directory of Open Access Journals (Sweden)

    Zhuyingjie Fu

    Full Text Available To investigate the prevalence, location and genetic environments of fosfomycin-resistance (fos genes in methicillin-resistant Staphylococcus aureus (MRSA clinical strains, 67 fosfomycin-resistant MRSA strains were isolated from the blood and cerebrospinal fluid samples at a teaching hospital in Shanghai. The presence of fos genes in these clinical strains was detected by PCR and sequencing. The locations of fos genes were determined by Southern blotting and genetic environments were analyzed by primer walking sequencing. Multiple locus sequence typing (MLST was used to characterize genetic diversity. Conjugation was performed to evaluate the transferability of fos genes. Among 67 fosfomycin-resistant MRSA strains, nine high level fosfomycin resistant strains (≥128 μg/ml were fosB-positive. Three new subtypes of fosB, designated as fosB4, fosB5, and fosB6, were identified. fosB1, fosB4 or fosB6 genes were located on small plasmids (ca. 2.5 kb and flanked by an analogous replication gene (rep. Differently, the fosB5 gene was surrounded by a shorter rep gene and two copies of a transposon gene (tnp that shared high identity with the IS257-like transposon. Four MLST types were found among the nine fosB-positive strains. Transconjugants with the fosB genes were resistant to fosfomycin with MIC 64 or 128 μg/ml. In conclusion, different subtypes and genetic environment of fosB genes indicate that gene heterogeneity for fosfomycin resistance in MRSA isolates.

  8. BacMet: antibacterial biocide and metal resistance genes database

    OpenAIRE

    Pal, Chandan; Bengtsson-Palme, Johan; Rensing, Christopher; Kristiansson, Erik; Larsson, D.G. Joakim

    2013-01-01

    Antibiotic resistance has become a major human health concern due to widespread use, misuse and overuse of antibiotics. In addition to antibiotics, antibacterial biocides and metals can contribute to the development and maintenance of antibiotic resistance in bacterial communities through co-selection. Information on metal and biocide resistance genes, including their sequences and molecular functions, is, however, scattered. Here, we introduce BacMet (http://bacmet.biomedicine.gu.se)—a manua...

  9. Pediatric fecal microbiota harbor diverse and novel antibiotic resistance genes.

    Directory of Open Access Journals (Sweden)

    Aimée M Moore

    Full Text Available Emerging antibiotic resistance threatens human health. Gut microbes are an epidemiologically important reservoir of resistance genes (resistome, yet prior studies indicate that the true diversity of gut-associated resistomes has been underestimated. To deeply characterize the pediatric gut-associated resistome, we created metagenomic recombinant libraries in an Escherichia coli host using fecal DNA from 22 healthy infants and children (most without recent antibiotic exposure, and performed functional selections for resistance to 18 antibiotics from eight drug classes. Resistance-conferring DNA fragments were sequenced (Illumina HiSeq 2000, and reads assembled and annotated with the PARFuMS computational pipeline. Resistance to 14 of the 18 antibiotics was found in stools of infants and children. Recovered genes included chloramphenicol acetyltransferases, drug-resistant dihydrofolate reductases, rRNA methyltransferases, transcriptional regulators, multidrug efflux pumps, and every major class of beta-lactamase, aminoglycoside-modifying enzyme, and tetracycline resistance protein. Many resistance-conferring sequences were mobilizable; some had low identity to any known organism, emphasizing cryptic organisms as potentially important resistance reservoirs. We functionally confirmed three novel resistance genes, including a 16S rRNA methylase conferring aminoglycoside resistance, and two tetracycline-resistance proteins nearly identical to a bifidobacterial MFS transporter (B. longum s. longum JDM301. We provide the first report to our knowledge of resistance to folate-synthesis inhibitors conferred by a predicted Nudix hydrolase (part of the folate synthesis pathway. This functional metagenomic survey of gut-associated resistomes, the largest of its kind to date, demonstrates that fecal resistomes of healthy children are far more diverse than previously suspected, that clinically relevant resistance genes are present even without recent selective

  10. Study on the interaction between methyl jasmonate and the coiled-coil domain of rice blast resistance protein Pi36 by spectroscopic methods

    Science.gov (United States)

    Liu, Xin Q.; Zhang, Dan; Zhang, Xiang M.; Wang, Chun T.; Liu, Xue Q.; Tan, Yan P.; Wu, Yun H.

    2012-03-01

    Interaction between the coiled-coil domain of rice blast resistance protein Pi36 and methyl-jasmonate (MeJA) was studied by fluorescence and UV-vis spectroscopic techniques. The quenching mechanism of fluorescence of MeJA by this domain was discussed to be a static quenching procedure. Fluorescence quenching was explored to measure the number of binding sites n and apparent binding constants K. The thermodynamics parameters ΔH, ΔG, ΔS were also calculated. The results indicate the binding reaction was not entropy-driven but enthalpy-driven, and hydrophobic binding played major role in the interaction. The binding sites of MeJA with the coiled-coil structural domain of rice blast resistance protein Pi36 were found to approach the microenvironment of both Tyr and Trp by the synchronous fluorescence spectrometry. The distance r between donor (the coiled-coil domain of rice blast resistance protein Pi36) and acceptor (MeJA) was obtained according to Förster theory of non-radioactive energy transfer.

  11. Gentamicin resistance genes in environmental bacteria: prevalence and transfer

    NARCIS (Netherlands)

    Heuer, H.; Krögerrecklenfort, E.; Wellington, E.M.H.; Egan, S.; Elsas, van J.D.; Overbeek, van L.S.; Collard, J.M.; Guillaume, G.; Karagouni, A.; Nikolakopoulou, D.; Smalla, K.

    2002-01-01

    A comprehensive multiphasic survey of the prevalence and transfer of gentamicin resistance (Gmr) genes in different non-clinical environments has been performed. We were interested to find out whether Gmr genes described from clinical isolates can be detected in different environmental habitats and

  12. Hygromycin-resistance vectors for gene expression in Pichia pastoris.

    Science.gov (United States)

    Yang, Junjie; Nie, Lei; Chen, Biao; Liu, Yingmiao; Kong, Yimeng; Wang, Haibin; Diao, Liuyang

    2014-04-01

    Pichia pastoris is a common host organism for heterologous protein expression and metabolic engineering. Zeocin-, G418-, nourseothricin- and blasticidin-resistance genes are the only dominant selectable markers currently available for selecting P. pastoris transformants. We describe here new P. pastoris expression vectors that confer a hygromycin resistance base on the Klebsiella pneumoniae hph gene. To demonstrate the application of the vectors for intracellular and secreted protein expression, green fluorescent protein (GFP) and human serum albumin (HSA) were cloned into the vectors and transformed into P. pastoris cells. The resulting strains expressed GFP and HSA constitutively or inducibly. The hygromycin resistance marker was also suitable for post-transformational vector amplication (PTVA) for obtaining strains with high plasmid copy numbers. A strain with multiple copies of the HSA expression cassette after PTVA had increased HSA expression compared with a strain with a single copy of the plasmid. To demonstrate compatibility of the new vectors with other vectors bearing antibiotic-resistance genes, P. pastoris was transformed with the Saccharomyces cerevisiae genes GSH1, GSH2 or SAM2 on plasmids containing genes for resistance to Zeocin, G418 or hygromycin. The resulting strain produced glutathione and S-adenosyl-L-methionine at levels approximately twice those of the parent strain. The new hygromycin-resistance vectors allow greater flexibility and potential applications in recombinant protein production and other research using P. pastoris. PMID:24822243

  13. Consolidating and Exploring Antibiotic Resistance Gene Data Resources

    DEFF Research Database (Denmark)

    Xavier, Basil Britto; Das, Anupam J.; Cochrane, Guy;

    2016-01-01

    The unrestricted use of antibiotics has resulted in rapid acquisition of antibiotic resistance (AR) and spread of multidrug-resistant (MDR) bacterial pathogens. With the advent of next-generation sequencing technologies and their application in understanding MDR pathogen dynamics, it has become...... imperative to unify AR gene data resources for easy accessibility for researchers. However, due to the absence of a centralized platform for AR gene resources, availability, consistency, and accuracy of information vary considerably across different databases. In this article, we explore existing AR gene...... data resources in order to make them more visible to the clinical microbiology community, to identify their limitations, and to propose potential solutions....

  14. Deinococcus geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks

    Energy Technology Data Exchange (ETDEWEB)

    Makarova, Kira S.; Omelchenko, Marina V.; Gaidamakova, Elena K.; Matrosova, Vera Y.; Vasilenko, Alexander; Zhai, Min; Lapidus, Alla; Copeland, Alex; Kim, Edwin; Land, Miriam; Mavrommatis, Konstantinos; Pitluck, Samuel; Richardson, Paul M.; Detter, Chris; Brettin, Thomas; Saunders, Elizabeth; Lai, Barry; Ravel, Bruce; Kemner, Kenneth M.; Wolf, Yuri I.; Sorokin, Alexander; Gerasimova, Anna V.; Gelfand, Mikhail S.; Fredrickson, James K.; Koonin, Eugene V.; Daly, Michael J.

    2007-07-24

    Bacteria of the genus Deinococcus are extremely resistant to ionizing radiation (IR), ultraviolet light (UV) and desiccation. The mesophile Deinococcus radiodurans was the first member of this group whose genome was completely sequenced. Analysis of the genome sequence of D. radiodurans, however, failed to identify unique DNA repair systems. To further delineate the genes underlying the resistance phenotypes, we report the whole-genome sequence of a second Deinococcus species, the thermophile Deinococcus geothermalis, which at itsoptimal growth temperature is as resistant to IR, UV and desiccation as D. radiodurans, and a comparative analysis of the two Deinococcus genomes. Many D. radiodurans genes previously implicated in resistance, but for which no sensitive phenotype was observed upon disruption, are absent in D. geothermalis. In contrast, most D. radiodurans genes whose mutants displayed a radiation-sensitive phenotype in D. radiodurans are conserved in D. geothermalis. Supporting the existence of a Deinococcus radiation response regulon, a common palindromic DNA motif was identified in a conserved set of genes associated with resistance, and a dedicated transcriptional regulator was predicted. We present the case that these two species evolved essentially the same diverse set of gene families, and that the extreme stress-resistance phenotypes of the Deinococcus lineage emerged progressively by amassing cell-cleaning systems from different sources, but not by acquisition of novel DNA repair systems. Our reconstruction of the genomic evolution of the Deinococcus-Thermus phylum indicates that the corresponding set of enzymes proliferated mainly in the common ancestor of Deinococcus. Results of the comparative analysis weaken the arguments for a role of higher-order chromosome alignment structures in resistance; more clearly define and substantially revise downward the number of uncharacterized genes that might participate in DNA repair and contribute to

  15. The relationship between codon usage bias and cold resistant genes

    International Nuclear Information System (INIS)

    This research is based on synonymous codon usage which has been well-known as a feature that affects typical expression level of protein in an organism. Different organisms prefer different codons for same amino acid and this is called Codon Usage Bias (CUB). The codon usage directly affects the level or even direction of changes in protein expression in responses to environmental stimuli. Cold stress is a major abiotic factor that limits the agricultural productivity of plants. In the recent study CUB has been studied in Arabidopsis thaliana cold resistant and housekeeping genes and their homologs in rice (Oryza sativa) to understand the cold stress and housekeeping genes relation with CUB. Six cold resistant and three housekeeping genes in Arabidopsis thaliana and their homologs in rice, were subjected to CUB analysis. The three cold resistant genes (DREB1B, RCI and MYB15) showed more than 50% (52%, 61% and 66% respectively) similar codon usage bias for Arabidopsis thaliana and rice. On the other hand three cold resistant genes (MPK3, ICE1 and ZAT12) showed less than 50% (38%, 38% and 47% respectively) similar codon usage bias for Arabidopsis thaliana and rice. The three housekeeping genes (Actin, Tubulin and Ubiquitin) showed 76% similar codon usage bias for Arabidopsis thaliana and rice. This study will help to manage the plant gene expression through codon optimization under the cold stress. (author)

  16. A Rice Gene Homologous to Arabidopsis AGD2-LIKE DEFENSE1 Participates in Disease Resistance Response against Infection with Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Ga Young Jung

    2016-08-01

    Full Text Available ALD1 (ABERRANT GROWTH AND DEATH2 [AGD2]-LIKE DEFENSE1 is one of the key defense regulators in Arabidopsis thaliana and Nicotiana benthamiana. In these model plants, ALD1 is responsible for triggering basal defense response and systemic resistance against bacterial infection. As well ALD1 is involved in the production of pipecolic acid and an unidentified compound(s for systemic resistance and priming syndrome, respectively. These previous studies proposed that ALD1 is a potential candidate for developing genetically modified (GM plants that may be resistant to pathogen infection. Here we introduce a role of ALD1-LIKE gene of Oryza sativa, named as OsALD1, during plant immunity. OsALD1 mRNA was strongly transcribed in the infected leaves of rice plants by Magnaporthe oryzae, the rice blast fungus. OsALD1 proteins predominantly localized at the chloroplast in the plant cells. GM rice plants over-expressing OsALD1 were resistant to the fungal infection. The stable expression of OsALD1 also triggered strong mRNA expression of PATHOGENESIS-RELATED PROTEIN1 genes in the leaves of rice plants during infection. Taken together, we conclude that OsALD1 plays a role in disease resistance response of rice against the infection with rice blast fungus.

  17. A Rice Gene Homologous to Arabidopsis AGD2-LIKE DEFENSE1 Participates in Disease Resistance Response against Infection with Magnaporthe oryzae.

    Science.gov (United States)

    Jung, Ga Young; Park, Ju Yeon; Choi, Hyo Ju; Yoo, Sung-Je; Park, Jung-Kwon; Jung, Ho Won

    2016-08-01

    ALD1 (ABERRANT GROWTH AND DEATH2 [AGD2]-LIKE DEFENSE1) is one of the key defense regulators in Arabidopsis thaliana and Nicotiana benthamiana. In these model plants, ALD1 is responsible for triggering basal defense response and systemic resistance against bacterial infection. As well ALD1 is involved in the production of pipecolic acid and an unidentified compound(s) for systemic resistance and priming syndrome, respectively. These previous studies proposed that ALD1 is a potential candidate for developing genetically modified (GM) plants that may be resistant to pathogen infection. Here we introduce a role of ALD1-LIKE gene of Oryza sativa, named as OsALD1, during plant immunity. OsALD1 mRNA was strongly transcribed in the infected leaves of rice plants by Magnaporthe oryzae, the rice blast fungus. OsALD1 proteins predominantly localized at the chloroplast in the plant cells. GM rice plants over-expressing OsALD1 were resistant to the fungal infection. The stable expression of OsALD1 also triggered strong mRNA expression of PATHOGENESIS-RELATED PROTEIN1 genes in the leaves of rice plants during infection. Taken together, we conclude that OsALD1 plays a role in disease resistance response of rice against the infection with rice blast fungus. PMID:27493611

  18. Characterization of Resistance Gene Analogs in Musa acuminata Cultivars Contrasting in Resistance to Biotic Stresses

    International Nuclear Information System (INIS)

    The majority of commercial banana cultivars (Musa sp.) have evolved via asexual vegetative propagation, with diversity dependent upon somatic mutation. Restricted variation has resulted in a crops with little resistance to pests and disease, and conventional breeding efforts are limited due to limited viable seed production. Numerous disease resistance genes (R-genes / R-proteins) have been characterized in plants, recognizing and conferring resistance to bacteria, virus, fungi and nematodes. The identification and cloning of R-genes in Musa would contribute to germplasm improvement. To date, five main R-gene classes have been identified, based upon protein domains, with the most abundant coding for nucleotide-binding site-leucine-rich repeat (NBS-LRR) proteins. Primers designed from conserved protein motifs have enabled amplification of NBS homologues across diverse plant species. In Musa, our group has identified over 50 distinct NBS-LRR type resistance gene analogs (RGAs) in the resistant wild diploid M. acuminata Calcutta 4. The aim of this work was to characterize RGAs in M. acuminata cultivars contrasting in resistance to Black leaf Streak Disease. PCR amplification was conducted using DNA from M. acuminata cultivars Calcutta 4 (resistant) and Pisang Berlin (susceptible). Degenerate primers targeted sequences homologous to the NBS-LRR R-gene family. Following sequencing and processing of cloned PCR products, 63 out of a total of 136 high quality sequences showed homology to R-genes or RGAs. Phylogenetic analysis was conducted on deduced amino-acid sequences. Degenerate primers were also developed targeting an R-gene family of cytoplasmic serine-threonine (Ser/Thr) receptor-like kinases (RLKs) with extracellular LRRs, for application across cultivars. Studies are also planned for selection and full length sequencing of clones from M. acuminata and M. balbisiana BAC libraries containing novel RGAs characterized in this study, as an approach for complete R-gene

  19. Characterization of resistance gene analogs in Musa acuminata cultivars contrasting in resistance to biotic stresses

    International Nuclear Information System (INIS)

    The majority of commercial banana cultivars (Musa sp.) have evolved via asexual vegetative propagation, with diversity dependent upon somatic mutation. Restricted variation has resulted in a crop with little resistance to pests and disease, and conventional breeding efforts are limited due to limited viable seed production. Numerous disease resistance genes (R-genes / R-proteins) have been characterized in plants, recognizing and conferring resistance to bacteria, virus, fungi and nematodes. The identification and cloning of R-genes in Musa would contribute to germplasm improvement. To date, five main R-gene classes have been identified, based upon protein domains, with the most abundant coding for nucleotidebinding site-leucine-rich repeat (NBS-LRR) proteins. Primers designed from conserved protein motifs have enabled amplification of NBS homologues across diverse plant species. In the case of Musa, our group has identified over 50 distinct NBS-LRR type resistance gene analogs (RGAs) in the resistant wild diploid M. acuminata Calcutta 4. The objective of this work was to characterize RGAs in M. acuminata cultivars contrasting in resistance to Black leaf Streak Disease. PCR amplification was conducted using DNA from M. acuminata cultivars Calcutta 4 (resistant) and Pisang Berlin (susceptible). Degenerate primers targeted sequences homologous to the NBS-LRR R-gene family. Following sequencing and processing of cloned PCR products, 63 out of a total of 136 high quality sequences showed homology to R-genes or RGAs. Phylogenetic analysis was conducted on deduced amino-acid sequences. Degenerate primers were also developed targeting an R-gene family of cytoplasmic serine-threonine (Ser/Thr) receptor-like kinases (RLKs) with extracellular LRRs, for application across cultivars. Studies are also planned for selection and full length sequencing of clones from M. acuminata and M. balbisiana BAC libraries containing novel RGAs characterized in this study, as an approach for

  20. Mining metagenomic datasets for antibiotic resistance genes

    Science.gov (United States)

    Antibiotics are medicines that are used to kill, slow down, or prevent the growth of susceptible bacteria. They became widely used in the mid 20th century for controlling disease in humans, animals, and plants, and for a variety of industrial purposes. Antibiotic resistance is a broad term. There ...

  1. Cytogenetic Mapping of Disease Resistance Genes and Analysis of Their Distribution Features on Chromosomes in Maize

    Institute of Scientific and Technical Information of China (English)

    LiLi-jia; SongYun-chun

    2003-01-01

    Cytogenetic maps of four clusters of disease resistance genes were generated by ISH of the two RFLP markers tightly linked to and flanking each of maize resistance genes and the cloned resistance genes from other plant species onto maize chromosomes, combining with data published before. These genes include Helminthosporium turcium Pass resistance genes Htl, Htnl and Ht2, Helminthosporium maydis Nisik resistance genes Rhml and Rhm2,maize dwarf mosaic virus resistance gene Mdml, wheat streak mosaic virus resistance gene Wsml, Helminthosporium carbonum ULLstrup resistance gene Hml and the cloned Xanthomonas oryzae pv. Oryzae resistance gene Xa21 of rice, Cladosporium fulvum resistance genes Cf-9 and Cf-2. 1 of tomato, and Pseudomonas syringae resistance gene RPS2 of Arabidopsis. Most of the tested disease resistance genes located on the four chromosomes, i. e. , chromosomesl, 3, 6 and 8, and they closely distributed at the interstitial regions of these chromosomal long arms with percentage distances ranging 31.44(±3.72)-72.40(±3. 25) except for genes Rhml, Rhm2, Mdml and Wsml which mapped on the satellites of the short arms of chromosome6. It showed that the tested RFLP markers and genes were duplicated or triplicated in maize genome. Homology and conservation of disease resistance genes among species, and relationship between distribution features and functions of the genes were discussed. The results provide important scientific basis for deeply understanding structure and function of disease resistance genes and breeding in maize.

  2. Spectrum of Resistance Conferred by ml-o Powdery Mildew Resistance Genes in Barley

    DEFF Research Database (Denmark)

    Jørgensen, Jørgen Helms

    1977-01-01

    Ten barley mutants and five Ethiopian barley lines representing 11 independently arisen powdery mildew resistance genes in the ml-o locus were tested at the seedling stage to cultures of the powdery mildew fungus from Europe, Israel, USA. Canada, and Japan. They were resistant with infection type 0...

  3. Plasmid-mediated formaldehyde resistance in Escherichia coli: characterization of resistance gene.

    OpenAIRE

    Kümmerle, N; Feucht, H H; Kaulfers, P M

    1996-01-01

    The formaldehyde resistance mechanisms in the formaldehyde-resistant strain Escherichia coli VU3695 were investigated. A large (4.6-kb) plasmid DNA fragment encompassing the formaldehyde resistance gene was sequenced. A single 1,107-bp open reading frame encoding a glutathione- and NAD-dependent formaldehyde dehydrogenase was identified and sequenced, and the enzyme was expressed in an in vitro assay and purified. Amino acid sequence homology studies showed 62.4 to 63.2% identity with class I...

  4. Antimicrobial Resistance and Resistance Genes in Aerobic Bacteria Isolated from Pork at Slaughter

    DEFF Research Database (Denmark)

    Li, Lili; Olsen, Rikke Heidemann; Ye, Lei;

    2016-01-01

    The aim of this study was to investigate the phenotypic and genotypic antimicrobial resistance, integrons, and transferability of resistance markers in 243 aerobic bacteria recovered from pork at slaughter in the People's Republic of China. The organisms belonged to 22 genera of gram...... aerobic bacteria from pork as reservoirs for antimicrobial resistance genes and mobile genetic elements that can readily be transferred intra- and interspecies....

  5. Soil metatranscriptomics for mining eukaryotic heavy metal resistance genes.

    Science.gov (United States)

    Lehembre, Frédéric; Doillon, Didier; David, Elise; Perrotto, Sandrine; Baude, Jessica; Foulon, Julie; Harfouche, Lamia; Vallon, Laurent; Poulain, Julie; Da Silva, Corinne; Wincker, Patrick; Oger-Desfeux, Christine; Richaud, Pierre; Colpaert, Jan V; Chalot, Michel; Fraissinet-Tachet, Laurence; Blaudez, Damien; Marmeisse, Roland

    2013-10-01

    Heavy metals are pollutants which affect all organisms. Since a small number of eukaryotes have been investigated with respect to metal resistance, we hypothesize that many genes that control this phenomenon remain to be identified. This was tested by screening soil eukaryotic metatranscriptomes which encompass RNA from organisms belonging to the main eukaryotic phyla. Soil-extracted polyadenylated mRNAs were converted into cDNAs and 35 of them were selected for their ability to rescue the metal (Cd or Zn) sensitive phenotype of yeast mutants. Few of the genes belonged to families known to confer metal resistance when overexpressed in yeast. Several of them were homologous to genes that had not been studied in the context of metal resistance. For instance, the BOLA ones, which conferred cross metal (Zn, Co, Cd, Mn) resistance may act by interfering with Fe homeostasis. Other genes, such as those encoding 110- to 130-amino-acid-long, cysteine-rich polypeptides, had no homologues in databases. This study confirms that functional metatranscriptomics represents a powerful approach to address basic biological processes in eukaryotes. The selected genes can be used to probe new pathways involved in metal homeostasis and to manipulate the resistance level of selected organisms. PMID:23663419

  6. [Investigation of Antibiotic Resistance Genes (ARGs) in Landfill].

    Science.gov (United States)

    Li, Lei; Xu, Jing; Zhao, You-cai; Song, Li-yan

    2015-05-01

    Antibiotic resistant genes (ARGs), an emerging contaminant, have been detected worldwide in various environments such as sediments and river. However, little is known about ARGs distribution in landfill. In this study, we investigated five ARGs [sulfonamides resistant genes (sulI and sulII), chloramphenicols resistant gene (cat), β-lactams resistant gene (bla-SHV), and tetracyclines resistant gene (tetW)] in refuse samples collected from jiangeungou landfill (Xi'an, China) by real-time PCR. We then correlated the ARGs and physiochemical properties of refuse to examine the link between them. Results showed that all tested ARGs have been detected in all samples, suggesting that landfill served as ARGs reservoir. The highest copies numbers of sulII, sulI, tetW, bla-SHV, and cat were (3.70 ± 0.06) x 10(8) copies · g(-1) ( dry refuse), (9.33 · 0.06) x 10(6) copies · g(-1) (dry refuse), (2.27 0.08) x 10(5) copies · g(-1) (dry refuse), (3.68 ± 0.09) x 10(4) copies · g(-1) (dry refuse), and (1.39 ± 0.10) x 10(4) copies · g(-1) (dry refuse), respectively. Further, sulI, sulII, and cat positively correlated to moisture and sulI and cat negatively correlated to pH. PMID:26314129

  7. Genomes, diversity and resistance gene analogues in Musa species.

    Science.gov (United States)

    Azhar, M; Heslop-Harrison, J S

    2008-01-01

    Resistance genes (R genes) in plants are abundant and may represent more than 1% of all the genes. Their diversity is critical to the recognition and response to attack from diverse pathogens. Like many other crops, banana and plantain face attacks from potentially devastating fungal and bacterial diseases, increased by a combination of worldwide spread of pathogens, exploitation of a small number of varieties, new pathogen mutations, and the lack of effective, benign and cheap chemical control. The challenge for plant breeders is to identify and exploit genetic resistances to diseases, which is particularly difficult in banana and plantain where the valuable cultivars are sterile, parthenocarpic and mostly triploid so conventional genetic analysis and breeding is impossible. In this paper, we review the nature of R genes and the key motifs, particularly in the Nucleotide Binding Sites (NBS), Leucine Rich Repeat (LRR) gene class. We present data about identity, nature and evolutionary diversity of the NBS domains of Musa R genes in diploid wild species with the Musa acuminata (A), M. balbisiana (B), M. schizocarpa (S), M. textilis (T), M. velutina and M. ornata genomes, and from various cultivated hybrid and triploid accessions, using PCR primers to isolate the domains from genomic DNA. Of 135 new sequences, 75% of the sequenced clones had uninterrupted open reading frames (ORFs), and phylogenetic UPGMA tree construction showed four clusters, one from Musa ornata, one largely from the B and T genomes, one from A and M. velutina, and the largest with A, B, T and S genomes. Only genes of the coiled-coil (non-TIR) class were found, typical of the grasses and presumably monocotyledons. The analysis of R genes in cultivated banana and plantain, and their wild relatives, has implications for identification and selection of resistance genes within the genus which may be useful for plant selection and breeding and also for defining relationships and genome evolution

  8. The Vf gene for scrab resistance in apple is linked to sub-lethal genes

    OpenAIRE

    Gao, Z.S.; Weg, van de, W.E.

    2006-01-01

    V f is the most widely used resistance gene in the breeding for scab resistant apple cultivars. Distorted segregation ratios for V f -resistance have frequently been reported. Here we revealed that sub-lethal genes caused the distorted segregation. The inheritance of V f was examined in six progenies by testing linked molecular markers. Three progenies showed distorted segregations that could be explained by three sub-lethal genes (sl1, sl2 and sl3), of which sl1, sl2 were closely linked to V...

  9. Differential Expression of Salinity Resistance Gene on Cotton

    Institute of Scientific and Technical Information of China (English)

    YE Wu-wei; YU Shu-xun

    2008-01-01

    @@ Salinity resistance and differential gene expression associated with salinity in cotton germplasm were studied,because of the large scale area of salinity in China,and its significant negative effects on the cotton production.The salinityresisted genes and their differential expression were studied under the stress of NaCI on cotton.There were found,under the NaCI stress,1644 genes differentially expressed from the salinity-sensitive cotton and only 817 genes differentially expressed from the salinityresisted cotton.

  10. Performance of resistance gene pyramids to races of rice bacterial blight in Zhejiang Province

    Institute of Scientific and Technical Information of China (English)

    ZHENGKangle; ZHUANGJieyun; WANGHanrong

    1998-01-01

    The effect of gene pyramiding on resistance to bacterial blight (BB) in rice was evahlated among the IR24-based near isogenic lines conraining single resistance gene and gene pyramids containing two, three or lour resistancegenes (see table).

  11. High chlorpyrifos resistance in Culex pipiens mosquitoes: strong synergy between resistance genes.

    Science.gov (United States)

    Alout, H; Labbé, P; Berthomieu, A; Makoundou, P; Fort, P; Pasteur, N; Weill, M

    2016-02-01

    We investigated the genetic determinism of high chlorpyrifos resistance (HCR), a phenotype first described in 1999 in Culex pipiens mosquitoes surviving chlorpyrifos doses ⩾1 mg l(-1) and more recently found in field samples from Tunisia, Israel or Indian Ocean islands. Through chlorpyrifos selection, we selected several HCR strains that displayed over 10 000-fold resistance. All strains were homozygous for resistant alleles at two main loci: the ace-1 gene, with the resistant ace-1(R) allele expressing the insensitive G119S acetylcholinesterase, and a resistant allele of an unknown gene (named T) linked to the sex and ace-2 genes. We constructed a strain carrying only the T-resistant allele and studied its resistance characteristics. By crossing this strain with strains harboring different alleles at the ace-1 locus, we showed that the resistant ace-1(R) and the T alleles act in strong synergy, as they elicited a resistance 100 times higher than expected from a simple multiplicative effect. This effect was specific to chlorpyrifos and parathion and was not affected by synergists. We also examined how HCR was expressed in strains carrying other ace-1-resistant alleles, such as ace-1(V) or the duplicated ace-1(D) allele, currently spreading worldwide. We identified two major parameters that influenced the level of resistance: the number and the nature of the ace-1-resistant alleles and the number of T alleles. Our data fit a model that predicts that the T allele acts by decreasing chlorpyrifos concentration in the compartment targeted in insects. PMID:26463842

  12. Comparative genome analysis and resistance gene mapping in grain legumes

    International Nuclear Information System (INIS)

    Using, DNA markers and genome organization, several important disease resistance genes have been analyzed in mungbean (Vigna radiata), cowpea (Vigna unguiculata), common bean (Phaseolus vulgaris), and soybean (Glycine max). In the process, medium-density linkage maps consisting of restriction fragment length polymorphism (RFLP) markers were constructed for both mungbean and cowpea. Comparisons between these maps, as well as the maps of soybean and common bean, indicate that there is significant conservation of DNA marker order, though the conserved blocks in soybean are much shorter than in the others. DNA mapping results also indicate that a gene for seed weight may be conserved between mungbean and cowpea. Using the linkage maps, genes that control bruchid (genus Callosobruchus) and powdery mildew (Erysiphe polygoni) resistance in mungbean, aphid resistance in cowpea (Aphis craccivora), and cyst nematode (Heterodera glycines) resistance in soybean have all been mapped and characterized. For some of these traits resistance was found to be oligogenic and DNA mapping uncovered multiple genes involved in the phenotype. (author)

  13. Dissemination of metal resistance genes among animal methicillin-resistant coagulase-negative Staphylococci.

    Science.gov (United States)

    Argudín, M Angeles; Butaye, Patrick

    2016-04-01

    The use of metals as feed supplement has been recognized as a potential driver for co-selection of methicillin-resistant Staphylococcus aureus in pigs. However, the prevalence of these determinants in methicillin-resistant coagulase-negative staphylococci (MRCoNS) is largely unknown. In this study, a collection of 130 MRCoNS from pigs and veal calves were investigated for the presence of metal-resistance genes (czrC, copB, cadD, arsA) associated to SCCmec. Near half of the isolates carried metal resistance genes (czrC 5.4%, copB 38.5%, cadD 7.7%, arsA 26.2%) regardless of their SCCmec type. The increased use of metals in livestock animals, especially zinc in pigs in several European countries may co-select for methicillin-resistance in several staphylococcal species. PMID:27033931

  14. The durably resistant rice cultivar Digu activates defence gene expression before the full maturation of Magnaporthe oryzae appressorium.

    Science.gov (United States)

    Li, Weitao; Liu, Ya; Wang, Jing; He, Min; Zhou, Xiaogang; Yang, Chao; Yuan, Can; Wang, Jichun; Chern, Mawsheng; Yin, Junjie; Chen, Weilan; Ma, Bingtian; Wang, Yuping; Qin, Peng; Li, Shigui; Ronald, Pamela; Chen, Xuewei

    2016-04-01

    Rice blast caused by the fungal pathogen Magnaporthe oryzae is one of the most destructive diseases worldwide. Although the rice-M. oryzae interaction has been studied extensively, the early molecular events that occur in rice before full maturation of the appressorium during M. oryzae invasion are unknown. Here, we report a comparative transcriptomics analysis of the durably resistant rice variety Digu and the susceptible rice variety Lijiangxintuanheigu (LTH) in response to infection by M. oryzae (5, 10 and 20 h post-inoculation, prior to full development of the appressorium). We found that the transcriptional responses differed significantly between these two rice varieties. Gene ontology and pathway analyses revealed that many biological processes, including extracellular recognition and biosynthesis of antioxidants, terpenes and hormones, were specifically activated in Digu shortly after infection. Forty-eight genes encoding receptor kinases (RKs) were significantly differentially regulated by M. oryzae infection in Digu. One of these genes, LOC_Os08g10300, encoding a leucine-rich repeat RK from the LRR VIII-2 subfamily, conferred enhanced resistance to M. oryzae when overexpressed in rice. Our study reveals that a multitude of molecular events occur in the durably resistant rice Digu before the full maturation of the appressorium after M. oryzae infection and that membrane-associated RKs play important roles in the early response. PMID:26095454

  15. Identification of putative candidate genes for red rot resistance in sugarcane (Saccharum species hybrid) using LD-based association mapping.

    Science.gov (United States)

    Singh, Ram K; Banerjee, Nandita; Khan, M S; Yadav, Sonia; Kumar, Sanjeev; Duttamajumder, S K; Lal, Ram Ji; Patel, Jinesh D; Guo, H; Zhang, Dong; Paterson, Andrew H

    2016-06-01

    Red rot is a serious disease of sugarcane caused by the fungus Colletotrichum falcatum that has a colossal damage potential. The fungus, prevalent mainly in the Indian sub-continent, keeps on producing new pathogenic strains leading to breakdown of resistance in newly released varieties and hence the deployment of linked markers for marker-assisted selection for resistance to this disease can fine tune the breeding programme. This study based on a panel of 119 sugarcane genotypes fingerprinted for 944 SSR alleles was undertaken with an aim to identify marker-trait associations (MTAs) for resistance to red rot. Mixed linear model containing population structure and kinship as co-factor detected four MTAs that were able to explain 10-16 % of the trait variation, individually. Among the four MTAs, EST sequences diagnostic of three could be BLAST searched to the sorghum genome with significant sequence homology. Several genes encoding important plant defence related proteins, viz., cytochrome P450, Glycerol-3-phosphate transporter-1, MAP Kinase-4, Serine/threonine-protein kinase, Ring finger domain protein and others were localized to the vicinity of these MTAs. These positional candidate genes are worth of further investigation and possibly these could contribute directly to red rot resistance, and may find a potential application in marker-assisted sugarcane breeding. PMID:26961118

  16. Molecular evolution of the disease resistance gene Rx in Solanum

    OpenAIRE

    Butterbach, P.B.E.

    2007-01-01

    Potato (Solanum tuberosum ssp. tuberosum) is the fourth most important food crop with an annual yield of about 300 million tons over the world. The history of the domestication of potato shows that disease-causing agents followed the tracks of potato cultivation in temperate climates across continents, resulting in substantial crop losses. Plants including potato have evolved defence mechanisms against pathogens, of which the pathotype-specific system involving resistance genes (R genes) is v...

  17. Natural selection mapping of the warfarin-resistance gene

    OpenAIRE

    Kohn, Michael H.; Pelz, Hans-Joachim; Wayne, Robert K.

    2000-01-01

    In theory, genes under natural selection can be revealed by unique patterns of linkage disequilibrium (LD) and polymorphism at physically linked loci. However, given the effects of recombination and mutation, the physical extent and persistence of LD patterns in natural populations is uncertain. To assess the LD signature of selection, we survey variation in 26 microsatellite loci spanning an ≈32-cM region that includes the warfarin-resistance gene (Rw) in five wild rat populations having res...

  18. Spread of tetracycline resistance genes at a conventional dairy farm

    Directory of Open Access Journals (Sweden)

    Martina eKyselkova

    2015-05-01

    Full Text Available The use of antibiotics in animal husbandry contributes to the worldwide problem of increasing antibiotic resistance in animal and human pathogens. Intensive animal production is considered an important source of antibiotic resistance genes released to the environment, while the contribution of smaller farms remains to be evaluated. Here we monitor the spread of tetracycline resistance (TC-r genes at a middle-size conventional dairy farm, where chlortetracycline (CTC, as intrauterine suppository is prophylactically used after each calving. Our study has shown that animals at the farm acquired the TC-r genes in their early age (1-2 weeks, likely due to colonization with TC-resistant bacteria from their mothers and/or the farm environment. The relative abundance of the TC-r genes tet(W, tet(Q and tet(M in fresh excrements of calves was about 1-2 orders of magnitude higher compared to heifers and dairy cows, possibly due to the presence of antibiotic residues in milk fed to calves. The occurrence and abundance of TC-r genes in fresh excrements of heifers and adult cows remained unaffected by intrauterine CTC applications, with tet(O, tet(Q and tet(W representing a ‘core TC-resistome’ of the farm, and tet(A, tet(M, tet(Y and tet(X occurring occasionally. The genes tet(A, tet(M, tet(Y and tet(X were shown to be respectively harbored by Shigella, Lactobacillus and Clostridium, Acinetobacter, and Wautersiella. Soil in the farm proximity, as well as field soil to which manure from the farm was applied, was contaminated with TC-r genes occurring in the farm, and some of the TC-r genes persisted in the field over 3 months following the manure application. Concluding, our study shows that antibiotic resistance genes may be a stable part of the intestinal metagenome of cattle even if antibiotics are not used for growth stimulation, and that smaller dairy farms may also contribute to environmental pollution with antibiotic resistance genes.

  19. Spread of tetracycline resistance genes at a conventional dairy farm.

    Science.gov (United States)

    Kyselková, Martina; Jirout, Jiří; Vrchotová, Naděžda; Schmitt, Heike; Elhottová, Dana

    2015-01-01

    The use of antibiotics in animal husbandry contributes to the worldwide problem of increasing antibiotic resistance in animal and human pathogens. Intensive animal production is considered an important source of antibiotic resistance genes released to the environment, while the contribution of smaller farms remains to be evaluated. Here we monitor the spread of tetracycline resistance (TC-r) genes at a middle-size conventional dairy farm, where chlortetracycline (CTC, as intrauterine suppository) is prophylactically used after each calving. Our study has shown that animals at the farm acquired the TC-r genes in their early age (1-2 weeks), likely due to colonization with TC-resistant bacteria from their mothers and/or the farm environment. The relative abundance of the TC-r genes tet(W), tet(Q), and tet(M) in fresh excrements of calves was about 1-2 orders of magnitude higher compared to heifers and dairy cows, possibly due to the presence of antibiotic residues in milk fed to calves. The occurrence and abundance of TC-r genes in fresh excrements of heifers and adult cows remained unaffected by intrauterine CTC applications, with tet(O), tet(Q), and tet(W) representing a "core TC-resistome" of the farm, and tet(A), tet(M), tet(Y), and tet(X) occurring occasionally. The genes tet(A), tet(M), tet(Y), and tet(X) were shown to be respectively harbored by Shigella, Lactobacillus and Clostridium, Acinetobacter, and Wautersiella. Soil in the farm proximity, as well as field soil to which manure from the farm was applied, was contaminated with TC-r genes occurring in the farm, and some of the TC-r genes persisted in the field over 3 months following the manure application. Concluding, our study shows that antibiotic resistance genes may be a stable part of the intestinal metagenome of cattle even if antibiotics are not used for growth stimulation, and that smaller dairy farms may also contribute to environmental pollution with antibiotic resistance genes. PMID:26074912

  20. Methods to predict antibiotic resistance: From genes to metagenomes

    OpenAIRE

    Lira, Felipe

    2015-01-01

    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 21-10-2015 As many antibiotics exist as many mechanisms of resistance will rise. Antibiotic resistance is a worldwide problem and deserves all sort of attention and dedication to identify the critical points which might promote or facilitate the emergence of novel resistance genes in one community, as well the propagation of the already kno...

  1. ENHANCEMENT OF CHLORIDE RESISTANCE OF PRE-STRESSED CONCRETE SHEET PILE BY BLAST FURNACE SLAG

    OpenAIRE

    Irmawaty, Rita

    2012-01-01

    Chloride-induced corrosion is one of the main mechanisms of deterioration affecting the long-term performance of concrete structures. In Japan, a large majority of structures are built either near the costal or indirect contact with seawater. The durability of reinforced or pre-stressed concrete structure depends on the resistance of concrete to chloride penetration. Naturally concrete provides physical and chemical protection to the reinforcing steel from chloride penetrating. The chloride ...

  2. NBS-LRR resistance gene homologues in rice

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Twenty three DNA fragments with a size of about 520 bp have been cloned from rice genome by PCR amplification using primers designed according to the conserved region of most plant resistance (R) genes which have Nucleotide Binding Site (NBS) and Leucine-Rich Repeat (LRR) domains. Homologous comparison showed that these fragments contained typical motifs of the NBS-LRR resistance gene class, kinase 1a, kinase 2a, kinase 3a and domain 2. Thus they were named R gene homologous sequences (RS). These RS were divided into 4 groups by clustering analysis and mapped onto chromosomes 1, 3, 4, 7, 8, 9, 10 and 11, respectively, by genetic mapping. Ten RS were located in the chromosomal intervals where known R genes had been mapped. Further RFLP analysis of an RS, RS13, near the bacterial blight resistance gene Xa4 locus on chromosome 11 among near isogenic lines and pyramiding lines of Xa4 showed that RS13 was possibly amplified from the gene family of Xa4.

  3. Bacterial metal resistance genes and metal bioavailability in contaminated sediments

    International Nuclear Information System (INIS)

    In bacteria a metal may be defined as bioavailable if it crosses the cytoplasmic membrane to reach the cytoplasm. Once inside the cell, specific metal resistance systems may be triggered. In this research, specific metal resistance genes were used to estimate metal bioavailability in sediment microbial communities. Gene levels were measured by quantitative PCR and correlated to metals in sediments using five different protocols to estimate dissolved, particle-adsorbed and occluded metals. The best correlations were obtained with czcA (a Cd/Zn/Co efflux pump) and Cd/Zn adsorbed or occluded in particles. Only adsorbed Co was correlated to czcA levels. We concluded that the measurement of czcA gene levels by quantitative PCR is a promising tool which may complement the classical approaches used to estimate Cd/Zn/Co bioavailability in sediment compartments. - Highlights: • Metal resistance genes were used to estimate metal bioavailability in sediments. • Gene levels were correlated to metals using 5 different metal extraction protocols. • CzcA gene levels determined by quantitative PCR is a promising tool for Cd/Zn/Co. - Capsule Bacterial czcA is a potential biomarker of Cd, Zn and Co bioavailability in aquatic sediments as shown by quantitative PCR and sequential metal extraction

  4. Major Gene for Field Stem Rust Resistance Co-Locates with Resistance Gene Sr12 in ‘Thatcher’ Wheat

    Science.gov (United States)

    Hiebert, Colin W.; Kolmer, James A.; McCartney, Curt A.; Briggs, Jordan; Fetch, Tom; Bariana, Harbans; Choulet, Frederic; Rouse, Matthew N.; Spielmeyer, Wolfgang

    2016-01-01

    Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effective stem rust resistance genes. ‘Thatcher’ wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was to examine APR in ‘Thatcher’ and look for genetic interactions with Lr34. A RIL population was tested for stem rust resistance in field nurseries in Canada, USA, and Kenya. BSA was used to find SNP markers associated with reduced stem rust severity. A major QTL was identified on chromosome 3BL near the centromere in all environments. Seedling testing showed that Sr12 mapped to the same region as the QTL for APR. The SNP markers were physically mapped and the region carrying the resistance was searched for sequences with homology to members of the NB-LRR resistance gene family. SNP marker from one NB-LRR-like sequence, NB-LRR3 co-segregated with Sr12. Two additional populations, including one that lacked Lr34, were tested in field nurseries. NB-LRR3 mapped near the maximum LOD for reduction in stem rust severity in both populations. Lines from a population that segregated for Sr12 and Lr34 were tested for seedling Pgt biomass and infection type, as well as APR to field stem rust which showed an interaction between the genes. We concluded that Sr12, or a gene closely linked to Sr12, was responsible for ‘Thatcher’-derived APR in several environments and this resistance was enhanced in the presence of Lr34. PMID:27309724

  5. Major Gene for Field Stem Rust Resistance Co-Locates with Resistance Gene Sr12 in 'Thatcher' Wheat.

    Science.gov (United States)

    Hiebert, Colin W; Kolmer, James A; McCartney, Curt A; Briggs, Jordan; Fetch, Tom; Bariana, Harbans; Choulet, Frederic; Rouse, Matthew N; Spielmeyer, Wolfgang

    2016-01-01

    Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effective stem rust resistance genes. 'Thatcher' wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was to examine APR in 'Thatcher' and look for genetic interactions with Lr34. A RIL population was tested for stem rust resistance in field nurseries in Canada, USA, and Kenya. BSA was used to find SNP markers associated with reduced stem rust severity. A major QTL was identified on chromosome 3BL near the centromere in all environments. Seedling testing showed that Sr12 mapped to the same region as the QTL for APR. The SNP markers were physically mapped and the region carrying the resistance was searched for sequences with homology to members of the NB-LRR resistance gene family. SNP marker from one NB-LRR-like sequence, NB-LRR3 co-segregated with Sr12. Two additional populations, including one that lacked Lr34, were tested in field nurseries. NB-LRR3 mapped near the maximum LOD for reduction in stem rust severity in both populations. Lines from a population that segregated for Sr12 and Lr34 were tested for seedling Pgt biomass and infection type, as well as APR to field stem rust which showed an interaction between the genes. We concluded that Sr12, or a gene closely linked to Sr12, was responsible for 'Thatcher'-derived APR in several environments and this resistance was enhanced in the presence of Lr34. PMID:27309724

  6. Genetic control of resistance to Coccidioides immitis: a single gene that is expressed in spleen cells determines resistance

    International Nuclear Information System (INIS)

    The authors have previously reported that inbred mice vary widely in their resistance to Coccidioides immitis peritonitis. To investigate the number of genes controlling resistance, (susceptible X resistant)F1 X susceptible backcross mice were tested for resistance to infection. A 1:1 ratio of resistant:susceptible offspring was observed, which is consistent with a single dominant gene determining resistance. To find out whether this gene, which was designated Cms, is expressed in the immune and/or the inflammatory responses, radiation chimeras were constructed by transplanting spleen cells from the resistant F1 mice into the susceptible parental strain. These chimeras were consistently more resistant to infection than the susceptible parental strain. The authors concluded that resistance to C. immitis is determined primarily by a single gene, and that this gene is expressed by spleen cells

  7. Fine Genetic Mapping Localizes Cucumber Scab Resistance Gene Ccu into an R Gene Cluster

    Science.gov (United States)

    The scab caused by Cladosporium cucumerinum, is an important disease of cucumber, Cucumis sativus. In this study, we conducted fine genetic mapping of the single dominant scab resistance gene, Ccu, with 148 F9 recombination inbreeding lines (RILs) and 1,944 F2 plants derived from the resistant cucum...

  8. Altered Gene Expression in Cultured Microglia in Response to Simulated Blast Overpressure: Possible Role of Pulse Duration

    OpenAIRE

    Kane, Michael J; Angoa-Pérez, Mariana; Francescutti, Dina M.; Sykes, Catherine E.; Briggs, Denise I.; Leung, Lai Yee; VandeVord, Pamela J.; Kuhn, Donald M.

    2012-01-01

    Blast overpressure has long been known to cause barotrauma to air-filled organs such as lung and middle ear. However, experience in Iraq and Afghanistan is revealing that individuals exposed to explosive munitions can also suffer traumatic brain injury (TBI) even in the absence of obvious external injury. The interaction of a blast shock wave with the brain in the intact cranial vault is extremely complex making it difficult to conclude that a blast wave interacts in a direct manner with the ...

  9. Identification of antimicrobial resistance genes in multidrug-resistant clinical Bacteroides fragilis isolates by whole genome shotgun sequencing

    DEFF Research Database (Denmark)

    Sydenham, Thomas Vognbjerg; Sóki, József; Hasman, Henrik;

    2015-01-01

    Bacteroides fragilis constitutes the most frequent anaerobic bacterium causing bacteremia in humans. The genetic background for antimicrobial resistance in B. fragilis is diverse with some genes requiring insertion sequence (IS) elements inserted upstream for increased expression. To evaluate whole...... genome shotgun sequencing as a method for predicting antimicrobial resistance properties, one meropenem resistant and five multidrug-resistant blood culture isolates were sequenced and antimicrobial resistance genes and IS elements identified using ResFinder 2.1 (http...

  10. ERG11 mutations and expression of resistance genes in fluconazole-resistant Candida albicans isolates.

    Science.gov (United States)

    Xu, Yonghao; Sheng, Fang; Zhao, Jie; Chen, Lamei; Li, Chunyang

    2015-11-01

    Azole resistance in the pathogenic yeast Candida albicans poses significant challenges for its antibiotic treatment. The conformational change of the target enzyme 14 alpha-demethylase (Erg11p) due to ERG11 gene mutations is one of the mechanisms resulting in the azole resistance. ERG11 of 23 isolates (8 susceptible and 15 resistant) and 6 standard strains of Candida albicans were amplified and sequenced. Nineteen missense mutations were detected. Two mutations, G487T (A114S) and T916C (Y257H), coexisted exclusively in 14 fluconazole-resistant isolates. To identify the resistance mechanisms in the isolates with G487T and T916C mutations, we compared the expression of 5 resistance-related genes in the 14 azole-resistant isolates with those in the susceptible type strain ATCC 10231, Saccharomyces cerevisiae AD/CDR1 and AD/CDR2. The tested values of mRNA transcription of CDR1 and CDR2 were higher than that of control strain, while the semi-quantified Cdr1p values were not higher in all of the 14 resistant isolates. And the data analyzed with t test suggest that both of the differences are significant (P ERG11, MDR1, and FLU1 varied in these isolates. These data suggested that overexpression of the five genes might not be the reason of resistance in the 14 isolates with G487T and T916C, especially in the 5 isolates (GZ09, GZ15, GZ16, GZ58, and 4263) in which neither translation of Cdr1p/Cdr2p nor transcription of ERG11, MDR1, or FLU1 was detected up-regulated. The results suggest that Erg11p conformational change due to the point mutations is most likely responsible for the azole resistance in these isolates. PMID:26349561

  11. Putative resistance genes in the CitEST database

    Directory of Open Access Journals (Sweden)

    Simone Guidetti-Gonzalez

    2007-01-01

    Full Text Available Disease resistance in plants is usually associated with the activation of a wide variety of defense responses to prevent pathogen replication and/or movement. The ability of the host plant to recognize the pathogen and to activate defense responses is regulated by direct or indirect interaction between the products of plant resistance (R and pathogen avirulence (Avr genes. Attempted infection of plants by avirulent pathogens elicits a battery of defenses often followed by the collapse of the challenged host cells. Localized host cell death may help to prevent the pathogen from spreading to uninfected tissues, known as hypersensitive response (HR. When either the plant or the pathogen lacks its cognate gene, activation of the plant’s defense responses fails to occur or is delayed and does not prevent pathogen colonization. In the CitEST database, we identified 1,300 reads related to R genes in Citrus which have been reported in other plant species. These reads were translated in silico, and alignments of their amino acid sequences revealed the presence of characteristic domains and motifs that are specific to R gene classes. The description of the reads identified suggests that they function as resistance genes in citrus.

  12. Polymorphisms in Plasmodium falciparum chloroquine resistance transporter and multidrug resistance 1 genes

    DEFF Research Database (Denmark)

    Venkatesan, Meera; Gadalla, Nahla B; Stepniewska, Kasia;

    2014-01-01

    Adequate clinical and parasitologic cure by artemisinin combination therapies relies on the artemisinin component and the partner drug. Polymorphisms in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1) genes are associated with...... effects on single-nucleotide polymorphisms in pfcrt and pfmdr1. Monitoring selection and responding to emerging signs of drug resistance are critical tools for preserving efficacy of artemisinin combination therapies; determination of the prevalence of at least pfcrt K76T and pfmdr1 N86Y should now be...... methods from the WorldWide Antimalarial Resistance Network. Data for more than 7,000 patients were analyzed to assess relationships between parasite polymorphisms in pfcrt and pfmdr1 and clinically relevant outcomes after treatment with AL or ASAQ. Presence of the pfmdr1 gene N86 (adjusted hazards ratio...

  13. Distribution of putative virulence genes and antimicrobial drug resistance in Vibrio harveyi

    Digital Repository Service at National Institute of Oceanography (India)

    Parvathi, A.; Mendez, D.; Anto, C.

    environments for understanding the distribution of putative virulence genes and antimicrobial drug resistance. The putative genes targeted for PCR detection included four reversible toxin (Rtx)/hemolysin genes, a gene encoding homologue of Vibrio cholerae...

  14. Removal characteristics of tetracyclines resistant bacteria and tetracycline resistance genes in sludge deep dehydration

    OpenAIRE

    TAN Guogan; DU Yongli; HUANG Manhong; Zhang, Wei

    2014-01-01

    In order to investigate the removal characteristics of Tetracyclines Resistant Bacteria (TRB) and Tetracycline Resistance Genes (TRGs) in sludge deep dehydration,Dilution plate coating method and Real-Time Polymerase chain reaction (RT-PCR) were used to detected the numbers of TRB and four tet genes (tetA、tetB、tetM and tetX) abundant before and after sludge dehydration,and then TRB and TRGs removal characteristics before and after sludge deep dehydration were analyzed.Results showed that:both...

  15. Functional study of the novel multidrug resistance gene HA117 and its comparison to multidrug resistance gene 1

    Directory of Open Access Journals (Sweden)

    Chen Tingfu

    2010-07-01

    Full Text Available Abstract Background The novel gene HA117 is a multidrug resistance (MDR gene expressed by all-trans retinoic acid-resistant HL-60 cells. In the present study, we compared the multidrug resistance of the HA117 with that of the classical multidrug resistance gene 1 (MDR1 in breast cancer cell line 4T1. Methods Transduction of the breast cancer cell line 4T1 with adenoviral vectors encoding the HA117 gene and the green fluorescence protein gene (GFP (Ad-GFP-HA117, the MDR1 and GFP (Ad-GFP-MDR1 or GFP (Ad-GFP was respectively carried out. The transduction efficiency and the multiplicity of infection (MOI were detected by fluorescence microscope and flow cytometry. The transcription of HA117 gene and MDR1 gene were detected by reverse transcription polymerase chain reaction (RT-PCR. Western blotting analysis was used to detect the expression of P-glycoprotein (P-gp but the expression of HA117 could not be analyzed as it is a novel gene and its antibody has not yet been synthesized. The drug-excretion activity of HA117 and MDR1 were determined by daunorubicin (DNR efflux assay. The drug sensitivities of 4T1/HA117 and 4T1/MDR1 to chemotherapeutic agents were detected by Methyl-Thiazolyl-Tetrazolium (MTT assay. Results The transducted efficiency of Ad-GFP-HA117 and Ad-GFP-MDR1 were 75%-80% when MOI was equal to 50. The transduction of Ad-GFP-HA117 and Ad-GFP-MDR1 could increase the expression of HA117 and MDR1. The drug resistance index to Adriamycin (ADM, vincristine (VCR, paclitaxel (Taxol and bleomycin (BLM increased to19.8050, 9.0663, 9.7245, 3.5650 respectively for 4T1/HA117 and 24.2236, 11.0480, 11.3741, 0.9630 respectively for 4T1/MDR1 as compared to the control cells. There were no significant differences in drug sensitivity between 4T1/HA117 and 4T1/MDR1 for the P-gp substrates (ADM, VCR and Taxol (P Conclusions These results confirm that HA117 is a strong MDR gene in both HL-60 and 4T1 cells. Furthermore, our results indicate that the MDR

  16. Heavy metal and disinfectant resistance genes among livestock-associated methicillin-resistant Staphylococcus aureus isolates.

    Science.gov (United States)

    Argudín, M Angeles; Lauzat, Birgit; Kraushaar, Britta; Alba, Patricia; Agerso, Yvonne; Cavaco, Lina; Butaye, Patrick; Porrero, M Concepción; Battisti, Antonio; Tenhagen, Bernd-Alois; Fetsch, Alexandra; Guerra, Beatriz

    2016-08-15

    Livestock associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has emerged in animal production worldwide. Most LA-MRSA in Europe belong to the clonal complex (CC) 398. The reason for the LA-MRSA emergence is not fully understood. Besides antimicrobial agents used for therapy, other substances with antimicrobial activity applied in animal feed, including metal-containing compounds might contribute to their selection. Some of these genes have been found in various novel SCCmec cassettes. The aim of this study was to assess the occurrence of metal-resistance genes among a LA-S. aureus collection [n=554, including 542 MRSA and 12 methicillin-susceptible S. aureus (MSSA)] isolated from livestock and food thereof. Most LA-MRSA isolates (76%) carried at least one metal-resistance gene. Among the LA-MRSA CC398 isolates (n=456), 4.8%, 0.2%, 24.3% and 71.5% were positive for arsA (arsenic compounds), cadD (cadmium), copB (copper) and czrC (zinc/cadmium) resistance genes, respectively. In contrast, among the LA-MRSA non-CC398 isolates (n=86), 1.2%, 18.6% and 16.3% were positive for the cadD, copB and czrC genes, respectively, and none were positive for arsA. Of the LA-MRSA CC398 isolates, 72% carried one metal-resistance gene, and the remaining harboured two or more in different combinations. Differences between LA-MRSA CC398 and non-CC398 were statistically significant for arsA and czrC. The czrC gene was almost exclusively found (98%) in the presence of SCCmec V in both CC398 and non-CC398 LA-MRSA isolates from different sources. Regarding the LA-MSSA isolates (n=12), some (n=4) were also positive for metal-resistance genes. This study shows that genes potentially conferring metal-resistance are frequently present in LA-MRSA. PMID:27374912

  17. The Optimization and Design of a Fully Austenitic, Gamma-Prime Strengthened TRIP Steel for Blast and Fragment Resistance

    Science.gov (United States)

    Wengrenovich, Nicholas J.

    Current analysis into the property requirements of materials designed for blast and fragment protection has led to the need for high tensile uniform ductility to withstand the pressure wave and high shear localization resistance to withstand fragment penetration. Additionally, it has been shown that steels with retained austenite are able to outperform standard martensitic steels when subjected to fragment simulating projectiles (FSP) in ballistic experiments. Using a systems based, computational materials design approach, a series of prototype precipitation strengthened, fully austenitic steels have been designed to obtain superior performance in blast and fragment protection. The most recent design, TRIP-180, explores optimized transformation induced plasticity (TRIP) to counteract strain softening and thus significantly increase uniform plastic deformation in both tension and shear at high strength (1241 MPa / 180 ksi). The transformation hardening delays the onset of localization, which in tension delays necking, and in shear delays plugging. Through precipitation heat treatment, the matrix composition can be varied to optimize the austenite stability, quantified by the Ms sigma temperature. Baseline data quantifying the martensitic transformation in shear was obtained through a series of quasi-static torsion experiments performed on TRIP-180. Analysis of the postmortem microstructures allowed for calibration of M_s. sigma(sh) temperatures with the transformation product morphologiesin the stress-assisted regime, where the plate martensite forms at the same locations as when quenching, and strain-induced regime, where the finely dispersed martensite forms at the intersections of shear bands. Dynamic testing (E = 104/s) identified the optimal austenite stability ( T -- Ms sigma(sh) = 60°C ) required to delay the shear localization instability at higher ultimate shear stress levels (1420 MPa) and larger plastic strains (0.103) than an existing Navy standard

  18. Multi drug resistance to cancer chemotherapy: Genes involved and blockers

    International Nuclear Information System (INIS)

    During the last three decades, important and considerable research efforts had been performed to investigate the mechanism through which cancer cells overcome the cytotoxic effects of a variety of chemotherapeutic drugs. Most of the previously published work has been focused on the resistance of tumor cells to those anticancer drugs of natural source. Multidrug resistance (MDR) is a cellular cross-resistance to a broad spectrum of natural products used in cancer chemotherapy and is believed to be the major cause of the therapeutic failures of the drugs belonging to different naturally obtained or semisynthetic groups including vinca alkaloids, taxans, epipodophyllotoxins and certain antibiotics. This phenomenon results from overexpression of four MDR genes and their corresponding proteins that act as membrane-bound ATP consuming pumps. These proteins mediate the efflux of many structurally and functionally unrelated anticancer drugs of natural source. MDR may be intrinsic or acquired following exposure to chemotherapy. The existence of intrinsically resistant tumor cell clone before and following chemotherapeutic treatment has been associated with a worse final outcome because of increased incidence of distant metasis. In view of irreplaceability of natural product anticancer drugs as effective chemotherapeutic agents, and in view of MDR as a major obstacle to successful chemotherapy, this review is aimed to highlight the genes involved in MDR, classical MDR blockers and gene therapy approaches to overcome MDR. (author)

  19. Development of genetic and molecular toolboxes to control both rice blast and sheath blight

    Science.gov (United States)

    Rice blast and sheath blight diseases are the two major constraints for stable rice production in the Southern USA. New genetic and molecular tool boxes have been developed at the USDA-ARS Dale Bumpers National Rice Research Center. Resistance (major and minor) genes from rice have been identified...

  20. Environmental and Public Health Implications of Water Reuse: Antibiotics, Antibiotic Resistant Bacteria, and Antibiotic Resistance Genes

    Directory of Open Access Journals (Sweden)

    Roderick I. Mackie

    2013-07-01

    Full Text Available Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.

  1. Environmental and Public Health Implications of Water Reuse: Antibiotics, Antibiotic Resistant Bacteria, and Antibiotic Resistance Genes

    KAUST Repository

    Hong, Pei-Ying

    2013-07-31

    Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.

  2. Spread of tetracycline resistance genes at a conventional dairy farm

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Jirout, Jiří; Vrchotová, Naděžda; Schmitt, H.; Elhottová, Dana

    2015-01-01

    Roč. 6, may (2015), s. 536. ISSN 1664-302X R&D Projects: GA ČR GAP504/10/2077; GA MŠk(CZ) EE2.3.30.0032; GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 ; RVO:60077344 Keywords : antibiotic resistance spread * animal manure * cattle intestinal microflora * chlortetracycline * dairy cattle * dairy farm * heavy metals * tetracycline resistance genes Subject RIV: EI - Biotechnology ; Bionics; EE - Microbiology, Virology (BC-A) Impact factor: 3.989, year: 2014

  3. Identification of Differentially-Expressed Genes in Response to Mycosphaerella fijiensis in the Resistant Musa Accession 'Calcutta-4' Using Suppression Subtractive Hybridization.

    Science.gov (United States)

    Sánchez Timm, Eduardo; Hidalgo Pardo, Lisette; Pacheco Coello, Ricardo; Chávez Navarrete, Tatiana; Navarrete Villegas, Oscar; Santos Ordóñez, Efrén

    2016-01-01

    Bananas and plantains are considered an important crop around the world. Banana production is affected by several constraints, of which Black Sigatoka Disease, caused by the fungus Mycosphaerella fijiensis, is considered one of the most important diseases in banana plantations. The banana accession 'Calcutta-4' has a natural resistance to Black Sigatoka; however, the fruit is not valuable for commercialization. Gene identification and expression studies in 'Calcutta-4' might reveal possible gene candidates for resistant to the disease and elucidate mechanisms for resistance. A subtracted cDNA library was generated from leaves after 6, 9 and 12 days inoculated with M. fijiensis conidia on greenhouse banana plants of the accession 'Calcutta-4'. Bioinformatic analysis revealed 99 good quality sequences. Blast2go analysis revealed that 31% of the sequences could not be categorized and, according to the Biological Process Category, 32 and 28 ESTs are related to general metabolic and cellular processes, respectively; while 10 ESTs response to stimulus. Seven sequences were redundant and one was similar to genes that may be involved in pathogen resistance including the putative disease resistance protein RGA1. Genes encoding zinc finger domains were identified and may play an important role in pathogen resistance by inducing the expression of downstream genes. Expression analysis of four selected genes was performed using RT-qPCR during the early stage of the disease development at 6, 9, 12 and 15 days post inoculation showing a peak of up regulation at 9 or 12 days post inoculation. Three of the four genes showed an up-regulation of expression in 'Calcutta-4' when compared to 'Williams' after inoculation with M. fijiensis, suggesting a fine regulation of specific gene candidates that may lead to a resistance response. The genes identified in early responses in a plant-pathogen interaction may be relevant for the resistance response of 'Calcutta-4' to Black Sigatoka

  4. Identification of Differentially-Expressed Genes in Response to Mycosphaerella fijiensis in the Resistant Musa Accession ‘Calcutta-4’ Using Suppression Subtractive Hybridization

    Science.gov (United States)

    Pacheco Coello, Ricardo; Chávez Navarrete, Tatiana; Navarrete Villegas, Oscar; Santos Ordóñez, Efrén

    2016-01-01

    Bananas and plantains are considered an important crop around the world. Banana production is affected by several constraints, of which Black Sigatoka Disease, caused by the fungus Mycosphaerella fijiensis, is considered one of the most important diseases in banana plantations. The banana accession ‘Calcutta-4’ has a natural resistance to Black Sigatoka; however, the fruit is not valuable for commercialization. Gene identification and expression studies in ‘Calcutta-4’ might reveal possible gene candidates for resistant to the disease and elucidate mechanisms for resistance. A subtracted cDNA library was generated from leaves after 6, 9 and 12 days inoculated with M. fijiensis conidia on greenhouse banana plants of the accession ‘Calcutta-4’. Bioinformatic analysis revealed 99 good quality sequences. Blast2go analysis revealed that 31% of the sequences could not be categorized and, according to the Biological Process Category, 32 and 28 ESTs are related to general metabolic and cellular processes, respectively; while 10 ESTs response to stimulus. Seven sequences were redundant and one was similar to genes that may be involved in pathogen resistance including the putative disease resistance protein RGA1. Genes encoding zinc finger domains were identified and may play an important role in pathogen resistance by inducing the expression of downstream genes. Expression analysis of four selected genes was performed using RT-qPCR during the early stage of the disease development at 6, 9, 12 and 15 days post inoculation showing a peak of up regulation at 9 or 12 days post inoculation. Three of the four genes showed an up-regulation of expression in ‘Calcutta-4’ when compared to ‘Williams’ after inoculation with M. fijiensis, suggesting a fine regulation of specific gene candidates that may lead to a resistance response. The genes identified in early responses in a plant-pathogen interaction may be relevant for the resistance response of ‘Calcutta-4

  5. Multiple resistance to sulfonylureas and imidazolinones conferred by an acetohydroxyacid synthase gene with separate mutations for selective resistance.

    Science.gov (United States)

    Hattori, J; Rutledge, R; Labbé, H; Brown, D; Sunohara, G; Miki, B

    1992-03-01

    The acetohydroxyacid synthase (AHAS) gene from the Arabidopsis thaliana mutant line GH90 carrying the imidazolinone resistance allele imr1 was cloned. Expression of the AHAS gene under the control of the CaMV 35S promoter in transgenic tobacco resulted in selective imidazolinone resistance, confirming that the single base-pair change found near the 3' end of the coding region of this gene is responsible for imidazolinone resistance. A chimeric AHAS gene containing both the imr1 mutation and the csr1 mutation, responsible for selective resistance to sulfonylurea herbicides, was constructed. It conferred on transgenic tobacco plants resistance to both sulfonylurea and imidazolinone herbicides. The data illustrate that a multiple-resistance phenotype can be achieved in an AHAS gene through combinations of separate mutations, each of which individually confers resistance to only one class of herbicides. PMID:1557022

  6. Antibiotic resistance and resistance genes in Escherichia coli from poultry farms, southwest Nigeria

    DEFF Research Database (Denmark)

    Adelowo, Olawale O.; Fagade, Obasola E.; Agersø, Yvonne

    2014-01-01

    %, ampicillin 36%, spectinomycin 28%, nalidixic acid 25%, chloramphenicol 22%, neomycin 14%, gentamicin 8%, amoxicillin-clavulanate, ceftiofur, cefotaxime, colistin, florfenicol and apramycin 0%. Resistance genes found among the isolates include bla-TEM (85%), sul2 (67%), sul3 (17%), aadA (65%), strA (70%), str...

  7. Occurrence of antibiotic resistance and characterization of resistant genes and integrons in Enterobacteriaceae isolated from integrated fish farms south China

    Science.gov (United States)

    Su, Hao-Chang; Ying, Guang-Guo; Tao, Ran; Zhang, Rui-Quan; Fogarty, Lisa R.; Kolpin, Dana W.

    2011-01-01

    Antibiotics are still widely applied in animal husbandry to prevent diseases and used as feed additives to promote animal growth. This could result in antibiotic resistance to bacteria and antibiotic residues in animals. In this paper, Enterobacteriaceae isolated from four integrated fish farms in Zhongshan, South China were tested for antibiotic resistance, tetracycline resistance genes, sulfonamide resistance genes, and class 1 integrons. The Kirby-Bauer disk diffusion method and polymerase chain reaction (PCR) assays were carried out to test antibiotic susceptibility and resistance genes, respectively. Relatively high antibiotic resistance frequencies were found, especially for ampicillin (80%), tetracycline (52%), and trimethoprim (50%). Out of 203 Enterobacteriaceae isolates, 98.5% were resistant to one or more antibiotics tested. Multiple antibiotic resistance (MAR) was found highest in animal manures with a MAR index of 0.56. Tetracycline resistance genes (tet(A), tet(C)) and sulfonamide resistance genes (sul2) were detected in more than 50% of the isolates. The intI1 gene was found in 170 isolates (83.7%). Both classic and non-classic class 1 integrons were found. Four genes, aadA5, aadA22, dfr2, and dfrA17, were detected. To our knowledge, this is the first report for molecular characterization of antibiotic resistance genes in Enterobacteriaceae isolated from integrated fish farms in China and the first time that gene cassette array dfrA17-aadA5 has been detected in such fish farms. Results of this study indicated that fish farms may be a reservoir of highly diverse and abundant antibiotic resistant genes and gene cassettes. Integrons may play a key role in multiple antibiotic resistances posing potential health risks to the general public and aquaculture.

  8. Cytogenetic Mapping of Disease Resistance Genes and Analysis of Their Distribution Features on Chromosomes in Maize

    Institute of Scientific and Technical Information of China (English)

    Li Li-jia; Song Yun-chun

    2003-01-01

    Cytogenetic maps of four clusters of disease resistance genes were generated by ISH of the two RFLP markers tightly linked to and flanking each of maize resistance genes and the cloned resistance genes from other plant species onto maize chromosomes, combining with data published before. These genes include Helminthosporium turcium Pass resistance genes Ht1, Htn1 and Ht2, Helminthosporium maydis Nisik resistance genes Rhm1 and Rhm2, maize dwarf mosaic virus resistance gene Mdm1, wheat streak mosaic virus resistance gene Wsm1, Helminthosporium carbonum ULLstrup resistance gene Hml and the cloned Xanthomonas oryzae pv. Oryzae resistance gene Xa21 of rice, Cladosporium fulvum resistance genes Cf-9 and Cf-2.1 of tomato,and Pseudomonas syringae resistance gene RPS2 of Arabidopsis. Most of the tested disease resistance genes located on the four chromosomes, i.e., chromosomes1, 3, 6 and 8, and they closely distributed at the interstitial regions of these chromosomal long arms with percentage distances ranging 31.44(±3.72)-72.40(±3.25) except for genes Rhm1, Rhm2, Mdm1 and Wsm1 which mapped on the satellites of the short arms of chromosome6. It showed that the tested RFLP markers and genes were duplicated or triplicated in maize genome. Homology and conservation of disease resistance genes among species, and relationship between distribution features and functions of the genes were discussed. The results provide important scientific basis for deeply understanding structure and function of disease resistance genes and breeding in maize.

  9. Comparative analysis of drought resistance genes in Arabidopsis and rice

    OpenAIRE

    Trijatmiko, K.R.

    2005-01-01

    Keywords: rice, Arabidopsis, drought, genetic mapping,microarray, transcription factor, AP2/ERF, SHINE, wax, stomata, comparative genetics, activation tagging, Ac/Ds, En/IThis thesis describes the use of genomics information and tools from Arabidopsis and rice to understand the mechanisms controlling drought resistance. Genetic mapping in a rice population revealed that around 30% of variation for grain yield under drought was controlled by a locus close to the dwarfing gene responsible for t...

  10. Resistance of Antimicrobial Peptide Gene Transgenic Rice to Bacterial Blight

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; WU Chao; LIU Mei; LIU Xu-ri; Hu Guo-cheng; SI Hua-min; SUN Zong-xiu; LIU Wen-zhen; Fu Ya-ping

    2011-01-01

    Antimierobial peptide is a polypeptide with antimicrobial activity.Antimicrobial peptide genes Np3 and Np5 from Chinese shrimp (Fenneropenaeus Chinensis) were integrated into Oryza sativa L.subsp.japonica cv.Aichi ashahi by Agrobacterium mediated transformation system.PCR analysis showed that the positive ratios of Np3 and Np5 were 36% and 45% in T0 generation,respectively.RT-PCR analysis showed that the antimicrobial peptide genes were expressed in T1 generation,and there was no obvious difference in agronomic traits between transgenic plants and non-transgenic plants.Four Np3 and Np5 transgenic lines in T1 generation were inoculated with ×anthomonas oryzae pv.oryzae strain CR4,and all the four transgenic lines had significantly enhanced resistance to bacterial blight caused by the strain CR4.The Np5 transgenic lines also showed higher resistance to bacterial blight caused by strains JS97-2,Zhe 173 and OS-225.It is suggested that transgenic lines with Np5 gene might possess broad spectrum resistance to rice bacterial blight.

  11. Novel streptomycin and spectinomycin resistance gene as a gene cassette within a class 1 integron isolated from Escherichia coli

    DEFF Research Database (Denmark)

    Sandvang, D.

    1999-01-01

    The aadA genes, encoding resistance to streptomycin and spectinomycin, have been found as gene cassettes in different gram-negative and gram-positive bacterial species. The present study has revealed the sequence of a new gene, aadA5, integrated as a gene cassette together with the trimethoprim r...... resistance gene dfr7 in a class 1 integron. The integron was located on a plasmid and was identified in a pathogenic porcine Escherichia coli isolate....

  12. Resistance Inheritance of Five Cultivars to Rice Blast Races IB-1, IE-1k and IG-1 of USA%5个水稻品种对美国稻瘟病小种(IB-1,IE-1k,IG-1)的抗性遗传

    Institute of Scientific and Technical Information of China (English)

    HUANG Bi-hu; 严宗卜; 游俊梅

    2012-01-01

    感病品种Katy、LaGrue和Newbonnet对IE-1k,抗病品种Katy、Mars和Newbonnet与感病品种LaGrue对IG-1,其正反交二代的抗病植株与感病植株的比例为3:1,说明,这些品种对IB-1、IE-1k和IG-1的抗性分别存在1对显隐性基因遗传关系.感病品种Mars、La-Grue、Newbonnet对IB-1和感病品种Katy、LaGrue、Newbonnet对IE-1k,其正反交二代全为感病植株,说明,这些感病品种分别对IB-1、IE-1k的感病基因是等位的.%In order to research the inheritance of rice blast (Magnaporthe grisea) resistance of five cultivars to three major races of IB-1,IE-1k and IG-1,four American cultivars,Katy,Mars,LaGrue,and Newbonnet,and one Chinese cultivar,Teging in a complete diallel design was conducted in University of Arkansas at Pine Bluff,USA in 2008 and 2009.The parents,F1 and F2 were inoculated with these three races separately to test blast responses in the greenhouse of Rice Research Center in Stuttgart,Arkansas,USA in 2008 and 2009.Results:Teqing was resistant to all the three races.Katy was resistant to IB-1 and IG-1,but not to IE-1k. Mars was resistant to IE-1k,but susceptible to the other two. LaGrue was susceptible to all the three races.Newbonnet was susceptible to IB-1 and IE-1k,but resistant to IG-1.Experimental data showed six types of segregation ratio in the F2 progenies of the complete diallel crosses:1) 63 R:1 S indicated three dominant genes independently responsible for blast resistance; 2) 15 R:1 S suggested two dominant genes independently responsible for blast resistance; 3) 7 R:9 S suggested two genes working dominantly and complementarily resulting in blast susceptibility; 4) 3 R:1 S fitted in the single dominant gene model controlling blast resistance; 5) 1 R:0 S indicated allelic genes in two resistant parents; 6) 0 R:1 S indicated allelic genes in two susceptible parents.In most cases,resistant gene(s) was dominant over susceptible regardless of parents and blast races with only one exception.Susceptible F1 derived from resistant Mars with

  13. Characterization of Resistance Gene Analog Polymorphisms in sugarcane cultivars with varying levels of red rot resistance

    Directory of Open Access Journals (Sweden)

    J. Jayashree, A. Selvi and N.V. Nair

    2010-07-01

    Full Text Available Resistance Gene Analog (RGA strategy is being exploited perfectly for the identification, tagging and mapping of majorgenes or Quantitative Trait Loci for disease resistance. About 29 RGA primers designed from the conserved domains ofresistance proteins, were used to analyse the genetic diversity among the 40 sugarcane cultivars that vary in their resistanceto red rot disease. The genetic similarity values ranged from 58.4 - 90% with the mean genetic similarity of 74.2%. Clusteranalysis resulted in a dendrogram with 3 major clusters and a clear distinction of resistant and susceptible varieties wasobserved. A total of 25 specific fragments amplified by 14 primers were identified to be associated with resistance and 8specific fragments amplified by 8 primers were associated with susceptibility. The primers RGA – 137, RGA 396, RGA-231 and RGA-118 amplified maximum number of resistant or susceptible specific fragments (3. Amplification of the red rotresistant variety Bo 91 and the red rot susceptible variety CoC 671 with the twenty nine RGA primers, followed bysequencing and homology analysis revealed significant homologies with the RGA’s of rice, maize and sugarcane. TheseRGA’s that were found to be associated with red rot resistant/ susceptible varieties are a valuable source of markers that canbe tested for screening red rot resistance in breeding programs

  14. Genetic analysis of leaf rust resistance genes and associated markers in the durable resistant wheat cultivar Sinvalocho MA.

    Science.gov (United States)

    Ingala, L; López, M; Darino, M; Pergolesi, M F; Diéguez, M J; Sacco, F

    2012-05-01

    In the cross of the durable leaf rust resistant wheat Sinvalocho MA and the susceptible line Gama6, four specific genes were identified: the seedling resistance gene Lr3, the adult plant resistance (APR) genes LrSV1 and LrSV2 coming from Sinvalocho MA, and the seedling resistance gene LrG6 coming from Gama6. Lr3 was previously mapped on 6BL in the same cross. LrSV1 was mapped on chromosome 2DS where resistance genes Lr22a and Lr22b have been reported. Results from rust reaction have shown that LrSV1 from Sinvalocho is not the same allele as Lr22b and an allelism test with Lr22a showed that they could be alleles or closely linked genes. LrSV1 was mapped in an 8.5-cM interval delimited by markers gwm296 distal and gwm261 proximal. Adult gene LrSV2 was mapped on chromosome 3BS, cosegregating with gwm533 in a 7.2-cM interval encompassed by markers gwm389 and gwm493, where other disease resistance genes are located, such as seedling gene Lr27 for leaf rust, Sr2 for stem rust, QTL Qfhs.ndsu-3BS for resistance to Fusarium gramineum and wheat powdery mildew resistance. The gene LrG6 was mapped on chromosome 2BL, with the closest marker gwm382 at 0.6 cM. Lines carrying LrSV1, LrSV2 and LrG6 tested under field natural infection conditions, showed low disease infection type and severity, suggesting that this kind of resistance can be explained by additive effects of APR and seedling resistance genes. The identification of new sources of resistance from South American land races and old varieties, supported by modern DNA technology, contributes to sustainability of agriculture through plant breeding. PMID:22278178

  15. Study on drug resistance of mycobacterium tuberculosis in patients with pulmonary tuberculosis by drug resistance gene detecting

    International Nuclear Information System (INIS)

    To investigate drug resistance of mycobacterium tuberculosis in different age group, compare detecting effect of two methods and evaluate their the clinical application value, all of the strains of mycobacterium tuberculosis were tested for resistance to RFP, INH SM PZA and EMB by the absolute concentration method on Lowenstein-Jensen medium and the mutation of the rpoB, katG, rpsL, pncA and embB resistance genes in M. tuberculosis was tested by PCR-SSCP. In youth, middle and old age group, the rate of acquired drug resistance was 89.2%, 85.3% and 67.6% respectively, the gene mutation rate was 76.2%, 81.3% and 63.2% respectively. The rate of acquired drug resistance and multiple drug resistance in youth group was much higher than those in other groups. The gene mutation was correlated with drug resistance level of mycobacterium tuberculosis. The gene mutation rate was higher in strains isolated from high concentration resistance than those in strains isolated from low concentration resistance. The more irregular treatment was longer, the rate of drug resistance was higher. Acquired drug resistance varies in different age group. It suggested that surveillance of drug resistence in different age group should be taken seriously, especially in youth group. PCR - SSCP is a sensitive and specific method for rapid detecting rpoB, katG, rpsL, pncA and embB genes mutations of MTB. (authors)

  16. Prognostic Significance of Multidrug Resistance Gene 1 (MDR1), Multidrug Resistance-related Protein (MRP) and Lung Resistance Protein (LRP) mRNA Expression in Acute Leukemia

    OpenAIRE

    Huh, Hee Jin; Park, Chan-Jeoung; Jang, Seongsoo; Seo, Eul-Ju; Chi, Hyun-Sook; Lee, Je-Hwan; Lee, Kyoo-Hyung; Seo, Jong Jin; Moon, Hyung Nam; Ghim, Thad

    2006-01-01

    The prognostic significance of multidrug resistance (MDR) gene expression is controversial. We investigated whether multidrug resistance gene 1 (MDR1), multidrug resistance-related protein (MRP) and lung resistance protein (LRP) mRNA expression are associated with outcomes in acute leukemia patients. At diagnosis we examined MDR1, MRP and LRP mRNA expression in bone marrow samples from 71 acute leukemia patients (39 myeloid, 32 lymphoblastic) using nested RT-PCR. The expression of each of the...

  17. Zinc-resistance gene CzrC identified in methicillin-resistant Staphylococcus hyicus isolated from pigs with exudative epidermitis.

    Science.gov (United States)

    Slifierz, Mackenzie J; Park, Jeonghwa; Friendship, Robert M; Weese, J Scott

    2014-05-01

    Methicillin-resistant Staphylococcus hyicus (MRSH) was investigated for czrC, a gene conferring zinc-resistance. The czrC gene was identified in 50% (14/28) of MRSH isolates, representing 14 pigs with exudative epidermitis from 8 farms. Newly weaned pigs, which are particularly susceptible to exudative epidermitis, are commonly fed high levels of zinc oxide. PMID:24790238

  18. Evolution by Pervasive Gene Fusion in Antibiotic Resistance and Antibiotic Synthesizing Genes

    Directory of Open Access Journals (Sweden)

    Orla Coleman

    2015-03-01

    Full Text Available Phylogenetic (tree-based approaches to understanding evolutionary history are unable to incorporate convergent evolutionary events where two genes merge into one. In this study, as exemplars of what can be achieved when a tree is not assumed a priori, we have analysed the evolutionary histories of polyketide synthase genes and antibiotic resistance genes and have shown that their history is replete with convergent events as well as divergent events. We demonstrate that the overall histories of these genes more closely resembles the remodelling that might be seen with the children’s toy Lego, than the standard model of the phylogenetic tree. This work demonstrates further that genes can act as public goods, available for re-use and incorporation into other genetic goods.

  19. Antimicrobial Resistance and Resistance Genes in Aerobic Bacteria Isolated from Pork at Slaughter.

    Science.gov (United States)

    Li, Lili; Olsen, Rikke Heidemann; Ye, Lei; Yan, He; Nie, Qing; Meng, Hecheng; Shi, Lei

    2016-04-01

    The aim of this study was to investigate the phenotypic and genotypic antimicrobial resistance, integrons, and transferability of resistance markers in 243 aerobic bacteria recovered from pork at slaughter in the People's Republic of China. The organisms belonged to 22 genera of gram-negative bacteria (92.2%) and gram-positive bacteria (7.8%). High levels of resistance were detected to tetracycline, trimethoprim-sulfamethoxazole, and ampicillin (36.2 to 54.3%), and lower levels were detected to nitrofurantoin, cefotaxime, gentamicin, ciprofloxacin, and chloramphenicol (7.8 to 29.2%). Across species, genes conferring antimicrobial resistance were observed with the following frequencies: blaTEM, 40.7%; blaCMY-2, 15.2%; blaCTX-M, 11.5%; sul2, 27.2%; sul1, 14.4%; tet(A), 5.4%; tet(L), 5.4%; tet(M), 5.0%; tet(E), 3.7%; tet(C), 3.3%; tet(S), 2.5%; and tet(K), 0.8%. Various antimicrobial resistance genes were found in new carriers: blaTEM in Lactococcus garvieae, Myroides odoratimimus, Aeromonas hydrophila, Staphylococcus sciuri, Raoultella terrigena, Macrococcus caseolyticus, Acinetobacter ursingii, Sphingobacterium sp., and Oceanobacillus sp.; blaCMY-2 in Lactococcus lactis, Klebsiella oxytoca, Serratia marcescens, Acinetobacter baumannii, and Myroides phaeus; tet(L) in M. caseolyticus; sul1 in Vibrio cincinnatiensis; sul2 in Acinetobacter bereziniae, Acinetobacter johnsonii, and V. cincinnatiensis; and the class 1 integron and gene cassette aadA2 in V. cincinnatiensis. Approximately 6.6% of isolates contained class 1 integrons, and one isolate harbored class 2 integrons. Plasmid associated intI1 and androgen receptor- encoding genes were transferred into Escherichia coli J53 and E. coli DH5α by conjugation and transformation experiments, respectively. Our study highlights the importance of aerobic bacteria from pork as reservoirs for antimicrobial resistance genes and mobile genetic elements that can readily be transferred intra- and interspecies. PMID:27052863

  20. Excavation of Pid3 Orthologs with Differential Resistance Spectra to Magnaporthe oryzae in Rice Resource

    OpenAIRE

    Xu, Xiao; Lv, Qiming; Shang, Junjun; Pang, Zhiqian; Zhou, Zhuangzhi; Wang, Jing; Jiang, Guanghuai; Tao, Yong; Xu, Qian; Li, Xiaobing; Zhao, Xianfeng; Li, Shigui; Xu, Jichen; Zhu, Lihuang

    2014-01-01

    Twenty-six orthologs of the rice blast resistance gene Pid3 from cultivated varieties and wild rice accessions distributed in different areas were cloned by allele mining. Sequence analysis showed that while each of the orthologous genes from indica varieties and most wild accessions encodes a complete NBS-LRR protein, each of the proteins encoded by those from japonica varieties and few wild rice accessions presents a premature termination. Eleven of the 26 orthologs were selected for blast ...

  1. Monitoring and Comparison of Antibiotic Resistant Bacteria and Their Resistance Genes in Municipal and Hospital Wastewaters

    Directory of Open Access Journals (Sweden)

    Rahim Aali

    2014-01-01

    Full Text Available Background: Human exposure to antibiotic resistant bacteria (ARB is a public health concern which could occur in a number of ways. Wastewaters seem to play an important role in the dissemination of bacteria and antibiotic resistant genes (ARGs in our environment. The aim of this study was to evaluate the occurrence of three groups of ARB and their resistance genes in hospital and municipal wastewaters (MWs as possible sources. Methods: A total of 66 samples were collected from raw MWs and hospital wastewaters (HWs and final effluents of related wastewater treatment plants (WWTPs. Samples were analyzed for the detection of three groups of ARB including gentamicin (GM, chloramphenicol (CHL and ceftazidime resistant bacteria and their ARGs (aac (3-1, cmlA1 and ctx-m-32, respectively. Results: The mean concentration of GM, CHL and ceftazidime resistant bacteria in raw wastewater samples was 1.24 × 10 7 , 3.29 × 10 7 and 5.54 × 10 7 colony forming unit/100 ml, respectively. There is a variation in prevalence of different groups of ARB in MWs and HWs. All WWTPs decreased the concentration of ARB. However, high concentration of ARB was found in the final effluent of WWTPs. Similar to ARB, different groups of ARGs were found frequently in both MWs and HWs. All genes also detected with a relative high frequency in effluent samples of MWs WWTPs. Conclusions: Discharge of final effluent from conventional WWTPs is a potential route for dissemination of ARB and ARGs into the natural environment and poses a hazard to environmental and public health.

  2. Effect of the sand-blasting of edge peeling tools on the cutting forces and wear resistance

    OpenAIRE

    Labidi, Chafik; DENAUD, Louis; Nouveau, Corinne; Collet, Robert; Henry, Laurent

    2007-01-01

    International audience One of the major problems concerning tools of wood industry is nicks occurrence on the cutting edge. This phenomenon is accentuated by the small tool angle of most of the wood machining tools. The aim of this present study is to look if the geometry modifications of the cutting edge permit to decrease the weakness of the tools, especially in peeling process. For this, different sand-blasted tools were tested in laboratory peeling of beech. In addition, the adhesion o...

  3. Mapping of QTL for resistance to powdery mildew and resistance gene analogues in perennial ryegrass

    DEFF Research Database (Denmark)

    Schejbel, B; Jensen, L B; Asp, T; Xing, Y; Lübberstedt, T

    2008-01-01

    The objective of this study was to map resistance gene analogues (RGA) and quantitative trait loci (QTL) for powdery mildew resistance in perennial ryegrass (Lolium perenne L.). The mapping population consisted of 184 F2 genotypes produced from a cross between one genotype of a synthetic perennial...... the heritability was 71.7%. In total, two QTL for powdery mildew resistance were identified, and mapped to linkage groups (LG) LG3 and LG7. Individually, these QTL explained between 7.5% and 22.1% of the total phenotypic variation. Six RGA and three laccases were mapped to LG2, LG3, LG4, LG5 and LG7...

  4. Heavy metal and disinfectant resistance genes among livestock-associated methicillin-resistant Staphylococcus aureus isolates

    DEFF Research Database (Denmark)

    Argudin, Maria Angeles; Lauzat, Birgit; Kraushaar, Britta;

    2016-01-01

    substances with antimicrobial activity applied in animal feed, including metal-containing compounds might contribute to their selection. Some of these genes have been found in various novel SCCmec cassettes. The aim of this study was to assess the occurrence of metal-resistance genes among a LA-S. aureus...... collection [n = 554, including 542 MRSA and 12 methicillin-susceptible S. aureus (MSSA)] isolated from livestock and food thereof. Most LA-MRSA isolates (76%) carried at least one metal-resistance gene. Among the LA-MRSA CC398 isolates (n = 456), 4.8%, 0.2%, 24.3% and 71.5% were positive for arsA (arsenic......Livestock associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has emerged in animal production worldwide. Most LA-MRSA in Europe belong to the clonal complex (CC)398. The reason for the LA-MRSA emergence is not fully understood. Besides antimicrobial agents used for therapy, other...

  5. Analysis of Antimicrobial Resistance Genes in Multiple Drug Resistant (MDR) Salmonella enterica Isolated from Animals and Humans

    Science.gov (United States)

    Background: Multiple Drug Resistant (MDR) foodborne bacteria are a concern in animal and human health. Identification of resistance genes in foodborne pathogens is necessary to determine similarities of resistance mechanisms in animal, food and human clinical isolates. This information will help us ...

  6. A review of the influence of treatment strategies on antibiotic resistant bacteria and antibiotic resistance genes.

    Science.gov (United States)

    Sharma, Virender K; Johnson, Natalie; Cizmas, Leslie; McDonald, Thomas J; Kim, Hyunook

    2016-05-01

    Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARG) in the aquatic environment have become an emerging contaminant issue, which has implications for human and ecological health. This review begins with an introduction to the occurrence of ARB and ARG in different environmental systems such as natural environments and drinking water resources. For example, ARG or ARB with resistance to ciprofloxacin, sulfamethoxazole, trimethoprim, quinolone, vancomycin, or tetracycline (e.g., tet(A), tet(B), tet(C), tet(G), tet(O), tet(M), tet(W), sul I, and sul II) have been detected in the environment. The development of resistance may be intrinsic, may be acquired through spontaneous mutations (de novo), or may occur due to horizontal gene transfer from donor bacteria, phages, or free DNA to recipient bacteria. An overview is also provided of the current knowledge regarding inactivation of ARB and ARG, and the mechanism of the effects of different disinfection processes in water and wastewater (chlorination, UV irradiation, Fenton reaction, ozonation, and photocatalytic oxidation). The effects of constructed wetlands and nanotechnology on ARB and ARG are also summarized. PMID:26775188

  7. Fate of antibiotic resistant cultivable heterotrophic bacteria and antibiotic resistance genes in wastewater treatment processes.

    Science.gov (United States)

    Zhang, Songhe; Han, Bing; Gu, Ju; Wang, Chao; Wang, Peifang; Ma, Yanyan; Cao, Jiashun; He, Zhenli

    2015-09-01

    Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are emerging contaminants of environmental concern. Heterotrophic bacteria in activated sludge have an important role in wastewater treatment plants (WWTPs). However, the fate of cultivable heterotrophic ARB and ARGs in WWPTs process remains unclear. In the present study, we investigated the antibiotic-resistant phenotypes of cultivable heterotrophic bacteria from influent and effluent water of three WWTPs and analysed thirteen ARGs in ARB and in activated sludge from anoxic, anaerobic and aerobic compartments. From each influent or effluent sample of the three plants, 200 isolates were randomly tested for susceptibility to 12 antibiotics. In these samples, between 5% and 64% isolates showed resistance to >9 antibiotics and the proportion of >9-drug-resistant bacteria was lower in isolates from effluent than from influent. Eighteen genera were identified in 188 isolates from influent (n=94) and effluent (n=94) of one WWTP. Six genera (Aeromonas, Bacillus, Lysinibacillus, Microbacterium, Providencia, and Staphylococcus) were detected in both influent and effluent samples. Gram-negative and -positive isolates dominated in influent and effluent, respectively. The 13 tetracycline-, sulphonamide-, streptomycin- and β-lactam-resistance genes were detected at a higher frequency in ARB from influent than from effluent, except for sulA and CTX-M, while in general, the abundances of ARGs in activated sludge from two of the three plants were higher in aerobic compartments than in anoxic ones, indicating abundant ARGs exit in the excess sledges and/or in uncultivable bacteria. These findings may be useful for elucidating the effect of WWTP on ARB and ARGs. PMID:25950407

  8. Novel Selection for Isoniazid (INH) Resistance Genes Supports a Role for NAD+-Binding Proteins in Mycobacterial INH Resistance

    OpenAIRE

    CHEN, PING; Bishai, William R.

    1998-01-01

    The genetic basis of isoniazid (INH) resistance remains unknown for a significant proportion of clinical isolates. To identify genes which might confer resistance by detoxifying or sequestering INH, we transformed the Escherichia coli oxyR mutant, which is relatively sensitive to INH, with a Mycobacterium tuberculosis plasmid library and selected for INH-resistant clones. Three genes were identified and called ceo for their ability to complement the Escherichia coli oxyR mutant. ceoA was the ...

  9. A Comprehensive Insight into Tetracycline Resistant Bacteria and Antibiotic Resistance Genes in Activated Sludge Using Next-Generation Sequencing

    OpenAIRE

    Kailong Huang; Junying Tang; Xu-Xiang Zhang; Ke Xu; Hongqiang Ren

    2014-01-01

    In order to comprehensively investigate tetracycline resistance in activated sludge of sewage treatment plants, 454 pyrosequencing and Illumina high-throughput sequencing were used to detect potential tetracycline resistant bacteria (TRB) and antibiotic resistance genes (ARGs) in sludge cultured with different concentrations of tetracycline. Pyrosequencing of 16S rRNA gene revealed that tetracycline treatment greatly affected the bacterial community structure of the sludge. Nine genera cons...

  10. Generation of broad-spectrum disease resistance by overexpression of an essential regulatory gene in systemic acquired resistance

    OpenAIRE

    Cao, Hui; Li, Xin; Dong, Xinnian

    1998-01-01

    The recently cloned NPR1 gene of Arabidopsis thaliana is a key regulator of acquired resistance responses. Upon induction, NPR1 expression is elevated and the NPR1 protein is activated, in turn inducing expression of a battery of downstream pathogenesis-related genes. In this study, we found that NPR1 confers resistance to the pathogens Pseudomonas syringae and Peronospora parasitica in a dosage-dependent fashion. Overexpression of NPR1 leads to enhanced resistance with no obvious detrimental...

  11. Genes for resistance to wheat powdery mildew in derivatives of Triticum Timopheevi and T. Carthlicum

    DEFF Research Database (Denmark)

    Jørgensen, Jørgen Helms; Jensen, C. J.

    1972-01-01

    and/or Ml designated genes; a temporary designation, Ml f ,is proposed for this gene. Gene Ml f is closely associated with a gene conditioning resistance to the stem rust fungus (Puccinia graminis f. sp. tritici), probably gene Sr9c. The winter wheat line TP 229 derived from Triticum carthlicum has......The winter wheat line TP 114 derived from CI 12633, a Triticum timopheevi derivative, has two unlinked dominant genes conditioning resistance to the powdery mildew fungus (Erysiphe graminis f. sp. tritici). One of the genes is identical to gene Pm2 (Ml u ). The other gene differs from the eleven Pm...

  12. A nanoplex PCR assay for the rapid detection of vancomycin and bifunctional aminoglycoside resistance genes in Enterococcus species

    Directory of Open Access Journals (Sweden)

    Ravichandran Manickam

    2007-12-01

    Full Text Available Abstract Background Enterococci have emerged as a significant cause of nosocomial infections in many parts of the world over the last decade. The most common enterococci strains present in clinical isolates are E. faecalis and E. faecium which have acquired resistant to either gentamicin or vancomycin. The conventional culture test takes 2–5 days to yield complete information of the organism and its antibiotic sensitivity pattern. Hence our present study was focused on developing a nanoplex PCR assay for the rapid detection of vancomycin and bifunctional aminoglycoside resistant enterococci (V-BiA-RE. This assay simultaneously detects 8 genes namely 16S rRNA of Enterococcus genus, ddl of E. faecalis and E. faecium, aacA-aphD that encodes high level gentamicin resistance (HLGR, multilevel vancomycin resistant genotypes such as vanA, vanB, vanC and vanD and one internal control gene. Results Unique and specific primer pairs were designed to amplify the 8 genes. The specificity of the primers was confirmed by DNA sequencing of the nanoplex PCR products and BLAST analysis. The sensitivity and specificity of V-BiA-RE nanoplex PCR assay was evaluated against the conventional culture method. The analytical sensitivity of the assay was found to be 1 ng at the DNA level while the analytical specificity was evaluated with 43 reference enterococci and non-enterococcal strains and was found to be 100%. The diagnostic accuracy was determined using 159 clinical specimens, which showed that 97% of the clinical isolates belonged to E. faecalis, of which 26% showed the HLGR genotype, but none were vancomycin resistant. The presence of an internal control in the V-BiA-RE nanoplex PCR assay helped us to rule out false negative cases. Conclusion The nanoplex PCR assay is robust and can give results within 4 hours about the 8 genes that are essential for the identification of the most common Enterococcus spp. and their antibiotic sensitivity pattern. The PCR assay

  13. Diversity of antimicrobial resistance and virulence genes in methicillin-resistant non-Staphylococcus aureus staphylococci from veal calves.

    Science.gov (United States)

    Argudín, M Angeles; Vanderhaeghen, Wannes; Butaye, Patrick

    2015-04-01

    In this study we determined whether methicillin-resistant non-Staphylococcus aureus (MRNAS) from veal calves may be a potential reservoir of antimicrobial-resistance and virulence genes. Fifty-eight MRNAS were studied by means of DNA-microarray and PCR for detection of antimicrobial resistance and virulence genes. The isolates carried a variety of antimicrobial-resistance genes [aacA-aphD, aadD, aph3, aadE, sat, spc, ampA, erm(A), erm(B), erm(C), erm(F), erm(T), lnu(A), msr(A)-msr(B), vga(A), mph(C), tet(K), tet(M), tet(L), cat, fexA, dfrA, dfrD, dfrG, dfrK, cfr, fusB, fosB, qacA, qacC, merA-merB]. Some isolates carried resistance genes without showing the corresponding resistance phenotype. Most MRNAS carried typical S. aureus virulence factors like proteases (sspP) and enterotoxins (seg) genes. Most Staphylococcus epidermidis isolates carried the arginine catabolic element, and nearly 40% of the Staphylococcus sciuri isolates carried leukocidins, and/or fibronectin-binding protein genes. MRNAS were highly multi-resistant and represent an important reservoir of antimicrobial resistance and virulence genes. PMID:25637268

  14. Survival of Antibiotic Resistant Bacteria and Horizontal Gene Transfer Control Antibiotic Resistance Gene Content in Anaerobic Digesters

    Science.gov (United States)

    Miller, Jennifer H.; Novak, John T.; Knocke, William R.; Pruden, Amy

    2016-01-01

    Understanding fate of antibiotic resistant bacteria (ARB) vs. their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1—a Pseudomonas sp.) and thermophilic (Iso T10—a Bacillus sp.) anaerobic digested sludge, into batch digesters and monitored their fate by plate counts and quantitative polymerase chain reaction (QPCR) of their corresponding tetracycline ARGs. In batch studies, spiked ARB plate counts returned to baseline (thermophilic) or 1-log above baseline (mesophilic) while levels of the ARG present in the spiked isolate [tet(G)] remained high in mesophilic batch reactors. To compare results under semi-continuous flow conditions with natural influent variation, tet(O), tet(W), and sul1 ARGs, along with the intI1 integrase gene, were monitored over a 9-month period in the raw feed sludge and effluent sludge of lab-scale thermophilic and mesophilic anaerobic digesters. sul1 and intI1 in mesophilic and thermophilic digesters correlated positively (Spearman rho = 0.457–0.829, P < 0.05) with the raw feed sludge. There was no correlation in tet(O) or tet(W) ratios in raw sludge and mesophilic digested sludge or thermophilic digested sludge (Spearman rho = 0.130–0.486, P = 0.075–0.612). However, in the thermophilic digester, the tet(O) and tet(W) ratios remained consistently low over the entire monitoring period. We conclude that the influent sludge microbial composition can influence the ARG content of a digester, apparently as a result of differential survival or death of ARBs or horizontal gene transfer of genes between raw sludge ARBs and the digester microbial community. Notably, mesophilic digestion was more susceptible to ARG intrusion than thermophilic digestion, which may be attributed to a higher rate of ARB survival and

  15. Survival of Antibiotic Resistant Bacteria and Horizontal Gene Transfer Control Antibiotic Resistance Gene Content in Anaerobic Digesters.

    Science.gov (United States)

    Miller, Jennifer H; Novak, John T; Knocke, William R; Pruden, Amy

    2016-01-01

    Understanding fate of antibiotic resistant bacteria (ARB) vs. their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1-a Pseudomonas sp.) and thermophilic (Iso T10-a Bacillus sp.) anaerobic digested sludge, into batch digesters and monitored their fate by plate counts and quantitative polymerase chain reaction (QPCR) of their corresponding tetracycline ARGs. In batch studies, spiked ARB plate counts returned to baseline (thermophilic) or 1-log above baseline (mesophilic) while levels of the ARG present in the spiked isolate [tet(G)] remained high in mesophilic batch reactors. To compare results under semi-continuous flow conditions with natural influent variation, tet(O), tet(W), and sul1 ARGs, along with the intI1 integrase gene, were monitored over a 9-month period in the raw feed sludge and effluent sludge of lab-scale thermophilic and mesophilic anaerobic digesters. sul1 and intI1 in mesophilic and thermophilic digesters correlated positively (Spearman rho = 0.457-0.829, P < 0.05) with the raw feed sludge. There was no correlation in tet(O) or tet(W) ratios in raw sludge and mesophilic digested sludge or thermophilic digested sludge (Spearman rho = 0.130-0.486, P = 0.075-0.612). However, in the thermophilic digester, the tet(O) and tet(W) ratios remained consistently low over the entire monitoring period. We conclude that the influent sludge microbial composition can influence the ARG content of a digester, apparently as a result of differential survival or death of ARBs or horizontal gene transfer of genes between raw sludge ARBs and the digester microbial community. Notably, mesophilic digestion was more susceptible to ARG intrusion than thermophilic digestion, which may be attributed to a higher rate of ARB survival and/or horizontal gene

  16. Novel Genes Related to Ceftriaxone Resistance Found among Ceftriaxone-Resistant Neisseria gonorrhoeae Strains Selected In Vitro.

    Science.gov (United States)

    Gong, Zijian; Lai, Wei; Liu, Min; Hua, Zhengshuang; Sun, Yayin; Xu, Qingfang; Xia, Yue; Zhao, Yue; Xie, Xiaoyuan

    2016-04-01

    The emergence of ceftriaxone-resistantNeisseria gonorrhoeaeis currently a global public health concern. However, the mechanism of ceftriaxone resistance is not yet fully understood. To investigate the potential genes related to ceftriaxone resistance inNeisseria gonorrhoeae, we subcultured six gonococcal strains with increasing concentrations of ceftriaxone and isolated the strains that became resistant. After analyzing several frequently reported genes involved in ceftriaxone resistance, we found only a single mutation inpenA(A501V). However, differential analysis of the genomes and transcriptomes between pre- and postselection strains revealed many other mutated genes as well as up- and downregulated genes. Transformation of the mutatedpenAgene into nonresistant strains increased the MIC between 2.0- and 5.3-fold, and transformation of mutatedftsXincreased the MIC between 3.3- and 13.3-fold. Genes encoding the ABC transporters FarB, Tfq, Hfq, and ExbB were overexpressed, whilepilM,pilN, andpilQwere downregulated. Furthermore, the resistant strain developed cross-resistance to penicillin and cefuroxime, had an increased biochemical metabolic rate, and presented fitness defects such as prolonged growth time and downregulated PilMNQ. In conclusion, antimicrobial pressure could result in the emergence of ceftriaxone resistance, and the evolution of resistance ofNeisseria gonorrhoeaeto ceftriaxone is a complicated process at both the pretranscriptional and posttranscriptional levels, involving several resistance mechanisms of increased efflux and decreased entry. PMID:26787702

  17. Preformed expression of defense is a hallmark of partial resistance to rice blast fungal pathogen Magnaporthe oryzae

    OpenAIRE

    Tharreau D; Saindrenan P; Chalvon Véronique; Ballini Elsa; Grand Xavier; Vergne Emilie; Nottéghem J-L; Morel J-B

    2010-01-01

    Abstract Background Partial resistance to plant pathogens is extensively used in breeding programs since it could contribute to resistance durability. Partial resistance often builds up during plant development and confers quantitative and usually broad-spectrum resistance. However, very little is known on the mechanisms underlying partial resistance. Partial resistance is often explained by poorly effective induction of plant defense systems. By exploring rice natural diversity, we asked whe...

  18. Linezolid Resistance in Staphylococcus aureus: Gene Dosage Effect, Stability, Fitness Costs, and Cross-Resistances▿

    OpenAIRE

    Besier, Silke; Ludwig, Albrecht; Zander, Johannes; Brade, Volker; Wichelhaus, Thomas A.

    2008-01-01

    Linezolid resistance in Staphylococcus aureus is typically associated with mutations in the 23S rRNA gene. Here we show that the accumulation of a single point mutation, G2576T, in the different copies of this gene causes stepwise increases in resistance, impairment of the biological fitness, and cross-resistance to quinupristin-dalfopristin and chloramphenicol.

  19. Gene expression patterns of wheat rust resistance gene Lr34/Yr18 indicate novel mode of action

    Science.gov (United States)

    The Lr34/Yr18 resistance gene provides durable, adult-plant, slow-rusting resistance to leaf rust and yellow rust of wheat. Patterns of gene expression were examined by microarray analysis in inoculated and mock-inoculated flag leaves of two pairs of near isogenic lines for Lr34/Yr18 (Thatcher/Thatc...

  20. Large-scale rewiring of innate immunity circuitry and microRNA regulation during initial rice blast infection.

    Science.gov (United States)

    Li, Ze-Yuan; Xia, Jing; Chen, Zheng; Yu, Yang; Li, Quan-Feng; Zhang, Yu-Chan; Zhang, Jin-Ping; Wang, Cong-Ying; Zhu, Xiao-Yuan; Zhang, Weixiong; Chen, Yue-Qin

    2016-01-01

    Rice blast is a recurrent fungal disease, and resistance to fungal infection is a complex trait. Therefore, a comprehensive examination of rice transcriptome and its variation during fungal infection is necessary to understand the complex gene regulatory networks. In this study, adopting Next-Generation Sequencing we profiled the transcriptomes and microRNAomes of rice varieties, one susceptible and the other resistant to M. oryzae, at multiple time points during the fungal infection. Our results revealed a substantial variation in the plant transcriptome and microRNAome as well as change to rice innate immunity during fungal infection. A number of putative R gene candidates were identified from a perturbed rice transcriptome analysis. The expression of genes and non-coding RNA molecules changed in both fungal resistant and susceptible plants during M. oryzae invasion discovered distinct pathways triggered in the susceptible and resistant plants. In addition, a number of fungus genes in the susceptible and resistant plants were constantly expressed at different time points, suggesting that they were likely to be the potential AVR genes. Our results revealed large-scale rewiring of innate immunity circuitry and microRNA regulation during initial rice blast infection, which would help to develop more robust blast-resistant rice plants. PMID:27150822

  1. Can chlorination co-select antibiotic-resistance genes?

    Science.gov (United States)

    Lin, Wenfang; Zhang, Menglu; Zhang, Shenghua; Yu, Xin

    2016-08-01

    Selective pressures, such as chemical or heavy metal pollution, may co-select for bacterial antibiotic resistance in the environment. However, whether chlorination in water treatment can co-select antibiotic-resistant bacteria is controversial. In this study, high capacity quantitative polymerase chain reaction (qPCR) analysis was applied to target almost all known antibiotic-resistance genes (ARGs) (282 types) and 13 mobile genetic elements (MGEs) in bacteria detected in secondary effluents from a municipal wastewater treatment plant after chlorination. The results revealed that 125 unique ARGs were detected in non-chlorinated samples, and the number decreased (79-91 types) as the chlorine concentration was increased. Moreover, 7.49 × 10(4)-3.92 × 10(7) copies/100 ml water reduction of ARGs occurred with 4 mg Cl2/l. Considering the relative abundance of ARGs (i.e., ARG copies normalized to 16S rRNA gene copies), 119 ARGs decreased in response to chlorination, whereas only six ARGs, such as dfrA1, tetPB-03, tetPA, ampC-04, tetA-02, and erm(36), were potentially enriched by 10.90-, 10.06-, 8.63-, 6.86-, 3.77-, and 1.09-fold, respectively. Furthermore, the relative abundance of 12 detected MGEs was lower after chlorination. Therefore, chlorination was effective in reducing ARGs and MGEs rather than co-selecting them. PMID:27192478

  2. WRKY76 is a rice transcriptional repressor playing opposite roles in blast disease resistance and cold stress tolerance

    OpenAIRE

    Yokotani, Naoki; Sato, Yuko; Tanabe, Shigeru; Chujo, Tetsuya; Shimizu, Takafumi; Okada, Kazunori; Yamane, Hisakazu; Shimono, Masaki; Sugano, Shoji; Takatsuji, Hiroshi; Kaku, Hisatoshi; Minami, Eiichi; Nishizawa, Yoko

    2013-01-01

    OsWRKY76 encodes a group IIa WRKY transcription factor of rice. The expression of OsWRKY76 was induced within 48h after inoculation with rice blast fungus (Magnaporthe oryzae), and by wounding, low temperature, benzothiadiazole, and abscisic acid. Green fluorescent protein-fused OsWRKY76 localized to the nuclei in rice epidermal cells. OsWRKY76 showed sequence-specific DNA binding to the W-box element in vitro and exhibited W-box-mediated transcriptional repressor activity in cultured rice ce...

  3. Detection of antibiotic resistance and tetracycline resistance genes in Enterobacteriaceae isolated from the Pearl rivers in South China

    Energy Technology Data Exchange (ETDEWEB)

    Tao Ran [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Ying Guangguo, E-mail: guangguo.ying@gmail.co [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Su Haochang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Zhou Hongwei [Department of Environmental Health, School of Public Health and Tropical Medicine, Southern Medical University, 1838 North Guangzhou Street, Baiyun District, Guangzhou 510515 (China); Sidhu, Jatinder P.S. [CSIRO Land and Water, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia QLD 4067 (Australia)

    2010-06-15

    This study investigated antibiotic resistance profiles and tetracycline resistance genes in Enterobacteriaceae family isolates from the Pearl rivers. The Enterobacteriaceae isolates were tested for susceptibility to seven antibiotics ampicillin, chloramphenicol, ciprofloxacin, levofloxacin, sulphamethoxazole/trimethoprim, tetracycline and trimethoprim. In Liuxi reservoir, with an exception to ampicillin resistant strains (11%) no other antibiotic resistance bacterial strains were detected. However, multiple drug resistance in bacterial isolates from the other sites of Pearl rivers was observed which is possibly due to sewage discharge and input from other anthropogenic sources along the rivers. Four tetracycline resistance genes tet A, tet B, tet C and tet D were detected in the isolates from the rivers. The genes tet A and tet B were widely detected with the detection frequencies of 43% and 40% respectively. Ciprofloxacin and levofloxacin resistant enteric bacteria were also isolated from the pig and duck manures which suggest a wider distribution of human specific drugs in the environment. This investigation provided a baseline data on antibiotic resistance profiles and tetracycline resistance genes in the Pearl rivers delta. - High rates of antibiotic resistance in Enterobacteriaceae from river water are attributed to wastewater contamination.

  4. Detection of antibiotic resistance and tetracycline resistance genes in Enterobacteriaceae isolated from the Pearl rivers in South China

    International Nuclear Information System (INIS)

    This study investigated antibiotic resistance profiles and tetracycline resistance genes in Enterobacteriaceae family isolates from the Pearl rivers. The Enterobacteriaceae isolates were tested for susceptibility to seven antibiotics ampicillin, chloramphenicol, ciprofloxacin, levofloxacin, sulphamethoxazole/trimethoprim, tetracycline and trimethoprim. In Liuxi reservoir, with an exception to ampicillin resistant strains (11%) no other antibiotic resistance bacterial strains were detected. However, multiple drug resistance in bacterial isolates from the other sites of Pearl rivers was observed which is possibly due to sewage discharge and input from other anthropogenic sources along the rivers. Four tetracycline resistance genes tet A, tet B, tet C and tet D were detected in the isolates from the rivers. The genes tet A and tet B were widely detected with the detection frequencies of 43% and 40% respectively. Ciprofloxacin and levofloxacin resistant enteric bacteria were also isolated from the pig and duck manures which suggest a wider distribution of human specific drugs in the environment. This investigation provided a baseline data on antibiotic resistance profiles and tetracycline resistance genes in the Pearl rivers delta. - High rates of antibiotic resistance in Enterobacteriaceae from river water are attributed to wastewater contamination.

  5. Functional Metagenome Mining of Soil for a Novel Gentamicin Resistance Gene.

    Science.gov (United States)

    Im, Hyunjoo; Kim, Kyung Mo; Lee, Sang-Heon; Ryu, Choong-Min

    2016-03-01

    Extensive use of antibiotics over recent decades has led to bacterial resistance against antibiotics, including gentamicin, one of the most effective aminoglycosides. The emergence of resistance is problematic for hospitals, since gentamicin is an important broad-spectrum antibiotic for the control of bacterial pathogens in the clinic. Previous study to identify gentamicin resistance genes from environmental samples have been conducted using culture-dependent screening methods. To overcome these limitations, we employed a metagenome-based culture-independent protocol to identify gentamicin resistance genes. Through functional screening of metagenome libraries derived from soil samples, a fosmid clone was selected as it conferred strong gentamicin resistance. To identify a specific functioning gene conferring gentamicin resistance from a selected fosmid clone (35-40 kb), a shot-gun library was constructed and four shot-gun clones (2-3 kb) were selected. Further characterization of these clones revealed that they contained sequences similar to that of the RNA ligase, T4 rnlA that is known as a toxin gene. The overexpression of the rnlA-like gene in Escherichia coli increased gentamicin resistance, indicating that this toxin gene modulates this trait. The results of our metagenome library analysis suggest that the rnlA-like gene may represent a new class of gentamicin resistance genes in pathogenic bacteria. In addition, we demonstrate that the soil metagenome can provide an important resource for the identification of antibiotic resistance genes, which are valuable molecular targets in efforts to overcome antibiotic resistance. PMID:26699755

  6. Evaluation of bacterial wilt resistance in tomato lines nearly isogenic for the Mi gene for resistance to root-knot

    OpenAIRE

    Deberdt, P.; Olivier, J; Thoquet, P; Quénéhervé, Patrick; Prior, P

    1999-01-01

    Resistance to bacterial wilt, caused by #Ralstonia solancearum$, in tomato lines CRA 66 and Caraïbo is reported to be decreased by root-knot nematode galling and by introduction of the #Mi$ gene for nematode resistance. The #Mi$ gene is located on tomato chromosome 6, which also carries a major quantitative trait locus (QTL) for resistance to bacterial wilt. Bacterial wilt resistance was evaluated in F3-progenies derived from two crosses between near-isogenic lines Caraïbo x Carmido and CRA 6...

  7. Abundance and dynamics of antibiotic resistance genes and integrons in lake sediment microcosms.

    Directory of Open Access Journals (Sweden)

    Björn Berglund

    Full Text Available Antibiotic resistance in bacteria causing disease is an ever growing threat to the world. Recently, environmental bacteria have become established as important both as sources of antibiotic resistance genes and in disseminating resistance genes. Low levels of antibiotics and other pharmaceuticals are regularly released into water environments via wastewater, and the concern is that such environmental contamination may serve to create hotspots for antibiotic resistance gene selection and dissemination. In this study, microcosms were created from water and sediments gathered from a lake in Sweden only lightly affected by human activities. The microcosms were exposed to a mixture of antibiotics of varying environmentally relevant concentrations (i.e., concentrations commonly encountered in wastewaters in order to investigate the effect of low levels of antibiotics on antibiotic resistance gene abundances and dynamics in a previously uncontaminated environment. Antibiotic concentrations were measured using liquid chromatography-tandem mass spectrometry. Abundances of seven antibiotic resistance genes and the class 1 integron integrase gene, intI1, were quantified using real-time PCR. Resistance genes sulI and ermB were quantified in the microcosm sediments with mean abundances 5 and 15 gene copies/10(6 16S rRNA gene copies, respectively. Class 1 integrons were determined in the sediments with a mean concentration of 3.8 × 10(4 copies/106 16S rRNA gene copies. The antibiotic treatment had no observable effect on antibiotic resistance gene or integron abundances.

  8. Fine genetic mapping localizes cucumber scab resistance gene Ccu into an R gene cluster.

    Science.gov (United States)

    Kang, Houxiang; Weng, Yiqun; Yang, Yuhong; Zhang, Zhonghua; Zhang, Shengping; Mao, Zhenchuan; Cheng, Guohua; Gu, Xingfang; Huang, Sanwen; Xie, Bingyan

    2011-03-01

    Scab, caused by Cladosporium cucumerinum, is an important disease of cucumber, Cucumis sativus. In this study, we conducted fine genetic mapping of the single dominant scab resistance gene, Ccu, with 148 F(9) recombinant inbred lines (RILs) and 1,944 F(2) plants derived from the resistant cucumber inbred line 9110Gt and the susceptible line 9930, whose draft genome sequence is now available. A framework linkage map was first constructed with simple sequence repeat markers placing Ccu into the terminal 670 kb region of cucumber Chromosome 2. The 9110Gt genome was sequenced at 5× genome coverage with the Solexa next-generation sequencing technology. Sequence analysis of the assembled 9110Gt contigs and the Ccu region of the 9930 genome identified three insertion/deletion (Indel) markers, Indel01, Indel02, and Indel03 that were closely linked with the Ccu locus. On the high-resolution map developed with the F(2) population, the two closest flanking markers, Indel01 and Indel02, were 0.14 and 0.15 cM away from the target gene Ccu, respectively, and the physical distance between the two markers was approximately 140 kb. Detailed annotation of the 180 kb region harboring the Ccu locus identified a cluster of six resistance gene analogs (RGAs) that belong to the nucleotide binding site (NBS) type R genes. Four RGAs were in the region delimited by markers Indel01 and Indel02, and thus were possible candidates of Ccu. Comparative DNA analysis of this cucumber Ccu gene region with a melon (C. melo) bacterial artificial chromosome (BAC) clone revealed a high degree of micro-synteny and conservation of the RGA tandem repeats in this region. PMID:21104067

  9. The aac(6'Ib gene in Proteus mirabilis strains resistant to aminoglycosides.

    Directory of Open Access Journals (Sweden)

    Jerzy Ratajczak

    2009-01-01

    Full Text Available The aim of this study was to evaluate the presence of aac(6'-Ib gene conferring resistance to aminoglycosides in Proteus mirabilis strains. Five isolates had aac(6'-Ib gene. In one case the gene was no-expressed. Three isolates were resistant to all aminoglycosides and minimum inhibitory concentrations were > or = 256 microg/ml. Additionally, all positive strains were resistant to tetracycline and ciprofloxacin.

  10. Antimicrobial-Resistant Bacterial Populations and Antimicrobial Resistance Genes Obtained from Environments Impacted by Livestock and Municipal Waste.

    Directory of Open Access Journals (Sweden)

    Getahun E Agga

    Full Text Available This study compared the populations of antimicrobial-resistant bacteria and the repertoire of antimicrobial resistance genes in four environments: effluent of three municipal wastewater treatment facilities, three cattle feedlot runoff catchment ponds, three swine waste lagoons, and two "low impact" environments (an urban lake and a relict prairie. Multiple liquid and solid samples were collected from each environment. The prevalences and concentrations of antimicrobial-resistant (AMR Gram-negative (Escherichia coli and Salmonella enterica and Gram-positive (enterococci bacteria were determined from individual samples (n = 174. The prevalences of 84 antimicrobial resistance genes in metagenomic DNA isolated from samples pooled (n = 44 by collection date, location, and sample type were determined. The prevalences and concentrations of AMR E. coli and Salmonella were similar among the livestock and municipal sample sources. The levels of erythromycin-resistant enterococci were significantly higher in liquid samples from cattle catchment ponds and swine waste lagoons than in liquid samples from municipal wastewater treatment facilities, but solid samples from these environments did not differ significantly. Similarly, trimethoprim/sulfamethoxazole-resistant E. coli concentrations were significantly higher in swine liquid than in municipal liquid samples, but there was no difference in solid samples. Multivariate analysis of the distribution of antimicrobial resistance genes using principal coordinate analysis showed distinct clustering of samples with livestock (cattle and swine, low impact environment and municipal samples forming three separate clusters. The numbers of class A beta-lactamase, class C beta-lactamase, and fluoroquinolone resistance genes detected were significantly higher (P < 0.05 in municipal samples than in cattle runoff or swine lagoon samples. In conclusion, we report that AMR is a very widespread phenomenon and that similar

  11. Resistance Genes and Genetic Elements Associated with Antibiotic Resistance in Clinical and Commensal Isolates of Streptococcus salivarius.

    Science.gov (United States)

    Chaffanel, Fanny; Charron-Bourgoin, Florence; Libante, Virginie; Leblond-Bourget, Nathalie; Payot, Sophie

    2015-06-15

    The diversity of clinical (n = 92) and oral and digestive commensal (n = 120) isolates of Streptococcus salivarius was analyzed by multilocus sequence typing (MLST). No clustering of clinical or commensal strains can be observed in the phylogenetic tree. Selected strains (92 clinical and 46 commensal strains) were then examined for their susceptibilities to tetracyclines, macrolides, lincosamides, aminoglycosides, and phenicol antibiotics. The presence of resistance genes tet(M), tet(O), erm(A), erm(B), mef(A/E), and catQ and associated genetic elements was investigated by PCR, as was the genetic linkage of resistance genes. High rates of erythromycin and tetracycline resistance were observed among the strains. Clinical strains displayed either the erm(B) (macrolide-lincosamide-streptogramin B [MLSB] phenotype) or mef(A/E) (M phenotype) resistance determinant, whereas almost all the commensal strains harbored the mef(A/E) resistance gene, carried by a macrolide efflux genetic assembly (MEGA) element. A genetic linkage between a macrolide resistance gene and genes of Tn916 was detected in 23 clinical strains and 5 commensal strains, with a predominance of Tn3872 elements (n = 13), followed by Tn6002 (n = 11) and Tn2009 (n = 4) elements. Four strains harboring a mef(A/E) gene were also resistant to chloramphenicol and carried a catQ gene. Sequencing of the genome of one of these strains revealed that these genes colocalized on an IQ-like element, as already described for other viridans group streptococci. ICESt3-related elements were also detected in half of the isolates. This work highlights the potential role of S. salivarius in the spread of antibiotic resistance genes both in the oral sphere and in the gut. PMID:25862227

  12. [Classification and prevalence of plasmid-mediated quinolone resistance qnr genes in China--A review].

    Science.gov (United States)

    Yan, Lei; Xu, Hai

    2016-02-01

    Quinolone antibacterial drugs, developing from the treatment of urinary tract infection in early time and now from the treatment of intestinal infection and respiratory infection, have been widely used in clinical, animal husbandry and aquaculture. Bacteria gradually become resistant to them and resistance mechanism is more and more complicated. Quinolone resistance mechanism is mainly divided into chromosome mediated resistance and plasmid mediated resistance, the latter plays an important role in spreading of antibiotic resistance. In 1998, plasmid mediated quinolone resistance mechanism was reported for the first time, namely the qnr gene mediated fluoroquinolone resistance mechanism. qnr genes can spread rapidly in different bacteria, which causes the infection difficult to control, makes the nosocomial infection popular in a wide range. In addition, qnr genes are usually associated with β-lactamase resistance gene. They exist in complex integron and integrate with the other varieties of resistance genes, which narrows the space of clinical medicine choose or drug combinations use to treat related bacterial infection and brings us a serious challenge. In this review, we provide a detailed overview for the historical discovery, classification, the resistance mechanisms of qnr genes, and the prevalence of those genes in China. PMID:27373065

  13. Strategy of gene silencing in cassava for validation of resistance genes

    International Nuclear Information System (INIS)

    Cassava (Manihot esculenta) is a major source of food for more than 1000 million people in the world and constitutes an important staple crop. Cassava bacterial blight, caused by the gram negative bacterium Xanthomonas axonopodis pv. manihotis, is one of the most important constraints for this crop. A candidate resistance gene against cassava bacterial blight, named RXam1, has been identified previously. In this work, we employed the gene silencing approach using the African cassava mosaic virus (ACMV) to validate the function of the RXam1 gene. We used as positive control the su gen, which produce photo blanching in leaves when is silenced. Plants from the SG10735 variety were bombardment with the ACMV-A-SU+ACMV-B y ACMV-A-RXam1+ACMV-B constructions. The silencing efficiency employing the su gene was low, only one of seven plants showed photo blanching. In the putative silenced plants for the RXam1 gene, no presence of siRNAs corresponding to RXam1 was observed; although a low diminution of the RXam1 gene expression was obtained. The growth curves for the Xam strain CIO136 in cassava plants inoculated showing a little but no significance difference in the susceptibility in the silenced plants compared to not silenced

  14. Mining microbial metatranscriptomes for expression of antibiotic resistance genes under natural conditions

    Science.gov (United States)

    Versluis, Dennis; D'Andrea, Marco Maria; Ramiro Garcia, Javier; Leimena, Milkha M.; Hugenholtz, Floor; Zhang, Jing; Öztürk, Başak; Nylund, Lotta; Sipkema, Detmer; Schaik, Willem Van; de Vos, Willem M.; Kleerebezem, Michiel; Smidt, Hauke; Passel, Mark W. J. Van

    2015-07-01

    Antibiotic resistance genes are found in a broad range of ecological niches associated with complex microbiota. Here we investigated if resistance genes are not only present, but also transcribed under natural conditions. Furthermore, we examined the potential for antibiotic production by assessing the expression of associated secondary metabolite biosynthesis gene clusters. Metatranscriptome datasets from intestinal microbiota of four human adults, one human infant, 15 mice and six pigs, of which only the latter have received antibiotics prior to the study, as well as from sea bacterioplankton, a marine sponge, forest soil and sub-seafloor sediment, were investigated. We found that resistance genes are expressed in all studied ecological niches, albeit with niche-specific differences in relative expression levels and diversity of transcripts. For example, in mice and human infant microbiota predominantly tetracycline resistance genes were expressed while in human adult microbiota the spectrum of expressed genes was more diverse, and also included β-lactam, aminoglycoside and macrolide resistance genes. Resistance gene expression could result from the presence of natural antibiotics in the environment, although we could not link it to expression of corresponding secondary metabolites biosynthesis clusters. Alternatively, resistance gene expression could be constitutive, or these genes serve alternative roles besides antibiotic resistance.

  15. Genotyping of Resistance to Blast Disease in Hybrid Rice from Sichuan Province%四川省杂交稻主栽品种抗稻瘟病基因型推导研究

    Institute of Scientific and Technical Information of China (English)

    张雪梅; 冯慧; 白玉连; 向芮琪; 黄富; 彭云良

    2012-01-01

    In this paper, the genotypes of the resistance to blast disease in 134 commercial rice varieties, of which the majority were hybrid rice, were postulated by inoculating 21 differentiated isolates of M. oryzae of different compatible spectra to 21 lines of which each had a single known resistance gene. The result showed that only 2 out of the tested accessions, i. e, Lu You No. 1 and Hong You 44 showed the same compatible spectra to the 21 differentiating isolates. The cluster analysis of the compatible spectra of the tested varieties resulted in 7 groups when the similarity index computed by DPS software was at 0.80. The genotypes of 2 hybrid rice, D Xiang 287 and Q You NO. 2 could be clearly postulated. The former probably contained Pi-km ,Pi-z1 and Pi-7 and the latter were considered to contain Pi-k, Pi-1, Pi-t and Pi-19. Unknown resistant genes were found to be present in all of the other varieties. The resistance frequencies to the 21 differential isolates of 134 accessions were negatively correlated to their available severity scores of leaf blast symptoms and average percentage of the disease ear necks (P<0.01).%本文对包括131个杂交稻品种在内的134个四川省水稻主栽品种接种了21个对已知抗稻瘟基因具鉴别力稻瘟病菌株,根据比较各品种和含已知抗瘟单基因系对鉴别菌株的抗谱对各主栽品种进行了抗稻瘟病基因型推导.结果表明,134个参试品种中,仅红优44和泸优1号对全部21个鉴别菌株的抗感反应完全一致;通过DPS统计软件对各品种的抗谱进行聚类分析,在相似距离为0.8时可将这些品种的抗性基因型划分为7个类群;应用基因型推导软件分析,推导出D香287可能携带Pi-km、Pi-z(k)和Pi-7等3个抗性基因,Q优2号则可能携带Pi-k、Pi-I、Pi-t和Pi-19等4个抗性基因,其余品种则均可能携带未知抗病基因.各品种在病(因)中的最高叶瘟级别和平均颈瘟率与其对21个鉴别菌株的抗

  16. Microarray-Based Detection of 90 Antibiotic Resistance Genes of Gram-Positive Bacteria

    OpenAIRE

    Perreten, Vincent; Vorlet-Fawer, Lorianne; Slickers, Peter; Ehricht, Ralf; Kuhnert, Peter; Frey, Joachim

    2005-01-01

    A disposable microarray was developed for detection of up to 90 antibiotic resistance genes in gram-positive bacteria by hybridization. Each antibiotic resistance gene is represented by two specific oligonucleotides chosen from consensus sequences of gene families, except for nine genes for which only one specific oligonucleotide could be developed. A total of 137 oligonucleotides (26 to 33 nucleotides in length with similar physicochemical parameters) were spotted onto the microarray. The mi...

  17. Class 1 and 2 integrons, sul resistance genes and antibiotic resistance in Escherichia coli isolated from Dongjiang River, South China

    International Nuclear Information System (INIS)

    Antibiotic susceptibility, detection of sul gene types and presence of class 1, 2 and 3 integrons and gene cassettes using PCR assays were investigated in 3456 Escherichia coli isolates obtained from 38 sampling sites of the Dongjiang River catchment in the dry and wet seasons. 89.1% of the isolates were resistant and 87.5% showed resistance to at least three antibiotics. sul2 was detected most frequently in 89.2% of 1403 SXT-resistant isolates. The presence of integrons (class 1 and 2) was frequently observed (82.3%) while no class 3 integron was found. In these integrons, 21 resistance genes of 14 gene cassette arrays and 10 different families of resistance genes were identified. Three gene cassette arrays, aac(6')-Ib-cr-aar-3-dfrA27-aadA16, aacA4-catB3-dfrA1 and aadA2-lnuF, were detected for the first time in surface water. The results showed that bacterial resistance in the catchment was seriously influenced by human activities, especially discharge of wastewater. Highlights: ► Antibiotic resistance was investigated for a river catchment of southern China. ► 87.5% of E coli isolates showed resistance to at least three antibiotics. ► The presence of integrons (class 1 and 2) was frequently observed (82.3%). ► Bacterial resistance in the catchment was seriously influenced by human activities. - Bacterial resistance to antibiotics in a catchment is related to the discharge of wastewater into the aquatic environment.

  18. Mapping of the oat crown rust resistance gene Pc91.

    Science.gov (United States)

    McCartney, C A; Stonehouse, R G; Rossnagel, B G; Eckstein, P E; Scoles, G J; Zatorski, T; Beattie, A D; Chong, J

    2011-02-01

    Crown rust is an important disease of oat caused by Puccinia coronata Corda f. sp. avenae Eriks. Crown rust is efficiently and effectively managed through the development of resistant oat varieties. Pc91 is a seedling crown rust resistance gene that is highly effective against the current P. coronata population in North America. The primary objective of this study was to develop DNA markers linked to Pc91 for purposes of marker-assisted selection in oat breeding programs. The Pc91 locus was mapped using a population of F7-derived recombinant inbred lines developed from the cross 'CDC Sol-Fi'/'HiFi' made at the Crop Development Centre, University of Saskatchewan. The population was evaluated for reaction to P. coronata in field nurseries in 2008 and 2009. Pc91 mapped to a linkage group consisting of 44 Diversity Array Technology (DArT) markers. DArTs were successfully converted to sequence characterized amplified region (SCAR) markers. Five robust SCARs were developed from three non-redundant DArTs that co-segregated with Pc91. SCAR markers were developed for different assay systems, such that SCARs are available for agarose gel electrophoresis, capillary electrophoresis, and Taqman single nucleotide polymorphism detection. The SCAR markers accurately postulated the Pc91 status of 23 North American oat breeding lines. PMID:20862449

  19. Antibiotic Resistant Bacteria And Their Associated Resistance Genes in a Conventional Municipal Wastewater Treatment Plant

    KAUST Repository

    Aljassim, Nada I.

    2013-12-01

    With water scarcity as a pressing issue in Saudi Arabia and other Middle Eastern countries, the treatment and reuse of municipal wastewater is increasingly being used as an alternative water source to supplement country water needs. Standards are in place to ensure a safe treated wastewater quality, however they do not regulate pathogenic bacteria and emerging contaminants. Information is lacking on the levels of risk to public health associated with these factors, the efficiency of conventional treatment strategies in removing them, and on wastewater treatment in Saudi Arabia in general. In this study, a municipal wastewater treatment plant in Saudi Arabia is investigated to assess the efficiency of conventional treatment in meeting regulations and removing pathogens and emerging contaminants. The study found pathogenic bacterial genera, antibiotic resistance genes and antibiotic resistant bacteria, many of which were multi-resistant in plant discharges. It was found that although the treatments are able to meet traditional quality guidelines, there remains a risk from the discussed contaminants with wastewater reuse. A deeper understanding of this risk, and suggestions for more thorough guidelines and monitoring are needed.

  20. Gene duplication and hypermutation of the pathogen Resistance gene SNC1 in the Arabidopsis bal variant.

    Science.gov (United States)

    Yi, Hankuil; Richards, Eric J

    2009-12-01

    The bal defect in the Arabidopsis thaliana Columbia strain was spontaneously generated in an inbred ddm1 (decrease in DNA methylation 1) mutant background in which various genetic and epigenetic alterations accumulate. The bal variant displays short stature and curled leaves due to the constitutive activation of defense signaling. These bal phenotypes are metastable and phenotypic suppression is evident in more than one-third of ethyl methanesulfonate (EMS)-treated bal M(1) plants. The semidominant bal allele maps to the RPP5 (recognition of Peronospora parasitica 5) locus, which includes a cluster of disease Resistance (R) genes, many of which show an increase in steady-state expression levels in the bal variant. Here, we report that activation of RPP5 locus R genes and dwarfing in the bal variant are caused by a 55-kb duplication within the RPP5 locus. Although many RPP5 locus R genes are duplicated in the bal variant, the duplication of SNC1 alone is necessary and sufficient for the phenotypic changes in the bal variant. Missense mutations in the SNC1 gene were identified in all three phenotypically suppressed EMS-treated bal lines investigated, indicating that the high-frequency phenotypic instability induced by EMS treatment is caused by a genetic mechanism. We propose that the high degree of variation in SNC1-related sequences among Arabidopsis natural accessions follows the two-step mechanism observed in the bal variant: gene duplication followed by hypermutation. PMID:19797048

  1. Cloning and characterization of gene-resistant analogs (RGAs) involved in rust (Puccinia psidii) resistance in Eucalyptus grandis

    Institute of Scientific and Technical Information of China (English)

    Marcelo Luiz Laia; Acelino Couto Alfenas; Sergio Hermnio Brommonschenkel; Shinitiro Oda; Eduardo Jose de Melo; Inae Marie de Arau jo Silva; Janana Fernandes Goncalves; Ariadne Marques

    2015-01-01

    Disease-resistant genes play an important role in defending against a variety of pathogens and insect pests in plants. Most of the disease-resistant genes encode pro-teins with conserved leucine rich repeat and nucleotide binding site domains. In this study, we cloned and char-acterized gene-resistant analogs (RGAs) from Eucalyptus grandis using degenerate PCR, with primers specifically targeting these two domains. The amplified fragments were cloned into the pGEM-T vector and transformed into Escherichia coli. Among the 90 clones obtained, 13 were sequenced and compared with each other and with previ-ously identified gene-resistant diseases. A BLASTX search in GenBank revealed high similarities among the con-served domains of these cloned genes with RGA genes. Some clones, however, showed no significant similarity with DNA sequences in GenBank. Southern blotting ana-lysis identified several polymorphic RFLP loci between distinct genotypes. However, none of them co-segregated with the Puccinia psidii Winter resistance gene 1 (Ppr1) in a population study.

  2. Soybean Resistance Genes Specific for Different Pseudomonas Syringae Avirulence Genes Are Allelic, or Closely Linked, at the Rpg1 Locus

    OpenAIRE

    Ashfield, T.; Keen, N. T.; Buzzell, R. I.; Innes, R W

    1995-01-01

    RPG1 and RPM1 are disease resistance genes in soybean and Arabidopsis, respectively, that confer resistance to Pseudomonas syringae strains expressing the avirulence gene avrB. RPM1 has recently been demonstrated to have a second specificity, also conferring resistance to P. syringae strains expressing avrRpm1. Here we show that alleles, or closely linked genes, exist at the RPG1 locus in soybean that are specific for either avrB or avrRpm1 and thus can distinguish between these two avirulenc...

  3. Who Possesses Drug Resistance Genes in the Aquatic Environment? : Sulfamethoxazole (SMX) Resistance Genes among the Bacterial Community in Water Environment of Metro-Manila, Philippines

    OpenAIRE

    Satoru eSuzuki; Mitsuko eOgo; Miller, Todd W.; Akiko eShimizu; Hideshige eTakada; Maria Auxilia eSiringan

    2013-01-01

    Recent evidence has shown that antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are ubiquitous in natural environments, including sites considered pristine. To understand the origin of ARGs and their dynamics, we must first define their actual presence in the natural bacterial assemblage. Here we found varying distribution profiles of sul genes in “colony forming bacterial assemblages” and “natural bacterial assemblages.” Our monitoring for antibiotic contamination r...

  4. Allele-mining and natural diversity in wheat powdery mildew resistance genes

    International Nuclear Information System (INIS)

    Using map-based cloning, we have isolated the Pm3b powdery mildew resistance gene from hexaploid bread wheat (Triticum aestivum L.). Based on haplotype studies, we have developed molecular tools to isolate all the 10 known Pm3 genes conferring resistance. We found that the Pm3 genes form a true allelic series and that they are highly conserved at the molecular level. The molecular work on Pm3 resistance genes has lead to very diagnostic tools for these genes which support the cloning of new functional alleles from this locus by allele-mining. We have used these tools to screen for new Pm3 alleles in the gene pools of (i) wild and domesticated tetraploid accessions and (ii) hexaploid wheat landraces. The Pm3 locus is conserved in tetraploid wheat, allowing a comparative evolutionary study of the same resistance locus in a domesticated species and one of its wild ancestors. We have identified 61 Pm3 allelic sequences from wild and domesticated tetraploid wheat subspecies. These alleles showed low sequence diversity, differing by few polymorphic sequence blocks that were further reshuffled between alleles by gene conversion and recombination. A new functional gene was identified in a wild wheat accession from Syria. This gene, Pm3k, conferred intermediate resistance to powdery mildew and consists of a mosaic of gene segments derived from non-functional alleles. From the hexaploid wheat gene pool, a set of 1320 landraces, mostly from Asia, was screened for powdery mildew resistance and the presence of a Pm3 haplotype. Most of these lines were found to contain a susceptible Pm3 allele which is closely related to the functional Pm3 resistance genes. We have also identified resistant lines with new types of Pm3 allelic sequences, resulting from point mutations, gene conversion and illegitimate recombination events. These new alleles are currently tested for resistance activity in a transient expression assay. (author)

  5. Sulfonamide-resistant bacteria and their resistance genes in soils fertilized with manures from Jiangsu Province, Southeastern China.

    Directory of Open Access Journals (Sweden)

    Na Wang

    Full Text Available Antibiotic-resistant bacteria and genes are recognized as new environmental pollutants that warrant special concern. There were few reports on veterinary antibiotic-resistant bacteria and genes in China. This work systematically analyzed the prevalence and distribution of sulfonamide resistance genes in soils from the environments around poultry and livestock farms in Jiangsu Province, Southeastern China. The results showed that the animal manure application made the spread and abundance of antibiotic resistance genes (ARGs increasingly in the soil. The frequency of sulfonamide resistance genes was sul1 > sul2 > sul3 in pig-manured soil DNA and sul2 > sul1 > sul3 in chicken-manured soil DNA. Further analysis suggested that the frequency distribution of the sul genes in the genomic DNA and plasmids of the SR isolates from manured soil was sul2 > sul1 > sul3 overall (p<0.05. The combination of sul1 and sul2 was the most frequent, and the co-existence of sul1 and sul3 was not found either in the genomic DNA or plasmids. The sample type, animal type and sampling time can influence the prevalence and distribution pattern of sulfonamide resistance genes. The present study also indicated that Bacillus, Pseudomonas and Shigella were the most prevalent sul-positive genera in the soil, suggesting a potential human health risk. The above results could be important in the evaluation of antibiotic-resistant bacteria and genes from manure as sources of agricultural soil pollution; the results also demonstrate the necessity and urgency of the regulation and supervision of veterinary antibiotics in China.

  6. Blast Waves

    CERN Document Server

    Needham, Charles E

    2010-01-01

    The primary purpose of this text is to document many of the lessons that have been learned during the author’s more than forty years in the field of blast and shock. The writing therefore takes on an historical perspective, in some sense, because it follows the author’s experience. The book deals with blast waves propagating in fluids or materials that can be treated as fluids. It begins by distinguishing between blast waves and the more general category of shock waves. It then examines several ways of generating blast waves, considering the propagation of blast waves in one, two and three dimensions as well as through the real atmosphere. One section treats the propagation of shocks in layered gases in a more detailed manner. The book also details the interaction of shock waves with structures in particular reflections, progressing from simple to complex geometries, including planar structures, two-dimensional structures such as ramps or wedges, reflections from heights of burst, and three-dimensional st...

  7. Presence of tetracycline resistance genes in ecosystems with distinct levels of human impact

    OpenAIRE

    STEHLÍKOVÁ, Zuzana

    2011-01-01

    The incidence of tetracycline resistance genes in the environments with different levels of human impact were compared in this work. The experimental part included detection of eight tetracycline resistance genes in soils from manured and non-manured farms (representing man-affected environment) and soils from national parks (representing non-affected environment).

  8. mmr, a Mycobacterium tuberculosis Gene Conferring Resistance to Small Cationic Dyes and Inhibitors

    OpenAIRE

    De Rossi, Edda; Branzoni, Manuela; Cantoni, Rita; Milano, Anna; Riccardi, Giovanna; Ciferri, Orio

    1998-01-01

    The mmr gene, cloned from Mycobacterium tuberculosis, was shown to confer to Mycobacterium smegmatis resistance to tetraphenylphosphonium (TPP), erythromycin, ethidium bromide, acriflavine, safranin O, and pyronin Y. The gene appears to code for a protein containing four transmembrane domains. Studies of [3H]TPP intracellular accumulation strongly suggest that the resistance mediated by the Mmr protein involves active extrusion of TPP.

  9. DNA Microarray Detection of Antimicrobial Resistance Genes in Bacteria Co-Cultured from Swine Feces

    Science.gov (United States)

    One factor leading to the spread of antimicrobial resistance (AR) in bacteria is the horizontal transfer of resistance genes. To study this, a DNA microarray was recently developed to detect these genes. To maximize the capability of this microarray, probes were designed and added to detect all AR g...

  10. Molecular ecology of tetracycline resistance: development and validation of primers for detection of tetracycline resistance genes encoding ribosomal protection proteins.

    Science.gov (United States)

    Aminov, R I; Garrigues-Jeanjean, N; Mackie, R I

    2001-01-01

    Phylogenetic analysis of tetracycline resistance genes encoding the ribosomal protection proteins (RPPs) revealed the monophyletic origin of these genes. The most deeply branching class, exemplified by tet and otrA, consisted of genes from the antibiotic-producing organisms Streptomyces rimosus and Streptomyces lividans. With a high degree of confidence, the corresponding genes of the other seven classes (Tet M, Tet S, Tet O, Tet W, Tet Q, Tet T, and TetB P) formed phylogenetically distinct separate clusters. Based on this phylogenetic analysis, a set of PCR primers for detection, retrieval, and sequence analysis of the corresponding gene fragments from a variety of bacterial and environmental sources was developed and characterized. A pair of degenerate primers targeted all tetracycline resistance genes encoding RPPs except otrA and tet, and seven other primer pairs were designed to target the specific classes. The primers were used to detect the circulation of these genes in the rumina of cows, in swine feed and feces, and in swine fecal streptococci. Classes Tet O and Tet W were found in the intestinal contents of both animals, while Tet M was confined to pigs and Tet Q was confined to the rumen. The tet(O) and tet(W) genes circulating in the microbiota of the rumen and the gastrointestinal tract of pigs were identical despite the differences in animal hosts and antibiotic use regimens. Swine fecal streptococci uniformly possessed the tet(O) gene, and 22% of them also carried tet(M). This population could be considered one of the main reservoirs of these two resistance genes in the pig gastrointestinal tract. All classes of RPPs except Tet T and TetB P were found in the commercial components of swine feed. This is the first demonstration of the applicability of molecular ecology techniques to estimation of the gene pool and the flux of antibiotic resistance genes in production animals. PMID:11133424

  11. Sequence and gene expression of chloroquine resistance transporter (pfcrt in the association of in vitro drugs resistance of Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Bray Patrick G

    2011-02-01

    Full Text Available Abstract Background Plasmodium falciparum chloroquine resistance (CQR transporter protein (PfCRT is known to be the important key of CQR. Recent studies have definitively demonstrated a link between mutations in the gene pfcrt and resistance to chloroquine in P. falciparum. Although these mutations are predictive of chloroquine resistance, they are not quantitatively predictive of the degree of resistance. Methods In this study, a total of 95 recently adapted P. falciparum isolates from Thailand were included in the analysis. Parasites were characterized for their drug susceptibility phenotypes and genotypes with respect to pfcrt. From the original 95 isolates, 20 were selected for complete pfcrt sequence analysis. Results Almost all of the parasites characterized carried the previously reported mutations K76T, A220S, Q271E, N326S, I356T and R371I. On complete sequencing, isolates were identified with novel mutations at K76A and E198K. There was a suggestion that parasites carrying E198K were less resistant than those that did not. In addition, pfcrt and pfmdr1 gene expression were investigated by real-time PCR. No relationship between the expression level of either of these genes and response to drug was observed. Conclusion Data from the present study suggest that other genes must contribute to the degree of resistance once the resistance phenotype is established through mutations in pfcrt.

  12. Accumulations of genes for durable resistance to wheat leaf rust pathogen

    Directory of Open Access Journals (Sweden)

    Bošković Jelena

    2008-01-01

    Full Text Available The individual use of single race-specific resistance genes with major phenotypic effects has rarely provided lasting resistance. However, breeding and combining or pyramiding of resistance genes into individual cultivars has had considerable success, particularly in situation where the pathogen does not reproduce sexually, as in the case of wheat leaf rust pathogen. Within international leaf rust of wheat investigations it was necessary, to create by breeding new resistant wheat lines to Puccinia recondita tritici for differentiation of pathogen population, as well as for sources of resistance in European-Mediterranean regions. In the beginning 18 donors of resistance had been selected after an extensive screening test of several International Rust Nurseries, to be crosses with recur- rent parents varieties Princ and Starke. These tests proved that in those lines were present new resistant genes. Eighth genetically different hybrids of the first back-cross had been selected and tested in the seedling stage with three international pathogen cultures (YU-13-19-1; H-13-9-1 and C2-13-Ar-3. Considerable influence of recurrent parent to the number of resistant genes in donors used was demonstrated. On the other side, it was established considerable influence of the pathogen culture to the number of resistant genes in donors used. The same crossing combinations tested with one pathogen culture results in presence of two resistance genes, but with another culture three or one resistant gene. In order to enhancement resistance and pyramiding genes in these hybrids, eight selected the most interesting lines have been crossed with only effective isogenic containing the strong genes Lr9, Lr19 and Lr24.The genetic analysis of twenty two crossing combinations have been realized by testing with three pathotypes of Puccinia recondita tritici ( Bg.s. 12/89; Is.w 8/89 and Chl.w. 14/89. On the base of different segregation ratios of all crossing combinations it

  13. Identification of I-7 expands the repertoire of genes for resistance to Fusarium wilt in tomato to three resistance gene classes

    Science.gov (United States)

    The tomato I-3 and I-7 genes confer resistance to Fusarium oxysporum f. sp. lycopersici (Fol) race 3 and both genes were introgressed into the cultivated tomato, Solanum lycopersicum, from the wild relative Solanum pennellii. I-3 was identified previously and encodes a S-receptor-like kinase, but li...

  14. Genes for resistance to stripe rust on chromosome 2B and their application in wheat breeding

    Institute of Scientific and Technical Information of China (English)

    Peigao Luo; Xueyun Hu; Huaiyu Zhang; Zhenglong Ren

    2009-01-01

    Stripe rust,caused by Puccinia striiformis f.sp.tritici,is one of the most damaging diseases of wheat worldwide.Growing resistant cultivars is the most economic and environmental friendly way to control the disease.There are many resistance genes to stripe rust located on wheat chromosome 2B.Here,we propose a strategy to construct the recombinant wheat chromosome 2B with multiple resistances to stripe rust by making crosses between wheat lines or cultivars carrying Yr genes and using marker-assisted selection,based on the reported information about resistance spectrum,chromosomal location,and linked markers of the genes.Pyramiding the resistance genes on 2B would afford a valuable strategy to control the disease by cultivating varieties with durable resistance.The possibility,efficiency,and prospect of the suggested strategy are reviewed in the paper.

  15. Detection of sulfonamide resistance genes via in situ PCR-FISH.

    Science.gov (United States)

    Gnida, Anna; Kunda, Katarzyna; Ziembińska, Aleksandra; Luczkiewicz, Aneta; Felis, Ewa; Surmacz-Górska, Joanna

    2014-01-01

    Due to the rising use of antibiotics and as a consequence of their concentration in the environment an increasing number of antibiotic resistant bacteria is observed. The phenomenon has a hazardous impact on human and animal life. Sulfamethoxazole is one of the sulfonamides commonly detected in surface waters and soil. The aim of the study was to detect sulfamethoxazole resistance genes in activated sludge biocenosis by use of in situ PCR and/or hybridization. So far no FISH probes for the detection of SMX resistance genes have been described in the literature. We have tested common PCR primers used for SMX resistance genes detection as FISH probes as well as a combination of in situ PCR and FISH. Despite the presence of SMX resistance genes in activated sludge confirmed via traditional PCR, the detection of the genes via microscopic visualization failed. PMID:25115110

  16. Recent Advances in Cloning and Characterization of Disease Resistance Genes in Rice

    Institute of Scientific and Technical Information of China (English)

    Liang-Ying Dai; Xiong-Lun Liu; Ying-Hui Xiao; Guo-Liang Wang

    2007-01-01

    Rice diseases caused by fungi, bacteria and viruses are one of the major constraints for sustainable rice (Oryza sativa L.) production worldwide. The use of resistant cultivars is considered the most economical and effective method to control rice diseases. In the last decade, a dozen resistance genes against the fungal pathogen Magnaporthe grisea and the bacterial pathogen Xanthomonas oryzae pv. oryzae have been cloned. Approximately half of them encode nuclear binding site (NBS) and leucine rich repeat (LRR)-containing proteins, the most common type of cloned plant resistance genes. Interestingly, four of them encode novel proteins which have not been identified in other plant species, suggesting that unique mechanisms might be involved in rice defense responses. This review summarizes the recent advances in cloning and characterization of disease resistance genes in rice and presents future perspectives for in-depth molecular analysis of the function and evolution of rice resistance genes and their interaction with avirulence genes in pathogens.

  17. The tetracycline resistance determinant Tet 39 and the sulphonamide resistance gene sulII are common among resistant Acinetobacter spp. isolated from integrated fish farms in Thailand

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Petersen, Andreas

    2007-01-01

    Objectives: To determine the genetic basis for tetracycline and sulphonamide resistance and the prevalence of class I and II integrons in oxytetracycline-resistant Acinetobacter spp. from integrated fish farms in Thailand. Methods: A total of 222 isolates were screened for tetracycline resistance...... Southern blots with sulII and tet(39) probes were performed on selected isolates. Results: The recently identified tetracycline resistance gene tet(39) was demonstrated in 75% (166/222) of oxytetracycline-resistant Acinetobacter spp. from integrated fish farms in Thailand. Isolates that were also...

  18. Antimicrobial-Resistant Bacterial Populations and Antimicrobial Resistance Genes Obtained from Environments Impacted by Livestock and Municipal Waste.

    Science.gov (United States)

    Agga, Getahun E; Arthur, Terrance M; Durso, Lisa M; Harhay, Dayna M; Schmidt, John W

    2015-01-01

    This study compared the populations of antimicrobial-resistant bacteria and the repertoire of antimicrobial resistance genes in four environments: effluent of three municipal wastewater treatment facilities, three cattle feedlot runoff catchment ponds, three swine waste lagoons, and two "low impact" environments (an urban lake and a relict prairie). Multiple liquid and solid samples were collected from each environment. The prevalences and concentrations of antimicrobial-resistant (AMR) Gram-negative (Escherichia coli and Salmonella enterica) and Gram-positive (enterococci) bacteria were determined from individual samples (n = 174). The prevalences of 84 antimicrobial resistance genes in metagenomic DNA isolated from samples pooled (n = 44) by collection date, location, and sample type were determined. The prevalences and concentrations of AMR E. coli and Salmonella were similar among the livestock and municipal sample sources. The levels of erythromycin-resistant enterococci were significantly higher in liquid samples from cattle catchment ponds and swine waste lagoons than in liquid samples from municipal wastewater treatment facilities, but solid samples from these environments did not differ significantly. Similarly, trimethoprim/sulfamethoxazole-resistant E. coli concentrations were significantly higher in swine liquid than in municipal liquid samples, but there was no difference in solid samples. Multivariate analysis of the distribution of antimicrobial resistance genes using principal coordinate analysis showed distinct clustering of samples with livestock (cattle and swine), low impact environment and municipal samples forming three separate clusters. The numbers of class A beta-lactamase, class C beta-lactamase, and fluoroquinolone resistance genes detected were significantly higher (P waste streams, but a higher diversity of antimicrobial resistance genes are present in treated human waste discharged from municipal wastewater treatment plants than in

  19. Candidate genes for cross-resistance against DNA-damaging drugs

    DEFF Research Database (Denmark)

    Wittig, Rainer; Nessling, Michelle; Will, Rainer D;

    2002-01-01

    Drug resistance of tumor cells leads to major drawbacks in the treatment of cancer. To identify candidate genes for drug resistance, we compared the expression patterns of the drug-sensitive human malignant melanoma cell line MeWo and three derived sublines with acquired resistance to the DNA-dam...

  20. Antibiotic resistance genes detected in the marine sponge Petromica citrina from Brazilian coast.

    Science.gov (United States)

    Laport, Marinella Silva; Pontes, Paula Veronesi Marinho; Dos Santos, Daniela Silva; Santos-Gandelman, Juliana de Fátima; Muricy, Guilherme; Bauwens, Mathieu; Giambiagi-deMarval, Marcia; George, Isabelle

    2016-01-01

    Although antibiotic-resistant pathogens pose a significant threat to human health, the environmental reservoirs of the resistance determinants are still poorly understood. This study reports the detection of resistance genes (ermB, mecA, mupA, qnrA, qnrB and tetL) to antibiotics among certain culturable and unculturable bacteria associated with the marine sponge Petromica citrina. The antimicrobial activities elicited by P. citrina and its associated bacteria are also described. The results indicate that the marine environment could play an important role in the development of antibiotic resistance and the dissemination of resistance genes among bacteria. PMID:27287338

  1. Detection of the mcr-1 Colistin Resistance Gene in Carbapenem-Resistant Enterobacteriaceae from Different Hospitals in China.

    Science.gov (United States)

    Yu, Hua; Qu, Fen; Shan, Bin; Huang, Bin; Jia, Wei; Chen, Cha; Li, Aiqing; Miao, Minhui; Zhang, Xin; Bao, Chunmei; Xu, Yunmin; Chavda, Kalyan D; Tang, Yi-Wei; Kreiswirth, Barry N; Du, Hong; Chen, Liang

    2016-08-01

    The spread of the plasmid-mediated colistin resistance gene, mcr-1, into carbapenem-resistant Enterobacteriaceae (CRE) clinical isolates poses a significant threat to global health. Here we report the identification of three mcr-1-harboring carbapenem-resistant Escherichia coli strains, collected from three patients in two provinces in China. Our results show that mcr-1-harboring CRE strains have started to spread in different hospitals in China. In addition, this report presents the first description of chromosomal integration of mcr-1 into a carbapenem-resistant E. coli strain. PMID:27216058

  2. Plasmid metagenomics reveals multiple antibiotic resistance gene classes among the gut microbiomes of hospitalised patients.

    Science.gov (United States)

    Jitwasinkul, Tossawan; Suriyaphol, Prapat; Tangphatsornruang, Sithichoke; Hansen, Martin Asser; Hansen, Lars Hestbjerg; Sørensen, Søren Johannes; Permpikul, Chairat; Rongrungruang, Yong; Tribuddharat, Chanwit

    2016-09-01

    Antibiotic resistance genes are rapidly spread between pathogens and the normal flora, with plasmids playing an important role in their circulation. This study aimed to investigate antibiotic resistance plasmids in the gut microbiome of hospitalised patients. Stool samples were collected from seven inpatients at Siriraj Hospital (Bangkok, Thailand) and were compared with a sample from a healthy volunteer. Plasmids from the gut microbiomes extracted from the stool samples were subjected to high-throughput DNA sequencing (GS Junior). Newbler-assembled DNA reads were categorised into known and unknown sequences (using >80% alignment length as the cut-off), and ResFinder was used to classify the antibiotic resistance gene pools. Plasmid replicon modules were used for plasmid typing. Forty-six genes conferring resistance to several classes of antibiotics were identified in the stool samples. Several antibiotic resistance genes were shared by the patients; interestingly, most were reported previously in food animals and healthy humans. Four antibiotic resistance genes were found in the healthy subject. One gene (aph3-III) was identified in the patients and the healthy subject and was related to that in cattle. Uncommon genes of hospital origin such as blaTEM-124-like and fosA, which confer resistance to extended-spectrum β-lactams and fosfomycin, respectively, were identified. The resistance genes did not match the patients' drug treatments. In conclusion, several plasmid types were identified in the gut microbiome; however, it was difficult to link these to the antibiotic resistance genes identified. That the antibiotic resistance genes came from hospital and community environments is worrying. PMID:27530840

  3. RICE BLAST CONTROL WITH RELEASE OF RESISTANT VARIETIES Борьба с пирикуляриозом риса путем создания устойчивых сортов

    OpenAIRE

    Zelenskiy G. L.

    2013-01-01

    Among fungus diseases of rice, blast is the most harm-ful. The disease is caused by Pyricularia oryzae Cav. Rice is sensitive to blast at all fazes of vegetation. In Russia, the purposeful breeding of rice varieties re-sistant to this disease began in 1982. Over the past period, the rice varieties which are genetically protect-ed from blast and not requiring crop protection have been created

  4. Analysis of the diversity and function of the alleles of the rice blast resistancegenesPiz-t,PitaandPikin 24 rice cultivars

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; ZHAO Jia-ming; ZHANG Li-xia; WANG Ping; WANG Shi-wei; WANG Hui; WANG Xiao-xi; LIU Zhi-heng; ZHENG Wen-jing

    2016-01-01

    Understanding the sequence diversity of rice blast resistance genes is important for breeding new resistant rice cultivars against the rice blast fungusMagnaporthe oryzae. In this study, we selected 24 rice cultivars with different genetic back-grounds to study the alelic diversity of rice blast resistance genesPiz-t, Pitaand Pik. For Piz-t, a total of 17 alelic types were found within the 24 cultivars. Blast inoculations showed that most of the mutations can affect the function of the resistance gene. For Pita, except for the difference at the 918th amino acid, a majority of the 21 mutations were detected among the cultivars. Inoculations with blast isolates carryingAvr-Pita revealed that cultivars with mutations in other sites except for the 918th amino acid did not affect the function of thePita gene. ForPik, a total of six alelic types were found within the 24 cultivars, but ifve of them lost the function of the resistance gene. In addition, we found thatPiz-t, Pita and Pik were expressed constitutively in the 24 rice cultivars and the expression level was not related to resistance. Our results have provided the sequence diversity information of the resistance genesPiz-t, Pita and Pik among the popular rice cultivars grown in the northeast region of China. Keywords:resistance gene, avirulence gene, aleles, function, genetic evolution zae(M. oryzae), is one of the most destructive diseases in rice production worldwide. Over the years, comprehensive studies on rice blast resistance have been conducted (Silue et al. 1992). The resistance in newly cultivated rice cultivars to M. oryzae can be lost quickly due to the high level of instability in the genome of the fungus (Bonmanet al. 1992). Previous studies show that cultivars with durable and broad-spectrum resistance againstM. oryzae carry multiple major resistance (R) and minor resistance genes (Liuet al. 2014). An effective way to control rice blast disease is, therefore, to breed rice cultivars with multiple R

  5. Genes Expressed Differentially in Hessian Fly Larvae Feeding in Resistant and Susceptible Plants

    Science.gov (United States)

    Chen, Ming-Shun; Liu, Sanzhen; Wang, Haiyan; Cheng, Xiaoyan; El Bouhssini, Mustapha; Whitworth, R. Jeff

    2016-01-01

    The Hessian fly, Mayetiola destructor, is a destructive pest of wheat worldwide and mainly controlled by deploying resistant cultivars. In this study, we investigated the genes that were expressed differentially between larvae in resistant plants and those in susceptible plants through RNA sequencing on the Illumina platform. Informative genes were 11,832, 14,861, 15,708, and 15,071 for the comparisons between larvae in resistant versus susceptible plants for 0.5, 1, 3, and 5 days, respectively, after larvae had reached the feeding site. The transcript abundance corresponding to 5401, 6902, 8457, and 5202 of the informative genes exhibited significant differences (p ≤ 0.05) in the respective paired comparisons. Overall, genes involved in nutrient metabolism, RNA and protein synthesis exhibited lower transcript abundance in larvae from resistant plants, indicating that resistant plants inhibited nutrient metabolism and protein production in larvae. Interestingly, the numbers of cytochrome P450 genes with higher transcript abundance in larvae from resistant plants were comparable to, or higher than those with lower transcript abundance, indicating that toxic chemicals from resistant plants may have played important roles in Hessian fly larval death. Our study also identified several families of genes encoding secreted salivary gland proteins (SSGPs) that were expressed at early stage of 1st instar larvae and with more genes with higher transcript abundance in larvae from resistant plants. Those SSGPs are candidate effectors with important roles in plant manipulation. PMID:27529231

  6. Identification of an integron containing the quinolone resistance gene qnrA1 in Shewanella xiamenensis.

    Science.gov (United States)

    Zhao, Jing-yi; Mu, Xiao-dong; Zhu, Yuan-qi; Xi, Lijun; Xiao, Zijun

    2015-09-01

    This study investigated multidrug resistance in Shewanella xiamenensis isolated from an estuarine water sample in China during 2014. This strain displayed resistance or decreased susceptibility to ampicillin, aztreonam, cefepime, cefotaxime, chloramphenicol, ciprofloxacin, erythromycin, kanamycin and trimethoprim-sulfamethoxazole. The antimicrobial resistance genes aacA3, blaOXA-199, qnrA1 and sul1 were identified by PCR amplification and by sequencing. Pulsed-field gel electrophoresis and DNA hybridization experiments showed that the quinolone resistance gene qnrA1 was chromosomally located. qnrA1 was located in a complex class 1 integron, downstream from an ISCR1, and bracketed by two copies of qacEΔ1-sul1 genes. This integron is similar to In825 with four gene cassettes aacA3, catB11c, dfrA1z and aadA2az. An IS26-mel-mph2-IS26 structure was also detected in the flanking sequences, conferring resistance to macrolides. This is the first identification of the class 1 integron in S. xiamenensis. This is also the first identification of the qnrA1 gene and IS26-mediated macrolide resistance genes in S. xiamenensis. Presence of a variety of resistance genetic determinants in environmental S. xiamenensis suggests the possibility that this species may serve as a potential vehicle of antimicrobial resistance genes in aquatic environments. PMID:26316545

  7. Integration and bioinformatics analysis of DNA-methylated genes associated with drug resistance in ovarian cancer

    Science.gov (United States)

    YAN, BINGBING; YIN, FUQIANG; WANG, QI; ZHANG, WEI; LI, LI

    2016-01-01

    The main obstacle to the successful treatment of ovarian cancer is the development of drug resistance to combined chemotherapy. Among all the factors associated with drug resistance, DNA methylation apparently plays a critical role. In this study, we performed an integrative analysis of the 26 DNA-methylated genes associated with drug resistance in ovarian cancer, and the genes were further evaluated by comprehensive bioinformatics analysis including gene/protein interaction, biological process enrichment and annotation. The results from the protein interaction analyses revealed that at least 20 of these 26 methylated genes are present in the protein interaction network, indicating that they interact with each other, have a correlation in function, and may participate as a whole in the regulation of ovarian cancer drug resistance. There is a direct interaction between the phosphatase and tensin homolog (PTEN) gene and at least half of the other genes, indicating that PTEN may possess core regulatory functions among these genes. Biological process enrichment and annotation demonstrated that most of these methylated genes were significantly associated with apoptosis, which is possibly an essential way for these genes to be involved in the regulation of multidrug resistance in ovarian cancer. In addition, a comprehensive analysis of clinical factors revealed that the methylation level of genes that are associated with the regulation of drug resistance in ovarian cancer was significantly correlated with the prognosis of ovarian cancer. Overall, this study preliminarily explains the potential correlation between the genes with DNA methylation and drug resistance in ovarian cancer. This finding has significance for our understanding of the regulation of resistant ovarian cancer by methylated genes, the treatment of ovarian cancer, and improvement of the prognosis of ovarian cancer. PMID:27347118

  8. Detection and Characterizations of Genes Resistant to Tetracycline and Sulfa among the Bacteria in Mariculture Water

    Science.gov (United States)

    Qu, L.; Li, Y.; Zhu, P.

    2013-12-01

    One hundred and thirty-five bacteria from maricultural environments were tested for sensitivity to tetracycline and sulfa. Result show that 72% of the bacteria were sulfa-resistant, 36% of the bacteria were tetracycline-resistant, and 16.5% of bacteria showed resistance to both tetracyclines and sulfa ,indicating that the proportion of sulfa and tetracycline resistance bacteria isvery large in the maricultural environments. PCR methods were used to detect if these resistant bacteria carry tetracycline and sulfa resistance genes. Out of the 33 tetracycline-resistant bacteria screened, 3 were positive for tetA, 6 were positive for tetB and no isolate wasboth positive for tetA and tetB. Of the 97 sulfa-resistant bacteria screened, 9 were positive for sul2, 6 were positive for sul1, 1 isolate was positive for bothsul1 and sul2. The minimum inhibitory concentration (MIC) of tetracycline for tetA-carrying isolates were higher than those tetB-carrying isolates.while The MIC of sulfa for sul2-carrying isolates were higher than those sul1-carrying isolates. Indicating that tetA and sul2 gene may play ubknown roles in resisting tetracycline and sulfa than tetB and sul1 genes. The results showed the 4 kinds of genes (tetA,tetB,sul1,sul2) has no host specificity. All these 16S sequence are from the isolates which are positive for the above genes, it indicated the above antibiotic resistance genes are widespread in the environment regardless of the host. While the DNA sequence of these four genes showed tetA, sul1, sul2 genes are conservative in different bacteria , etB gene conserved poorly. The research aim is to get a preliminary understanding of resistance mechanism related to the resistant bacteria and the resistance genes in marine aquaculture environment through the analysis of resistant genes, providing research base for the prevention and treatment of drug-resistant bacteria so as to reduce the threat to the ecological environment, aquaculture and human health.

  9. Genome-wide identification of NBS-encoding resistance genes in Brassica rapa

    OpenAIRE

    Mun, Jeong-Hwan; Yu, Hee-Ju; Park, Soomin; Park, Beom-Seok

    2009-01-01

    Nucleotide-binding site (NBS)-encoding resistance genes are key plant disease-resistance genes and are abundant in plant genomes, comprising up to 2% of all genes. The availability of genome sequences from several plant models enables the identification and cloning of NBS-encoding genes from closely related species based on a comparative genomics approach. In this study, we used the genome sequence of Brassica rapa to identify NBS-encoding genes in the Brassica genome. We identified 92 non-re...

  10. Application of genomic and quantitative genetic tools to identify candidate resistance genes for brown rot resistance in peach.

    Directory of Open Access Journals (Sweden)

    Pedro J Martínez-García

    Full Text Available The availability of a complete peach genome assembly and three different peach genome sequences created by our group provide new opportunities for application of genomic data and can improve the power of the classical Quantitative Trait Loci (QTL approaches to identify candidate genes for peach disease resistance. Brown rot caused by Monilinia spp., is the most important fungal disease of stone fruits worldwide. Improved levels of peach fruit rot resistance have been identified in some cultivars and advanced selections developed in the UC Davis and USDA breeding programs. Whole genome sequencing of the Pop-DF parents lead to discovery of high-quality SNP markers for QTL genome scanning in this experimental population. Pop-DF created by crossing a brown rot moderately resistant cultivar 'Dr. Davis' and a brown rot resistant introgression line, 'F8,1-42', derived from an initial almond × peach interspecific hybrid, was evaluated for brown rot resistance in fruit of harvest maturity over three seasons. Using the SNP linkage map of Pop-DF and phenotypic data collected with inoculated fruit, a genome scan for QTL identified several SNP markers associated with brown rot resistance. Two of these QTLs were placed on linkage group 1, covering a large (physical region on chromosome 1. The genome scan for QTL and SNP effects predicted several candidate genes associated with disease resistance responses in other host-pathogen systems. Two potential candidate genes, ppa011763m and ppa026453m, may be the genes primarily responsible for M. fructicola recognition in peach, activating both PAMP-triggered immunity (PTI and effector-triggered immunity (ETI responses. Our results provide a foundation for further genetic dissection, marker assisted breeding for brown rot resistance, and development of peach cultivars resistant to brown rot.

  11. Application of genomic and quantitative genetic tools to identify candidate resistance genes for brown rot resistance in peach.

    Science.gov (United States)

    Martínez-García, Pedro J; Parfitt, Dan E; Bostock, Richard M; Fresnedo-Ramírez, Jonathan; Vazquez-Lobo, Alejandra; Ogundiwin, Ebenezer A; Gradziel, Thomas M; Crisosto, Carlos H

    2013-01-01

    The availability of a complete peach genome assembly and three different peach genome sequences created by our group provide new opportunities for application of genomic data and can improve the power of the classical Quantitative Trait Loci (QTL) approaches to identify candidate genes for peach disease resistance. Brown rot caused by Monilinia spp., is the most important fungal disease of stone fruits worldwide. Improved levels of peach fruit rot resistance have been identified in some cultivars and advanced selections developed in the UC Davis and USDA breeding programs. Whole genome sequencing of the Pop-DF parents lead to discovery of high-quality SNP markers for QTL genome scanning in this experimental population. Pop-DF created by crossing a brown rot moderately resistant cultivar 'Dr. Davis' and a brown rot resistant introgression line, 'F8,1-42', derived from an initial almond × peach interspecific hybrid, was evaluated for brown rot resistance in fruit of harvest maturity over three seasons. Using the SNP linkage map of Pop-DF and phenotypic data collected with inoculated fruit, a genome scan for QTL identified several SNP markers associated with brown rot resistance. Two of these QTLs were placed on linkage group 1, covering a large (physical) region on chromosome 1. The genome scan for QTL and SNP effects predicted several candidate genes associated with disease resistance responses in other host-pathogen systems. Two potential candidate genes, ppa011763m and ppa026453m, may be the genes primarily responsible for M. fructicola recognition in peach, activating both PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI) responses. Our results provide a foundation for further genetic dissection, marker assisted breeding for brown rot resistance, and development of peach cultivars resistant to brown rot. PMID:24244329

  12. Risk assessment for Helicoverpa zea (Lepidoptera: Noctuidae) resistance on dual-gene versus single-gene corn

    Science.gov (United States)

    Recent changes in EPA regulations have prompted concern in some experts that transgenic corn expressing two lepidopteran-active genes from the soil bacterium Bacillus thuringiensis (Bt) (dual-gene) may result in more rapid selection for resistance in Helicoverpa zea (Boddie) than corn expressing a s...

  13. Characterisation of integrons and antibiotic resistance genes in Danish multiresistant Salmonella enterica Typhimurium DT104

    DEFF Research Database (Denmark)

    Sandvang, Dorthe; Aarestrup, Frank Møller; Jensen, Lars Bogø

    1998-01-01

    the sul1 and qacE Delta 1 genes characteristic of integrons. The first integron encoded the ant (3")-Ia gene that specified resistance to spectinomycin and streptomycin. The second contained the pse-1 beta-lactamase gene. All the multiresistant strains contained both integrons. The presence of these...

  14. Characterisation of integrons and antibiotic resistance genes in Danish multiresistant Salmonella enterica Typhimurium DT104

    DEFF Research Database (Denmark)

    Sandvang, Dorthe; Aarestrup, Frank Møller; Jensen, Lars Bogø

    1997-01-01

    sul1 and qacE Delta 1 genes characteristic of integrons. The first integron encoded the ant (3 ")-Ia gene that specified resistance to spectinomycin and streptomycin. The second contained the pse-l beta-lactamase gene. All the multiresistant strains contained both integrons. The presence of these two...

  15. Resistance to Ag(I) Cations in Bacteria: Environments, Genes and Proteins

    OpenAIRE

    Silver, Simon; Gupta, Amit; Matsui, Kazuaki; Lo, Jeng-Fan

    1999-01-01

    Bacterial resistance to Ag(I) has been reported periodically with isolates from many environments where toxic levels of silver might be expected to occur, but initial reports were limited to the occurrence of resistant bacteria. The availability of silver-resistance conferring DNA sequences now allow genetic and mechanistic studies that had basically been missing. The genes determining Ag(I) resistance were sequenced from a plasmid found in a burn ward isolate. The 14.2 kb determinant contain...

  16. Functional Analysis of Esterase TCE2 Gene from Tetranychus cinnabarinus (Boisduval) involved in Acaricide Resistance

    OpenAIRE

    Li Shi; Peng Wei; Xiangzun Wang; Guangmao Shen; Jiao Zhang; Wei Xiao; Zhifeng Xu; Qiang Xu; Lin He

    2016-01-01

    The carmine spider mite, Tetranychus cinnabarinus is an important pest of crops and vegetables worldwide, and it has the ability to develop resistance against acaricides rapidly. Our previous study identified an esterase gene (designated TCE2) over-expressed in resistant mites. To investigate this gene’s function in resistance, the expression levels of TCE2 in susceptible, abamectin-, fenpropathrin-, and cyflumetofen-resistant strains were knocked down (65.02%, 63.14%, 57.82%, and 63.99%, res...

  17. Cloning, characterization and expression analysis of NBS-LRR-type resistance gene analogues (RGAs) in coconut

    OpenAIRE

    Rachana, Kaitheri Edathil; NAGANEESWARAN, SUDALAIMUTHU ASARI; Fayas, Thayale Purayil; Thomas, Regi Jacob; RAJESH, MULIYAR KRISHNA

    2016-01-01

    Coconut palms are highly susceptible to diseases caused by different pathogens, and replanting with resistant varieties is the best way to manage them. Obtaining a collection of resistance gene analogues (RGAs) is an effective strategy to identify genomic regions linked to disease resistance. We have successfully used a comparative genomics approach to amplify putative RGAs from the coconut root (wilt) disease resistant cultivar Chowghat Green Dwarf (CGD) by using primers designed based on co...

  18. Carbapenemase Genes among Multidrug Resistant Gram Negative Clinical Isolates from a Tertiary Hospital in Mwanza, Tanzania

    OpenAIRE

    2014-01-01

    The burden of antimicrobial resistance (AMR) is rapidly growing across antibiotic classes, with increased detection of isolates resistant to carbapenems. Data on the prevalence of carbapenem resistance in developing countries is limited; therefore, in this study, we determined the prevalence of carbapenemase genes among multidrug resistant gram negative bacteria (MDR-GNB) isolated from clinical specimens in a tertiary hospital in Mwanza, Tanzania. A total of 227 MDR-GNB isolates were analyzed...

  19. The Chromosomal Arsenic Resistance Genes of Thiobacillus ferrooxidans Have an Unusual Arrangement and Confer Increased Arsenic and Antimony Resistance to Escherichia coli

    OpenAIRE

    Butcher, Bronwyn G.; Deane, Shelly M.; Rawlings, Douglas E.

    2000-01-01

    The chromosomal arsenic resistance genes of the acidophilic, chemolithoautotrophic, biomining bacterium Thiobacillus ferrooxidans were cloned and sequenced. Homologues of four arsenic resistance genes, arsB, arsC, arsH, and a putative arsR gene, were identified. The T. ferrooxidans arsB (arsenite export) and arsC (arsenate reductase) gene products were functional when they were cloned in an Escherichia coli ars deletion mutant and conferred increased resistance to arsenite, arsenate, and anti...

  20. The LBP Gene and Its Association with Resistance to Aeromonas hydrophila in Tilapia

    Directory of Open Access Journals (Sweden)

    Gui Hong Fu

    2014-12-01

    Full Text Available Resistance to pathogens is important for the sustainability and profitability of food fish production. In immune-related genes, the lipopolysaccharide-binding protein (LBP gene is an important mediator of the inflammatory reaction. We analyzed the cDNA and genomic structure of the LBP gene in tilapia. The full-length cDNA (1901 bp of the gene contained a 1416 bp open reading frame, encoding 471 amino acid residues. Its genomic sequence was 5577 bp, comprising 15 exons and 14 introns. Under normal conditions, the gene was constitutively expressed in all examined tissues. The highest expression was detected in intestine and kidney. We examined the responses of the gene to challenges with two bacterial pathogens Streptcoccus agalactiae and Aeromonas hydrophila. The gene was significantly upregulated in kidney and spleen post-infection with S. agalactiae and A. hydrophila, respectively. However, the expression profiles of the gene after the challenge with the two pathogens were different. Furthermore, we identified three SNPs in the gene. There were significant associations (p < 0.05 of two of the three SNPs with the resistance to A. hydrophila, but not with the resistance to S. agalactiae or growth performance. These results suggest that the LBP gene is involved in the acute-phase immunologic response to the bacterial infections, and the responses to the two bacterial pathogens are different. The two SNPs associated with the resistance to A. hydrophila may be useful in the selection of tilapia resistant to A. hydrophila.

  1. Modified cellulose synthase gene from Arabidopsis thaliana confers herbicide resistance to plants

    Science.gov (United States)

    Somerville, Chris R.; Scheible, Wolf

    2007-07-10

    Cellulose synthase ("CS"), a key enzyme in the biosynthesis of cellulose in plants is inhibited by herbicides comprising thiazolidinones such as 5-tert-butyl-carbamoyloxy-3-(3-trifluromethyl)phenyl-4-thiazolidinone (TZ), isoxaben and 2,6-dichlorobenzonitrile (DCB). Two mutant genes encoding isoxaben and TZ-resistant cellulose synthase have been isolated from isoxaben and TZ-resistant Arabidopsis thaliana mutants. When compared with the gene coding for isoxaben or TZ-sensitive cellulose synthase, one of the resistant CS genes contains a point mutation, wherein glycine residue 998 is replaced by an aspartic acid. The other resistant mutation is due to a threonine to isoleucine change at amino acid residue 942. The mutant CS gene can be used to impart herbicide resistance to a plant; thereby permitting the utilization of the herbicide as a single application at a concentration which ensures the complete or substantially complete killing of weeds, while leaving the transgenic crop plant essentially undamaged.

  2. Isolation and Linkage Mapping of NBS-LRR Resistance Gene Analogs in Red Raspberry (Rubus idaeus L.) and Classification Among 269 Rosaceae NGS-LRR Genes

    Science.gov (United States)

    Plant R genes are known to confer resistance to a variety of pathogens in a gene-for-gene mode. Seventy-five putative resistance gene analogs (RGAs) containing conserved domains were cloned and sequenced from the red raspberry (Rubus idaeus L.) cultivar ‘Latham’ using degenerate primers based on RGA...

  3. Carbapenemase Genes among Multidrug Resistant Gram Negative Clinical Isolates from a Tertiary Hospital in Mwanza, Tanzania

    Directory of Open Access Journals (Sweden)

    Martha F. Mushi

    2014-01-01

    Full Text Available The burden of antimicrobial resistance (AMR is rapidly growing across antibiotic classes, with increased detection of isolates resistant to carbapenems. Data on the prevalence of carbapenem resistance in developing countries is limited; therefore, in this study, we determined the prevalence of carbapenemase genes among multidrug resistant gram negative bacteria (MDR-GNB isolated from clinical specimens in a tertiary hospital in Mwanza, Tanzania. A total of 227 MDR-GNB isolates were analyzed for carbapenem resistance genes. For each isolate, five different PCR assays were performed, allowing for the detection of the major carbapenemase genes, including those encoding the VIM-, IMP-, and NDM-type metallo-beta-lactamases, the class A KPC-type carbapenemases, and the class D OXA-48 enzyme. Of 227 isolates, 80 (35% were positive for one or more carbapenemase gene. IMP-types were the most predominant gene followed by VIM, in 49 (21.59% and 28 (12% isolates, respectively. Carbapenemase genes were most detected in K. pneumoniae 24 (11%, followed by P. aeruginosa 23 (10%, and E. coli with 19 isolates (8%. We have demonstrated for the first time a high prevalence of MDR-GNB clinical isolates having carbapenem resistance genes in Tanzania. We recommend routine testing for carbapenem resistance among the MDR-GNB particularly in systemic infections.

  4. The gene Sr33, an ortholog of barley Mla genes, encodes resistance to wheat stem rust race Ug99.

    Science.gov (United States)

    Periyannan, Sambasivam; Moore, John; Ayliffe, Michael; Bansal, Urmil; Wang, Xiaojing; Huang, Li; Deal, Karin; Luo, Mingcheng; Kong, Xiuying; Bariana, Harbans; Mago, Rohit; McIntosh, Robert; Dodds, Peter; Dvorak, Jan; Lagudah, Evans

    2013-08-16

    Wheat stem rust, caused by the fungus Puccinia graminis f. sp. tritici, afflicts bread wheat (Triticum aestivum). New virulent races collectively referred to as "Ug99" have emerged, which threaten global wheat production. The wheat gene Sr33, introgressed from the wild relative Aegilops tauschii into bread wheat, confers resistance to diverse stem rust races, including the Ug99 race group. We cloned Sr33, which encodes a coiled-coil, nucleotide-binding, leucine-rich repeat protein. Sr33 is orthologous to the barley (Hordeum vulgare) Mla mildew resistance genes that confer resistance to Blumeria graminis f. sp. hordei. The wheat Sr33 gene functions independently of RAR1, SGT1, and HSP90 chaperones. Haplotype analysis from diverse collections of Ae. tauschii placed the origin of Sr33 resistance near the southern coast of the Caspian Sea. PMID:23811228

  5. Small RNAs and Gene Network in a Durable Disease Resistance Gene--Mediated Defense Responses in Rice.

    Directory of Open Access Journals (Sweden)

    Hanming Hong

    Full Text Available Accumulating data have suggested that small RNAs (sRNAs have important functions in plant responses to pathogen invasion. However, it is largely unknown whether and how sRNAs are involved in the regulation of rice responses to the invasion of Xanthomonas oryzae pv. oryzae (Xoo, which causes bacterial blight, the most devastating bacterial disease of rice worldwide. We performed simultaneous genome-wide analyses of the expression of sRNAs and genes during early defense responses of rice to Xoo mediated by a major disease resistance gene, Xa3/Xa26, which confers durable and race-specific qualitative resistance. A large number of sRNAs and genes showed differential expression in Xa3/Xa26-mediated resistance. These differentially expressed sRNAs include known microRNAs (miRNAs, unreported miRNAs, and small interfering RNAs. The candidate genes, with expression that was negatively correlated with the expression of sRNAs, were identified, indicating that these genes may be regulated by sRNAs in disease resistance in rice. These results provide a new perspective regarding the putative roles of sRNA candidates and their putative target genes in durable disease resistance in rice.

  6. Molecular mapping of a gene for stripe rust resistance in spring wheat cultivar IDO377s.

    Science.gov (United States)

    Cheng, P; Chen, X M

    2010-06-01

    Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most important diseases of wheat worldwide. The best strategy to control stripe rust is to grow resistant cultivars. One such cultivar resistant to most races in North America is 'IDO377s'. To study the genetics of its resistance this spring wheat cultivar was crossed with 'Avocet Susceptible' (AvS). Seedlings of the parents, F(2) plants, and F(3) lines were tested under controlled greenhouse conditions with races PST-43 and PST-45 of P. striiformis f. sp. tritici. IDO377s carries a single dominant gene for resistance. Resistance gene analog polymorphism (RGAP) and simple sequence repeat (SSR) techniques were used to identify molecular markers linked to the resistance gene. A total of ten markers were identified, two of which flanked the locus at 4.4 and 5.5 cM. These flanking RGAP markers were located on chromosome 2B with nulli-tetrasomic lines of 'Chinese Spring'. Their presence in the ditelosomic 2BL line localized them to the long arm. The chromosomal location of the resistance gene was further confirmed with two 2BL-specific SSR markers and a sequence tagged site (STS) marker previously mapped to 2BL. Based on the chromosomal location, reactions to various races of the pathogen and tests of allelism, the IDO377s gene is different from all previously designated genes for stripe rust resistance, and is therefore designated Yr43. A total of 108 wheat breeding lines and cultivars with IDO377s or related cultivars in their parentage were assayed to assess the status of the closest flanking markers and to select lines carrying Yr43. The results showed that the flanking markers were reliable for assisting selection of breeding lines carrying the resistance gene. A linked stripe rust resistance gene, previously identified as YrZak, in cultivar Zak was designated Yr44. PMID:20198466

  7. Environmental effects on resistance gene expression in milk stage popcorn kernels and associations with mycotoxin production.

    Science.gov (United States)

    Dowd, Patrick F; Johnson, Eric T

    2015-05-01

    Like other forms of maize, popcorn is subject to increased levels of contamination by a variety of different mycotoxins under stress conditions, although levels generally are less than dent maize under comparable stress. Gene array analysis was used to determine expression differences of disease resistance-associated genes in milk stage kernels from commercial popcorn fields over 3 years. Relatively lower expression of resistance gene types was noted in years with higher temperatures and lower rainfall, which was consistent with prior results for many previously identified resistance response-associated genes. The lower rates of expression occurred for genes such as chitinases, protease inhibitors, and peroxidases; enzymes involved in the synthesis of cell wall barriers and secondary metabolites; and regulatory proteins. However, expression of several specific resistance genes previously associated with mycotoxins, such as aflatoxin in dent maize, was not affected. Insect damage altered the spectrum of resistance gene expression differences compared to undamaged ears. Correlation analyses showed expression differences of some previously reported resistance genes that were highly associated with mycotoxin levels and included glucanases, protease inhibitors, peroxidases, and thionins. PMID:25512225

  8. Postulation of Leaf Rust Resistance Genes in Seven Chinese Spring Wheat Cultivars

    Institute of Scientific and Technical Information of China (English)

    SHI Li-hong; ZHANG Na; HU Ya-ya; WEI Xue-jun; YANG Wen-xiang; LIU Da-qun

    2013-01-01

    To detect the leaf rust resistance genes in the 7 Chinese spring wheat clultivars Shenmian 99025, Shenmia 99042, Shenmian 85, Shenmian 91, Shenmian 96, Shenmian 1167 and Shenmian 962, Thatcher, Thatcher backgrounded near-isogenic lines and 15 pathotypes of P. triticina were used for gene postulate at the seedling stage, and 9 of the 15 pathotypes were used in the field tests. Molecular markers closely linked to, or co-segregated with resistance genes Lr1, Lr9, Lr10, Lr19, Lr20, Lr21, Lr24, Lr26, Lr28, Lr29, Lr32, Lr34, Lr35, Lr37, Lr38, and Lr47 were screened to assist detection of the resistance genes. As results, 4 known resistance genes, including Lr1, Lr9, Lr26, and Lr34, and other unknown resistance genes were postulated singly or in combination in the tested cultivars. Shenmian 85, Shenmian 91, Shenmian 96, Shenmian 962, Shenmian 1167, and Shenmian 99042 are potentially useful for wheat production and breeding programs. The result suggested that combining gene postulation, molecular markers and pedigrees is effective and more accuracy method to know the resistance genes in cultivars.

  9. Detection of resistance genes and evaluation of water quality at zoo lakes in Brazil

    Directory of Open Access Journals (Sweden)

    Ana Carolina Silva de Faria

    2016-05-01

    Full Text Available ABSTRACT: The investigation of the presence of antibiotic-resistance genes in aquatic environments is important to identify possible reservoirs of resistant microorganisms that could be a threat to human and animal health. The aims of this study were to analyze the presence of genes conferring resistance to antimicrobials in the aquatic environment and to assess the quality of water in zoo lakes. Results showed a pattern of genes conferring resistance to multiple antibiotics and turbidity, which was expected to be due to the presence of contaminants. The most frequent genes were sul I and sul II (sulfonamides, which were present in all the lakes, followed by genes encoding β-lactamases such as blaPSE I (77.8% and ampC (66.7%. However, tet(K, tet(M, and ermC genes were not detected. There was a positive correlation between the number of Enterobacteriaceae and resistance genes. In conclusion, the source of contamination of all lakes was probably the neighboring urban sewage or wastewater that increased the frequency of the total coliforms and resistance genes, which in turn posed a threat to the conservation of the animal life inhabiting the zoo.

  10. Discovery of clubroot-resistant genes in Brassica napus by transcriptome sequencing.

    Science.gov (United States)

    Chen, S W; Liu, T; Gao, Y; Zhang, C; Peng, S D; Bai, M B; Li, S J; Xu, L; Zhou, X Y; Lin, L B

    2016-01-01

    Clubroot significantly affects plants of the Brassicaceae family and is one of the main diseases causing serious losses in B. napus yield. Few studies have investigated the clubroot-resistance mechanism in B. napus. Identification of clubroot-resistant genes may be used in clubroot-resistant breeding, as well as to elucidate the molecular mechanism behind B. napus clubroot-resistance. We used three B. napus transcriptome samples to construct a transcriptome sequencing library by using Illumina HiSeq™ 2000 sequencing and bioinformatic analysis. In total, 171 million high-quality reads were obtained, containing 96,149 unigenes of N50-value. We aligned the obtained unigenes with the Nr, Swiss-Prot, clusters of orthologous groups, and gene ontology databases and annotated their functions. In the Kyoto encyclopedia of genes and genomes database, 25,033 unigenes (26.04%) were assigned to 124 pathways. Many genes, including broad-spectrum disease-resistance genes, specific clubroot-resistant genes, and genes related to indole-3-acetic acid (IAA) signal transduction, cytokinin synthesis, and myrosinase synthesis in the Huashuang 3 variety of B. napus were found to be related to clubroot-resistance. The effective clubroot-resistance observed in this variety may be due to the induced increased expression of these disease-resistant genes and strong inhibition of the IAA signal transduction, cytokinin synthesis, and myrosinase synthesis. The homology observed between unigenes 0048482, 0061770 and the Crr1 gene shared 94% nucleotide similarity. Furthermore, unigene 0061770 could have originated from an inversion of the Crr1 5'-end sequence. PMID:27525940

  11. Deletions of Immunoglobulin heavy chain and T cell receptor gene regions are uniquely associated with lymphoid blast transformation of chronic myeloid leukemia

    Directory of Open Access Journals (Sweden)

    Valgañon Mikel

    2010-01-01

    Full Text Available Abstract Background Chronic myelogenous leukemia (CML results from the neoplastic transformation of a haematopoietic stem cell. The hallmark genetic abnormality of CML is a chimeric BCR/ABL1 fusion gene resulting from the Philadelphia chromosome rearrangement t(9;22(q34;q11. Clinical and laboratory studies indicate that the BCR/ABL1 fusion protein is essential for initiation, maintenance and progression of CML, yet the event(s driving the transformation from chronic phase to blast phase are poorly understood. Results Here we report multiple genome aberrations in a collection of 78 CML and 14 control samples by oligonucleotide array comparative genomic hybridization. We found a unique signature of genome deletions within the immunoglobulin heavy chain (IGH and T cell receptor regions (TCR, frequently accompanied by concomitant loss of sequences within the short arm regions of chromosomes 7 and 9, including IKZF1, HOXA7, CDKN2A/2B, MLLT3, IFNA/B, RNF38, PAX5, JMJD2C and PDCD1LG2 genes. Conclusions None of these genome losses were detected in any of the CML samples with myeloid transformation, chronic phase or controls, indicating that their presence is obligatory for the development of a malignant clone with a lymphoid phenotype. Notably, the coincidental deletions at IGH and TCR regions appear to precede the loss of IKZF1 and/or p16 genes in CML indicating a possible involvement of RAG in these deletions.

  12. Application of Genomic and Quantitative Genetic Tools to Identify Candidate Resistance Genes for Brown Rot Resistance in Peach

    OpenAIRE

    Martínez-García, Pedro J.; Parfitt, Dan E; Bostock, Richard M.; Fresnedo-Ramírez, Jonathan; Vazquez-Lobo, Alejandra; Ogundiwin, Ebenezer A; Gradziel, Thomas M.; Crisosto, Carlos H

    2013-01-01

    The availability of a complete peach genome assembly and three different peach genome sequences created by our group provide new opportunities for application of genomic data and can improve the power of the classical Quantitative Trait Loci (QTL) approaches to identify candidate genes for peach disease resistance. Brown rot caused by Monilinia spp., is the most important fungal disease of stone fruits worldwide. Improved levels of peach fruit rot resistance have been identified in some culti...

  13. Prevalence of tetracycline resistance genes among multi-drug resistant bacteria from selected water distribution systems in southwestern Nigeria

    OpenAIRE

    Adesoji, Ayodele. T.; Ogunjobi, Adeniyi. A.; Olatoye, Isaac. O.; Douglas, Douglas. R.

    2015-01-01

    Background Antibiotic resistance genes [ARGs] in aquatic systems have drawn increasing attention they could be transferred horizontally to pathogenic bacteria. Water treatment plants (WTPs) are intended to provide quality and widely available water to the local populace they serve. However, WTPs in developing countries may not be dependable for clean water and they could serve as points of dissemination for antibiotic resistant bacteria. Only a few studies have investigated the occurrence of ...

  14. Gene Expression Analysis of Plum pox virus (Sharka Susceptibility/Resistance in Apricot (Prunus armeniaca L..

    Directory of Open Access Journals (Sweden)

    Manuel Rubio

    Full Text Available RNA-Seq has proven to be a very powerful tool in the analysis of the Plum pox virus (PPV, sharka disease/Prunus interaction. This technique is an important complementary tool to other means of studying genomics. In this work an analysis of gene expression of resistance/susceptibility to PPV in apricot is performed. RNA-Seq has been applied to analyse the gene expression changes induced by PPV infection in leaves from two full-sib apricot genotypes, "Rojo Pasión" and "Z506-7", resistant and susceptible to PPV, respectively. Transcriptomic analyses revealed the existence of more than 2,000 genes related to the pathogen response and resistance to PPV in apricot. These results showed that the response to infection by the virus in the susceptible genotype is associated with an induction of genes involved in pathogen resistance such as the allene oxide synthase, S-adenosylmethionine synthetase 2 and the major MLP-like protein 423. Over-expression of the Dicer protein 2a may indicate the suppression of a gene silencing mechanism of the plant by PPV HCPro and P1 PPV proteins. On the other hand, there were 164 genes involved in resistance mechanisms that have been identified in apricot, 49 of which are located in the PPVres region (scaffold 1 positions from 8,050,804 to 8,244,925, which is responsible for PPV resistance in apricot. Among these genes in apricot there are several MATH domain-containing genes, although other genes inside (Pleiotropic drug resistance 9 gene or outside (CAP, Cysteine-rich secretory proteins, Antigen 5 and Pathogenesis-related 1 protein; and LEA, Late embryogenesis abundant protein PPVres region could also be involved in the resistance.

  15. Gene Expression Analysis of Plum pox virus (Sharka) Susceptibility/Resistance in Apricot (Prunus armeniaca L.).

    Science.gov (United States)

    Rubio, Manuel; Ballester, Ana Rosa; Olivares, Pedro Manuel; Castro de Moura, Manuel; Dicenta, Federico; Martínez-Gómez, Pedro

    2015-01-01

    RNA-Seq has proven to be a very powerful tool in the analysis of the Plum pox virus (PPV, sharka disease)/Prunus interaction. This technique is an important complementary tool to other means of studying genomics. In this work an analysis of gene expression of resistance/susceptibility to PPV in apricot is performed. RNA-Seq has been applied to analyse the gene expression changes induced by PPV infection in leaves from two full-sib apricot genotypes, "Rojo Pasión" and "Z506-7", resistant and susceptible to PPV, respectively. Transcriptomic analyses revealed the existence of more than 2,000 genes related to the pathogen response and resistance to PPV in apricot. These results showed that the response to infection by the virus in the susceptible genotype is associated with an induction of genes involved in pathogen resistance such as the allene oxide synthase, S-adenosylmethionine synthetase 2 and the major MLP-like protein 423. Over-expression of the Dicer protein 2a may indicate the suppression of a gene silencing mechanism of the plant by PPV HCPro and P1 PPV proteins. On the other hand, there were 164 genes involved in resistance mechanisms that have been identified in apricot, 49 of which are located in the PPVres region (scaffold 1 positions from 8,050,804 to 8,244,925), which is responsible for PPV resistance in apricot. Among these genes in apricot there are several MATH domain-containing genes, although other genes inside (Pleiotropic drug resistance 9 gene) or outside (CAP, Cysteine-rich secretory proteins, Antigen 5 and Pathogenesis-related 1 protein; and LEA, Late embryogenesis abundant protein) PPVres region could also be involved in the resistance. PMID:26658051

  16. Diversity of Plasmids and Antimicrobial Resistance Genes in Multidrug-Resistant Escherichia coli Isolated from Healthy Companion Animals.

    Science.gov (United States)

    Jackson, C R; Davis, J A; Frye, J G; Barrett, J B; Hiott, L M

    2015-09-01

    The presence and transfer of antimicrobial resistance genes from commensal bacteria in companion animals to more pathogenic bacteria may contribute to dissemination of antimicrobial resistance. The purpose of this study was to determine antimicrobial resistance gene content and the presence of genetic elements in antimicrobial resistant Escherichia coli from healthy companion animals. In our previous study, from May to August, 2007, healthy companion animals (155 dogs and 121 cats) from three veterinary clinics in the Athens, GA, USA area were sampled and multidrug-resistant E. coli (n = 36; MDR, resistance to ≥ 2 antimicrobial classes) were obtained. Of the 25 different plasmid replicon types tested by PCR, at least one plasmid replicon type was detected in 94% (34/36) of the MDR E. coli; four isolates contained as many as five different plasmid replicons. Nine replicon types (FIA, FIB, FII, I2, A/C, U, P, I1 and HI2) were identified with FIB, FII, I2 as the most common pattern. The presence of class I integrons (intI) was detected in 61% (22/36) of the isolates with eight isolates containing aminoglycoside- and/or trimethoprim-resistance genes in the variable cassette region of intI. Microarray analysis of a subset of the MDR E. coli (n = 9) identified the presence of genes conferring resistance to aminoglycosides (aac, aad, aph and strA/B), β-lactams (ampC, cmy, tem and vim), chloramphenicol (cat), sulfonamides (sulI and sulII), tetracycline [tet(A), tet(B), tet(C), tet(D) and regulator, tetR] and trimethoprim (dfrA). Antimicrobial resistance to eight antimicrobials (ampicillin, cefoxitin, ceftiofur, amoxicillin/clavulanic acid, streptomycin, gentamicin, sulfisoxazole and trimethoprim-sulfamethoxazole) and five plasmid replicons (FIA, FIB, FII, I1 and I2) were transferred via conjugation. The presence of antimicrobial resistance genes, intI and transferable plasmid replicons indicate that E. coli from companion animals may play an important role in the

  17. Phylogenetic analyses of peanut resistance gene candidates and screening of different genotypes for polymorphic markers.

    Science.gov (United States)

    Radwan, Osman E; Ahmed, Talaat A; Knapp, Steven J

    2010-01-01

    The nucleotide-binding-site-leucine-rich-repeat (NBS-LRR)-encoding gene family has attracted much research interest because approximately 75% of the plant disease resistance genes that have been cloned to date are from this gene family. Here, we describe a collection of peanut NBS-LRR resistance gene candidates (RGCs) isolated from peanut (Arachis) species by mining Gene Bank data base. NBS-LRR sequences assembled into TIR-NBS-LRR (75.4%) and non-TIR-NBS-LRR (24.6%) subfamilies. Total of 20 distinct clades were identified and showed a high level of sequence divergence within TIR-NBS and non-TIR-NBS subfamilies. Thirty-four primer pairs were designed from these RGC sequences and used for screening different genotypes belonging to wild and cultivated peanuts. Therefore, peanut RGC identified in this study will provide useful tools for developing DNA markers and cloning the genes for resistance to different pathogens in peanut. PMID:23961057

  18. The Am Gene Controlling Resistance to Alfalfa mosaic virus in Tomato Is Located in the Cluster of Dominant Resistance Genes on Chromosome 6.

    Science.gov (United States)

    Parrella, Giuseppe; Moretti, André; Gognalons, Patrick; Lesage, Marie-Laure; Marchoux, George; Gebre-Selassie, Kashay; Caranta, Carole

    2004-04-01

    ABSTRACT The dominant gene Am from Lycopersicon hirsutum f. sp. glabratum PI134417 confers resistance to most strains of Alfalfa mosaic virus, including the recently identified necrotic strains. The phenotypic response includes a lack of symptom development following mechanical inoculation of leaves. To study the resistance mechanism controlled by Am, biological (back-inoculation to susceptible hosts), serological (double-antibody sandwich, enzyme-linked immunosorbent assay), and molecular (reverse transcription-polymerase chain reaction and hybridization with specific riboprobes) methods of virus detection have been conducted on mechanically inoculated PI134417 leaves. The virus was never recovered, indicating that Am acts by an inhibition of viral accumulation during the early events of the virus life cycle. Am has been mapped genetically to the short arm of tomato chromosome 6 in the resistance hotspot, which includes the R-genes Mi and Cf-2/Cf-5 and the quantitative resistance factors Ty-1, Ol-1, and Bw-5. PMID:18944110

  19. Identification and characterization of a resistance gene analog (RGA from the Caricaceae Dumort family Identificação e caracterização de um análogo de gene de resistência (AGR da família de Caricaceae Dumort

    Directory of Open Access Journals (Sweden)

    Paulo de Paiva Rosa Amaral

    2006-12-01

    Full Text Available The majority of cloned resistance (R genes characterized so far contain a nucleotide-binding site (NBS and a leucine-rich repeat (LRR domain, where highly conserved motifs are found. Resistance genes analogs (RGAs are genetic markers obtained by a PCR-based strategy using degenerated oligonucleotide primers drawn from these highly conserved "motifs". This strategy has the advantage of the high degree of structural and amino acid sequence conservation that is observed in R genes. The objective of the present study was to search for RGAs in Carica papaya L. and Vasconcellea cauliflora Jacq. A. DC. Out of three combinations of primers tested, only one resulted in amplification. The amplified product was cloned in pCR2.1TOPO and than sequenced using M13 forward and reverse primers. Forty-eight clones were sequenced from each species. The 96 sequences generated for each species were cleaned of vector sequences and clustered using CAP3 assembler. From the GENEBANK, one RGA was identified in C. papaya showing a BlastX e-value of 2x10-61 to the gb|AAP45165.1| putative disease resistant protein RGA3 (Solanum bulbocastanum. To the extent of our knowledge this is the first report of a RGA in the Caricaceae Dumort family. Preliminary structural studies were performed to further characterize this putative NBS-LRR type protein. Efforts to search for other RGAs in papaya should continue, mostly to provide basis for the development of transgenic papaya with resistance to diseases.A maioria dos genes de resistência (R clonados e caracterizados até o momento contém domínios NBS (nucleotide binding site e LRR (leucine-rich repeat. Dentro destes domínios, encontram-se "motifs" altamente conservados. Análogos de genes de resistência (RGAs são marcadores genéticos obtidos por uma estratégia, baseada em PCR, que usa primers degenerados desenhados a partir desses "motifs" altamente conservados dos genes R. Esta estratégia possui a vantagem do elevado grau de

  20. Paradoxical DNA repair and peroxide resistance gene conservation in Bacillus pumilus SAFR-032.

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    Jason Gioia

    Full Text Available BACKGROUND: Bacillus spores are notoriously resistant to unfavorable conditions such as UV radiation, gamma-radiation, H2O2, desiccation, chemical disinfection, or starvation. Bacillus pumilus SAFR-032 survives standard decontamination procedures of the Jet Propulsion Lab spacecraft assembly facility, and both spores and vegetative cells of this strain exhibit elevated resistance to UV radiation and H2O2 compared to other Bacillus species. PRINCIPAL FINDINGS: The genome of B. pumilus SAFR-032 was sequenced and annotated. Lists of genes relevant to DNA repair and the oxidative stress response were generated and compared to B. subtilis and B. licheniformis. Differences in conservation of genes, gene order, and protein sequences are highlighted because they potentially explain the extreme resistance phenotype of B. pumilus. The B. pumilus genome includes genes not found in B. subtilis or B. licheniformis and conserved genes with sequence divergence, but paradoxically lacks several genes that function in UV or H2O2 resistance in other Bacillus species. SIGNIFICANCE: This study identifies several candidate genes for further research into UV and H2O2 resistance. These findings will help explain the resistance of B. pumilus and are applicable to understanding sterilization survival strategies of microbes.

  1. Class 1 integrase, sulfonamide and tetracycline resistance genes in wastewater treatment plant and surface water.

    Science.gov (United States)

    Makowska, Nicoletta; Koczura, Ryszard; Mokracka, Joanna

    2016-02-01

    Wastewater treatment plants are considered hot spots for multiplication and dissemination of antibiotic-resistant bacteria and resistance genes. In this study, we determined the presence of class 1 integron integrase and genes conferring resistance to tetracyclines and sulfonamides in the genomes of culturable bacteria isolated from a wastewater treatment plant and the river that receives the treated wastewater. Moreover, using PCR-based metagenomic approach, we quantified intI1, tet and sul genes. Wastewater treatment caused the decrease in the total number of culturable heterotrophs and bacteria resistant to tetracycline and sulfonamides, along with the decrease in the number of intI1, sul and tet gene copies per ml, with significant reduction of tet(B). On the other hand, the treatment process increased both the frequency of tetracycline- and sulfonamide-resistant bacteria and intI1-positive strains, and the relative abundance of all quantified antibiotic resistance genes (ARGs) and intI1 gene; in the case of tet(A) and sul2 significantly. The discharge of treated wastewater increased the number of intI1, tet and sul genes in the receiving river water both in terms of copy number per ml and relative abundance. Hence, despite the reduction of the number of ARGs and ARBs, wastewater treatment selects for bacteria with ARGs in effluent. PMID:26519797

  2. The sul1 gene in Stenotrophomonas maltophilia with high-level resistance to trimethoprim/sulfamethoxazole.

    Science.gov (United States)

    Chung, Hae-Sun; Kim, Kyeongmi; Hong, Sang Sook; Hong, Seong Geun; Lee, Kyungwon; Chong, Yunsop

    2015-03-01

    Emerging resistance to trimethoprim/sulfamethoxazole (SXT) poses a serious threat to the treatment of Stenotrophomonas maltophilia infections. We determined the prevalence and molecular characteristics of acquired SXT resistance in recent clinical S. maltophilia isolates obtained from Korea. A total of 252 clinical isolates of S. maltophilia were collected from 10 university hospitals in Korea between 2009 and 2010. Antimicrobial susceptibility was determined by using the CLSI agar dilution method. The sul1, sul2, and sul3 genes, integrons, insertion sequence common region (ISCR) elements, and dfrA genes were detected using PCR. The presence of the sul1 gene and integrons was confirmed through sequence analysis. Among the 32 SXT-resistant isolates, sul1 was detected in 23 isolates (72%), all of which demonstrated high-level resistance (≥64 mg/L) to SXT. The sul1 gene (varying in size and structure) was linked to class 1 integrons in 15 of the 23 isolates (65%) harboring this gene. None of the SXT-susceptible isolates or the SXT-resistant isolates with a minimum inhibitory concentration of 4 and 8 mg/L were positive for sul1. Moreover, the sul2, sul3, and dfrA genes or the ISCR elements were not detected. The sul1 gene may play an important role in the high-level SXT resistance observed in S. maltophilia. PMID:25729729

  3. Overexpression of multiple detoxification genes in deltamethrin resistant Laodelphax striatellus (Hemiptera: Delphacidae in China.

    Directory of Open Access Journals (Sweden)

    Lu Xu

    Full Text Available BACKGROUND: The small brown planthopper (SBPH, Laodelphax striatellus (Fallén, is one of the major rice pests in Asia and has developed resistance to multiple classes of insecticides. Understanding resistance mechanisms is essential to the management of this pest. Biochemical and molecular assays were performed in this study to systematically characterize deltamethrin resistance mechanisms with laboratory-selected resistant and susceptible strains of SBPH. METHODOLOGY/PRINCIPAL FINDINGS: Deltamethrin resistant strains of SBPH (JH-del were derived from a field population by continuously selections (up to 30 generations in the laboratory, while a susceptible strain (JHS was obtained from the same population by removing insecticide pressure for 30 generations. The role of detoxification enzymes in the resistance was investigated using synergism and enzyme activity assays with strains of different resistant levels. Furthermore, 71 cytochrome P450, 93 esterases and 12 glutathione-S-transferases cDNAs were cloned based on transcriptome data of a field collected population. Semi-quantitative RT-PCR screening analysis of 176 identified detoxification genes demonstrated that multiple P450 and esterase genes were overexpressed (>2-fold in JH-del strains (G4 and G30 when compared to that in JHS, and the results of quantitative PCR coincided with the semi-quantitative RT-PCR results. Target mutation at IIS3-IIS6 regions encoded by the voltage-gated sodium channel gene was ruled out for conferring the observed resistance. CONCLUSION/SIGNIFICANCE: As the first attempt to discover genes potentially involved in SBPH pyrethroid resistance, this study putatively identified several candidate genes of detoxification enzymes that were significantly overexpressed in the resistant strain, which matched the synergism and enzyme activity testing. The biochemical and molecular evidences suggest that the high level pyrethroid resistance in L. striatellus could be due to

  4. Effect of surface finishing such as sand-blasting and CrAlN hard coatings on the cutting edge’s peeling tools’ wear resistance

    OpenAIRE

    Nouveau, Corinne; Labidi, Chafik; Collet, Robert; Benlatreche, Yacine; DJOUADI, Mohamed Abdou

    2009-01-01

    The authors would like to thank IonBond (Chassieu-France) who made the sand-blasting treatments and the Regional Council of Burgundy and CTBA (Wood and Furniture Technical Centre) for their financial support.

  5. Blast from the Past: Reassessing Forgotten Translation Inhibitors, Antibiotic Selectivity, and Resistance Mechanisms to Aid Drug Development.

    Science.gov (United States)

    Arenz, Stefan; Wilson, Daniel N

    2016-01-01

    Protein synthesis is a major target within the bacterial cell for antibiotics. Investigations into ribosome-targeting antibiotics have provided much needed functional and structural insight into their mechanism of action. However, the increasing prevalence of multi-drug-resistant bacteria has limited the utility of our current arsenal of clinically relevant antibiotics, highlighting the need for the development of new classes. Recent structural studies have characterized a number of antibiotics discovered decades ago that have unique chemical scaffolds and/or utilize novel modes of action to interact with the ribosome and inhibit translation. Additionally, structures of eukaryotic cytoplasmic and mitochondrial ribosomes have provided further structural insight into the basis for specificity and toxicity of antibiotics. Together with our increased understanding of bacterial resistance mechanisms, revisiting our treasure trove of "forgotten" antibiotics could pave the way for the next generation of antimicrobial agents. PMID:26585390

  6. Transcriptome Profiling Revealed Stress-Induced and Disease Resistance Genes Up-Regulated in PRSV Resistant Transgenic Papaya.

    Science.gov (United States)

    Fang, Jingping; Lin, Aiting; Qiu, Weijing; Cai, Hanyang; Umar, Muhammad; Chen, Rukai; Ming, Ray

    2016-01-01

    Papaya is a productive and nutritious tropical fruit. Papaya Ringspot Virus (PRSV) is the most devastating pathogen threatening papaya production worldwide. Development of transgenic resistant varieties is the most effective strategy to control this disease. However, little is known about the genome-wide functional changes induced by particle bombardment transformation. We conducted transcriptome sequencing of PRSV resistant transgenic papaya SunUp and its PRSV susceptible progenitor Sunset to compare the transcriptional changes in young healthy leaves prior to infection with PRSV. In total, 20,700 transcripts were identified, and 842 differentially expressed genes (DEGs) randomly distributed among papaya chromosomes. Gene ontology (GO) category analysis revealed that microtubule-related categories were highly enriched among these DEGs. Numerous DEGs related to various transcription factors, transporters and hormone biosynthesis showed clear differences between the two cultivars, and most were up-regulated in transgenic papaya. Many known and novel stress-induced and disease-resistance genes were most highly expressed in SunUp, including MYB, WRKY, ERF, NAC, nitrate and zinc transporters, and genes involved in the abscisic acid, salicylic acid, and ethylene signaling pathways. We also identified 67,686 alternative splicing (AS) events in Sunset and 68,455 AS events in SunUp, mapping to 10,994 and 10,995 papaya annotated genes, respectively. GO enrichment for the genes displaying AS events exclusively in Sunset was significantly different from those in SunUp. Transcriptomes in Sunset and transgenic SunUp are very similar with noteworthy differences, which increased PRSV-resistance in transgenic papaya. No detrimental pathways and allergenic or toxic proteins were induced on a genome-wide scale in transgenic SunUp. Our results provide a foundation for unraveling the mechanism of PRSV resistance in transgenic papaya. PMID:27379138

  7. Phylogenetic relatedness determined between antibiotic resistance and 16S rRNA genes in actinobacteria

    Czech Academy of Sciences Publication Activity Database

    Ságová-Marečková, M.; Ulanová, Dana; Šanderová, P.; Omelka, M.; Kameník, Zdeněk; Olšovská, J.; Kopecký, J.

    2015-01-01

    Roč. 15, APR 2015 (2015). ISSN 1471-2180 Institutional support: RVO:61388971 Keywords : Actinobacteria * 16S rRNA diversity * Resistance genes Subject RIV: EE - Microbiology , Virology Impact factor: 2.729, year: 2014

  8. De Novo Transcriptome Sequencing of Oryza officinalis Wall ex Watt to Identify Disease-Resistance Genes

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    Bin He

    2015-12-01

    Full Text Available Oryza officinalis Wall ex Watt is one of the most important wild relatives of cultivated rice and exhibits high resistance to many diseases. It has been used as a source of genes for introgression into cultivated rice. However, there are limited genomic resources and little genetic information publicly reported for this species. To better understand the pathways and factors involved in disease resistance and accelerating the process of rice breeding, we carried out a de novo transcriptome sequencing of O. officinalis. In this research, 137,229 contigs were obtained ranging from 200 to 19,214 bp with an N50 of 2331 bp through de novo assembly of leaves, stems and roots in O. officinalis using an Illumina HiSeq 2000 platform. Based on sequence similarity searches against a non-redundant protein database, a total of 88,249 contigs were annotated with gene descriptions and 75,589 transcripts were further assigned to GO terms. Candidate genes for plant–pathogen interaction and plant hormones regulation pathways involved in disease-resistance were identified. Further analyses of gene expression profiles showed that the majority of genes related to disease resistance were all expressed in the three tissues. In addition, there are two kinds of rice bacterial blight-resistant genes in O. officinalis, including two Xa1 genes and three Xa26 genes. All 2 Xa1 genes showed the highest expression level in stem, whereas one of Xa26 was expressed dominantly in leaf and other 2 Xa26 genes displayed low expression level in all three tissues. This transcriptomic database provides an opportunity for identifying the genes involved in disease-resistance and will provide a basis for studying functional genomics of O. officinalis and genetic improvement of cultivated rice in the future.

  9. Environmental dissemination of antibiotic resistance genes and correlation to anthropogenic contamination with antibiotics

    Directory of Open Access Journals (Sweden)

    Björn Berglund

    2015-09-01

    Full Text Available Antibiotic resistance is a growing problem which threatens modern healthcare globally. Resistance has traditionally been viewed as a clinical problem, but recently non-clinical environments have been highlighted as an important factor in the dissemination of antibiotic resistance genes (ARGs. Horizontal gene transfer (HGT events are likely to be common in aquatic environments; integrons in particular are well suited for mediating environmental dissemination of ARGs. A growing body of evidence suggests that ARGs are ubiquitous in natural environments. Particularly, elevated levels of ARGs and integrons in aquatic environments are correlated to proximity to anthropogenic activities. The source of this increase is likely to be routine discharge of antibiotics and resistance genes, for example, via wastewater or run-off from livestock facilities and agriculture. While very high levels of antibiotic contamination are likely to select for resistant bacteria directly, the role of sub-inhibitory concentrations of antibiotics in environmental antibiotic resistance dissemination remains unclear. In vitro studies have shown that low levels of antibiotics can select for resistant mutants and also facilitate HGT, indicating the need for caution. Overall, it is becoming increasingly clear that the environment plays an important role in dissemination of antibiotic resistance; further studies are needed to elucidate key aspects of this process. Importantly, the levels of environmental antibiotic contamination at which resistant bacteria are selected for and HGT is facilitated at should be determined. This would enable better risk analyses and facilitate measures for preventing dissemination and development of antibiotic resistance in the environment.

  10. Does human activity impact the natural antibiotic resistance background? Abundance of antibiotic resistance genes in 21 Swiss lakes.

    Science.gov (United States)

    Czekalski, Nadine; Sigdel, Radhika; Birtel, Julia; Matthews, Blake; Bürgmann, Helmut

    2015-08-01

    Antibiotic resistance genes (ARGs) are emerging environmental contaminants, known to be continuously discharged into the aquatic environment via human and animal waste. Freshwater aquatic environments represent potential reservoirs for ARG and potentially allow sewage-derived ARG to persist and spread in the environment. This may create increased opportunities for an eventual contact with, and gene transfer to, human and animal pathogens via the food chain or drinking water. However, assessment of this risk requires a better understanding of the level and variability of the natural resistance background and the extent of the human impact. We have analyzed water samples from 21 Swiss lakes, taken at sampling points that were not under the direct influence of local contamination sources and analyzed the relative abundance of ARG using quantitative real-time PCR. Copy numbers of genes mediating resistance to three different broad-spectrum antibiotic classes (sulfonamides: sul1, sul2, tetracyclines: tet(B), tet(M), tet(W) and fluoroquinolones: qnrA) were normalized to copy numbers of bacterial 16S rRNA genes. We used multiple linear regression to assess if ARG abundance is related to human activities in the catchment, microbial community composition and the eutrophication status of the lakes. Sul genes were detected in all sampled lakes, whereas only four lakes contained quantifiable numbers of tet genes, and qnrA remained below detection in all lakes. Our data indicate higher abundance of sul1 in lakes with increasing number and capacity of wastewater treatment plants (WWTPs) in the catchment. sul2 abundance was rather related to long water residence times and eutrophication status. Our study demonstrates the potential of freshwater lakes to preserve antibiotic resistance genes, and provides a reference for ARG abundance from lake systems with low human impact as a baseline for assessing ARG contamination in lake water. PMID:25913323

  11. tcrB, a gene conferring transferable copper resistance in Enterococcus faecium: occurrence, transferability, and linkage to macrolide and glycopeptide resistance

    DEFF Research Database (Denmark)

    Hasman, Henrik; Aarestrup, Frank Møller

    2002-01-01

    B protein from Enterococcus hirae. The tcrB gene was found in E. faecium isolated from pigs (75%), broilers (34%), calves (16%), and humans (10%) but not in isolates from sheep. Resistant isolates, containing the tcrB gene, grew on brain heart infusion agar plates containing up to 28 mM CuSO4 compared to...... only 4 mM for the susceptible isolates. Copper resistance, and therefore the presence of the tcrB gene, was strongly correlated to macrolide and glycopeptide resistance in isolates from pigs, and the tcrB gene was shown to be located on the same conjugative plasmid as the genes responsible for...... resistance to these two antimicrobial agents. The frequent occurrence of this new copper resistance gene in isolates from pigs, where copper sulfate is being used in large amounts as feed additive, suggests that the use of copper has selected for resistance....

  12. A Comprehensive Insight into Tetracycline Resistant Bacteria and Antibiotic Resistance Genes in Activated Sludge Using Next-Generation Sequencing

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    Kailong Huang

    2014-06-01

    Full Text Available In order to comprehensively investigate tetracycline resistance in activated sludge of sewage treatment plants, 454 pyrosequencing and Illumina high-throughput sequencing were used to detect potential tetracycline resistant bacteria (TRB and antibiotic resistance genes (ARGs in sludge cultured with different concentrations of tetracycline. Pyrosequencing of 16S rRNA gene revealed that tetracycline treatment greatly affected the bacterial community structure of the sludge. Nine genera consisting of Sulfuritalea, Armatimonas, Prosthecobacter, Hyphomicrobium, Azonexus, Longilinea, Paracoccus, Novosphingobium and Rhodobacter were identified as potential TRB in the sludge. Results of qPCR, molecular cloning and metagenomic analysis consistently indicated that tetracycline treatment could increase both the abundance and diversity of the tet genes, but decreased the occurrence and diversity of non-tetracycline ARG, especially sulfonamide resistance gene sul2. Cluster analysis showed that tetracycline treatment at subinhibitory concentrations (5 mg/L was found to pose greater effects on the bacterial community composition, which may be responsible for the variations of the ARGs abundance. This study indicated that joint use of 454 pyrosequencing and Illumina high-throughput sequencing can be effectively used to explore ARB and ARGs in the environment, and future studies should include an in-depth investigation of the relationship between microbial community, ARGs and antibiotics in sewage treatment plant (STP sludge.

  13. Genetic diversity analysis in a set of Caricaceae accessions using resistance gene analogues

    OpenAIRE

    Sengupta, Samik; Das, Basabdatta; Acharyya, Pinaki; Prasad, Manoj; Ghose, Tapas Kumar

    2014-01-01

    Background In order to assess genetic diversity of a set of 41 Caricaceae accessions, this study used 34 primer pairs designed from the conserved domains of bacterial leaf blight resistance genes from rice, in a PCR based approach, to identify and analyse resistance gene analogues from various accessions of Carica papaya, Vasconcellea goudotiana, V. microcarpa, V. parviflora, V. pubescens, V. stipulata and, V. quercifolia and Jacaratia spinosa. Results Of the 34 primer pairs fourteen gave amp...

  14. ABCB1 gene polymorphisms is not associated with drug-resistant epilepsy in Romanian children

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    Butila Anamaria Todoran

    2015-12-01

    Full Text Available Background: P-glycoprotein (P-gp, a drug efflux transporter, encoded by the gene MDR1 ABCB1 multidrug resistant, reduces the penetration through the brain by the AEDs. Overexpression of Pgp in blood-brain barrier in epileptic patients play an important rol in pharmacoresistance. The aim of this study was to evaluate a possible association between C1236T and G2677T ABCB1 gene polymorphisms and drug-resistant epilepsy in Romanian children.

  15. Simple Method for Markerless Gene Deletion in Multidrug-Resistant Acinetobacter baumannii

    OpenAIRE

    Oh, Man Hwan; Lee, Je Chul; Kim, Jungmin; Choi, Chul Hee; Han, Kyudong

    2015-01-01

    The traditional markerless gene deletion technique based on overlap extension PCR has been used for generating gene deletions in multidrug-resistant Acinetobacter baumannii. However, the method is time-consuming because it requires restriction digestion of the PCR products in DNA cloning and the construction of new vectors containing a suitable antibiotic resistance cassette for the selection of A. baumannii merodiploids. Moreover, the availability of restriction sites and the selection of re...

  16. Novel nickel resistance genes from the rhizosphere metagenome of plants adapted to acid mine drainage

    OpenAIRE

    Mirete, Salvador; González de Figueras, Carolina; González-Pastor, José Eduardo

    2007-01-01

    Metal resistance determinants have traditionally been found in cultivated bacteria. To search for genes involved in nickel resistance, we analyzed the bacterial community of the rhizosphere of Erica andevalensis, an endemic heather which grows at the banks of the Tinto River, a naturally metal-enriched and extremely acidic environment in southwestern Spain. 16S rRNA gene sequence analysis of rhizosphere DNA revealed the presence of members of five phylogenetic groups of Bacteria and the two m...

  17. Use of the lambda Red recombinase system to produce recombinant prophages carrying antibiotic resistance genes

    Directory of Open Access Journals (Sweden)

    Jofre Juan

    2006-09-01

    Full Text Available Abstract Background The Red recombinase system of bacteriophage lambda has been used to inactivate chromosomal genes in E. coli K-12 through homologous recombination using linear PCR products. The aim of this study was to induce mutations in the genome of some temperate Shiga toxin encoding bacteriophages. When phage genes are in the prophage state, they behave like chromosomal genes. This enables marker genes, such as antibiotic resistance genes, to be incorporated into the stx gene. Once the phages' lytic cycle is activated, recombinant Shiga toxin converting phages are produced. These phages can transfer the marker genes to the bacteria that they infect and convert. As the Red system's effectiveness decreased when used for our purposes, we had to introduce significant variations to the original method. These modifications included: confirming the stability of the target stx gene increasing the number of cells to be transformed and using a three-step PCR method to produce the amplimer containing the antibiotic resistance gene. Results Seven phages carrying two different antibiotic resistance genes were derived from phages that are directly involved in the pathogenesis of Shiga toxin-producing strains, using this modified protocol. Conclusion This approach facilitates exploration of the transduction processes and is a valuable tool for studying phage-mediated horizontal gene transfer.

  18. [Effects of Thermophilic Composting on Antibiotic Resistance Genes (ARGs) of Swine Manure Source].

    Science.gov (United States)

    Zheng, Ning-guo; Huang, Nan; Wang, Wei-wei; Yu, Man; Chen, Xiao-yang; Yao, Yan-lai; Wang, Wei-ping; Hong, Chun-lai

    2016-05-15

    To investigate the effects of thermophilic composting process on antibiotic resistance genes (ARGs) of swine manure source at a field scale, the abundance of four erythromycin resistance genes (ermA, ermB, ermC and ermF), three β-lactam resistance genes (blaTEM, blaCTX and blaSHV) and two quinolone resistance genes (qnrA and qnrS) were quantified by quantitative PCR ( qPCR) during the composting process. The results suggested that the erm genes' copy numbers were significantly higher than those of the bla and qnr genes in the early stage of composting (P < 0.01). The maximum abundance of erm genes was ermB (9.88 x 10⁸ copies · g⁻¹), following by ermF (9.4 x 10⁸ copies · g⁻¹). At the end of the composting process, bla and qnr genes were at low levels, while erm genes were still at high levels. Even through ermF was proliferated comparing with the initial copies. These results indicated that thermophilic composting process could not effectively remove all ARGs. For some ARGs, compost may be a good bioreactor resulting in their proliferation. Application of composting products on farmland may cause transference of ARGs. PMID:27506057

  19. Metagenomic Evidence of the Prevalence and Distribution Patterns of Antimicrobial Resistance Genes in Dairy Agroecosystems.

    Science.gov (United States)

    Pitta, Dipti W; Dou, Zhengxia; Kumar, Sanjay; Indugu, Nagaraju; Toth, John Daniel; Vecchiarelli, Bonnie; Bhukya, Bhima

    2016-06-01

    Antimicrobial resistance (AR) is a global problem with serious implications for public health. AR genes are frequently detected on animal farms, but little is known about their origin and distribution patterns. We hypothesized that AR genes can transfer from animal feces to the environment through manure, and to this end, we characterized and compared the resistomes (collections of AR genes) of animal feces, manure, and soil samples collected from five dairy farms using a metagenomics approach. Resistomes constituted only up to 1% of the total gene content, but were variable by sector and also farm. Broadly, the identified AR genes were associated with 18 antibiotic resistances classes across all samples; however, the most abundant genes were classified under multidrug transporters (44.75%), followed by resistance to vancomycin (12.48%), tetracycline (10.52%), bacitracin (10.43%), beta-lactam resistance (7.12%), and MLS efflux pump (6.86%) antimicrobials. The AR gene profiles were variable between farms. Farm 09 was categorized as a high risk farm, as a greater proportion of AR genes were common to at least three sectors, suggesting possible horizontal transfer of AR genes. Taxonomic characterization of AR genes revealed that a majority of AR genes were associated with the phylum Proteobacteria. Nonetheless, there were several members of Bacteroidetes, particularly Bacteroides genus and several lineages from Firmicutes that carried similar AR genes in different sectors, suggesting a strong potential for horizontal transfer of AR genes between unrelated bacterial hosts in different sectors of the farms. Further studies are required to affirm the horizontal gene transfer mechanisms between microbiomes of different sectors in animal agroecosystems. PMID:27046731

  20. Antibiotic resistance genes in the bacteriophage DNA fraction of environmental samples.

    Science.gov (United States)

    Colomer-Lluch, Marta; Jofre, Juan; Muniesa, Maite

    2011-01-01

    Antibiotic resistance is an increasing global problem resulting from the pressure of antibiotic usage, greater mobility of the population, and industrialization. Many antibiotic resistance genes are believed to have originated in microorganisms in the environment, and to have been transferred to other bacteria through mobile genetic elements. Among others, β-lactam antibiotics show clinical efficacy and low toxicity, and they are thus widely used as antimicrobials. Resistance to β-lactam antibiotics is conferred by β-lactamase genes and penicillin-binding proteins, which are chromosomal- or plasmid-encoded, although there is little information available on the contribution of other mobile genetic elements, such as phages. This study is focused on three genes that confer resistance to β-lactam antibiotics, namely two β-lactamase genes (blaTEM and blaCTX-M9) and one encoding a penicillin-binding protein (mecA) in bacteriophage DNA isolated from environmental water samples. The three genes were quantified in the DNA isolated from bacteriophages collected from 30 urban sewage and river water samples, using quantitative PCR amplification. All three genes were detected in the DNA of phages from all the samples tested, in some cases reaching 104 gene copies (GC) of blaTEM or 102 GC of blaCTX-M and mecA. These values are consistent with the amount of fecal pollution in the sample, except for mecA, which showed a higher number of copies in river water samples than in urban sewage. The bla genes from phage DNA were transferred by electroporation to sensitive host bacteria, which became resistant to ampicillin. blaTEM and blaCTX were detected in the DNA of the resistant clones after transfection. This study indicates that phages are reservoirs of resistance genes in the environment. PMID:21390233

  1. Prevalence of Antibiotic Resistance Genes in Subjects with Successful and Failing Dental Implants. A Pilot Study

    Science.gov (United States)

    Koukos, Georgios; Papadopoulos, Christos; Tsalikis, Lazaros; Sakellari, Dimitra; Arsenakis, Minas; Konstantinidis, Antonios

    2015-01-01

    Objectives : To investigate the prevalence of the bacterial genes encoding resistance to beta-lactams, tetracyclines and metronidazole respectively, in subjects with successful and failing dental implants and to assess the presence of Staphylococcus aureus and the mecA gene encoding for Methicillin Resistant Staphylococcus aureus (MRSA) in the same samples. Materials and Methodology: The subject sample included 20 participants with clinically healthy osseointegrated implants and 20 participants with implants exhibiting peri-implantitis. Clinical parameters were assessed with an automated probe, samples were collected from the peri-implant sulcus or pocket and analyzed with Polymerase Chain Reaction for blaTEM, tetM, tetQ and nim genes, S. aureus and MRSA using primers and conditions previously described in the literature. Results: Findings have shown high frequencies of detection for both groups for the tetracycline resistance genes tetM (>30%), tetQ (>65%) with no statistical differences between them (z-test with Bonferroni corrections, p<0.05). The blaTEM gene, which encodes resistance to beta-lactams, was detected in <15% of the samples. The nim gene, which encodes resistance to metronidazole, S.aureus and the mecA gene encoding for MRSA were not detected in any of the analyzed samples. Conclusions: Healthy peri-implant sulci and peri-implantitis cases often harbor bacterial genes encoding for resistance to the tetracyclines and less often for beta-lactams. Thus, the antimicrobial activity of the tetracyclines and to a lower extent to beta-lactams, might be compromised for treatment of peri-implantitis. Since no metronidazole resistance genes were detected in the present study, its clinical use is supported by the current findings. S.aureus may not participate in peri-implant pathology. PMID:25646133

  2. Transferring Sclerotinia stalk rot resistance genes from wild Helianthus species into cultivated sunflower

    Science.gov (United States)

    Replicated field tests of 313 progeny families screened for stalk rot resistance at Carrington, ND in 2009 showed good introgression of resistance genes. These materials were planted again in 2010 for a second year of field evaluation, as well as the new families with seed increased in 2009. In 2010...

  3. Analysis of rice PDR-like ABC transporter genes in sheath blight resistance

    Science.gov (United States)

    Sheath blight caused by Rhizoctonia solani is one of the most damaging diseases of rice worldwide. To understand the molecular mechanism of resistance, we identified 450 differentially expressed genes in a resistant rice cultivar Jasmine 85 after R. solani infection with a combination of DNA microar...

  4. Molecular mapping of greenbug (Schizaphis graminum) resistance gene Rsg1 in barley

    Science.gov (United States)

    The greenbug, Schizaphis graminum (Rondani) is an extremely damaging aphid pest of barley (Hordeum vulgare L., 2n = 2x =14 L.) particularly in the southern Great Plains of the US. The simply inherited, dominant resistance gene Rsg1 is presented in all greenbug-resistant US barley cultivars, includi...

  5. Expression of Heterogenous Arsenic Resistance Genes in the Obligately Autotrophic Biomining Bacterium Thiobacillus ferrooxidans

    OpenAIRE

    Peng, Ji-Bin; Yan, Wang-Ming; Bao, Xue-Zhen

    1994-01-01

    Two arsenic-resistant plasmids were constructed and introduced into Thiobacillus ferrooxidans strains by conjugation. The plasmids with the replicon of wide-host-range plasmid RSF1010 were stable in T. ferrooxidans. The arsenic resistance genes originating from the heterotroph were expressed in this obligately autotrophic bacterium, but the promoter derived from T. ferrooxidans showed no special function in its original host.

  6. Isolation, Sequence Analysis, and Linkage Mapping of NBS-LRR Disease Resistance Gene Analogs in Watermelon

    Science.gov (United States)

    Cultivated watermelon (Citrullus lanatus var. lanatus) is susceptible to a wide range of pathogens. Sixty-six watermelon resistance gene homologs were cloned from ‘Calhoun Gray’, PI 296341, and PI 595203 using degenerate primers to select for the nucleotide binding site (NBS) from the NBS-LRR resist...

  7. An accurate DNA marker assay for stem rust resistance gene Sr2 in wheat

    Science.gov (United States)

    The stem rust resistance gene Sr2 has provided broad-spectrum protection against stem rust (Puccinia graminis) since its wide spread deployment in wheat from the 1940s. Because Sr2 confers partial resistance which is difficult to select under field conditions, a DNA marker is desirable that accurate...

  8. Candidate fire blight resistance genes in Malus identified with the use of genomic tools and approaches

    Science.gov (United States)

    The goal of this research is to utilize current advances in Rosaceae genomics to identify DNA markers for use in marker-assisted selection of durable resistance to fire blight. Candidate fire blight resistance genes were selected and ranked based upon differential expression after inoculation with ...

  9. Resistance training alters cytokine gene expression in skeletal muscle of adults with type 2 diabetes

    Science.gov (United States)

    Resistance training results in muscle hypertrophy and improves glycemic control in patients with type 2 diabetes. Whether resistance training modulates inflammation in muscles of diabetic patients remains unknown. We examined the expression of genes encoding the cytokines, tumor necrosis factor-al...

  10. Dissemination of tetracycline resistance genes from a convential dairy farm via manure into field soil

    Czech Academy of Sciences Publication Activity Database

    Elhottová, Dana; Slaninová Kyselková, Martina; Chroňáková, Alica; Jirout, Jiří; Chrudimský, Tomáš; Schmitt, H.; Smalla, K.

    Braunschweig: Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, 2015. s. 48. [EDAR 3 - International Symposium on the Environmental Dimension of Antibiotic Resistance /3./. 17.05.2015-21.05.2015, Wernigerode] Institutional support: RVO:60077344 Keywords : dissemination * tetracycline resistance genes * dairy farm Subject RIV: EE - Microbiology, Virology

  11. Fine genetic mapping of greenbug aphid resistance gene Gb3 in Aegilops tauschii

    Science.gov (United States)

    The greenbug is a serious aphid pest of wheat and sorghum in the southern High Plains of the US. The greenbug resistant gene Gb3 originated from the goatgrass has shown consistent and durable resistance against prevailing greenbug biotypes in wheat fields for moer than 30 years. Our goal is to clone...

  12. Aerobic digestion reduces the quantity of antibiotic resistance genes in residual municipal wastewater solids

    OpenAIRE

    Burch, Tucker R.; Sadowsky, Michael J.; LaPara, Timothy M.

    2013-01-01

    Numerous initiatives have been undertaken to circumvent the problem of antibiotic resistance, including the development of new antibiotics, the use of narrow spectrum antibiotics, and the reduction of inappropriate antibiotic use. We propose an alternative but complimentary approach to reduce antibiotic resistant bacteria (ARB) by implementing more stringent technologies for treating municipal wastewater, which is known to contain large quantities of ARB and antibiotic resistance genes (ARGs)...

  13. Occurrence and Diversity of Tetracycline Resistance Genes in Lagoons and Groundwater Underlying Two Swine Production Facilities

    Science.gov (United States)

    Chee-Sanford, J. C.; Aminov, R.I.; Krapac, I.J.; Garrigues-Jeanjean, N.; Mackie, R.I.

    2001-01-01

    In this study, we used PCR typing methods to assess the presence of tetracycline resistance determinants conferring ribosomal protection in waste lagoons and in groundwater underlying two swine farms. All eight classes of genes encoding this mechanism of resistance [tet(O), tet(Q), tet(W), tet(M), tetB(P), tet(S), tet(T), and otrA] were found in total DNA extracted from water of two lagoons. These determinants were found to be seeping into the underlying groundwater and could be detected as far as 250 m downstream from the lagoons. The identities and origin of these genes in groundwater were confirmed by PCR-denaturing gradient gel electrophoresis and sequence analyses. Tetracycline-resistant bacterial isolates from groundwater harbored the tet(M) gene, which was not predominant in the environmental samples and was identical to tet(M) from the lagoons. The presence of this gene in some typical soil inhabitants suggests that the vector of antibiotic resistance gene dissemination is not limited to strains of gastrointestinal origin carrying the gene but can be mobilized into the indigenous soil microbiota. This study demonstrated that tet genes occur in the environment as a direct result of agriculture and suggested that groundwater may be a potential source of antibiotic resistance in the food chain.

  14. Streptomycin use in apple orchards did not increase abundance of mobile resistance genes.

    Science.gov (United States)

    Duffy, Brion; Holliger, Eduard; Walsh, Fiona

    2014-01-01

    Streptomycin is used as a first-line defense and tetracycline as a second-line defense, in the fight against fire blight disease in apple and pear orchards. We have performed the first study to quantitatively analyze the influence of streptomycin use in agriculture on the abundance of streptomycin and tetracycline resistance genes in apple orchards. Flowers, leaves, and soil were collected from three orchard sites in 2010, 2011, and 2012. Gene abundance distribution was analyzed using two-way anova and principal component analysis to investigate relationships between gene abundance data over time and treatment. The mobile antibiotic resistance genes, strA, strB, tetB, tetM, tetW, and the insertion sequence IS1133, were detected prior to streptomycin treatment in almost all samples, indicating the natural presence of these resistance genes in nature. Statistically significant increases in the resistance gene abundances were occasional, inconsistent, and not reproducible from one year to the next. We conclude that the application of streptomycin in these orchards was not associated with sustained increases in streptomycin or tetracycline resistance gene abundances. PMID:24164283

  15. Genetic mapping of stem rust resistance gene Sr13 in tetraploid wheat (Triticum turgidum ssp. durum L.)

    OpenAIRE

    Simons, K; Abate, Z.; Chao, S; Zhang, W.; Rouse, M; Jin, Y.; Elias, E; Dubcovsky, J

    2011-01-01

    Wheat stem rust caused by Puccinia graminis f. sp. tritici, can cause significant yield losses. To combat the disease, breeders have deployed resistance genes both individually and in combinations to increase resistance durability. A new race, TTKSK (Ug99), identified in Uganda in 1999 is virulent on most of the resistance genes currently deployed, and is rapidly spreading to other regions of the world. It is therefore important to identify, map, and deploy resistance genes that are still eff...

  16. Dynamic evolution of resistance gene analogs in the orthologous genomic regions of powdery mildew resistance gene MlIW170 in Triticum dicoccoides and Aegilops tauschii

    Science.gov (United States)

    Wheat is one of the most important staple grain crops in the world. Powdery mildew disease caused by Blumeria graminis f.sp. tritici can result in significant losses in both grain yield and quality in wheat. In this study, the wheat powdery mildew resistance gene MlIW170 locus located on the short ...

  17. Fabrication of microstructures by powder blasting

    OpenAIRE

    Wensink, Hendrik

    2002-01-01

    This thesis deals with the use of powder blasting as a micromachining technique to create micro systems. Powder blasting is a technology in which small particles, accelerated by an air jet, are directed towards a brittle target for mechanical material removal. It is especially useful for glass machining due to the limitations of other glass micromachining techniques. Particle jets have been used for many years to test the wear resistance of materials. Chapter 2 gives a literature overview of ...

  18. Functional metagenomics reveals previously unrecognized diversity of antibiotic resistance genes in gulls

    Directory of Open Access Journals (Sweden)

    AdamCamilloMartiny

    2011-11-01

    Full Text Available Wildlife may facilitate the spread of antibiotic resistance (AR between human-dominated habitats and the surrounding environment. Here, we use functional metagenomics to survey the diversity and genomic context of AR genes in gulls. Using this approach, we found a variety of AR genes not previously detected in gulls and wildlife, including class A and C beta-lactamases as well as six tetracycline resistance gene types. An analysis of the flanking sequences indicates that most of these genes are present in Enterobacteraceae and various gram positive bacteria. In addition to finding known gene types, we detected thirty-one previously undescribed AR genes. These undescribed genes include one most similar to an uncharacterized gene in Verrucomicrobium and another to a putative DNA repair protein in Lactobacillus. Overall, the study more than doubled the number of clinically relevant AR gene types known to be carried by gulls or by wildlife in general. Together with the propensity of gulls to visit human-dominated habitats, this high diversity of AR gene types suggests that gulls could facilitate the spread of antibiotic resistance.

  19. 40 CFR 174.513 - Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Potato Leaf Roll Virus Resistance Gene... REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.513 Potato Leaf Roll... protectant Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene) in or on all...

  20. Reprogramming resistant genes: in-depth comparison of gene expressions among iPS, ES and somatic cells.

    Directory of Open Access Journals (Sweden)

    Natalia ePolouliakh

    2013-01-01

    Full Text Available Transcription factor based reprogramming reverts adult cells to an embryonic state, yielding potential for generating different tissue types. However, recent reports indicated the substantial differences in pattern of gene expression between induced pluripotent stem (iPS cells and embryonic stem (ES cells. In this study we compare gene expression signatures of different iPS and ES cell lines and relate expression profiles of differently expressed genes to their expression status in somatic cells. As a result, we discovered that genes resistant to reprogramming comprise two major clusters, which are reprogramming dependent ‘Induced Genes’ and somatic origin ‘Inherited Genes’, both exhibiting preferences in methylation marks. Closer look into the Induced Genes by means of the transcription regulation analysis predicted several groups of genes with various roles in reprogramming and transgene DNA binding model. We believe that our results are a helpful source for biologists for further improvement of iPS cell technology.

  1. Drug-resistant genes carried by Acinetobacter baumanii isolated from patients with lower respiratory tract infection

    Institute of Scientific and Technical Information of China (English)

    DAI Ning; ZHANG Wei; LI Jia-shu; YU Qin; WAN Huan-ying; MU Lan; ZHONG Xiao-ning; WEI Li-ping; MA Jian-jun; WANG Qiu-yue; HU Ke; LI De-zhi; TIAN Gui-zhen; CAI Shao-xi; WANG Rui-qin; HE Bei; WANG Si-qin; WANG Zhan-wei; ZHAO Su-rui; GAO Zhan-cheng; CHEN Ji-chao; CHEN Yu-sheng; GENG Rong; HU Ying-hui; YANG Jing-ping; DU Juan; HU Cheng-ping

    2010-01-01

    Background Acinetobacter baumanii (A. baumanii) remains an important microbial pathogen resulting in nosocomial acquired infections with significant morbidity and mortality. The mechanism by which nosocomial bacteria, like A.baumanii, attain multidrug resistance to antibiotics is of considerable interest. The aim in this study was to investigate the spread status of antibiotic resistance genes, such as multiple β-lactamase genes and aminoglycoside-modifying enzyme genes, from A. baumanii strains isolated from patients with lower respiratory tract infections (LRTIs).Methods Two thousand six hundred and ninety-eight sputum or the bronchoalveolar lavage samples from inpatients with LRTIs were collected in 21 hospitals in the mainland of China from November 2007 to February 2009. All samples were routinely inoculated. The isolated bacterial strains and their susceptibility were analyzed via VITEK-2 expert system.Several kinds of antibiotic resistant genes were further differentiated via polymerase chain reaction and sequencing methods.Results Totally, 39 A. baumanii strains were isolated from 2698 sputum or bronchoalveolar lavage samples. There was not only a high resistant rate of the isolated A. baumanii strains to ampicillin and first- and second-generation cephalosporins (94.87%, 100% and 97.44%, respectively), but also to the third-generation cephalosporins (ceftriaxone at 92.31%, ceftazidine at 51.28%) and imipenem (43.59%) as well. The lowest antibiotic resistance rate of 20.51% was found to amikacin. The OXA-23 gene was identified in 17 strains of A. baumanii, and the AmpC gene in 23 strains. The TEM-1 gene was carried in 15 strains. PER-1 and SHV-2 genes were detected in two different strains.Aminoglycoside-modifying enzyme gene aac-3-la was found in 23 strains, and the aac-6'-lb gene in 19 strains, aac-3-la and aac-6'-lb genes hibernated in three A. baumanii strains that showed no drug-resistant phenotype.Conclusions A. baumaniican carry multiple drug-resistant

  2. EVALUATION OF MACROLIDE RESISTANCE AND DISTRIBUTION OF RESISTANT GENES IN STAPHYLOCOCCUS AUREUS BETWEEN, 2010 – 2013; A SYSTEMATIC REVIEW

    Directory of Open Access Journals (Sweden)

    MOHAMAD REZA HAVASIAN

    2015-01-01

    Full Text Available Objective: Staphylococci aureus and Coagulase-negative staphylococci (CoNS are a major source of infections associated with indwelling medical devices. Macrolide antimicrobial agents are widely used across the world to protect against bacterial infection. Methods: This is a systematic review study valuating all pubmed, science direct, Scopus and Google scholar articles about the Evaluation of macrolide resistance in Staphylococcus aureus between 2010 – 2013 using analytical statistical analysis. Data were collected and the related information extracted and put in statistical package and analyzed. Results: According the result of this study prevalence of macrolide resistant in some of region was more than other region and it caused by different conditions. The most common genes in macrolide resistant was erm(A but could not be found in regulatory region of the isolates. Conclusion: We should try to reduce the resistant to antimicrobial drug by set the healthy plane and reduce using of antimicrobial drug.

  3. The Order Bacillales Hosts Functional Homologs of the Worrisome cfr Antibiotic Resistance Gene

    DEFF Research Database (Denmark)

    Hansen, Lykke H.; Planellas, Mercè H.; Long, Katherine S.; Vester, Birte

    2012-01-01

    coli, and MICs for selected antibiotics indicate that the cfr-like genes confer resistance to PhLOPSa (phenicol, lincosamide, oxazolidinone, pleuromutilin, and streptogramin A) antibiotics in the same way as the cfr gene. In addition, modification at A2503 on 23S rRNA was confirmed by primer extension...

  4. Colistin Resistance mcr-1-Gene-Bearing Escherichia coli Strain from the United States

    Science.gov (United States)

    Ladely, Scott R.; Plumblee, Jodie R.; Hall, M. Carolina; Simpson, Sheron A.; Ballard, Linda L.; Scheffler, Brian E.; Genzlinger, Linda L.; Cook, Kimberly L.

    2016-01-01

    Transmissible colistin resistance in the form of an mcr-1-gene-bearing plasmid has been recently reported in Enterobacteriaceae in several parts of the world. We report here the completed genome sequence of an Escherichia coli strain isolated from swine in the United States that carried the mcr-1 gene on an IncI2-type plasmid. PMID:27587816

  5. Prevalence of Tetracycline Resistance Genes in Oral Bacteria

    OpenAIRE

    Villedieu, A.; Diaz-Torres, M. L.; Hunt, N; McNab, R; Spratt, D. A.; Wilson, M.; Mullany, P.

    2003-01-01

    Tetracycline is a broad-spectrum antibiotic used in humans, animals, and aquaculture; therefore, many bacteria from different ecosystems are exposed to this antibiotic. In order to determine the genetic basis for resistance to tetracycline in bacteria from the oral cavity, saliva and dental plaque samples were obtained from 20 healthy adults who had not taken antibiotics during the previous 3 months. The samples were screened for the presence of bacteria resistant to tetracycline, and the tet...

  6. Worldwide Disseminated armA Aminoglycoside Resistance Methylase Gene Is Borne by Composite Transposon Tn1548

    OpenAIRE

    Galimand, M.; Sabtcheva, S.; Courvalin, P; Lambert, T.

    2005-01-01

    The armA (aminoglycoside resistance methylase) gene, which confers resistance to 4,6-disubstituted deoxystreptamines and fortimicin, was initially found in Klebsiella pneumoniae BM4536 on IncL/M plasmid pIP1204 of ca. 90 kb which also encodes the extended-spectrum β-lactamase CTX-M-3. Thirty-four enterobacteria from various countries that were likely to produce a CTX-M enzyme since they were more resistant to cefotaxime than to ceftazidime were studied. The armA gene was detected in 12 clinic...

  7. Variation in virulence in the rice blast fungus Magnaporthe grisea in São Paulo State

    Directory of Open Access Journals (Sweden)

    Urashima Alfredo Seiiti

    2002-01-01

    Full Text Available Resistant varieties have been the preferred means to control Magnaporthe grisea, the causal organism of the rice blast disease. The objective of this study was to examine the degree of diversity of the pathogen in different rice growing regions of São Paulo State, Brazil. Blast samples collected from rice varieties in three different regions (Tremembé, Mococa and José Bonifácio were analyzed for race structure employing the Japanese rice differentials. The highest degree of virulence diversity was observed in Tremembé with 22 different races in three different varieties. Furthermore, no resistance gene in the Japanese differentials was effective to all isolates of M. grisea from São Paulo State.

  8. Analysis of drought resistance HVA1 gene under drought stress in different Poa pratensis cultivars

    Institute of Scientific and Technical Information of China (English)

    WU Yanhua; CHEN Yajun; SHEN Fengjuan; SUN Xiaoyan

    2007-01-01

    Total RNA from leaves of Poa pratensis cultivars under drought stress was extracted for reversing transcription to cDNA and then cDNA as template for PCR reaction by designing primer of cds of Hordeum valgare HVA1 drought resistance gene from GenBank. The amplified products were positive recon identified by using procedures of recovery, connection, transformation and enzyme separation. The length of cloned gene sequence was 324 bp, identity reached 79.27% with Barley HVA1 gene that meaned the cloned gene sequence was the partial HVA1 gene of Poa pratensis.

  9. Functional Characterization of Mi, a Root-knot Nematode Resistance Gene from Tomato( Lycopersicon esculentum L.)

    Institute of Scientific and Technical Information of China (English)

    Ru-Gang Chen; Li-Ying Zhang; Jun-Hong Zhang; Wei Zhang; Xue Wang; Bo Ouyang; Han-Xia Li; Zhi-Biao Ye

    2006-01-01

    Root-knot nematodes (Meloidogyne spp.) cause major economic damage to numerous crop species around the world. Plant resistance is the most important attribute that is able to suppress invasion by the rootknot nematodes. In the present study, a candidate root-knot nematode resistance gene (Mi) was isolated from the resistant tomato (Lycopersicon esculentum L.) line RN-1. Expression profiling analysis revealed that this gene was expressed specifically in the roots, stems, and leaves, but not in the flowers or fruits.To verify the real function of this candidate gene, both sense and inteference RNA (RNAi) vectors were constructed. We obtained 31 transgenic plants with between one and seven copies of T-DNA inserts of sense Mi from two nematode-susceptible tomato cultivars as assayed by polymerase chain reaction (PCR)and Southern blotting analysis. Reverse transcription-PCR analysis revealed that expression levels of the Mi gene varied in different transgenic plants. Nematode assays showed that the resistance to root-knot nematodes was significantly improved in some transgenic lines compared with untransformed susceptible controls and that the resistance was heritable in selfed progeny. Loss of function via RNAi further confirmed the role of the Mi gene and the original resistant lines became susceptible to root-knot nematodes.

  10. Role of a qnr-Like Gene in the Intrinsic Resistance of Enterococcus faecalis to Fluoroquinolones▿

    OpenAIRE

    Arsène, Stéphanie; Leclercq, Roland

    2007-01-01

    Fluoroquinolones are poorly active against enterococci. Recently, plasmid-borne resistance to fluoroquinolones due to the qnr gene was reported in members of the Enterobacteriaceae family. The gene encodes a pentapeptide repeat protein that protects DNA gyrase from inhibition by fluoroquinolones. We have identified in the genome of Enterococcus faecalis V583 a qnr-like gene, named E. faecalis qnr (qnrE. faecalis), encoding a putative pentapeptide repeat protein that shares 25% identity with Q...

  11. Fast and Accurate Large-Scale Detection of β-Lactamase Genes Conferring Antibiotic Resistance

    OpenAIRE

    Lee, Jae Jin; Lee, Jung Hun; Kwon, Dae Beom; Jeon, Jeong Ho; Park, Kwang Seung; Lee, Chang-Ro; Lee, Sang Hee

    2015-01-01

    Fast detection of β-lactamase (bla) genes allows improved surveillance studies and infection control measures, which can minimize the spread of antibiotic resistance. Although several molecular diagnostic methods have been developed to detect limited bla gene types, these methods have significant limitations, such as their failure to detect almost all clinically available bla genes. We developed a fast and accurate molecular method to overcome these limitations using 62 primer pairs, which we...

  12. Quantitative gene monitoring of microbial tetracycline resistance using magnetic luminescent nanoparticles

    OpenAIRE

    Son, Ahjeong; Kennedy, Ian M.; Scow, Kate M.; Hristova, Krassimira R.

    2010-01-01

    A magnetic/luminescent nanoparticles (MLNPs) based DNA hybridization method was developed for quantitative monitoring of antibiotic resistance genes and gene-expression in environmental samples. Manipulation of magnetic field enabled the separation of the MLNPs-DNA hybrids from the solution and the fluorescence of MLNPs normalized the quantity of target DNA. In our newly developed MLNPs-DNA assay, linear standard curves (R2 = 0.99) of target gene was determined with the detection limit of 620...

  13. Cloning and expression in Escherichia coli of the Azospirillum brasilense Sp7 gene encoding ampicillin resistance.

    OpenAIRE

    Verreth, C; Cammue, B; Swinnen, P; Crombez, D; Michielsen, A; Michiels, K.; Gool, A. van; Vanderleyden, J.

    1989-01-01

    The Azospirillum brasilense ATCC 29145 gene coding for beta-lactamase was cloned in Escherichia coli. The gene was expressed in E. coli from its own promoter as a 30-kilodalton protein, conferring resistance to high levels of beta-lactam antibiotics. The DNA sequence containing the beta-lactamase gene was found to be highly amplified in the Azospirillum genome, scattered in the chromosomal as well as in the plasmidic DNA.

  14. Introgression of a leaf rust resistance gene from Aegilops caudata to bread wheat

    Indian Academy of Sciences (India)

    Amandeep Kaur Riar; Satinder Kaur; H. S. Dhaliwal; Kuldeep Singh; Parveen Chhuneja

    2012-08-01

    Rusts are the most important biotic constraints limiting wheat productivity worldwide. Deployment of cultivars with broad spectrum rust resistance is the only environmentally viable option to combat these diseases. Identification and introgression of novel sources of resistance is a continuous process to combat the ever evolving pathogens. The germplasm of nonprogenitor Aegilops species with substantial amount of variability has been exploited to a limited extent. In the present investigation introgression, inheritance and molecular mapping of a leaf rust resistance gene of Ae. caudata (CC) acc. pau3556 in cultivated wheat were undertaken. An F2 population derived from the cross of Triticum aestivum cv.WL711 – Ae. caudata introgression line T291-2 with wheat cultivar PBW343 segregated for a single dominant leaf rust resistance gene at the seedling and adult plant stages. Progeny testing in F3 confirmed the introgression of a single gene for leaf rust resistance. Bulked segregant analysis using polymorphic D-genome-specific SSR markers and the cosegregation of the 5DS anchored markers (Xcfd18, Xcfd78, Xfd81 and Xcfd189) with the rust resistance in the F2 population mapped the leaf rust resistance gene (LrAC) on the short arm of wheat chromosome 5D. Genetic complementation and the linked molecular markers revealed that LrAC is a novel homoeoallele of an orthologue Lr57 already introgressed from the 5M chromosome of Ae. geniculata on 5DS of wheat.

  15. Overcoming doxorubicin resistance of cancer cells by Cas9-mediated gene disruption

    OpenAIRE

    Jong Seong Ha; Juyoung Byun; Dae-Ro Ahn

    2016-01-01

    In this study, Cas9 system was employed to down-regulate mdr1 gene for overcoming multidrug resistance of cancer cells. Disruption of the MDR1 gene was achieved by delivery of the Cas9-sgRNA plasmid or the Cas9-sgRNA ribonucleoprotein complex using a conventional gene transfection agent and protein transduction domain (PTD). Doxorubicin showed considerable cytotoxicity to the drug-resistant breast cancer cells pre-treated with the RNA-guided endonuclease (RGEN) systems, whereas virtually non-...

  16. Bacteriophages Carrying Antibiotic Resistance Genes in Fecal Waste from Cattle, Pigs, and Poultry▿

    Science.gov (United States)

    Colomer-Lluch, Marta; Imamovic, Lejla; Jofre, Juan; Muniesa, Maite

    2011-01-01

    This study evaluates the occurrence of bacteriophages carrying antibiotic resistance genes in animal environments. blaTEM, blaCTX-M (clusters 1 and 9), and mecA were quantified by quantitative PCR in 71 phage DNA samples from pigs, poultry, and cattle fecal wastes. Densities of 3 to 4 log10 gene copies (GC) of blaTEM, 2 to 3 log10 GC of blaCTX-M, and 1 to 3 log10 GC of mecA per milliliter or gram of sample were detected, suggesting that bacteriophages can be environmental vectors for the horizontal transfer of antibiotic resistance genes. PMID:21807968

  17. Transgenic Rape with hrf2 Gene Encoding HarpinXooc Resistant to Sclerotinia sclerotinorium

    Institute of Scientific and Technical Information of China (English)

    MA Ling-li; HUO Rong; GAO Xue-wen; HE Dan; SHAO Min; WANG Qi

    2008-01-01

    The objective of this study was to increase the resistance of rape using the method of transformation. The gene hrf2 derived from Xathomonas oryzae pv. oryzicola encoding harpinXooc protein was constructed into transgenic vector pCAMBIA1301. The cotyledonal petiole segments from rapeseed variety Yangyou 4 were infected by Agrobacterium tumefaciens strain LBA4404/pCAMBIA1301-hrf2. Hygromycin-resistant green shoots were obtained. Successful integration of the foreign gene into the genome of the rapeseed variety Yangyou 4 was confirmed by PCR, RT-PCR, and β-glucuronidase analyses. Disease bioassays of transgenic plants revealed an improved resistance of transgenic plants to Rape sclerotiniose. In brief, the hrf2 gene can be transferred into rape using the method of Agrobacterium-medmted transformation, which increased the resistance to Sclerotinia sclerotinorium in the transgenic plant.

  18. Plasmid metagenomics reveals multiple antibiotic resistance gene classes among the gut microbiomes of hospitalised patients

    DEFF Research Database (Denmark)

    Jitwasinkul, Tossawan; Suriyaphol, Prapat; Tangphatsornruang, Sithichoke;

    2016-01-01

    Antibiotic resistance genes are rapidly spread between pathogens and the normal flora, with plasmids playing an important role in their circulation. This study aimed to investigate antibiotic resistance plasmids in the gut microbiome of hospitalised patients. Stool samples were collected from seven...... inpatients at Siriraj Hospital (Bangkok, Thailand) and were compared with a sample from a healthy volunteer. Plasmids from the gut microbiomes extracted from the stool samples were subjected to high-throughput DNA sequencing (GS Junior). Newbler-assembled DNA reads were categorised into known and unknown...... sequences (using >80% alignment length as the cut-off), and ResFinder was used to classify the antibiotic resistance gene pools. Plasmid replicon modules were used for plasmid typing. Forty-six genes conferring resistance to several classes of antibiotics were identified in the stool samples. Several...

  19. Transcriptome Analysis of an Anthracnose-Resistant Tea Plant Cultivar Reveals Genes Associated with Resistance to Colletotrichum camelliae.

    Directory of Open Access Journals (Sweden)

    Lu Wang

    Full Text Available Tea plant breeding is a topic of great economic importance. However, disease remains a major cause of yield and quality losses. In this study, an anthracnose-resistant cultivar, ZC108, was developed. An infection assay revealed different responses to Colletotrichum sp. infection between ZC108 and its parent cultivar LJ43. ZC108 had greater resistance than LJ43 to Colletotrichum camelliae. Additionally, ZC108 exhibited earlier sprouting in the spring, as well as different leaf shape and plant architecture. Microarray data revealed that the genes that are differentially expressed between LJ43 and ZC108 mapped to secondary metabolism-related pathways, including phenylpropanoid biosynthesis, phenylalanine metabolism, and flavonoid biosynthesis pathways. In addition, genes involved in plant hormone biosynthesis and signaling as well as plant-pathogen interaction pathways were also changed. Quantitative real-time PCR was used to examine the expression of 27 selected genes in infected and uninfected tea plant leaves. Genes encoding a MADS-box transcription factor, NBS-LRR disease-resistance protein, and phenylpropanoid metabolism pathway components (CAD, CCR, POD, beta-glucosidase, ALDH and PAL were among those differentially expressed in ZC108.

  20. Identification and characterization of potential NBS-encoding resistance genes and induction kinetics of a putative candidate gene associated with downy mildew resistance in Cucumis

    Directory of Open Access Journals (Sweden)

    Wan Hongjian

    2010-08-01

    Full Text Available Abstract Background Due to the variation and mutation of the races of Pseudoperonospora cubensis, downy mildew has in recent years become the most devastating leaf disease of cucumber worldwide. Novel resistance to downy mildew has been identified in the wild Cucumis species, C. hystrix Chakr. After the successful hybridization between C. hystrix and cultivated cucumber (C. sativus L., an introgression line (IL5211S was identified as highly resistant to downy mildew. Nucleotide-binding site and leucine-rich repeat (NBS-LRR genes are the largest class of disease resistance genes cloned from plant with highly conserved domains, which can be used to facilitate the isolation of candidate genes associated with downy mildew resistance in IL5211S. Results Degenerate primers that were designed based on the conserved motifs in the NBS domain of resistance (R proteins were used to isolate NBS-type sequences from IL5211S. A total of 28 sequences were identified and named as cucumber (C. sativus = CS resistance gene analogs as CSRGAs. Polygenetic analyses separated these sequences into four different classes. Quantitative real-time polymerase chain reaction (qRT-PCR analysis showed that these CSRGAs expressed at different levels in leaves, roots, and stems. In addition, introgression from C. hystrix induced expression of the partial CSRGAs in cultivated cucumber, especially CSRGA23, increased four-fold when compared to the backcross parent CC3. Furthermore, the expression of CSRGA23 under P. cubensis infection and abiotic stresses was also analyzed at different time points. Results showed that the P. cubensis treatment and four tested abiotic stimuli, MeJA, SA, ABA, and H2O2, triggered a significant induction of CSRGA23 within 72 h of inoculation. The results indicate that CSRGA23 may play a critical role in protecting cucumber against P. cubensis through a signaling the pathway triggered by these molecules. Conclusions Four classes of NBS-type RGAs were

  1. Fine mapping of the Ht2 (Helminthosporium turcicum resistance 2) gene in maize

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Fine mapping of Helminthosporium turcicum resistance gene Ht2 is extremely valuable for map-based cloning of the Ht2 gene, gaining a better knowledge of the distribution of resistance genes in maize genome and marker-assisted selection in maize breeding. An F2 mapping population was developed from a cross between a resistant inbred line 77Ht2 and a susceptible inbred line Huobai. With the aid of RFLP marker analyses, the Ht2 gene was mapped between the RFLP markers UMC89 and BNL2.369 on chromosome 8, with a genetic distance of 0.9 cM to BNL2.369. There was a linkage between SSR markers UMC1202, BNLG1152, UMC1149 and the Ht2 gene by SSR assay. Among the SSR markers, the genetic distance between UMC1149 and the Ht2 gene was 7.2 cM. By bulked segregant analysis 7 RAPD-amplified products which were probably linked to the Ht2 gene were selected after screening 450 RAPD primers and converted the single-copy ones into SCAR markers. Linkage analysis showed that the genetic distance between the SCAR marker SD-06633 and the Ht2 gene was 0.4 cM. From these results, a part of linkage map around the Ht2 gene was constructed.

  2. Transposon tagging of disease resistance genes. Final report, May 1, 1988--April 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Michelmore, R.

    1994-09-01

    The goal of this project was to develop a transposon mutagenesis system for lettuce and to clone and characterize disease resistance genes by transposon tagging. The majority of studies were conducted with the Ac/Ds System. Researchers made and tested several constructs as well as utilized constructions shown to be functional in other plant species. Researchers demonstrated movement of Ac and DS in lettuce; however, they transposed at much lower frequencies in lettuce than in other plant species. Therefore, further manipulation of the system, particularly for flower specific expression of transposase, is required before a routine transposon system is available for lettuce. Populations of lettuce were generated and screened to test for the stability of resistance genes and several spontaneous mutations were isolated. Researchers also identified a resistance gene mutant in plants transformed with a Ds element and chimeric transposase gene. This is currently being characterized in detail.

  3. Relationship between antimicrobial resistance and aminoglycoside-modifying enzyme gene expressions in Acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    SHI Wei-feng; JIANG Jian-ping; MI Zu-huang

    2005-01-01

    Background Acinetobacter baumannii is one of the main gram-negative bacilli in clinical practice. Nosocomial infections caused by multi-drug resistance Acinetobacter baumannii is very difficult to treat. This study was designed to investigate the antimicrobial resistance characteristics and four resistant gene expressions of aminoglycoside-modifying enzymes including N-acetyltransferases and O-phosphotransferases in Acinetobacter baumannii. Methods Bacterial identification and antimicrobial susceptibility test were performed by PhoenixTM system in 247 strains of Acinetobacter baumannii. Minimal inhibitory concentrations (MICs) of seven aminoglycosides including gentamicin, amikacin, kanamycin, tobramycin, netilmicin, neomycin and streptomycin in 15 strains of multi-drug resistant Acinetobacter baumannii were detected by agar dilution. Four aminoglycoside-modifying enzyme genes were amplified by polymerase chain reaction (PCR) and verified by DNA sequencer.Results The resistance rates of 247 strains of Acinetobacter baumannii against cefotaxime, levofloxacin, piperacillin, aztreonam, tetracycline, ciprofloxacin and chloramphenicol were more than 50%. Imipenem and meropenem showed high antibacterial activities with resistance rates of 3.2% and 4.1%. MIC50 and MIC90 of gentamicin, amikacin, streptomycin and kanamycin in 15 strains of multi-drug resistant Acinetobacter baumanii were all more than 1024 mg/L, and the resistance rates were 100%, 100%, 100% and 93.3%, respectively. But their resistance rates to tobramycin, netilmicin and neomycin were 86.7%, 93.3% and 46.7%, respectively. Three modifying enzyme genes, including aacC1, aacC2 and aacA4 genes, were found in 15 strains, but aphA6 had not been detected. Their positive rates were 93.3%, 20.0% and 20.0%, respectively. These three genes existed simultaneously in No.19 strain. Nucleotide sequences of aacC1, aacC2 and aacA4 genes shared 100%, 97.9% and 99.7% identities with GenBank genes (AY307113, S68058 and AY

  4. Genetic Analysis of Major and Minor Gene(s) Resistant to Stripe Rust in Important Resource Wheat Line Jinghe891-1

    Institute of Scientific and Technical Information of China (English)

    XU Shi-chang; ZHANG Jing-yuan; ZHAO Wen-sheng; WU Li-ren; ZHANG Ji-xin; YUAN Zhen-dong

    2002-01-01

    Inheritance of line Jinghe891-1 resistant to pathotype of Puccinia striiformis in two patterns of temperature (Normal: day 18℃/night 10℃, High: day 24℃/night 15℃ )was studied in this paper. The results showed that there were at least two pairs of dominant major genes and one pair of recessive minor genes in Jinghe 891-1. The two pairs of major genes that conferred resistance to CY31 were allelic or linked closely with resistance gene in Jubilejna Ⅱ , Kangyin655 and T. spelta Album. They were novel resistance genes and were inherited in a repeated or independent mode. The minor genes, which could modify the major genes,were sensitive to temperature and conferred resistance to all pathotypes of Puccinia striiformis in China. It is recommended that this line can be used as an important resource stock.

  5. Who possesses drug resistance genes in the aquatic environment?: sulfamethoxazole (SMX) resistance genes among the bacterial community in water environment of Metro-Manila, Philippines

    Science.gov (United States)

    Suzuki, Satoru; Ogo, Mitsuko; Miller, Todd W.; Shimizu, Akiko; Takada, Hideshige; Siringan, Maria Auxilia T.

    2013-01-01

    Recent evidence has shown that antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are ubiquitous in natural environments, including sites considered pristine. To understand the origin of ARGs and their dynamics, we must first define their actual presence in the natural bacterial assemblage. Here we found varying distribution profiles of sul genes in “colony forming bacterial assemblages” and “natural bacterial assemblages.” Our monitoring for antibiotic contamination revealed that sulfamethoxazole (SMX) is a major contaminant in aquatic environments of Metro-Manila, which would have been derived from human and animal use, and subsequently decreased through the process of outflow from source to the sea. The SMX-resistant bacterial rate evaluated by the colony forming unit showed 10 to 86% of the total colony numbers showed higher rates from freshwater sites compared to marine sites. When sul genes were quantified by qPCR, colony-forming bacteria conveyed sul1 and sul2 genes in freshwater and seawater (10−5–10−2 copy/16S) but not sul3. Among the natural bacterial assemblage, all sul1, sul2, and sul3 were detected (10−5–10−3 copy/16S), whereas all sul genes were at an almost non-detectable level in the freshwater assemblage. This study suggests that sul1 and sul2 are main sul genes in culturable bacteria, whereas sul3 is conveyed by non-culturable bacteria in the sea. As a result marine bacteria possess sul1, sul2 and sul3 genes in the marine environment. PMID:23641240

  6. RETROVIRAL MEDIATED EFFICIENT TRANSFER ANDEXPRESSION OF MULTIPLE DRUG RESISTANCE GENE TO HUMAN LEUKEMIC CELLS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To investigate retroviral-mediated transfer and expression of human multidrug resistance (MDR) gene MDR1 in leukemic cells. Methods: Human myeloid cells, K562 and NB4, were infected by MDR retrovirus from the producer PA317/HaMDR, and the resistant cells were selected with cytotoxic drug. The transfer and expression of MDR1 gene was analyzed by using polymerase chain reaction (PCR), flow cytometry (FCM) and semisolid colonies cultivation. Results: The resistant cells, K562/MDR and NB4/MDR, in which integration of the exogenous MDR1 gene was confirmed by PCR analysis, displayed a typical MDR phenotype. The expression of MDR1 transgene was detected on truncated as well as full-length transcripts. Moreover, the resistant cells were P-glycoprotein postiive at 78.0% to 98.7% analyzed with FCM. The transduction efficieny in K562 cells was studied on suspension cultures and single-cell colonies. The transduction was more efficient in coculture system (67.9%~ 72.5%) than in supernatant system (33.1%~ 46.8%), while growth factors may improve the efficiency. Conclusion: Retrovirus could allow a functional transfer and expression of MDR1 gene in human leukemia cells, and MDR1 might act as a dominant selectable gene for coexpression with the genes of interest in gene therapy.

  7. High-throughput quantification of antibiotic resistance genes from an urban wastewater treatment plant.

    Science.gov (United States)

    Karkman, Antti; Johnson, Timothy A; Lyra, Christina; Stedtfeld, Robert D; Tamminen, Manu; Tiedje, James M; Virta, Marko

    2016-03-01

    Antibiotic resistance among bacteria is a growing problem worldwide, and wastewater treatment plants have been considered as one of the major contributors to the dissemination of antibiotic resistance to the environment. There is a lack of comprehensive quantitative molecular data on extensive numbers of antibiotic resistance genes (ARGs) in different seasons with a sampling strategy that would cover both incoming and outgoing water together with the excess sludge that is removed from the process. In order to fill that gap we present a highly parallel quantitative analysis of ARGs and horizontal gene transfer potential over four seasons at an urban wastewater treatment plant using a high-throughput qPCR array. All analysed transposases and two-thirds of primer sets targeting ARGs were detected in the wastewater. The relative abundance of most of the genes was highest in influent and lower in effluent water and sludge. The resistance profiles of the samples cluster by sample location with a shift from raw influent through the final effluents and dried sludge to the sediments. Wastewater discharge enriched only a few genes, namely Tn25 type transposase gene and clinical class 1 integrons, in the sediment near the discharge pipe, but those enriched genes may indicate a potential for horizontal gene transfer. PMID:26832203

  8. Allele characterization of genes required for rpg4-mediated wheat stem rust resistance identifies Rpg5 as the R gene.

    Science.gov (United States)

    Arora, D; Gross, T; Brueggeman, R

    2013-11-01

    A highly virulent form of the wheat stem rust pathogen Puccinia graminis f. sp. tritici race TTKSK is virulent on both wheat and barley, presenting a major threat to world food security. The recessive and temperature-sensitive rpg4 gene is the only effective source of resistance identified in barley (Hordeum vulgare) against P. graminis f. sp. tritici race TTKSK. Efforts to position clone rpg4 localized resistance to a small interval on barley chromosome 5HL, tightly linked to the rye stem rust (P. graminis f. sp. secalis) resistance (R) gene Rpg5. High-resolution genetic analysis and post-transcriptional gene silencing of the genes at the rpg4/Rpg5 locus determined that three tightly linked genes (Rpg5, HvRga1, and HvAdf3) are required together for rpg4-mediated wheat stem rust resistance. Alleles of the three genes were analyzed from a diverse set of 14 domesticated barley lines (H. vulgare) and 8 wild barley accessions (H. vulgare subsp. spontaneum) to characterize diversity that may determine incompatibility (resistance). The analysis determined that HvAdf3 and HvRga1 code for predicted functional proteins that do not appear to contain polymorphisms determining the compatible (susceptible) interactions with the wheat stem rust pathogen and were expressed at the transcriptional level from both resistant and susceptible barley lines. The HvAdf3 alleles shared 100% amino acid identity among all 22 genotypes examined. The P. graminis f. sp. tritici race QCCJ-susceptible barley lines with HvRga1 alleles containing the limited amino acid substitutions unique to the susceptible varieties also contained predicted nonfunctional rpg5 alleles. Thus, susceptibility in these lines is likely due to the nonfunctional RPG5 proteins. The Rpg5 allele analysis determined that 9 of the 13 P. graminis f. sp. tritici race QCCJ-susceptible barley lines contain alleles that either code for predicted truncated proteins as the result of a single nucleotide substitution, resulting in a

  9. 水稻品种对美国稻瘟病小种IB-33、IB-45和IE-1的抗性遗传%Inheritance of Resistance to Blast Races IB-33,IB-45 and IE-1 of Pyricularia grisea in Rice Cultivars of the United States of America

    Institute of Scientific and Technical Information of China (English)

    严宗卜

    2004-01-01

    Teqing, Katy, Mars, LaGrue, Newbonnet to identify the inheritance of rice blast (Pyricularia grisea) resistance to three rice blast races IB-33, IB-45 and IE-1 of the USA. The parents, F1 and F2 were tested for their resistance to these races in the greenhouse at Stuttgart, Arkansas in the USA during October 1995 to November 1997. Parents LA110 and Jasmine-85 in the first group were resistant to all races. Teqing in the second group was resistant to all the three races. Katy was resistant to two races IB-45 and IE-1. Mars was only resistant to IE-1. LaGrue was susceptible to all the three races. Newbonnet was susceptible to two races IB-33, IE-1. The resistance was controlled by dominant genes to all races and all F1 were resistant to all the three races. There were allelic genes to race IB-33 in the crosses between resistant parent LA110 and resistant parent Jasmine-85, and to race IE-1 in the crosses between LA110 and resistant parent Teqing or Jasmine-85, and also to race IE-1 in the crosses between Jasmine-85 and Teqing. It might be three dominant resistance genes to race IB-33 in the crosses between LA110 or Jasmine-85 and Teqing. The resistance was controlled by two dominant independent resistance genes to race IB-45 in the crosses among resistant parents LA110 and Teqing, Katy, Newbonnet or Jasmine-85, and also to race IB45 in crosses among resistant parents Jasmine-85 and Teqing, Katy or Newbonnet; and to race IE-1 in the crosses between resistant parents LA110 and Katy or Mars; and also to race IE-1 in the crosses between resistant parents Jasmine-85 and Katy or Mars. It might be two dominant complementary resistance genes controlling inheritance to race IB-33 in the crosses between resistant parent LA110 or Jasmine-85 and susceptible parent Mars; and also to race IB-45 in the crosses between LA110 and Mars. The resistance could be controlled by a single dominant resistance gene to race IB-33 in the crosses between LA110 or Jasmine-85 and susceptible parent Katy

  10. dfrA25, a novel trimethoprim resistance gene from Salmonella Agona isolated from a human urine sample in Brazil

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Peirano, Gisele; Aarestrup, Frank Møller

    2006-01-01

    Objectives: To describe a novel trimethoprim resistance gene, designated dfrA25, which was detected as a gene cassette within a class 1 integron in Salmonella Agona. Methods: The gene was cloned into Escherichia coli MT102 and resistance to 10 different antimicrobial drugs was measured. A...

  11. Coral thermal tolerance: tuning gene expression to resist thermal stress.

    Directory of Open Access Journals (Sweden)

    Anthony J Bellantuono

    Full Text Available The acclimatization capacity of corals is a critical consideration in the persistence of coral reefs under stresses imposed by global climate change. The stress history of corals plays a role in subsequent response to heat stress, but the transcriptomic changes associated with these plastic changes have not been previously explored. In order to identify host transcriptomic changes associated with acquired thermal tolerance in the scleractinian coral Acropora millepora, corals preconditioned to a sub-lethal temperature of 3°C below bleaching threshold temperature were compared to both non-preconditioned corals and untreated controls using a cDNA microarray platform. After eight days of hyperthermal challenge, conditions under which non-preconditioned corals bleached and preconditioned corals (thermal-tolerant maintained Symbiodinium density, a clear differentiation in the transcriptional profiles was revealed among the condition examined. Among these changes, nine differentially expressed genes separated preconditioned corals from non-preconditioned corals, with 42 genes differentially expressed between control and preconditioned treatments, and 70 genes between non-preconditioned corals and controls. Differentially expressed genes included components of an apoptotic signaling cascade, which suggest the inhibition of apoptosis in preconditioned corals. Additionally, lectins and genes involved in response to oxidative stress were also detected. One dominant pattern was the apparent tuning of gene expression observed between preconditioned and non-preconditioned treatments; that is, differences in expression magnitude were more apparent than differences in the identity of genes differentially expressed. Our work revealed a transcriptomic signature underlying the tolerance associated with coral thermal history, and suggests that understanding the molecular mechanisms behind physiological acclimatization would be critical for the modeling of reefs

  12. Marker-free plasmids for gene therapeutic applications--lack of antibiotic resistance gene substantially improves the manufacturing process.

    Science.gov (United States)

    Mairhofer, Jürgen; Cserjan-Puschmann, Monika; Striedner, Gerald; Nöbauer, Katharina; Razzazi-Fazeli, Ebrahim; Grabherr, Reingard

    2010-04-01

    Plasmid DNA is being considered as a promising alternative to traditional protein vaccines or viral delivery methods for gene therapeutic applications. DNA-based products are highly flexible, stable, are easily stored and can be manufactured on a large scale. Although, much safer than viral approaches, issues have been raised with regard to safety due to possible integration of plasmid DNA into cellular DNA or spread of antibiotic resistance genes to intestinal bacteria by horizontal gene transfer. Accordingly, there is interest in methods for the production of plasmid DNA that lacks the antibiotic resistance gene to further improve their safety profile. Here, we report for the first time the gram-scale manufacturing of a minimized plasmid that is devoid of any additional sequence elements on the plasmid backbone, and merely consists of the target expression cassette and the bacterial origin of replication. Three different host/vector combinations were cultivated in a fed-batch fermentation process, comparing the progenitor strain JM108 to modified strains JM108murselect, hosting a plasmid either containing the aminoglycoside phosphotransferase which provides kanamycin resistance, or a marker-free variant of the same plasmid. The metabolic load exerted by expression of the aminoglycoside phosphotransferase was monitored by measuring ppGpp- and cAMP-levels. Moreover, we revealed that JM108 is deficient of the Lon protease and thereby refined the genotype of JM108. The main consequences of Lon-deficiency with regard to plasmid DNA production are discussed herein. Additionally, we found that the expression of the aminoglycoside phosphotransferase, conferring resistance to kanamycin, was very high in plasmid DNA producing processes that actually inclusion bodies were formed. Thereby, a severe metabolic load on the host cell was imposed, detrimental for overall plasmid yield. Hence, deleting the antibiotic resistance gene from the vector backbone is not only beneficial

  13. SSTAR, a Stand-Alone Easy-To-Use Antimicrobial Resistance Gene Predictor

    Science.gov (United States)

    Limbago, Brandi M.

    2016-01-01

    ABSTRACT We present the easy-to-use Sequence Search Tool for Antimicrobial Resistance, SSTAR. It combines a locally executed BLASTN search against a customizable database with an intuitive graphical user interface for identifying antimicrobial resistance (AR) genes from genomic data. Although the database is initially populated from a public repository of acquired resistance determinants (i.e., ARG-ANNOT), it can be customized for particular pathogen groups and resistance mechanisms. For instance, outer membrane porin sequences associated with carbapenem resistance phenotypes can be added, and known intrinsic mechanisms can be included. Unique about this tool is the ability to easily detect putative new alleles and truncated versions of existing AR genes. Variants and potential new alleles are brought to the attention of the user for further investigation. For instance, SSTAR is able to identify modified or truncated versions of porins, which may be of great importance in carbapenemase-negative carbapenem-resistant Enterobacteriaceae. SSTAR is written in Java and is therefore platform independent and compatible with both Windows and Unix operating systems. SSTAR and its manual, which includes a simple installation guide, are freely available from https://github.com/tomdeman-bio/Sequence-Search-Tool-for-Antimicrobial-Resistance-SSTAR-. IMPORTANCE Whole-genome sequencing (WGS) is quickly becoming a routine method for identifying genes associated with antimicrobial resistance (AR). However, for many microbiologists, the use and analysis of WGS data present a substantial challenge. We developed SSTAR, software with a graphical user interface that enables the identification of known AR genes from WGS and has the unique capacity to easily detect new variants of known AR genes, including truncated protein variants. Current software solutions do not notify the user when genes are truncated and, therefore, likely nonfunctional, which makes phenotype predictions less

  14. Adaptive Landscapes of Resistance Genes Change as Antibiotic Concentrations Change.

    Science.gov (United States)

    Mira, Portia M; Meza, Juan C; Nandipati, Anna; Barlow, Miriam

    2015-10-01

    Most studies on the evolution of antibiotic resistance are focused on selection for resistance at lethal antibiotic concentrations, which has allowed the detection of mutant strains that show strong phenotypic traits. However, solely focusing on lethal concentrations of antibiotics narrowly limits our perspective of antibiotic resistance evolution. New high-resolution competition assays have shown that resistant bacteria are selected at relatively low concentrations of antibiotics. This finding is important because sublethal concentrations of antibiotics are found widely in patients undergoing antibiotic therapies, and in nonmedical conditions such as wastewater treatment plants, and food and water used in agriculture and farming. To understand the impacts of sublethal concentrations on selection, we measured 30 adaptive landscapes for a set of TEM β-lactamases containing all combinations of the four amino acid substitutions that exist in TEM-50 for 15 β-lactam antibiotics at multiple concentrations. We found that there are many evolutionary pathways within this collection of landscapes that lead to nearly every TEM-genotype that we studied. While it is known that the pathways change depending on the type of β-lactam, this study demonstrates that the landscapes including fitness optima also change dramatically as the concentrations of antibiotics change. Based on these results we conclude that the presence of multiple concentrations of β-lactams in an environment result in many different adaptive landscapes through which pathways to nearly every genotype are available. Ultimately this may increase the diversity of genotypes in microbial populations. PMID:26113371

  15. PCR detection of oxytetracycline resistance genes otr(A) and otr(B) in tetracycline-resistant streptomycete isolates from diverse habitats

    NARCIS (Netherlands)

    Nikolakopoulou, T; Egan, S; van Overbeek, L; Guillaume, G; Heuer, H; Wellington, EMH; van Elsas, JD; Collard, JM; Smalla, K; Karagouni, A

    2005-01-01

    A range of European habitats was screened by PCR for detection of the oxytetracycline resistance genes otr(A) and otr(B), found in the oxytetracycline-producing strain Streptomyces rimosus. Primers were developed to detect these otr genes in tetracycline-resistant (Tc-R) streptomycete isolates from

  16. Genetic engineering in insects: Cloning and transformation of genes conferring resistance to insecticides

    International Nuclear Information System (INIS)

    Genetic engineering and transformation offer the possibility of modifying the genetic material of insects. These techniques will make it possible, for example, to transfer genes conferring resistance to insecticides into the genome of beneficial species, or to develop new methods of combating insect pests and disease carrying insects. We cloned two genes which contain the code for proteins that detoxify insecticides. The first, esterase B1 from Culex quinquefasciatus, is amplified approximately 250 times in Californian mosquitoes resistant to organic phosphate insecticides. A second esterase gene was cloned from bacteria which break down various organic phosphates. Experiments are in progress to transfer these genes to Drosophila and beneficial insects. These same genes could also serve as selection markers for the purpose of developing transformation techniques for different insects whose genome one wishes to modify using genetic engineering techniques. (author). 5 refs

  17. Rapid cloning of disease-resistance genes in plants using mutagenesis and sequence capture.

    Science.gov (United States)

    Steuernagel, Burkhard; Periyannan, Sambasivam K; Hernández-Pinzón, Inmaculada; Witek, Kamil; Rouse, Matthew N; Yu, Guotai; Hatta, Asyraf; Ayliffe, Mick; Bariana, Harbans; Jones, Jonathan D G; Lagudah, Evans S; Wulff, Brande B H

    2016-06-01

    Wild relatives of domesticated crop species harbor multiple, diverse, disease resistance (R) genes that could be used to engineer sustainable disease control. However, breeding R genes into crop lines often requires long breeding timelines of 5-15 years to break linkage between R genes and deleterious alleles (linkage drag). Further, when R genes are bred one at a time into crop lines, the protection that they confer is often overcome within a few seasons by pathogen evolution. If several cloned R genes were available, it would be possible to pyramid R genes in a crop, which might provide more durable resistance. We describe a three-step method (MutRenSeq)-that combines chemical mutagenesis with exome capture and sequencing for rapid R gene cloning. We applied MutRenSeq to clone stem rust resistance genes Sr22 and Sr45 from hexaploid bread wheat. MutRenSeq can be applied to other commercially relevant crops and their relatives, including, for example, pea, bean, barley, oat, rye, rice and maize. PMID:27111722

  18. Screening for metronidazole-resistance associated gene fragments of H pylori by suppression subtractive hybridization

    Institute of Scientific and Technical Information of China (English)

    Ai-Qing Li; Ning Dai; Jie Yan; Yong-Liang Zhu

    2007-01-01

    AIM:To screen for metronidazole (MTZ)-resistance associated gene fragments of H pylori by suppression subtractive hybridization (SSH).METHODS:Five MTZ-resistant (tester,T) and 1 MTZ-susceptible (driver,D) clinical H pylori isolates were selected. Genomic DMAs were prepared and submitted to Rsa I digestion. Then two different adaptors were ligated respectively to the 5'-end of two aliquots of the tester DNA fragments and SSH was made between the tester and driver DNAs. The specific inserts of tester strains were screened and MTZ-resistance related gene fragments were identified by dot blotting.RESULTS:Among the randomly selected 120 subtractive colonies,37 DNA fragments had a different number of DNA copies (≥2 times) in resistant and susceptible strains and 17 of them had a significantly different number of DNA copies (≥3 times). Among the sequences obtained from the 17 DNA fragments,new sequences were found in 10 DNA fragments and duplicated sequences in 7 DNA fragments,representing respectively the sequences of depeptide ABC transporter periplasmic dipeptide-binding protein (dppA),permease protein (dppB),ribosomal protein S4 (rps4),ribonuclease in (rnc),protease (pqqE),diaminopimelate epimerase (dapF),acetatekinase (ackA),H pylori plasmid pHPSl and H pylori gene 1334.CONCLUSION:Gene fragments specific to MTZ-resistant H pylori strains can be screened by SSH and may be associated with MTZ-resistant H pylori.

  19. Ibuprofen reverts antifungal resistance on Candida albicans showing overexpression of CDR genes.

    Science.gov (United States)

    Ricardo, Elisabete; Costa-de-Oliveira, Sofia; Dias, Ana Silva; Guerra, José; Rodrigues, Acácio Gonçalves; Pina-Vaz, Cidália

    2009-06-01

    Several mechanisms may be associated with Candida albicans resistance to azoles. Ibuprofen was described as being able to revert resistance related to efflux activity in Candida. The aim of this study was to uncover the molecular base of antifungal resistance in C. albicans clinical strains that could be reverted by ibuprofen. Sixty-two clinical isolates and five control strains of C. albicans were studied: the azole susceptibility phenotype was determined according to the Clinical Laboratory for Standards Institute, M27-A2 protocol and minimal inhibitory concentration values were recalculated with ibuprofen (100 microg mL(-1)); synergistic studies between fluconazole and FK506, a Cdr1p inhibitor, were performed using an agar disk diffusion assay and were compared with ibuprofen results. Gene expression was quantified by real-time PCR, with and without ibuprofen, regarding CDR1, CDR2, MDR1, encoding for efflux pumps, and ERG11, encoding for azole target protein. A correlation between susceptibility phenotype and resistance gene expression profiles was determined. Ibuprofen and FK506 showed a clear synergistic effect when combined with fluconazole. Resistant isolates reverting to susceptible after incubation with ibuprofen showed CDR1 and CDR2 overexpression especially of the latter. Conversely, strains that did not revert displayed a remarkable increase in ERG11 expression along with CDR genes. Ibuprofen did not alter resistance gene expression significantly (P>0.05), probably acting as a Cdrp blocker. PMID:19416368

  20. Increased Expression of Several Collagen Genes is Associated with Drug Resistance in Ovarian Cancer Cell Lines.

    Science.gov (United States)

    Januchowski, Radosław; Świerczewska, Monika; Sterzyńska, Karolina; Wojtowicz, Karolina; Nowicki, Michał; Zabel, Maciej

    2016-01-01

    Ovarian cancer is the most lethal gynaecological cancer. The main reason for the high mortality among ovarian cancer patients is the development of drug resistance. The expression of collagen genes by cancer cells can increase drug resistance by inhibiting the penetration of the drug into the cancer tissue as well as increase apoptosis resistance. In this study, we present data that shows differential expression levels of collagen genes and proteins in cisplatin- (CIS), paclitaxel- (PAC), doxorubicin- (DOX), topotecan- (TOP), vincristine- (VIN) and methotrexate- (MTX) resistant ovarian cancer cell lines. Quantitative real-time polymerase chain reactions were performed to determine the mRNA levels. Protein expression was detected using Western blot and immunocytochemistry assays. In the drug resistant cell lines, we observed the upregulation of eight collagen genes at the mRNA level and based on these expression levels, we divided the collagen genes into the following three groups: 1. Genes with less than a 50-fold increase in expression: COL1A1, COL5A2, COL12A1 and COL17A1. 2. Genes with greater than a 50-fold increase in expression: COL1A2, COL15A1 and COL21A1. 3. Gene with a very high level of expression: COL3A1. Expression of collagen (COL) proteins from groups 2 and 3 were also confirmed using immunocytochemistry. Western blot analysis showed very high expression levels of COL3A1 protein, and immunocytochemistry analysis showed the presence of extracellular COL3A1 in the W1TR cell line. The cells mainly responsible for the extracellular COL3A1 production are aldehyde dehydrogenase-1A1 (ALDH1A1) positive cells. All correlations between the types of cytostatic drugs and the expression levels of different COL genes were studied, and our results suggest that the expression of fibrillar collagens may be involved in the TOP and PAC resistance of the ovarian cancer cells. The expression pattern of COL genes provide a preliminary view into the role of these proteins in

  1. Genetic and physical localization of an anthracnose resistance gene in Medicago truncatula.

    Science.gov (United States)

    Yang, Shengming; Gao, Muqiang; Deshpande, Shweta; Lin, Shaoping; Roe, Bruce A; Zhu, Hongyan

    2007-12-01

    Anthracnose of alfalfa, caused by the fungal pathogen Colletotrichum trifolii, is one of the most destructive diseases of alfalfa worldwide. An improved understanding of the genetic and molecular mechanisms underlying host resistance will facilitate the development of resistant alfalfa cultivars, thus providing the most efficient and environmentally sound strategy to control alfalfa diseases. Unfortunately, cultivated alfalfa has an intractable genetic system because of its tetrasomic inheritance and out-crossing nature. Nevertheless, the model legume Medicago truncatula, a close relative of alfalfa, has the potential to serve as a surrogate to map and clone the counterparts of agronomically important genes in alfalfa -- particularly, disease resistance genes against economically important pathogens. Here we describe the high-resolution genetic and physical mapping of RCT1, a host resistance gene against C. trifolii race 1 in M. truncatula. We have delimited the RCT1 locus within a physical interval spanning approximately 200 kb located on the top of M. truncatula linkage group 4. RCT1 is part of a complex locus containing numerous genes homologous to previously characterized TIR-NBS-LRR type resistance genes. The result presented in this paper will facilitate the positional cloning of RCT1 in Medicago. PMID:17891371

  2. Metagenomic analysis reveals that bacteriophages are reservoirs of antibiotic resistance genes.

    Science.gov (United States)

    Subirats, Jéssica; Sànchez-Melsió, Alexandre; Borrego, Carles M; Balcázar, José Luis; Simonet, Pascal

    2016-08-01

    A metagenomics approach was applied to explore the presence of antibiotic resistance genes (ARGs) in bacteriophages from hospital wastewater. Metagenomic analysis showed that most phage sequences affiliated to the order Caudovirales, comprising the tailed phage families Podoviridae, Siphoviridae and Myoviridae. Moreover, the relative abundance of ARGs in the phage DNA fraction (0.26%) was higher than in the bacterial DNA fraction (0.18%). These differences were particularly evident for genes encoding ATP-binding cassette (ABC) and resistance-nodulation-cell division (RND) proteins, phosphotransferases, β-lactamases and plasmid-mediated quinolone resistance. Analysis of assembled contigs also revealed that blaOXA-10, blaOXA-58 and blaOXA-24 genes belonging to class D β-lactamases as well as a novel blaTEM (98.9% sequence similarity to the blaTEM-1 gene) belonging to class A β-lactamases were detected in a higher proportion in phage DNA. Although preliminary, these findings corroborate the role of bacteriophages as reservoirs of resistance genes and thus highlight the necessity to include them in future studies on the emergence and spread of antibiotic resistance in the environment. PMID:27312355

  3. Horizontal Transfer of Plasmid-Mediated Cephalosporin Resistance Genes in the Intestine of Houseflies (Musca domestica).

    Science.gov (United States)

    Fukuda, Akira; Usui, Masaru; Okubo, Torahiko; Tamura, Yutaka

    2016-06-01

    Houseflies are a mechanical vector for various types of bacteria, including antimicrobial-resistant bacteria (ARB). If the intestine of houseflies is a suitable site for the transfer of antimicrobial resistance genes (ARGs), houseflies could also serve as a biological vector for ARB. To clarify whether cephalosporin resistance genes are transferred efficiently in the housefly intestine, we compared with conjugation experiments in vivo (in the intestine) and in vitro by using Escherichia coli with eight combinations of four donor and two recipient strains harboring plasmid-mediated cephalosporin resistance genes and chromosomal-encoded rifampicin resistance genes, respectively. In the in vivo conjugation experiment, houseflies ingested donor strains for 6 hr and then recipient strains for 3 hr, and 24 hr later, the houseflies were surface sterilized and analyzed. In vitro conjugation experiments were conducted using the broth-mating method. In 3/8 combinations, the in vitro transfer frequency (Transconjugants/Donor) was ≥1.3 × 10(-4); the in vivo transfer rates of cephalosporin resistance genes ranged from 2.0 × 10(-4) to 5.7 × 10(-5). Moreover, cephalosporin resistance genes were transferred to other species of enteric bacteria of houseflies such as Achromobacter sp. and Pseudomonas fluorescens. These results suggest that houseflies are not only a mechanical vector for ARB but also a biological vector for the occurrence of new ARB through the horizontal transfer of ARGs in their intestine. PMID:26683492

  4. Developing transgenic maize (Zea mays L.) with insect resistance and glyphosate tolerance by fusion gene transformation

    Institute of Scientific and Technical Information of China (English)

    SUN He; LANG Zhi-hong; LU Wei; ZHANG Jie; HE Kang-lai; ZHU Li; LIN Min; HUANG Da-fang

    2015-01-01

    Using linker peptide LP4/2A for multiple gene transformation is considered to be an effective method to stack or pyramid several traits in plants. Bacil us thuringiensis (Bt) cry gene and epsps (5-enolpyruvylshikimate-3-phosphate synthase) gene are two important genes for culturing pest-resistant and glyphosate-tolerant crops. We used linker peptide LP4/2A to connect the Bt cry1Ah gene with the 2mG2-epsps gene and combined the wide-used manA gene as a selective marker to construct one coordinated expression vector cal ed p2EPUHLAGN. The expression vector was transferred into maize by Agrobacterium tumefaciens-mediated transformation, and 60 plants were obtained, 40%of which were positive transformants. Molecular detection demonstrated that the two genes in the fusion vector were expressed simultaneously and spliced correctly in translation processing;meanwhile bioassay detection proved the transgenic maize had preferable pest resistance and glyphosate tolerance. Therefore, linker peptide LP4/2A provided a simple and reliable strategy for producing gene stacking in maize and the result showed that the fusion gene transformation system of LP4/2A was feasible in monocot plants.

  5. Simple Method for Markerless Gene Deletion in Multidrug-Resistant Acinetobacter baumannii.

    Science.gov (United States)

    Oh, Man Hwan; Lee, Je Chul; Kim, Jungmin; Choi, Chul Hee; Han, Kyudong

    2015-05-15

    The traditional markerless gene deletion technique based on overlap extension PCR has been used for generating gene deletions in multidrug-resistant Acinetobacter baumannii. However, the method is time-consuming because it requires restriction digestion of the PCR products in DNA cloning and the construction of new vectors containing a suitable antibiotic resistance cassette for the selection of A. baumannii merodiploids. Moreover, the availability of restriction sites and the selection of recombinant bacteria harboring the desired chimeric plasmid are limited, making the construction of a chimeric plasmid more difficult. We describe a rapid and easy cloning method for markerless gene deletion in A. baumannii, which has no limitation in the availability of restriction sites and allows for easy selection of the clones carrying the desired chimeric plasmid. Notably, it is not necessary to construct new vectors in our method. This method utilizes direct cloning of blunt-end DNA fragments, in which upstream and downstream regions of the target gene are fused with an antibiotic resistance cassette via overlap extension PCR and are inserted into a blunt-end suicide vector developed for blunt-end cloning. Importantly, the antibiotic resistance cassette is placed outside the downstream region in order to enable easy selection of the recombinants carrying the desired plasmid, to eliminate the antibiotic resistance cassette via homologous recombination, and to avoid the necessity of constructing new vectors. This strategy was successfully applied to functional analysis of the genes associated with iron acquisition by A. baumannii ATCC 19606 and to ompA gene deletion in other A. baumannii strains. Consequently, the proposed method is invaluable for markerless gene deletion in multidrug-resistant A. baumannii. PMID:25746991

  6. A novel method to discover fluoroquinolone antibiotic resistance (qnr genes in fragmented nucleotide sequences

    Directory of Open Access Journals (Sweden)

    Boulund Fredrik

    2012-12-01

    Full Text Available Abstract Background Broad-spectrum fluoroquinolone antibiotics are central in modern health care and are used to treat and prevent a wide range of bacterial infections. The recently discovered qnr genes provide a mechanism of resistance with the potential to rapidly spread between bacteria using horizontal gene transfer. As for many antibiotic resistance genes present in pathogens today, qnr genes are hypothesized to originate from environmental bacteria. The vast amount of data generated by shotgun metagenomics can therefore be used to explore the diversity of qnr genes in more detail. Results In this paper we describe a new method to identify qnr genes in nucleotide sequence data. We show, using cross-validation, that the method has a high statistical power of correctly classifying sequences from novel classes of qnr genes, even for fragments as short as 100 nucleotides. Based on sequences from public repositories, the method was able to identify all previously reported plasmid-mediated qnr genes. In addition, several fragments from novel putative qnr genes were identified in metagenomes. The method was also able to annotate 39 chromosomal variants of which 11 have previously not been reported in literature. Conclusions The method described in this paper significantly improves the sensitivity and specificity of identification and annotation of qnr genes in nucleotide sequence data. The predicted novel putative qnr genes in the metagenomic data support the hypothesis of a large and uncharacterized diversity within this family of resistance genes in environmental bacterial communities. An implementation of the method is freely available at http://bioinformatics.math.chalmers.se/qnr/.

  7. Impact of major gene resistance management for sunflower on fitness of Plasmopara halstedii (downy mildew populations

    Directory of Open Access Journals (Sweden)

    Tourvieille de Labrouhe Denis

    2010-01-01

    Full Text Available Changes in virulence of Plasmopara halstedii populations under different major gene (Pl management strategies were studied over 5 years continuous cropping of one sunflower hybrid under netting cages. Strategies were monoculture of forms of the hybrid with 1 gene or with combinations of 2 genes, alternation of different genes, and mixtures of several different forms of the hybrid. Monoculture with single resistance genes led to loss of efficient resistance after 3 years, with high levels of disease and increased variability of the pathogen, whatever the Pl gene used. Combinations of genes, alternation and mixtures gave longer term control of downy mildew. In particular, combinations of resistance genes coming from both female and male parents of the hybrid (such that even impurities had a resistance gene gave the best control and least variation in pathogen virulence. Results are discussed with the object of durable control of downy mildew by all methods available.

  8. Resistance gene expression determines the in vitro chemosensitivity of non-small cell lung cancer (NSCLC

    Directory of Open Access Journals (Sweden)

    Amer Khalid

    2009-08-01

    Full Text Available Abstract Background NSCLC exhibits considerable heterogeneity in its sensitivity to chemotherapy and similar heterogeneity is noted in vitro in a variety of model systems. This study has tested the hypothesis that the molecular basis of the observed in vitro chemosensitivity of NSCLC lies within the known resistance mechanisms inherent to these patients' tumors. Methods The chemosensitivity of a series of 49 NSCLC tumors was assessed using the ATP-based tumor chemosensitivity assay (ATP-TCA and compared with quantitative expression of resistance genes measured by RT-PCR in a Taqman Array™ following extraction of RNA from formalin-fixed paraffin-embedded (FFPE tissue. Results There was considerable heterogeneity between tumors within the ATP-TCA, and while this showed no direct correlation with individual gene expression, there was strong correlation of multi-gene signatures for many of the single agents and combinations tested. For instance, docetaxel activity showed some dependence on the expression of drug pumps, while cisplatin activity showed some dependence on DNA repair enzyme expression. Activity of both drugs was influenced more strongly still by the expression of anti- and pro-apoptotic genes by the tumor for both docetaxel and cisplatin. The doublet combinations of cisplatin with gemcitabine and cisplatin with docetaxel showed gene expression signatures incorporating resistance mechanisms for both agents. Conclusion Genes predicted to be involved in known mechanisms drug sensitivity and resistance correlate well with in vitro chemosensitivity and may allow the definition of predictive signatures to guide individualized chemotherapy in lung cancer.

  9. Breeding and Identification of Insect-Resistant Rice by Transferring Two Insecticidal Genes, sbk and sck

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qi-jun; LI Cong; LIU Shao-kui; LAI Dong; QI Qing-ming; LU Chuan-gen

    2013-01-01

    The plasmid of pCDMARUBA-Hyg,which contained two insect-resistance genes,sbk (modified from Cry1A(c)) and sck (modified from CpTI),was transformed into an Agrobacterium EHA105 for infection of the calli of a super japonica rice Nanjing 45.Primarily,using polymerase chain reaction (PCR) detection with the primers of sbk and sck genes,42 positive transgenic plants that were marker-free and contained the two target genes were selected from 97 regenerated plants.Results of southern-blotting indicated that 23,11,5,2 and 1 plants had one,two,three,four and five copies of the transformed genes,respectively.Analysis of reverse transcription PCR (RT-PCR) and Bt gene testing paper showed that 28 T3 generation plants derived from four transgenic plants having a single copy were insect-resistant.Feeding experiment with rice stem borer revealed that the insect resistance was greatly increased with the larva mortality ranging from 94% to 100%.In addition,among the transgenic plants,three T3 transgenic plants possessed some desirable characteristics for breeding and production,such as plant height,seed-setting rate,1000-grain weight and larva mortality.The mechanism of insect resistance of Bt gene and its application in rice transgenic research were also briefly discussed.

  10. The barley stem rust-resistance gene Rpg1 is a novel disease-resistance gene with homology to receptor kinases

    OpenAIRE

    Brueggeman, R.; Rostoks, N.; Kudrna, D.; Kilian, A.; Han, F.; Chen, J; Druka, A.; Steffenson, B.; Kleinhofs, A

    2002-01-01

    Stem rust caused by Puccinia graminis f. sp. tritici was among the most devastating diseases of barley in the northern Great Plains of the U.S. and Canada before the deployment of the stem rust-resistance gene Rpg1 in 1942. Since then, Rpg1 has provided durable protection against stem rust losses in widely grown barley cultivars (cvs.). Extensive efforts to clone Rpg1 by synteny with rice provided excellent flanking markers but failed to yield the gene because it does ...

  11. Identification of Wheat Gene Sr35 that Confers Resistance to Ug99 Stem Rust Race Group

    OpenAIRE

    Saintenac, Cyrille; Zhang, Wenjun; Salcedo, Andres; Rouse, Matthew N.; Trick, Harold N.; Akhunov, Eduard; Dubcovsky, Jorge

    2013-01-01

    Wheat stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), is a devastating disease that can cause severe yield losses. A new Pgt race designated Ug99 has overcome most of the widely used resistance genes and is threatening major wheat production areas. Here we demonstrate that the Sr35 gene from Triticum monococcum is a coiled coil-nucleotide binding-leucine rich repeat gene that confers near-immunity to Ug99 and related races. This gene is absent in the A-genome diploid donor and in...

  12. Identification of wheat gene Sr35 that confers resistance to Ug99 stem rust race group

    OpenAIRE

    Saintenac, C; Zhang, W.; Salcedo, A.; Rouse, MN; Trick, HN; Akhunov, E.; Dubcovsky, J

    2013-01-01

    Wheat stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), is a devastating disease that can cause severe yield losses. A previously uncharacterized Pgt race, designated Ug99, has overcome most of the widely used resistance genes and is threatening major wheat production areas. Here, we demonstrate that the Sr35 gene from Triticum monococcum is a coiled-coil, nucleotide-binding, leucine-rich repeat gene that confers near immunity to Ug99 and related races. This gene is absent in the A...

  13. Erythromycin-resistant genes in group A β-haemolytic Streptococci in Chengdu, Southwestern China

    Directory of Open Access Journals (Sweden)

    W Zhou

    2014-01-01

    Full Text Available Context: The management of Group A β-haemolytic Streptococci (Streptococcus pyogenes or GAS infection include the use of penicillins, cephalosporins or macrolides for treatment. A general increase in macrolides resistance in GAS has been observed in recent years. Differences in rates of resistance to these agents have existed according to geographical location and investigators. Aims: To investigate the antibiotic pattern and erythromycin-resistant genes of GAS isolates associated with acute tonsillitis and scarlet fever in Chengdu, southwestern China. Settings and Design: To assess the macrolide resistance, phenotype, and genotypic characterization of GAS isolated from throat swabs of children suffering from different acute tonsillitis or scarlet fever between 2004 and 2011 in the city of Chengdu, located in the southwestern region of China. Materials and Methods: Minimal inhibitory concentration with seven antibiotics was performed on 127 GAS isolates. Resistance phenotypes of erythromycin-resistant GAS isolates were determined by the double-disk test. Their macrolide-resistant genes (mefA, ermB and ermTR were amplified by PCR. Results: A total of 98.4% (125/127 of the isolates exhibited resistance to erythromycin, clindamycin and tetracycline. All isolates were sensitive to penicillin G and cefotaxime. Moreover, 113 ermB-positive isolates demonstrating the cMLS phenotype of erythromycin resistance were predominant (90.4% and these isolates showed high-level resistance to both erythromycin and clindamycin (MIC 90 > 256 μg/ml; 12 (9.6% isolates demonstrating the MLS phenotype of erythromycin resistance carried the mefA gene, which showed low-level resistance to both erythromycin (MIC 90 = 8 μg/ml and clindamycin (MIC 90 = 0.5 μg/ml; and none of the isolates exhibited the M phenotype. Conclusions: The main phenotype is cMLS, and the ermB gene code is the main resistance mechanism against macrolides in GAS. Penicillin is the most beneficial

  14. The heterotrimeric G protein α subunit acts upstream of the small GTPase Rac in disease resistance of rice

    OpenAIRE

    Suharsono, Utut; Fujisawa, Yukiko; Kawasaki, Tsutomu; Iwasaki, Yukimoto; Satoh, Hikaru; Shimamoto, Ko

    2002-01-01

    We used rice dwarf1 (d1) mutants lacking a single-copy Gα gene and addressed Gα's role in disease resistance. d1 mutants exhibited a highly reduced hypersensitive response to infection by an avirulent race of rice blast. Activation of PR gene expression in the leaves of the mutants infected with rice blast was delayed for 24 h relative to the wild type. H2O2 production and PR gene expression induced by sphingolipid elicitors (SE) were strongly suppressed in d1 cell cultures. Expression of the...

  15. Creating mutations in plant resistance genes to parasitic weed

    International Nuclear Information System (INIS)

    The parasitic weed Orobanche crenata Forsk. (crenate broomrape, Scrophulariaceae) represents a major limiting factor for production of food legumes. Current management methods are not ideal. Indeed herbicide selectivity remains insufficient to control the parasite without decreasing crop yield significantly. Creating such mutant legumes, by mutagenesis has become an important tool to have resistance to broomrape. Gamma radiation from cobalt 60 source was selected as the mutagen to create such mutant plants. Seeds were exposed to the radioactive source to determine the proper dose of radioactivity for mutagenesis. A kill curve has been generated using doses exposures ranging from 0 to 200 Gy. The kill curve data was used to expose legumes seeds to enough radiation to create a survival rate of 50%. The surviving plants will be exposed to the parasitic plant Orobanche crenata and scored for resistance to infection. All phenotypic plant mutations will be logged for future reference. (author)

  16. Identification of genes associated with cisplatin resistance in human oral squamous cell carcinoma cell line

    Directory of Open Access Journals (Sweden)

    Zhang Ping

    2006-09-01

    Full Text Available Abstract Background Cisplatin is widely used for chemotherapy of head and neck squamous cell carcinoma. However, details of the molecular mechanism responsible for cisplatin resistance are still unclear. The aim of this study was to identify the expression of genes related to cisplatin resistance in oral squamous cell carcinoma cells. Methods A cisplatin-resistant cell line, Tca/cisplatin, was established from a cisplatin-sensitive cell line, Tca8113, which was derived from moderately-differentiated tongue squamous cell carcinoma. Global gene expression in this resistant cell line and its sensitive parent cell line was analyzed using Affymetrix HG-U95Av2 microarrays. Candidate genes involved in DNA repair, the MAP pathway and cell cycle regulation were chosen to validate the microarray analysis results. Cell cycle distribution and apoptosis following cisplatin exposure were also investigated. Results Cisplatin resistance in Tca/cisplatin cells was stable for two years in cisplatin-free culture medium. The IC50 for cisplatin in Tca/cisplatin was 6.5-fold higher than that in Tca8113. Microarray analysis identified 38 genes that were up-regulated and 25 that were down-regulated in this cell line. Some were novel candidates, while others are involved in well-characterized mechanisms that could be relevant to cisplatin resistance, such as RECQL for DNA repair and MAP2K6 in the MAP pathway; all the genes were further validated by Real-time PCR. The cell cycle-regulated genes CCND1 and CCND3 were involved in cisplatin resistance; 24-hour exposure to 10 μM cisplatin induced a marked S phase block in Tca/cisplatin cells but not in Tca8113 cells. Conclusion The Tca8113 cell line and its stable drug-resistant variant Tca/cisplatin provided a useful model for identifying candidate genes responsible for the mechanism of cisplatin resistance in oral squamous cell carcinoma. Our data provide a useful basis for screening candidate targets for early diagnosis

  17. Identification of genes associated with cisplatin resistance in human oral squamous cell carcinoma cell line

    International Nuclear Information System (INIS)

    Cisplatin is widely used for chemotherapy of head and neck squamous cell carcinoma. However, details of the molecular mechanism responsible for cisplatin resistance are still unclear. The aim of this study was to identify the expression of genes related to cisplatin resistance in oral squamous cell carcinoma cells. A cisplatin-resistant cell line, Tca/cisplatin, was established from a cisplatin-sensitive cell line, Tca8113, which was derived from moderately-differentiated tongue squamous cell carcinoma. Global gene expression in this resistant cell line and its sensitive parent cell line was analyzed using Affymetrix HG-U95Av2 microarrays. Candidate genes involved in DNA repair, the MAP pathway and cell cycle regulation were chosen to validate the microarray analysis results. Cell cycle distribution and apoptosis following cisplatin exposure were also investigated. Cisplatin resistance in Tca/cisplatin cells was stable for two years in cisplatin-free culture medium. The IC50 for cisplatin in Tca/cisplatin was 6.5-fold higher than that in Tca8113. Microarray analysis identified 38 genes that were up-regulated and 25 that were down-regulated in this cell line. Some were novel candidates, while others are involved in well-characterized mechanisms that could be relevant to cisplatin resistance, such as RECQL for DNA repair and MAP2K6 in the MAP pathway; all the genes were further validated by Real-time PCR. The cell cycle-regulated genes CCND1 and CCND3 were involved in cisplatin resistance; 24-hour exposure to 10 μM cisplatin induced a marked S phase block in Tca/cisplatin cells but not in Tca8113 cells. The Tca8113 cell line and its stable drug-resistant variant Tca/cisplatin provided a useful model for identifying candidate genes responsible for the mechanism of cisplatin resistance in oral squamous cell carcinoma. Our data provide a useful basis for screening candidate targets for early diagnosis and further intervention in cisplatin resistance

  18. Multidrug resistance 1 gene polymorphisms may determine Crohn's disease behavior in patients from Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Ana Teresa P. Carvalho

    2014-01-01

    Full Text Available OBJECTIVES: Conflicting data from studies on the potential role of multidrug resistance 1 gene polymorphisms in inflammatory bowel disease may result from the analysis of genetically and geographically distinct populations. Here, we investigated whether multidrug resistance 1 gene polymorphisms are associated with inflammatory bowel diseases in patients from Rio de Janeiro. METHODS: We analyzed 123 Crohn's disease patients and 83 ulcerative colitis patients to determine the presence of the multidrug resistance 1 gene polymorphisms C1236T, G2677T and C3435T. In particular, the genotype frequencies of Crohn's disease and ulcerative colitis patients were analyzed. Genotype-phenotype associations with major clinical characteristics were established, and estimated risks were calculated for the mutations. RESULTS: No significant difference was observed in the genotype frequencies of the multidrug resistance 1 G2677T/A and C3435T polymorphisms between Crohn's disease and ulcerative colitis patients. In contrast, the C1236T polymorphism was significantly more common in Crohn's disease than in ulcerative colitis (p = 0.047. A significant association was also found between the multidrug resistance 1 C3435T polymorphism and the stricturing form of Crohn's disease (OR: 4.13; p = 0.009, whereas no association was found with penetrating behavior (OR: 0.33; p = 0.094. In Crohn's disease, a positive association was also found between the C3435T polymorphism and corticosteroid resistance/refractoriness (OR: 4.14; p = 0.010. However, no significant association was found between multidrug resistance 1 gene polymorphisms and UC subphenotypic categories. CONCLUSION: The multidrug resistance 1 gene polymorphism C3435T is associated with the stricturing phenotype and an inappropriate response to therapy in Crohn's disease. This association with Crohn's disease may support additional pathogenic roles for the multidrug resistance 1 gene in regulating gut

  19. Dihydropteroate Synthase Gene Mutations in Pneumocystis and Sulfa Resistance

    OpenAIRE

    Haung, L.; Crothers, K. A.; Atzori, C.; Benfield, T.; Miller, R.; Rabodonirina, M; Helweg-Larsen, J.

    2004-01-01

    Pneumocystis pneumonia (PCP) remains a major cause of illness and death in HIV-infected persons. Sulfa drugs, trimethoprim-sulfamethoxazole (TMP-SMX) and dapsone are mainstays of PCP treatment and prophylaxis. While prophylaxis has reduced the incidence of PCP, its use has raised concerns about development of resistant organisms. The inability to culture human Pneumocystis, Pneumocystis jirovecii, in a standardized culture system prevents routine susceptibility testing and detection of drug r...

  20. Porcine E. coli: virulence-associated genes, resistance genes and adhesion and probiotic activity tested by a new screening method.

    Directory of Open Access Journals (Sweden)

    Peter Schierack

    Full Text Available We established an automated screening method to characterize adhesion of Escherichia coli to intestinal porcine epithelial cells (IPEC-J2 and their probiotic activity against infection by enteropathogenic E. coli (EPEC. 104 intestinal E. coli isolates from domestic pigs were tested by PCR for the occurrence of virulence-associated genes, genes coding for resistances to antimicrobial agents and metals, and for phylogenetic origin by PCR. Adhesion rates and probiotic activity were examined for correlation with the presence of these genes. Finally, data were compared with those from 93 E. coli isolates from wild boars. Isolates from domestic pigs carried a broad variety of all tested genes and showed great diversity in gene patterns. Adhesions varied with a maximum of 18.3 or 24.2 mean bacteria adherence per epithelial cell after 2 or 6 hours respectively. Most isolates from domestic pigs and wild boars showed low adherence, with no correlation between adhesion/probiotic activity and E. coli genes or gene clusters. The gene sfa/foc, encoding for a subunit of F1C fimbriae did show a positive correlative association with adherence and probiotic activity; however E. coli isolates from wild boars with the sfa/foc gene showed less adhesion and probiotic activity than E. coli with the sfa/foc gene isolated from domestic pigs after 6 hour incubation. In conclusion, screening porcine E. coli for virulence associated genes genes, adhesion to intestinal epithelial cells, and probiotic activity revealed a single important adhesion factor, several probiotic candidates, and showed important differences between E. coli of domestic pigs and wild boars.

  1. Co-occurrence of resistance genes to antibiotics, biocides and metals reveals novel insights into their co-selection potential

    OpenAIRE

    Pal, Chandan; Bengtsson-Palme, Johan; Kristiansson, Erik; Larsson, D. G. Joakim

    2015-01-01

    Background Antibacterial biocides and metals can co-select for antibiotic resistance when bacteria harbour resistance or tolerance genes towards both types of compounds. Despite numerous case studies, systematic and quantitative data on co-occurrence of such genes on plasmids and chromosomes is lacking, as is knowledge on environments and bacterial taxa that tend to carry resistance genes to such compounds. This effectively prevents identification of risk scenarios. Therefore, we aimed to ide...

  2. Characterization of Antibiotic Resistance Gene Abundance and Microbiota Composition in Feces of Organic and Conventional Pigs from Four EU Countries

    DEFF Research Database (Denmark)

    Gerzova, Lenka; Babak, Vladimir; Sedlar, Karel;

    2015-01-01

    to our expectations, there were no extensive differences between the abundance of tested antibiotic resistance genes in microbiota originating from organic or conventionally housed pigs within individual countries. There were also no differences in the microbiota composition of organic and conventional...... pigs. The only significant difference was the difference in the abundance of antibiotic resistance genes in the samples from different countries. Fecal microbiota in the samples originating from southern European countries (Italy, France) exhibited significantly higher antibiotic resistance gene...

  3. Selective killing of methotrexate-resistant cells carrying amplified dihydrofolate reductase genes

    International Nuclear Information System (INIS)

    A method for the selective killing of methotrexate (MTX)-resistant cells has been developed. The selection is based on the incorporation of tritiated deoxyuridine into the DNA of MTX-resistant cells but not normal MTX-sensitive cells in the presence of the drug. A Chinese hamster ovary cell mutant that overproduces dihydrofolate reductase was used as an example of a MTX-resistant cell line. In this system, a 10,000-fold enrichment for wild-type MTX-sensitive cells could be achieved after 24 hr of exposure to the drug combination. This selection technique was applied to the isolation of MTX-sensitive segregants from hybrid cells formed between the MTX-resistant mutant and wild-type cells. The loss of MTX resistance and dihydrofolate reductase overproduction was always accompanied by the loss of a homogeneously staining region on chromosome 2 of the resistant parent that contains the amplified genes specifying this enzyme. While this region is always lost, other parts of chromosome 2 are almost always retained, suggesting that deletion rather than chromosome loss underlies marker segregation in this case. When the selection was applied to the resistant mutant itself, no MTX-sensitive revertants were obtained among 10(5) cells screened, attesting to the stability of gene amplification in this clone. It is suggested that this combination of drugs may be useful for the elimination of MTX-resistant tumor cells that develop after MTX chemotherapy

  4. Codon-optimized antibiotic resistance gene improves efficiency of transient transformation in Frankia

    Indian Academy of Sciences (India)

    Ken-ichi Kucho; Kentaro Kakoi; Masatoshi Yamaura; Mari Iwashita; Mikiko Abe; Toshiki Uchiumi

    2013-11-01

    Frankia is a unique actinobacterium having abilities to fix atmospheric dinitrogen and to establish endosymbiosis with trees, but molecular bases underlying these interesting characteristics are poorly understood because of a lack of stable transformation system. Extremely high GC content of Frankia genome (> 70%) can be a hindrance to successful transformation. We generated a synthetic gentamicin resistance gene whose codon usage is optimized to Frankia (fgmR) and evaluated its usefulness as a selection marker using a transient transformation system. Success rate of transient transformation and cell growth in selective culture were significantly increased by use of fgmR instead of a native gentamicin resistance gene, suggesting that codon optimization improved translation efficiency of the marker gene and increased antibiotic resistance. Our result shows that similarity in codon usage pattern is an important factor to be taken into account when exogenous transgenes are expressed in Frankia cells.

  5. Evolving of mutant lines resistant to lodging, blast, and high yield in rice by induce mutation using gamma ray (physical mutagen)

    International Nuclear Information System (INIS)

    Induction of mutation for the purpose of producing variations in the gene pool has been used in recent years. In this experiment the locally adapted rice C V Moosa-Tarom was used as a high quality, tall and very lodging susceptible mutation material. The main purpose of this project was to evolve lodging resistant mutants of high yielding. The elite seeds of Moosa-Tarom variety after moisture regulation were exposed to 100, 200 and 300 Gy from Cobalt 60 source at the Nuclear Research Center. The irradiated seeds were sown in the field along with a comparable number of unirradiated seeds taken as control. All the first panicles of M1 plants were individually harvested and classified according to the dose rate as M2 material . Among M2 plant populations 203 plants that appeared from the agronomic point of view, along with a number of on unirradiated seeds, were selected and moved to the next generations. During subsequent screening for three generations (M 3-M 5) and due to lodging resistant, height and efficient factors of yield potential some mutant lines were harvested. From these lines in a preliminary and advanced randomized complete design agronomic traits, 13 promising lines were selected. From the experiment, line 43-3 were confirmed, which is characterized by lodging resistant and high yield. This line showed relative superiority and introduced to Rice Research Institute

  6. Mapping of Defense Response Gene Homologs and Their Association with Resistance Loci in Maize

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Defense response genes in higher plant species are involved in a variety of signal tranaduction pathways and biochemical reactions to counterattack invading pathogens. In this study, a total of 366 non-redundant defense response gene homologs (DRHs), Including 124 unigenes/expressed sequence tags, 226 tentative consensuses, and 16 DRH contigs have been identified by mining the Maize Genetics and Genomics and The Institute for Genomic Research maize databases using 35 essential defense response genes. Of 366 DRHs, 202 are mapped to 152 loci across ten maize chromosomes via both the genetic and in silico mapping approaches. The mapped DRHs seem to cluster together rather than be evenly distributed along the maize genome. Approximately half of these DHRs are located in regions harboring either major resistance genes or quantitative trait loci(QTL). Therefore, this comprehensive DRH linkage map will provide reference sequences to Identify either positional candidate genes for resistance genes and/or QTLs or to develop makers for fine-mapping and marker-assisted selection of resistance genes and/or QTLs.

  7. Specific myeloprotection via multidrug resistance 1 gene controlled by aminopeptidase N myeloid promoter

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the treatment of tumor patients introduction of multidrug resistance genes into hematopoietic cells has been reported as an approach for reducing myelotoxicity created by antitumor drugs. However, the nonspecific expression of the genes can also increase the chemoresistance of the tumor cells invaded into bone marrow, which influences seriously the effectiveness of chemotherapy. In this study, a new strategy is described for specific myeloprotection. The recombinant retroviral vector containing multidrug resistance 1 (MDR1) gene regulated by aminopeptidase N (APN) myeloid promoter was constructed and then introduced into myeloblastic cells KG1a and tumor cell line BEL7402. The specific transcript of MDR1 was detected in KG1a cells transduced with MDR1 gene and rhodamine 123 was effectively extruded by Pgp, the protein of MDR1 gene. The resistance elevated markedly by 10.6, 10.4, 11.2, 4.2 and 14.2 folds in MDR1 gene-transduced KG1a cells to chemotherapeutic drugs such as cochicine, VP-16, vincristine, doxorubi- cin and paclitaxel, respectively. In contrast, the chemoresistance had no significant changes in BEL7402 cells transduced with MDR1 gene. Expression of MDR1 directed by APN myeloid promoter resulted in myelospecific protection during the killing of tumor cells treated with antitumor drugs. The study would provide a new mean for circumventing myelosuppression of tumor patients undergoing chemotherapy.

  8. Identification of two new genes conferring resistance to Colletotrichum acutatum in Capsicum baccatum.

    Science.gov (United States)

    Mahasuk, P; Taylor, P W J; Mongkolporn, O

    2009-09-01

    Resistance to anthracnose, caused by Colletotrichum capsici and C. acutatum, was investigated in Capsicum baccatum PBC80 and PBC1422 and C. chinense PBC932. Mature green and ripe fruit were inoculated with 13 isolates of the two Colletotrichum species PBC80 contained the broadest spectrum of resistance to both Colletotrichum species because none of the isolates were able to infect the genotype. At both fruit maturity stages, PBC1422 was infected by only Colletotrichum acutatum. PBC932 at ripe fruit stage was infected by both C. capsici and C. acutatum, except for one isolate, 158ci, that did not infect PBC932. PBC932 at the mature green fruit stage was infected by only C. acutatum. An intraspecific cross between PBC80 and PBC1422 was developed to determine inheritance of resistance to C. acutatum. Anthracnose resistance was assessed at mature green and ripe fruit stages using 0 to 9 disease severity scores. Frequency distribution of the disease scores in the F(2) and BC(1) populations suggested a single recessive gene responsible for the resistance at mature green fruit stage and a single dominant gene for the resistance at ripe fruit stage. Linkage analysis between the two genes identified in both fruit maturity stages showed the genes to be independent. Based on phenotypic data, the two newly identified genes, co4 and Co5, from PBC80 appeared to be different loci from the co1 and co2 previously identified from PBC932 and will be valuable sources of resistance to anthracnose in chili breeding programs. PMID:19671013

  9. Detection of antibiotic resistance genes in wastewater treatment plant – molecular and classical approach

    Directory of Open Access Journals (Sweden)

    Ziembińska-Buczyńska Aleksandra

    2015-12-01

    Full Text Available Antibiotics are a group of substances potentially harmful to the environment. They can play a role in bacterial resistance transfer among pathogenic and non-pathogenic bacteria. In this experiment three representatives of medically important chemotherapeutics, confirmed to be present in high concentrations in wastewater treatment plants with HPLC analysis were used: erythromycin, sulfamethoxazole and trimethoprim. Erythromycin concentration in activated sludge was not higher than 20 ng L−1. N-acetylo-sulfamethoxazole concentration was 3349 ± 719 in winter and 2933 ± 429 ng L−1 in summer. Trimethoprim was present in wastewater at concentrations 400 ± 22 and 364 ± 60 ng L−1, respectively in winter and summer. Due to a wide variety of PCR-detectable resistance mechanisms towards these substances, the most common found in literature was chosen. For erythromycin: erm and mef genes, for sulfamethoxazole: sul1, sul2, sul3 genes, in the case of trimethoprim resistance dhfrA1 and dhfr14 were used in this study. The presence of resistance genes were analyzed in pure strains isolated from activated sludge and in the activated sludge sample itself. The research revealed that the value of minimal inhibitory concentration (MIC did not correspond with the expected presence of more than one resistance mechanisms. Most of the isolates possessed only one of the genes responsible for a particular chemotherapeutic resistance. It was confirmed that it is possible to monitor the presence of resistance genes directly in activated sludge using PCR. Due to the limited isolates number used in the experiment these results should be regarded as preliminary.

  10. Glycogen Metabolic Genes Are Involved in Trehalose-6-Phosphate Synthase-Mediated Regulation of Pathogenicity by the Rice Blast Fungus Magnaporthe oryzae

    OpenAIRE

    Badaruddin, Muhammad; Holcombe, Lucy J.; Richard A. Wilson; Wang, Zheng-Yi; Kershaw, Michael J.; Talbot, Nicholas J.

    2013-01-01

    Author Summary The fungus Magnaporthe oryzae causes a devastating disease of rice called blast. Each year, rice blast disease destroys almost a quarter of the potential global rice harvest. The fungus infects rice plants by elaborating a special infection structure called an appressorium, which physically breaks the tough outer cuticle of a rice leaf. Magnaporthe can develop appressoria in the absence of a nutrient source. We are therefore studying how the fungus utilizes energy stores in its...

  11. Characterization of broad-spectrum antibiotic resistance genes in wastewater treatment reactors through metagenomic approaches

    OpenAIRE

    Yang, Ying; 楊穎

    2014-01-01

    The spread of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have attracted great concerns worldwide. Wastewater treatment plants (WWTPs) are reservoirs of ARGs while wastewater/sludge treatment processes are considered as important means to control these emerging biological pollutants. However, the full profiles of ARGs in WWTPs or the removal efficiency of ARGs by wastewater/sludge treatment process was not well characterized yet. Thus, the major tasks in this st...

  12. Excretion of Antibiotic Resistance Genes by Dairy Calves Fed Milk Replacers with Varying Doses of Antibiotics

    OpenAIRE

    Thames, Callie H; Pruden, Amy; James, Robert E.; Ray, Partha P.; Knowlton, Katharine F.

    2012-01-01

    Elevated levels of antibiotic resistance genes (ARGs) in soil and water have been linked to livestock farms and in some cases feed antibiotics may select for antibiotic resistant gut microbiota. The purpose of this study was to examine the establishment of ARGs in the feces of calves receiving milk replacer containing no antibiotics versus subtherapeutic or therapeutic doses of tetracycline and neomycin. The effect of antibiotics on calf health was also of interest. Twenty-eight male and fema...

  13. Mutations in the 16S rRNA Genes of Helicobacter pylori Mediate Resistance to Tetracycline

    OpenAIRE

    Trieber, Catharine A.; Taylor, Diane E.

    2002-01-01

    Low-cost and rescue treatments for Helicobacter pylori infections involve combinations of several drugs including tetracycline. Resistance to tetracycline has recently emerged in H. pylori. The 16S rRNA gene sequences of two tetracycline-resistant clinical isolates (MIC = 64 μg/ml) were determined and compared to the consensus H. pylori 16S rRNA sequence. One isolate had four nucleotide substitutions, and the other had four substitutions and two deletions. Natural transformation with the 16S ...

  14. BLOOD FLOW RESTRICTED RESISTANCE TRAINING ATTENUATES MYOSTATIN GENE EXPRESSION IN A PATIENT WITH INCLUSION BODY MYOSITIS

    OpenAIRE

    2014-01-01

    Inclusion body myositis is a rare idiopathic inflammatory myopathy that produces extreme muscle weakness. Blood flow restricted resistance training has been shown to improve muscle strength and muscle hypertrophy in inclusion body myositis. Objective: The aim of this study was to evaluate the effects of a resistance training programme on the expression of genes related to myostatin (MSTN) signalling in one inclusion body myositis patient. Methods: A 65-year-old man with inclusion body myositi...

  15. Epigenetic modulation of the drug resistance genes MGMT, ABCB1 and ABCG2 in glioblastoma multiforme

    OpenAIRE

    Oberstadt, Moritz C.; Bien-Möller, Sandra; Weitmann, Kerstin; Herzog, Susann; Hentschel, Katharina; Rimmbach, Christian; Vogelgesang, Silke; Balz, Ellen; Fink, Matthias; Michael, Heike; Zeden, Jan-Philip; Bruckmüller, Henrike; Werk, Anneke N.; Cascorbi, Ingolf; Hoffmann, Wolfgang

    2013-01-01

    Background Resistance of the highly aggressive glioblastoma multiforme (GBM) to drug therapy is a major clinical problem resulting in a poor patient’s prognosis. Beside promoter methylation of the O 6 -methylguanine-DNA-methyltransferase (MGMT) gene the efflux transporters ABCB1 and ABCG2 have been suggested as pivotal factors contributing to drug resistance, but the methylation of ABCB1 and ABCG2 has not been assessed before in GBM. Methods Therefore, we evaluated the proportion and pr...

  16. Expression of Heterogenous Arsenic Resistance Genes in the Obligately Autotrophic Biomining Bacterium Thiobacillus ferrooxidans.

    Science.gov (United States)

    Peng, J B; Yan, W M; Bao, X Z

    1994-07-01

    Two arsenic-resistant plasmids were constructed and introduced into Thiobacillus ferrooxidans strains by conjugation. The plasmids with the replicon of wide-host-range plasmid RSF1010 were stable in T. ferrooxidans. The arsenic resistance genes originating from the heterotroph were expressed in this obligately autotrophic bacterium, but the promoter derived from T. ferrooxidans showed no special function in its original host. PMID:16349341

  17. Gene Expression Noise Facilitates Adaptation and Drug Resistance Independently of Mutation

    CERN Document Server

    Charlebois, Daniel A; Kaern, Mads

    2011-01-01

    We show that the effect of stress on the reproductive fitness of noisy cell populations can be modelled as first-passage time problem, and demonstrate that even relatively short-lived fluctuations in gene expression can ensure long-term survival of a drug-resistant population. We examine how this effect contributes to the development of drug-resistant cancer cells, and demonstrate that permanent immunity can arise independently of mutations.

  18. A Corynebacterium glutamicum gene conferring multidrug resistance in the heterologous host Escherichia coli.

    OpenAIRE

    Jäger, W; Kalinowski, J.; Pühler, A

    1997-01-01

    A chromosomal DNA fragment from the erythromycin-sensitive bacterium Corynebacterium glutamicum ATCC 13032 was shown to mediate resistance against erythromycin, tetracycline, puromycin, and bleomycin in Escherichia coli. Multicopy cloning of the fragment did not cause a resistance phenotype in C. glutamicum. The corresponding gene encodes a hydrophobic protein with 12 potential transmembrane-spanning ex-helical segments showing similarity to drug-H+ antiporters.

  19. Surveillance of multidrug resistance-associated genes in Acinetobacter baumannii isolates from elderly patients

    Directory of Open Access Journals (Sweden)

    Zhe DONG

    2012-03-01

    Full Text Available Objective To understand the status of multidrug resistance-associated genes carried by Acinetobacter baumannii isolates from elderly patients in our hospital in order to provide a basis for surveillance of drug-resistance and inflection control. Methods One hundred and twenty A. baumannii isolates were collected from elderly patients between 2008 and 2010. The mean age of the patients was 85 (65 to 95 years. Whonet 5.6 software was used to analyze the resistance rate of 16 antimicrobial agents. Polymerase chain reaction (PCR and the sequencing method were adopted to detect 10 kinds of resistance genes (blaOXA-51-like, blaOXA- 23-like, blaOXA-24-like, blaOXA-58-like, blaTEM, blaampC, armA, ISAba1, intI 1, and intI 2. The corresponding resistance gene profiling(RGP was analyzed and designated according to the status of resistance genes. Results The resistance rates to the remaining 15 kinds of antibiotics varied between 70.8% and 97.5%, with the exception of the sensitivity rate to polymyxin B by up to more than 90%. The positivity rates of blaOXA-51-like, blaOXA-23-like, blaOXA-58-like, blaTEM, blaampC, armA, ISAba1 and intI 1 were 100%, 81.7%, 0.8%, 10.8%, 91.7%, 81.7%, 86.7%, and 83.3% respectively. A total of 18 kinds of drug-resistant gene maps were found, but blaOXA-24-like and intI 2 were not detected. Among these gene maps, the rate of RGP1 (blaOXA-23-like+blaampC+armA+ISAba1+ intI 1 was as high as 60.8%. Conclusions A. baumannii isolates from elderly patients have a higher carrying rate of drug-resistant genes, resulting in severe multidrugresistant conditions. Therefore, full-time infection control personnel and clinical physicians should actively participate in the surveillance, prevention, and control of infections caused by A. baumannii in the elderly.

  20. Genetic mapping of two genes conferring resistance to powdery mildew in common bean (Phaseolus vulgaris L.).

    Science.gov (United States)

    Pérez-Vega, Elena; Trabanco, Noemí; Campa, Ana; Ferreira, Juan José

    2013-06-01

    Powdery mildew (PM) is a serious disease in many legume species, including the common bean (Phaseolus vulgaris L.). This study investigated the genetic control behind resistance reaction to PM in the bean genotype, Cornell 49242. The results revealed evidence supporting a qualitative mode of inheritance for resistance and the involvement of two independent genes in the resistance reaction. The location of these resistance genes was investigated in a linkage genetic map developed for the XC RIL population. Contingency tests revealed significant associations for 28 loci out of a total of 329 mapped loci. Fifteen were isolated or formed groups with less than two loci. The thirteen remaining loci were located at three regions in linkage groups Pv04, Pv09, and Pv11. The involvement of Pv09 was discarded due to the observed segregation in the subpopulation obtained from the Xana genotype for the loci located in this region. In contrast, the two subpopulations obtained from the Xana genotype for the BM161 locus, linked to the Co-3/9 anthracnose resistance gene (Pv04), and from the Xana genotype for the SCAReoli locus, linked to the Co-2 anthracnose resistance gene (Pv11), exhibited monogenic segregations, suggesting that both regions were involved in the genetic control of resistance. A genetic dissection was carried out to verify the involvement of both regions in the reaction to PM. Two resistant recombinant lines were selected, according to their genotypes, for the block of loci included in the Co-2 and Co-3/9 regions, and they were crossed with the susceptible parent, Xana. Linkage analysis in the respective F2 populations supported the hypothesis that a dominant gene (Pm1) was located in the linkage group Pv11 and another gene (Pm2) was located in the linkage group Pv04. This is the first report showing the localization of resistance genes against powdery mildew in Phaseolus vulgaris and the results offer the opportunity to increase the efficiency of breeding