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Sample records for bemisia tabaci genome

  1. The Bemisia tabaci functional genomic project

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci, the genome of the whitefly and its expression has not been investigated on a large scale. To address this general shortage of information, we have constructed several cDNA libraries from virulifurous and non-viruliferous whiteflies. A cDNA spotted microarray was constructed in parall...

  2. Complete mitochondrial DNA genome of Bemisia tabaci cryptic pest species complex Asia I (Hemiptera: Aleyrodidae).

    PubMed

    Tay, W T; Elfekih, S; Court, L; Gordon, K H; De Barro, P J

    2016-01-01

    The complete length of the Asia I member of the Bemisia tabaci species complex mitochondrial DNA genome (mitogenome) is 15,210 bp (GenBank accession no. KJ778614) with an A-T biased nucleotide composition (A: 32.7%; T: 42.4%; G: 14.0%; C: 10.8%). The mitogenome consists of 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNA (rRNAs) and a 467 bp putative control region which also includes the A+T rich repeat region. All PCGs have an ATA (n = 8) or ATG (n = 5) start codon. Gene synteny of Asia I is overall similar to B. afer and two other members of the B. tabaci species complex Mediterranean and New World 1, and contains the tRNA-Ser2 located between the Cytb and ND1 genes found in Mediterranean and New World 1, but which is absent in B. afer. The orientation of the tRNA-Arg in Asia I is on the "plus" strand and differed from Mediterranean which is found on the "minus" strand. The Asia I mitogenome size is currently ranked the second smallest after B. afer (14,968 bp) followed by New World 1 (15,322 bp) and Mediterranean (15,632 bp). PMID:24960562

  3. Estimation of the Whitefly Bemisia tabaci Genome Size Based on k-mer and Flow Cytometric Analyses.

    PubMed

    Chen, Wenbo; Hasegawa, Daniel K; Arumuganathan, Kathiravetpillai; Simmons, Alvin M; Wintermantel, William M; Fei, Zhangjun; Ling, Kai-Shu

    2015-01-01

    Whiteflies of the Bemisia tabaci (Hemiptera: Aleyrodidae) cryptic species complex are among the most important agricultural insect pests in the world. These phloem-feeding insects can colonize over 1000 species of plants worldwide and inflict severe economic losses to crops, mainly through the transmission of pathogenic viruses. Surprisingly, there is very little genomic information about whiteflies. As a starting point to genome sequencing, we report a new estimation of the genome size of the B. tabaci B biotype or Middle East-Asia Minor 1 (MEAM1) population. Using an isogenic whitefly colony with over 6500 haploid male individuals for genomic DNA, three paired-end genomic libraries with insert sizes of ~300 bp, 500 bp and 1 Kb were constructed and sequenced on an Illumina HiSeq 2500 system. A total of ~50 billion base pairs of sequences were obtained from each library. K-mer analysis using these sequences revealed that the genome size of the whitefly was ~682.3 Mb. In addition, the flow cytometric analysis estimated the haploid genome size of the whitefly to be ~690 Mb. Considering the congruency between both estimation methods, we predict the haploid genome size of B. tabaci MEAM1 to be ~680-690 Mb. Our data provide a baseline for ongoing efforts to assemble and annotate the B. tabaci genome. PMID:26463411

  4. Estimation of the Whitefly Bemisia tabaci Genome Size Based on k-mer and Flow Cytometric Analyses

    PubMed Central

    Chen, Wenbo; Hasegawa, Daniel K.; Arumuganathan, Kathiravetpillai; Simmons, Alvin M.; Wintermantel, William M.; Fei, Zhangjun; Ling, Kai-Shu

    2015-01-01

    Whiteflies of the Bemisia tabaci (Hemiptera: Aleyrodidae) cryptic species complex are among the most important agricultural insect pests in the world. These phloem-feeding insects can colonize over 1000 species of plants worldwide and inflict severe economic losses to crops, mainly through the transmission of pathogenic viruses. Surprisingly, there is very little genomic information about whiteflies. As a starting point to genome sequencing, we report a new estimation of the genome size of the B. tabaci B biotype or Middle East-Asia Minor 1 (MEAM1) population. Using an isogenic whitefly colony with over 6500 haploid male individuals for genomic DNA, three paired-end genomic libraries with insert sizes of ~300 bp, 500 bp and 1 Kb were constructed and sequenced on an Illumina HiSeq 2500 system. A total of ~50 billion base pairs of sequences were obtained from each library. K-mer analysis using these sequences revealed that the genome size of the whitefly was ~682.3 Mb. In addition, the flow cytometric analysis estimated the haploid genome size of the whitefly to be ~690 Mb. Considering the congruency between both estimation methods, we predict the haploid genome size of B. tabaci MEAM1 to be ~680–690 Mb. Our data provide a baseline for ongoing efforts to assemble and annotate the B. tabaci genome. PMID:26463411

  5. Flow cytometry and K-mer analysis estimates of the genome sizes of Bemisia tabaci B and Q (Hemiptera: Aleyrodidae)

    PubMed Central

    Guo, Li T.; Wang, Shao L.; Wu, Qing J.; Zhou, Xu G.; Xie, Wen; Zhang, You J.

    2015-01-01

    The genome sizes of the B- and Q-types of the whitefly Bemisia tabaci (Gennnadius) were estimated using flow cytometry (Drosophila melanogaster as the DNA reference standard and propidium iodide (PI) as the fluorochrome) and k-mer analysis. For flow cytometry, the mean nuclear DNA content was 0.686 pg for B-type males, 1.392 pg for B-type females, 0.680 pg for Q-type males, and 1.306 pg for Q-type females. Based on the relationship between DNA content and genome size (1 pg DNA = 980 Mbp), the haploid genome size of B. tabaci ranged from 640 to 682 Mbp. For k-mer analysis, genome size of B-type by two methods were consistent highly, but the k-mer depth distribution graph of Q-type was not enough perfect and the genome size was estimated about 60 M larger than its flow cytometry result. These results corroborate previous reports of genome size based on karyotype analysis and chromosome counting. However, these estimates differ from previous flow cytometry estimates, probably because of differences in the DNA reference standard and dyeing time, which were superior in the current study. For Q-type genome size difference by two method, some discussion were also stated, and all these results represent a useful foundation for B. tabaci genomics research. PMID:26042041

  6. Estimation of the whitefly Bemisia tabaci genome size based on k-mer and flow cytometry analyses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whiteflies, Bemisia tabaci (Hemiptera: Aleyrodidae), are one of the most important agricultural insect pests in the world. These phloem-feeding insects can colonize over 500 crop plants worldwide and inflict severe economic losses, mainly through the transmission of pathogenic viruses. Surprisingl...

  7. Genome sequencing and analysis of the whitefly (Bemisia tabaci) MEAM1, one of the most important vectors for plant viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Among whiteflies, the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex is particularly important because of its ability to transmit hundreds of plant viruses, resulting in the loss of billions of U.S. dollars on agronomically important crops such as tomato, cucurbits, cassava, and cotton worl...

  8. Sequencing and comparison of the Rickettsia genomes from the whitefly Bemisia tabaci Middle East Asia Minor I.

    PubMed

    Zhu, Dan-Tong; Xia, Wen-Qiang; Rao, Qiong; Liu, Shu-Sheng; Ghanim, Murad; Wang, Xiao-Wei

    2016-08-01

    The whitefly, Bemisia tabaci, harbors the primary symbiont 'Candidatus Portiera aleyrodidarum' and a variety of secondary symbionts. Among these secondary symbionts, Rickettsia is the only one that can be detected both inside and outside the bacteriomes. Infection with Rickettsia has been reported to influence several aspects of the whitefly biology, such as fitness, sex ratio, virus transmission and resistance to pesticides. However, mechanisms underlying these differences remain unclear, largely due to the lack of genomic information of Rickettsia. In this study, we sequenced the genome of two Rickettsia strains isolated from the Middle East Asia Minor 1 (MEAM1) species of the B. tabaci complex in China and Israel. Both Rickettsia genomes were of high coding density and AT-rich, containing more than 1000 coding sequences, much larger than that of the coexisted primary symbiont, Portiera. Moreover, the two Rickettsia strains isolated from China and Israel shared most of the genes with 100% identity and only nine genes showed sequence differences. The phylogenetic analysis using orthologs shared in the genus, inferred the proximity of Rickettsia in MEAM1 and Rickettsia bellii. Functional analysis revealed that Rickettsia was unable to synthesize amino acids required for complementing the whitefly nutrition. Besides, a type IV secretion system and a number of virulence-related genes were detected in the Rickettsia genome. The presence of virulence-related genes might benefit the symbiotic life of the bacteria, and hint on potential effects of Rickettsia on whiteflies. The genome sequences of Rickettsia provided a basis for further understanding the function of Rickettsia in whiteflies. PMID:27273750

  9. Impact of insecticide residue on Bemisia tabaci (B-Biotype)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2005, the Q-biotype of Bemisia tabaci was identified in the United States. This find and increased problems with management of the B-biotype of Bemisia tabaci have resulted in a national effort to develop a comprehensive management plan for whiteflies on ornamental crops. The objective of the fol...

  10. Whitefly (Bemisia tabaci) genome project: analysis of sequenced clones from egg, instar, and adult (viruliferous and non-viruliferous) cDNA libraries

    PubMed Central

    Leshkowitz, Dena; Gazit, Shirley; Reuveni, Eli; Ghanim, Murad; Czosnek, Henryk; McKenzie, Cindy; Shatters, Robert L; Brown, Judith K

    2006-01-01

    Background The past three decades have witnessed a dramatic increase in interest in the whitefly Bemisia tabaci, owing to its nature as a taxonomically cryptic species, the damage it causes to a large number of herbaceous plants because of its specialized feeding in the phloem, and to its ability to serve as a vector of plant viruses. Among the most important plant viruses to be transmitted by B. tabaci are those in the genus Begomovirus (family, Geminiviridae). Surprisingly, little is known about the genome of this whitefly. The haploid genome size for male B. tabaci has been estimated to be approximately one billion bp by flow cytometry analysis, about five times the size of the fruitfly Drosophila melanogaster. The genes involved in whitefly development, in host range plasticity, and in begomovirus vector specificity and competency, are unknown. Results To address this general shortage of genomic sequence information, we have constructed three cDNA libraries from non-viruliferous whiteflies (eggs, immature instars, and adults) and two from adult insects that fed on tomato plants infected by two geminiviruses: Tomato yellow leaf curl virus (TYLCV) and Tomato mottle virus (ToMoV). In total, the sequence of 18,976 clones was determined. After quality control, and removal of 5,542 clones of mitochondrial origin 9,110 sequences remained which included 3,843 singletons and 1,017 contigs. Comparisons with public databases indicated that the libraries contained genes involved in cellular and developmental processes. In addition, approximately 1,000 bases aligned with the genome of the B. tabaci endosymbiotic bacterium Candidatus Portiera aleyrodidarum, originating primarily from the egg and instar libraries. Apart from the mitochondrial sequences, the longest and most abundant sequence encodes vitellogenin, which originated from whitefly adult libraries, indicating that much of the gene expression in this insect is directed toward the production of eggs. Conclusion This

  11. The Genome of Cardinium cBtQ1 Provides Insights into Genome Reduction, Symbiont Motility, and Its Settlement in Bemisia tabaci

    PubMed Central

    Santos-Garcia, Diego; Rollat-Farnier, Pierre-Antoine; Beitia, Francisco; Zchori-Fein, Einat; Vavre, Fabrice; Mouton, Laurence; Moya, Andrés; Latorre, Amparo; Silva, Francisco J.

    2014-01-01

    Many insects harbor inherited bacterial endosymbionts. Although some of them are not strictly essential and are considered facultative, they can be a key to host survival under specific environmental conditions, such as parasitoid attacks, climate changes, or insecticide pressures. The whitefly Bemisia tabaci is at the top of the list of organisms inflicting agricultural damage and outbreaks, and changes in its distribution may be associated to global warming. In this work, we have sequenced and analyzed the genome of Cardinium cBtQ1, a facultative bacterial endosymbiont of B. tabaci and propose that it belongs to a new taxonomic family, which also includes Candidatus Amoebophilus asiaticus and Cardinium cEper1, endosymbionts of amoeba and wasps, respectively. Reconstruction of their last common ancestors’ gene contents revealed an initial massive gene loss from the free-living ancestor. This was followed in Cardinium by smaller losses, associated with settlement in arthropods. Some of these losses, affecting cofactor and amino acid biosynthetic encoding genes, took place in Cardinium cBtQ1 after its divergence from the Cardinium cEper1 lineage and were related to its settlement in the whitefly and its endosymbionts. Furthermore, the Cardinium cBtQ1 genome displays a large proportion of transposable elements, which have recently inactivated genes and produced chromosomal rearrangements. The genome also contains a chromosomal duplication and a multicopy plasmid, which harbors several genes putatively associated with gliding motility, as well as two other genes encoding proteins with potential insecticidal activity. As gene amplification is very rare in endosymbionts, an important function of these genes cannot be ruled out. PMID:24723729

  12. The Bemisia tabaci (Hemiptera: Aleyrodidae) as a pest in Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) has many common names including sweetpotato whitefly, silverleaf whitefly, tobacco whitefly, tomato whitefly, and cassava whitefly. It is an important global pest of numerous field and greenhouse agricultural crops. It damages plants from its fee...

  13. Natural Enemies of Bemisia tabaci: Predators and Parasitiods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a worldwide problem in numerous agricultural crops. The known parasitoids of B. tabaci include 43 species of Encarsia, 19 Eretmocerus, and a few other genera. Some of these species are more cosmopolitan than others. Work has been conducted ...

  14. Ecological determinants of resistance to insecticides in Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insecticide resistance is a critical issue in pest management and has often been implicated as the primary cause of outbreaks of the global whitefly pest Bemisia tabaci Gennadius. Resistance to all modes of action used commonly against B. tabaci has been documented in various locations throughout t...

  15. The Importance of Maintaining Protected Zone Status against Bemisia tabaci.

    PubMed

    Cuthbertson, Andrew G S; Vänninen, Irene

    2015-01-01

    The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of economically important crops worldwide. Both the United Kingdom (UK) and Finland hold Protected Zone status against this invasive pest. As a result B. tabaci entering these countries on plants and plant produce is subjected to a policy of eradication. The impact of B. tabaci entering, and becoming established, is that it is an effective vector of many plant viruses that are not currently found in the protected zones. The Mediterranean species is the most commonly intercepted species of B. tabaci entering both the UK and Finland. The implications of maintaining Protected Zone status are discussed. PMID:26463194

  16. The Importance of Maintaining Protected Zone Status against Bemisia tabaci

    PubMed Central

    Cuthbertson, Andrew G. S.; Vänninen, Irene

    2015-01-01

    The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of economically important crops worldwide. Both the United Kingdom (UK) and Finland hold Protected Zone status against this invasive pest. As a result B. tabaci entering these countries on plants and plant produce is subjected to a policy of eradication. The impact of B. tabaci entering, and becoming established, is that it is an effective vector of many plant viruses that are not currently found in the protected zones. The Mediterranean species is the most commonly intercepted species of B. tabaci entering both the UK and Finland. The implications of maintaining Protected Zone status are discussed. PMID:26463194

  17. [Insecticide resistance of Bemisia tabaci field populations].

    PubMed

    He, Yu-Xian; Weng, Qi-Yong; Huang, Jian; Liang, Zhi-Sheng; Lin, Gui-Jun; Wu, Dong-Dong

    2007-07-01

    Resistance to 13 insecticides in field populations of Bemisia tabaci from six regions (Fuzhou, Zhangzhou, Longyan, Sanming, Nanping, Ningde) of Fujian Province, China was monitored by adult leaf-dipping bioassay. Compared with the susceptible SUD-S strain, all the six field populations exhibited high levels of resistance to lambda-cyhalothrin (838.38-2460.52 fold), fenpropathrin (244.64-834.29 fold), cypermethrin (116.02-266.35 fold), deltamethrin (81.75-124.18 fold), acephate (425.18-875.56 fold) and chlorpyrifos (54.53-78.43 fold), moderate levels of resistance to dimethoate (14.16-17.66 fold), low to moderate levels of resistance to dichlorvos (6.23-11.25 fold) and low levels of resistance to methomyl (4.07-5.66 fold), respectively. Among these six field-collected populations, only Zhangzhou population had moderate resistance to imidacloprid, acetamiprid and thiamethoxam (23.08 fold, 10.32 fold and 24.60 fold, respectively). All field strains tested displayed no resistance to abamectin. PMID:17886654

  18. Life History of Delphastus Catalinae: a predator of Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immature development and reproductive life history of Delphastus catalinae (Coleoptera: Coccinellidae) feeding on Bemisia tabaci (Homoptera: Aleyrodidae) immatures was studied at three constant temperatures: 22, 26 and 30 ºC. Development rates and lower temperature threshold temperatures (T0) were e...

  19. Bemisia tabaci (Homoptera: Aleyrodidae) and Indian cassava mosaic virus transmission

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci (Gennadius) adults from colonies reared on cassava or sweet potato plants were studied to determine their ability to transmit Indian cassava mosaic virus (ICMV) (Geminiviridae: Begomovirus) from cassava to cassava. Virus acquisition access (feeding) periods (AAP) of 48 h on ICMV-infec...

  20. Inheritance of Resistance to Whitefly Bemisia tabaci (Gennadius) in Soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whitefly Bemisia tabaci (Gennadius) is a common economic pest in a great number of crops throughout the world. In soybean, they can be vectors of viruses, e.g. soybean crinkle mosaic and soybean dwarf mosaic. Resistance to whitefly has been identified in soybean, however, whitefly resistance genes h...

  1. Population Dynamics, Demography, Dispersal and Spread of Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci is an insect pest of global significance. It attacks multiple crops and causes damage through feeding and transmission of plant viruses. This review focuses on the current state of knowledge of the population dynamics, demography and dispersal of this important pest. Sampling metho...

  2. Baseline susceptibility of Bemisia tabaci B biotype (Hemiptera: Aleyrodidae) populations from California and Arizona to spiromesifen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Susceptibility to spiromesifen, a tetronic acid derivative, was determined for three imidacloprid-resistant strains and 12 geographically discrete natural populations of Bemisia tabaci (Gennadius) (= Bemisia argentifolii Bellows and Perring) from California and Arizona by laboratory bioassays. Newl...

  3. Extensive survey of Bemisia tabaci (Hemiptera: Aleyrodidae) biotypes in Florida investigating the Q invasion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    After the discovery of the Bemisia tabaci Q biotype in the U.S., there was an urgent need to determine its spread. As part of a coordinated whole country survey, an extensive survey of Bemisia tabaci biotypes was conducted in Florida through cooperation with growers and state agencies. This was done...

  4. Distribution of Bemisia tabaci Genetic Groups in India.

    PubMed

    Ellango, R; Singh, Shalini Thakur; Rana, Vipin Singh; Gayatri Priya, N; Raina, Harpreet; Chaubey, Rahul; Naveen, N C; Mahmood, Riaz; Ramamurthy, V V; Asokan, R; Rajagopal, R

    2015-08-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a phloem-feeding, economically important pest of crops worldwide. In addition to direct damage, it also vectors a number of plant viruses belonging to the family Geminiviridae. Its populations differ biologically with respect to insecticide resistance, virus transmission and host range. Therefore, understanding genetic variation among populations is important for management. We sequenced 850 bp of the mitochondrial COI (mtCOI) gene from B. tabaci populations surveyed across India. BLAST analysis of the mtCOI sequences generated in this study with sequences from the mtCOI dataset showed the presence of one invasive group, MEAM1, and eight other groups of B. tabaci in India. mtCOI sequence analyses showed the presence of Asia I, Asia I-India, Asia II-1, Asia II-5, Asia II-7, Asia II-8, and Asia II-11 genetic groups. We also found China-3 in a field in Birbhum district, West Bengal, India, suggesting a role of anthropogenic activities in the distribution of B. tabaci. Interestingly, more than one genetic group was found coexisting in the same field. PMID:26314072

  5. Comparative susceptibility of bemisia tabaci to imidacloprid in field- and laboratory-based bioassays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci biotype B is a resistance-prone pest of protected and open agriculture. Systemic uptake bioassays used in resistance monitoring programs have provided important information on susceptibility to neonicotinoid insecticides, but have remained decoupled from field performance. Simultaneou...

  6. Bemisia tabaci (Aleyrodidae: Homoptera) nymphal feeding in cotton (Gossypium hirsutum) leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We used brightfield electron microscopy (BEM), differential interference contrast microscopy (DICM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and confocal laser scanning microscopy (CLSM) to investigate the stylet pathways of Bemisia tabaci during nymphal feeding b...

  7. First report of the Q biotype of Bemisia tabaci (Gennadius) in Guatemala

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci (Gennadius) adults were collected from poinsettia plants at a commercial greenhouse, bean and zucchini vegetable fields, weed species, and wild ornamentals species in selected locations in Guatemala. Both adult and immature whiteflies were observed on infested poinsettias. Whiteflies ...

  8. Monitoring changes in bemisia tabaci susceptibility to neonicotinoid insecticides in Arizona and California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory bioassays were carried out on field-collected and laboratory strains of Bemisia tabaci to evaluate relative toxicities of four neonicotinoid insecticides: acetamiprid, dinotefuran, imidacloprid and thiamethoxam. Susceptibility to all four neonicotinoids in leaf-uptake bioassays varied co...

  9. Distribution of Bemisia tabaci (Hemiptera: Aleyrodidae) biotypes in Florida - Investigating the "Q" invasion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    After the 2004 discovery of the Bemisia tabaci Q biotype in the U.S., there was an urgent need to determine its distribution. As part of a coordinated country-wide effort, an extensive survey of B. tabaci biotypes was conducted in Florida, with the cooperation of growers and state agencies, to moni...

  10. Impact of Relative Humidity on Adult Weight and Size of Bemisia tabaci (Gennadius)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci (Gennadius), sweetpotato whitefly, is a serious global sap-sucking insect pest that carries many infectious diseases when feeding on many types of crops. A study was conducted to determine the influence of relative humidity (RH) on body size and mass of B. tabaci. The B-biotype B. t...

  11. Sweet Potato Leaf Curl Virus: Efficiency of Acquisition, Retention and Transmission by Bemisia tabaci (Hemiptera: Aleyrodidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a global pest which damages plants directly by feeding on leaves. Moreover, the problem is compounded because B. tabaci also vectors numerous plant viruses, including Begomoviruses (Geminiviridae) such as the Sweet Potato Leaf Curl Virus (SPL...

  12. BAYESIAN PHYLOGENETIC ANALYSIS OF MITOCHONDRIAL COI DNA SEQUENCE FROM GLOBAL SAMPLES OF BEMISIA TABACI (HEMIPTERA: ALEYRODIDAE)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci (Gen.)(Hemiptera: Aleyrodidae) is one of the most devastating agricultural pests worldwide and affects the yield of a broad range of agricultural, fiber, vegetable and ornamental crops. Global phylogenetic relationships of the major races of B. tabaci remain unresolved thus a Bayesi...

  13. Oogenesis in the Bemisia tabaci MEAM1 species complex.

    PubMed

    Guo, Jian-Yang; Wan, Fang-Hao; Ye, Gong-Yin

    2016-04-01

    The whitefly Bemisia tabaci MEAM1 species complex has invaded several parts of the world in the past 30 years and replaced native whitefly populations in the invaded regions, including certain areas of China. One of the possible reasons for the invasion is that MEAM1 whiteflies are more fecund than native species. However, the factors that affect the reproduction of the B. tabaci cryptic species are not clearly known. The regulation of oogenesis is thought to be one of the essential processes for egg formation and ovary development and could affect its population dynamics. In this study, the ovariole structure and oogenesis of the MEAM1 species complex was examined using light and transmission electron microscopy. Telotrophic ovarioles were observed in the MEAM1 species complex. Each ovariole had two well defined regions: the tropharium and the vitellarium. The tropharium always had more than ten trophocytes. The development of a single oocyte in the vitellarium has four phases: oocyte formation, previtellogenesis, vitellogenesis and choriogenesis. Two arrested oocytes, follicular cells and uncompleted oocytes were separated from the tropharium by microtubule and microfilaments. Early previtellogenesis oocytes absorbed nutrients and endosymbiont bacteria through a nutritive cord. However, the vitellogenesis of oocytes transmitted Vg through both the nutritive cord and the space between follicular cells. Each mature oocyte with deposited yolk proteins had only one bacteriocyte and was surrounded by a single layer of follicular cells. The oogenesis in the B. tabaci MEAM1 species complex concluded with the differentiation of oocytes, the transport of yolk and endosymbionts as well as the development and maturation of oocytes. This result provides important information that further defines the regulation of oogenesis in the B. tabaci complex. PMID:26826802

  14. Glucosinolate Desulfation by the Phloem-Feeding Insect Bemisia tabaci.

    PubMed

    Malka, Osnat; Shekhov, Anton; Reichelt, Michael; Gershenzon, Jonathan; Vassão, Daniel Giddings; Morin, Shai

    2016-03-01

    Glucosinolates are plant secondary defense metabolites confined nearly exclusively to the order Brassicales. Upon tissue rupture, glucosinolates are hydrolyzed to various bioactive breakdown products by the endogenous plant enzyme myrosinase. As the feeding of chewing insect herbivores is associated with plant tissue damage, these insects have developed several independent strategies for coping with the glucosinolate-myrosinase defense system. On the other hand, our knowledge of how phloem-feeding insects interact with the glucosinolate-myrosinase system is much more limited. In fact, phloem feeders might avoid contact with myrosinase altogether so their susceptibility to intoxication by glucosinolate hydrolysis products is unclear. Previous studies utilizing Arabidopsis thaliana plants accumulating high levels of aliphatic- or indolic-glucosinolates indicated that both glucosinolate groups have moderate negative effects on the reproductive performance of Bemisia tabaci, a generalist phloem-feeding insect. To get a deeper understanding of the interaction between B. tabaci and glucosinolate-defended plants, adults were allowed to feed on artificial diet containing intact glucosinolates or on Brussels sprout and A. thaliana plants, and their honeydew was analyzed for the presence of possible metabolites. We found that B. tabaci is capable of cleaving off the sulfate group of intact glucosinolates, producing desulfoglucosinolates that cannot be activated by myrosinases, a mechanism described to date only in several chewing insect herbivores. The presence of desulfated glucosinolates in the honeydew of a generalist phloem-feeder may indicate the necessity to detoxify glucosinolates, likely due to some level of cellular damage during feeding, which results in glucosinolate activation, or as a mechanism to circumvent the non-enzymatic breakdown of indolic glucosinolates. PMID:26961756

  15. Sequence variation of Bemisia tabaci Chemosensory Protein 2 in cryptic species B and Q: New DNA markers for whitefly recognition.

    PubMed

    Liu, Guo-Xia; Ma, Hong-Mei; Xie, Hong-Yan; Xuan, Ning; Picimbon, Jean-François

    2016-01-15

    Bemisia tabaci Gennadius biotypes B and Q are two of the most important worldwide agricultural insect pests. Genomic sequences of Type-2 B. tabaci chemosensory protein (BtabCSP2) were cloned and sequenced in B and Q biotypes, revealing key biotype-specific variations in the intron sequence. A Q260 sequence was found specifically in Q-BtabCSP2 and Cucumis melo LN692399, suggesting ancestral horizontal transfer of gene between the insect and the plant through bacteria. A cleaved amplified polymorphic sequences (CAPS) method was then developed to differentiate B and Q based on the sequence variation in exon of BtabCSP2 gene. The performances of CSP2-based CAPS for whitefly recognition were assessed using B. tabaci field collections from Shandong Province (P.R. China). Our SacII based CAPS method led to the same result compared to mitochondrial cytochrome oxidase-based CAPS method in the field collections. We therefore propose an explanation for CSP origin and a new rapid simple molecular method based on genomic DNA and chemosensory gene to differentiate accurately the B and Q whiteflies of the Bemisia complex around the world. PMID:26481237

  16. Toxicity of selected insecticides to a strain of Bemisia tabaci Biotype Q from Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius), (Homoptera: Aleyrodidae), is an important pest in many cropping systems throughout the world. Currently two biotypes of this species are present in Florida, the B-biotype discovered in Florida in 1986 and the recently introduced Q-biotype. B-biot...

  17. Evaluating companion plants and plant products to control sweetpotato whitefly, Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major insect pest of vegetables and horticultural crops in the southeast US is the sweetpotato whitefly, Bemisia tabaci. We are evaluating the effect of companion/ repellent plants and products such as plant oils against this whitefly pest. In laboratory tests, whiteflies were released in potted...

  18. Survey of Reproductive Host Plants of Bemisia tabaci (Hemiptera: Aleyrodidae) in Egypt, Including New Host Records

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host plants can affect the population dynamics of the sweetpotato whitefly, Bemisia tabaci (Gennadius), and the plants can be potential sources of numerous whitefly-vectored viruses. This important pest attacks a wide range of agricultural plants, and feed on an extensive number of feral species of...

  19. Looking for Bemisia tabaci biotype Q in Florida: Results of Biotype sampling from 2005-2006

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In March 2005, Arizona scientists identified the Q biotype of Bemisia tabaci from Poinsettia plants that originated from California. Soon after, Florida began forming a plan for surveying, identifying and dealing with the Q biotype. Efforts for surveying began immediately in March 2005 and have cont...

  20. Insecticidal Activity of Chromobacterium subtsugae on the Sweet Potato Whitefly, Bemisia tabaci, Biotype B

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chromobacterium subtsugae crude extracts contain compounds that are toxic to nymphal and adult Bemisia tabaci. When fed on artificial diet containing 10% of the supernatant of an aqueous cell-free extract of C subtsugae, the number of 2nd and 4th instar nymphs and of emerged adults was significantl...

  1. Sampling and Management of Bemisia tabaci (Genn.) Biotype B in Australian Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A management strategy for the B biotype of Bemisia tabaci (silverleaf whitefly) in Australian cotton crops is presented. A fixed-sample size binomial (presence or absence) model based on a tally threshold of 2 adults/leaf was tested using a computer resampling approach and used to develop a sampling...

  2. Molecular and functional characterization of Bemisia tabaci aquaporins reveals the water channel diversity of hemipteran insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Middle East-Asia Minor 1 (MEAM1) whitefly, Bemisia tabaci (Gennadius) is an economically important pest of food, fiber, and ornamental crops. This pest has evolved a number of adaptations to overcome physiological challenges, including 1) the ability to regulate osmotic stress between gut lumen ...

  3. Climate change and Bemisia tabaci (Hemiptera: Aleyrodidae): Impacts of temperature and carbon dioxide on life history

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate change is relevant to life around the globe. A rise in ambient temperature and CO2 may have various impacts on arthropods such as altered life cycles, modified reproductive patterns, and changes in distribution. The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a global agricultural...

  4. Distribution of Bemisia tabaci (Hemiptera: Aleyrodidae) biotypes in North America following the Q invasion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    After the 2004 discovery of the Bemisia tabaci (Gennadius) Q biotype in the U.S., there was a vital need to determine its distribution and its interaction with the resident B biotype because of its innate ability to rapidly develop high level insecticide resistance that does not revert back to susce...

  5. Releases of exotic parasitoids of Bemisia tabaci in San Joaquin Valley, California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 1991, Bemisia tabaci was reported in the southern San Joaquin Valley infesting crops outside of greenhouses for the first time. From 1994 to 1996, 24 species/ strains of imported aphelinids, primarily species of Eretmocerus, were released in urban and agricultural settings for control of this whi...

  6. Effect of dinotefuran on Bemisia tabaci (MED whitefly) and Amblyseius swirskii, 2016

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci is a polyphagous pest known to feed upon over 900 plant taxa, and is an effective vector of more than 100 plant damaging viruses. Among different biotypes of this cryptic species complex, MEAM1 and MED whitefly are the two most destructive members posing threats of several crops of ec...

  7. Population genetics of invasive Bemisia tabaci cryptic species in the United States based on microsatellite markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Bemisia tabaci cryptic species complex of whiteflies contains two species, MEAM1 and MED, that are highly invasive in supportive climates the world over. In the United States MEAM1 occurs both in the field and in the greenhouse, but MED is only found in the greenhouse. In order to make inference...

  8. Extraordinary resistance to insecticides reveals exotic Q biotype of Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The whitefly Bemisia tabaci (Gennadius) possessing unusually high levels of resistance to a wide range of insecticides were discovered in 2004 in the course of routine resistance monitoring in Arizona. The multiply-resistant insects, collected from poinsettia (Euphorbia pulcherrima) plants purchased...

  9. Extraordinary resistance to insecticides reveals exotic Q biotype of Bemisia tabaci (Gennadius) in the New World

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The whitefly Bemisia tabaci (Gennadius) possessing unusually high levels of resistance to a wide range of insecticides were discovered in 2004 in the course of routine resistance monitoring in Arizona. The multiply-resistant insects, collected from poinsettia (Euphorbia pulcherrima) plants purchased...

  10. Mortality and Population Dynamics of Bemisia tabaci within a Multi-Crop System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The population dynamics of mobile polyphagous pests is governed by a complex set of interacting factors that involve multiple host-plants, seasonality, movement and demography. Bemisia tabaci is a multivoltine insect with no diapause that maintains population continuity by moving from one host to a...

  11. Aerial electrostatic-charged spray for deposition and efficacy against sweetpotato whitefly (Bemisia tabaci) on cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Efficacy of aerial electrostatic-charged sprays was evaluated for spray deposit characteristics and season-long control of sweet potato whitefly (SWF), Bemisia tabaci biotype B (a.k.a. B. argentifolii), in an irrigated 24-ha cotton field. Treatments included electrostatic-charged sprays at full and ...

  12. Identification and characterization of functional aquaporin water channel protein from alimentary tract of whitefly, Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some hemipteran xylem and phloem feeding insects have evolved specialized alimentary structures or filter chambers that rapidly transport water for excretion or osmoregulation. In the whitefly, Bemisia tabaci, mass movement of water through opposing alimentary tract tissues within the filter chamber...

  13. Biochemical study of resistance to imidacloprid in B-biotype Bemisia tabaci from Guatemala

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Systemic uptake bioassays using excised cotton leaves confirmed resistance to imidacloprid in a Guatemalan population of the tobacco whitefly Bemisia tabaci Gennadius. Polyacrylamide gel electrophoresis of naphthyl esterases identified the insects as B-types. Upon collection from the field, resistan...

  14. COTTON WATER STRESS ON BEMISIA TABACI STRAIN B (HOMOPTERA: ALEYRODIDAE) ON HONEYDEW PRODUCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Comparisons of honeydew production by sweetpotato whitefly (SPW), Bemisia tabaci (Gennadius) Strain B while feeding on water-stressed or non-water-stressed cotton showed that more honeydew sugars were produced on non water-stressed leaves of cotton plants (four days after irrigation) compared to tho...

  15. EFFECTS OF COTTON PLANT WATER STRESS ON BEMISIA TABACI STRAIN B (HOMOPTERA: ALEYRODIDAE) HONEYDEW PRODUCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Honeydew production by sweetpotato whitefly (SPW), Bemisia tabaci (Gennadius) Strain B, feeding on water-stressed and non-water-stressed cotton was compared in field and greenhouse studies. In the field in 1999, leaf water potentials, as a measure of water stress, decreased with increasing numbers ...

  16. Host plant influences on susceptibility of bemisia tabaci (Hemiptera: Aleyrodidae) to insecticides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : A resistance monitoring program conducted for the polyphagous whitefly Bemisia tabaci (Gennadius) in Imperial Valley, CA, USA generated a large set of LC50s for adults collected from broccoli, cantaloupe and cotton crops over a four-year period. A vial bioassay and subsequently a yellow-sticky ca...

  17. OUT OF AFRICA: DIVERSITY AND HOST PLANT UTILIZATION IN SUB-SAHARAN BEMISIA TABACI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diversity of Bemisia tabaci in Sub-Saharan Africa is greater than in any other geographic location and suggests Sub-Saharan Africa is the likely evolutionary origin of the species. Sampling in Africa is now quite extensive and includes a number of studies that have analyzed host preference withi...

  18. Insecticidal Activity of Some Reducing Sugars Against the Sweet Potato Whitefly, Bemisia tabaci, Biotype B

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of 15 sugars on sweet potato whitefly (Bemisia tabaci) survival were determined using bioassays. Arabinose, mannose, ribose and xylose were strongly inhibitory to both nymphal and adult survival. When 10% mannose was added to the diet, 10.5%, 1.0% and 0% of nymphs developed to the 2nd, ...

  19. Forty-nine New Host Plant Species for Bemisia tabaci (Hemiptera: Aleyrodidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a worldwide pest of numerous agricultural and ornamental crops. In addition to directly feeding on plants, it also acts as a vector of plant viruses of cultivated and uncultivated host plant species. Moreover, host plants can affect the popula...

  20. Global relationships of Bemisia tabaci (Hemiptera: Aleyrodidae) revealed using Bayesian analysis of mitochondrial COI DNA sequence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci (Gen.)(Hemiptera: Aleyrodidae) is a species complex that is one of the most devastating agricultural pests worldwide and affects a broad range of food, fiber and ornamental crops. Unfortunately, using parsimony and neighbor joining methods, global phylogenetic relationships of the ma...

  1. Molecular Characterization of Vitellogenin and Vitellogenin Receptor of Bemisia tabaci.

    PubMed

    Upadhyay, Santosh Kumar; Singh, Harpal; Dixit, Sameer; Mendu, Venugopal; Verma, Praveen C

    2016-01-01

    Vitellogenin (Vg) plays vital role in oocytes and embryo development in insects. Vg is synthesized in the fat body, moves through haemolymph and accumulates in oocytes. Vitellogenin receptors (VgR) present on the surface of oocytes, are responsible for Vg transportation from haemolymph to oocytes. Here, we cloned and characterized these genes from Bemisia tabaci Asia1 (BtA1) species. The cloned BtA1Vg and BtA1VgR genes consisted of 6,330 and 5,430 bp long open reading frames, which encoded 2,109 and 1,809 amino acid (AA) residues long protein. The BtA1Vg protein comprised LPD_N, DUF1943 and VWFD domains, typical R/KXXR/K, DGXR and GL/ICG motifs, and polyserine tracts. BtA1VgR protein contained 12 LDLa, 10 LDLb and 7 EGF domains, and a trans-membrane and cytoplasmic region at C-terminus. Phylogenetic analyses indicated evolutionary association of BtA1Vg and BtA1VgR with the homologous proteins from various insect species. Silencing of BtA1VgR by siRNA did not affect the transcript level of BtA1Vg. However, BtA1Vg protein accumulation in oocytes was directly influenced with the expression level of BtA1VgR. Further, BtA1VgR silencing caused significant mortality and reduced fecundity in adult whiteflies. The results established the role of BtA1VgR in transportation of BtA1Vg in oocytes. Further, these proteins are essential for fecundity, and therefore these can be potential RNAi targets for insect control in crop plants. PMID:27159161

  2. Molecular Characterization of Vitellogenin and Vitellogenin Receptor of Bemisia tabaci

    PubMed Central

    Upadhyay, Santosh Kumar; Singh, Harpal; Dixit, Sameer; Mendu, Venugopal; Verma, Praveen C.

    2016-01-01

    Vitellogenin (Vg) plays vital role in oocytes and embryo development in insects. Vg is synthesized in the fat body, moves through haemolymph and accumulates in oocytes. Vitellogenin receptors (VgR) present on the surface of oocytes, are responsible for Vg transportation from haemolymph to oocytes. Here, we cloned and characterized these genes from Bemisia tabaci Asia1 (BtA1) species. The cloned BtA1Vg and BtA1VgR genes consisted of 6,330 and 5,430 bp long open reading frames, which encoded 2,109 and 1,809 amino acid (AA) residues long protein. The BtA1Vg protein comprised LPD_N, DUF1943 and VWFD domains, typical R/KXXR/K, DGXR and GL/ICG motifs, and polyserine tracts. BtA1VgR protein contained 12 LDLa, 10 LDLb and 7 EGF domains, and a trans-membrane and cytoplasmic region at C-terminus. Phylogenetic analyses indicated evolutionary association of BtA1Vg and BtA1VgR with the homologous proteins from various insect species. Silencing of BtA1VgR by siRNA did not affect the transcript level of BtA1Vg. However, BtA1Vg protein accumulation in oocytes was directly influenced with the expression level of BtA1VgR. Further, BtA1VgR silencing caused significant mortality and reduced fecundity in adult whiteflies. The results established the role of BtA1VgR in transportation of BtA1Vg in oocytes. Further, these proteins are essential for fecundity, and therefore these can be potential RNAi targets for insect control in crop plants. PMID:27159161

  3. Compatibility of the insect pathogenic fungus Beauveria bassiana with neem against sweetpotato whitefly, Bemisia tabaci, on eggplant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study on the compatibility of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) with neem was conducted against sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on eggplant. Initially, three concentrations of B. bassiana (106, 1...

  4. New records of entomopathogenic fungi infecting Bemisia tabaci and Trialeurodes vaporariorum, pests of horticultural crops, in Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The whiteflies (Hemiptera: Aleyrodidae) Bemisia tabaci (Gennadius), and Trialeurodes vaporariorum (Westwood) are major crop pests throughout the world. Although extensive research about biological control of whitefly has been conducted towards these insect's parasitoids and predators, several entom...

  5. Tomato yellow leaf curl virus alters the host preferences of its vector Bemisia tabaci

    PubMed Central

    Fang, Yong; Jiao, Xiaoguo; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Shi, Xiaobin; Chen, Gong; Su, Qi; Yang, Xin; Pan, Huipeng; Zhang, Youjun

    2013-01-01

    Bemisia tabaci, the whitefly vector of Tomato yellow leaf curl virus (TYLCV), seriously reduces tomato production and quality. Here, we report the first evidence that infection by TYLCV alters the host preferences of invasive B. tabaci B (Middle East-Minor Asia 1) and Q (Mediterranean genetic group), in which TYLCV-free B. tabaci Q preferred to settle on TYLCV-infected tomato plants over healthy ones. TYLCV-free B. tabaci B, however, preferred healthy tomato plants to TYLCV-infected plants. In contrast, TYLCV-infected B. tabaci, either B or Q, did not exhibit a preference between TYLCV-infected and TYLCV-free tomato plants. Based on gas chromatography-mass spectrometry (GCMS)analysis of plant terpene volatiles, significantly more β-myrcene, thymene, β-phellandrene, caryophyllene, (+)-4-carene, and α-humulene were released from the TYLCV-free tomato plants than from the TYLCV-infected ones. The results indicate TYLCV can alter the host preferences of its vector Bemisia tabaci B and Q. PMID:24096821

  6. RNA Interference based Approach to Down Regulate Osmoregulators of Whitefly (Bemisia tabaci): Potential Technology for the Control of Whitefly

    PubMed Central

    Raza, Amir; Malik, Hassan Jamil; Shafiq, Muhammad; Amin, Imran; Scheffler, Jodi A.; Scheffler, Brian E.; Mansoor, Shahid

    2016-01-01

    Over the past decade RNA interference (RNAi) technology has emerged as a successful tool not only for functional genomics, but in planta expression of short interfering RNAs (siRNAs) that could offer great potential for insect pest management. The diet of insects feeding exclusively on phloem sieves contains water and sugars as main components, and the uptake of the liquid food greatly depends on the osmotic pressure within the insect body. Based on this physiological mechanism, transgenic plants of Nicotiana tabacum were generated expressing double stranded RNA (dsRNA) against both aquaporin (AQP) and a sucrase gene, alpha glucosidase (AGLU). These two genes are involved in osmotic pressure maintenance particularly in sap sucking insects, and the aim was to disrupt osmoregulation within the insect ultimately leading to mortality. Real time quantitative PCR (RT-qPCR) was performed to assess the suppression of gene expression in Bemisia tabaci (B. tabaci) and mortality was recorded during transgenic tobacco feeding bioassays. Feeding of insects on plants expressing dsRNA significantly reduced the transcript level of the target genes in B. tabaci after six days of feeding and more than 70% mortality was observed in B. tabaci fed on transgenic plants compared to the control plants. Our data shows that down-regulation of genes related to osmoregulation may find practical applications for the control of this important pest in cotton and other crops. PMID:27105353

  7. RNA Interference based Approach to Down Regulate Osmoregulators of Whitefly (Bemisia tabaci): Potential Technology for the Control of Whitefly.

    PubMed

    Raza, Amir; Malik, Hassan Jamil; Shafiq, Muhammad; Amin, Imran; Scheffler, Jodi A; Scheffler, Brian E; Mansoor, Shahid

    2016-01-01

    Over the past decade RNA interference (RNAi) technology has emerged as a successful tool not only for functional genomics, but in planta expression of short interfering RNAs (siRNAs) that could offer great potential for insect pest management. The diet of insects feeding exclusively on phloem sieves contains water and sugars as main components, and the uptake of the liquid food greatly depends on the osmotic pressure within the insect body. Based on this physiological mechanism, transgenic plants of Nicotiana tabacum were generated expressing double stranded RNA (dsRNA) against both aquaporin (AQP) and a sucrase gene, alpha glucosidase (AGLU). These two genes are involved in osmotic pressure maintenance particularly in sap sucking insects, and the aim was to disrupt osmoregulation within the insect ultimately leading to mortality. Real time quantitative PCR (RT-qPCR) was performed to assess the suppression of gene expression in Bemisia tabaci (B. tabaci) and mortality was recorded during transgenic tobacco feeding bioassays. Feeding of insects on plants expressing dsRNA significantly reduced the transcript level of the target genes in B. tabaci after six days of feeding and more than 70% mortality was observed in B. tabaci fed on transgenic plants compared to the control plants. Our data shows that down-regulation of genes related to osmoregulation may find practical applications for the control of this important pest in cotton and other crops. PMID:27105353

  8. The Endosymbiont Hamiltonella Increases the Growth Rate of Its Host Bemisia tabaci during Periods of Nutritional Stress

    PubMed Central

    Su, Qi; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Liu, Baiming; Fang, Yong; Xu, Baoyun; Zhang, Youjun

    2014-01-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) harbors several bacterial symbionts. Among the secondary (facultative) symbionts, Hamiltonella has high prevalence and high infection frequencies, suggesting that it may be important for the biology and ecology of its hosts. Previous reports indicated that Hamiltonella increases whitefly fitness and, based on the complete sequencing of its genome, may have the ability to synthesize cofactors and amino acids that are required by its host but that are not sufficiently synthesized by the host or by the primary endosymbiont, Portiera. Here, we assessed the effects of Hamiltonella infection on the growth of B. tabaci reared on low-, standard-, or high-nitrogen diets. When B. tabaci was reared on a standard-nitrogen diet, no cost or benefit was associated with Hamiltonella infection. But, if we reared whiteflies on low-nitrogen diets, Hamiltonella-infected whiteflies often grew better than uninfected whiteflies. Furthermore, nitrogen levels in field-collected whiteflies indicated that the nutritional conditions in the field were comparable to the low-nitrogen diet in our laboratory experiment. These data suggest that Hamiltonella may play a previously unrecognized role as a nutritional mutualist in B. tabaci. PMID:24558462

  9. Prey Preference and Life Table of Amblyseius orientalis on Bemisia tabaci and Tetranychus cinnabarinus.

    PubMed

    Zhang, Xiaoxiao; Lv, Jiale; Hu, Yue; Wang, Boming; Chen, Xi; Xu, Xuenong; Wang, Endong

    2015-01-01

    Amblyseius orientalis (Ehara) (Acari: Phytoseiidae) is a native predatory mite species in China. It used to be considered as a specialist predator of spider mites. However, recent studies show it also preys on other small arthropod pests, such as Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Experiments were conducted to investigate (1) prey preference of A. orientalis between Tetranychus cinnabarinus (Boisd.) (Acari: Tetranychidae) and B. tabaci, and (2) development, consumption and life table parameters of A. orientalis when reared on T. cinnabarinus, B. tabaci or a mix of both prey species. When preying on different stages of T. cinnabarinus, A. orientalis preferred protonymphs, whereas when preying on different stages of B. tabaci, A. orientalis preferred eggs. When these two most preferred stages were provided together (T. cinnabarinus protonymphs and B. tabaci eggs), A. orientalis randomly selected its prey. Amblyseius orientalis was able to complete its life cycle on B. tabaci eggs, T. cinnabarinus protonymphs, or a mix of both prey. However, its developmental duration was 53.9% and 30.0% longer when reared on B. tabaci eggs than on T. cinnabarinus and a mix of both prey, respectively. In addition, it produced only a few eggs and its intrinsic rate of increase was negative when reared on B. tabaci eggs, which indicates that B. tabaci is not sufficient to maintain A. orientalis population. The intrinsic rates of increase were 0.16 and 0.23 when A. orientalis was fed on the prey mix and T. cinnabarinus, respectively. These results suggest that although B. tabaci is a poor food resource for A. orientalis in comparison to T. cinnabarinus, A. orientalis is able to sustain its population on a mix of both prey. This predatory mite may thus be a potential biological control agent of B. tabaci when this pest co-occurs with the alternative minor pest T. cinnabarinus. PMID:26436422

  10. Prey Preference and Life Table of Amblyseius orientalis on Bemisia tabaci and Tetranychus cinnabarinus

    PubMed Central

    Hu, Yue; Wang, Boming; Chen, Xi; Xu, Xuenong; Wang, Endong

    2015-01-01

    Amblyseius orientalis (Ehara) (Acari: Phytoseiidae) is a native predatory mite species in China. It used to be considered as a specialist predator of spider mites. However, recent studies show it also preys on other small arthropod pests, such as Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Experiments were conducted to investigate (1) prey preference of A. orientalis between Tetranychus cinnabarinus (Boisd.) (Acari: Tetranychidae) and B. tabaci, and (2) development, consumption and life table parameters of A. orientalis when reared on T. cinnabarinus, B. tabaci or a mix of both prey species. When preying on different stages of T. cinnabarinus, A. orientalis preferred protonymphs, whereas when preying on different stages of B. tabaci, A. orientalis preferred eggs. When these two most preferred stages were provided together (T. cinnabarinus protonymphs and B. tabaci eggs), A. orientalis randomly selected its prey. Amblyseius orientalis was able to complete its life cycle on B. tabaci eggs, T. cinnabarinus protonymphs, or a mix of both prey. However, its developmental duration was 53.9% and 30.0% longer when reared on B. tabaci eggs than on T. cinnabarinus and a mix of both prey, respectively. In addition, it produced only a few eggs and its intrinsic rate of increase was negative when reared on B. tabaci eggs, which indicates that B. tabaci is not sufficient to maintain A. orientalis population. The intrinsic rates of increase were 0.16 and 0.23 when A. orientalis was fed on the prey mix and T. cinnabarinus, respectively. These results suggest that although B. tabaci is a poor food resource for A. orientalis in comparison to T. cinnabarinus, A. orientalis is able to sustain its population on a mix of both prey. This predatory mite may thus be a potential biological control agent of B. tabaci when this pest co-occurs with the alternative minor pest T. cinnabarinus. PMID:26436422

  11. Tomato yellow leaf curl virus: No evidence for replication in the insect vector Bemisia tabaci

    PubMed Central

    Sánchez-Campos, Sonia; Rodríguez-Negrete, Edgar A.; Cruzado, Lucía; Grande-Pérez, Ana; Bejarano, Eduardo R.; Navas-Castillo, Jesús; Moriones, Enrique

    2016-01-01

    Begomovirus ssDNA plant virus (family Geminiviridae) replication within the Bemisia tabaci vector is controversial. Transovarial transmission, alteration to whitefly biology, or detection of viral transcripts in the vector are proposed as indirect evidence of replication of tomato yellow leaf curl virus (TYLCV). Recently, contrasting direct evidence has been reported regarding the capacity of TYLCV to replicate within individuals of B. tabaci based on quantitave PCR approaches. Time-course experiments to quantify complementary and virion sense viral nucleic acid accumulation within B. tabaci using a recently implemented two step qPCR procedure revealed that viral DNA quantities did not increase for time points up to 96 hours after acquisition of the virus. Our findings do not support a recent report claiming TYLCV replication in individuals of B. tabaci. PMID:27476582

  12. Tomato yellow leaf curl virus: No evidence for replication in the insect vector Bemisia tabaci.

    PubMed

    Sánchez-Campos, Sonia; Rodríguez-Negrete, Edgar A; Cruzado, Lucía; Grande-Pérez, Ana; Bejarano, Eduardo R; Navas-Castillo, Jesús; Moriones, Enrique

    2016-01-01

    Begomovirus ssDNA plant virus (family Geminiviridae) replication within the Bemisia tabaci vector is controversial. Transovarial transmission, alteration to whitefly biology, or detection of viral transcripts in the vector are proposed as indirect evidence of replication of tomato yellow leaf curl virus (TYLCV). Recently, contrasting direct evidence has been reported regarding the capacity of TYLCV to replicate within individuals of B. tabaci based on quantitave PCR approaches. Time-course experiments to quantify complementary and virion sense viral nucleic acid accumulation within B. tabaci using a recently implemented two step qPCR procedure revealed that viral DNA quantities did not increase for time points up to 96 hours after acquisition of the virus. Our findings do not support a recent report claiming TYLCV replication in individuals of B. tabaci. PMID:27476582

  13. Chemical class rotations for control of Bemisia tabaci (Hemiptera: Aleyrodidae) on poinsettia and their effect on cryptic species population composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci, a polyphagous insect with over 900 host plants, is an effective vector of more than 100 plant viruses. Being highly fecund, B. tabaci has the potential to develop insecticide resistance rapidly as demonstrated by reports of use failures with MEAM1 and MED cryptic species (commonly kn...

  14. The Contribution of Conservation Biological Control to Management of Bemisia tabaci in Cotton: A Life Table Analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural enemies in Arizona cotton can be conserved with the use of selective insect growth regulators (IGRs) for control of Bemisia tabaci. To examine the interaction of mortality forces, cohort-based life tables were constructed for B. tabaci populations subject to three different pest control stra...

  15. A knottin-like putative antimicrobial gene family in the Whitefly Bemisia tabaci B: cloning and transcript regulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The whitefly, Bemisia tabaci, is a worldwide plant pest and the vector of agriculturally important plant pathogenic begomoviruses. Of two vectored begomoviruses, Tomato yellow leaf curl virus (TYLCV) is transcriptionally active in B. tabaci and Tomato mottle virus (ToMoV)is not. Comparative analyses...

  16. Baseline susceptibility of Bemisia tabaci B biotype (Hemiptera:Aleyrodidae) populations from Californis and Arizona to spirotetramat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Baseline toxicity levels to foliarly applied spirotetramat were established for 19 field populations of whiteflies, Bemisia tabaci B biotype from Arizona and California in 2008 and 2009. The susceptibility data was determined against the 2nd instar of B. tabaci field collections before the registrat...

  17. Genetic distinctions among the Mediterranean and Chinese populations of Bemisia tabaci Q biotype and their endosymbiont Wolbachia populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci, is a cryptic species complex composed of more than 24 different biotypes around the world. The Q biotype of B. tabaci, which is thought to have originated in the Mediterranean Basin, is now a widespread and serious agricultural pest. In this study, the genet...

  18. Feeding Experience of Bemisia tabaci (Hemiptera: Aleyrodidae) Affects Their Performance on Different Host Plants

    PubMed Central

    Shah, M. Mostafizur Rahman; Liu, Tong-Xian

    2013-01-01

    The sweetpotato whitefly, Bemisia tabaci biotype B is extremely polyphagous with >600 species of host plants. We hypothesized that previous experience of the whitefly on a given host plant affects their host selection and performance on the plants without previous experience. We investigated the host selection for feeding and oviposition of adults and development and survival of immatures of three host-plant-experienced populations of B. tabaci, namely Bemisia-eggplant, Bemisia-tomato and Bemisia-cucumber, on their experienced host plant and each of the three other plant species (eggplant, tomato, cucumber and pepper) without previous experience. We found that the influence of previous experience of the whiteflies varied among the populations. All populations refused pepper for feeding and oviposition, whereas the Bemisia-cucumber and the Bemisia-eggplant strongly preferred cucumber. Bemisia-tomato did not show strong preference to any of the three host palnts. Development time from egg to adult eclosion varied among the populations, being shortest on eggplant, longest on pepper, and intermediate on tomato and cucumber except for the Bemisia-cucumber developed similarly on tomato and pepper. The survivorship from egg to adult eclosion of all populations was highest on eggplant (80-98%), lowest on pepper (0-20%), and intermediate on tomato and cucumber. In conclusion, the effects of previous experience of whiteflies on host selection for feeding and oviposition, development, and survivorship varied depending on host plants, and host plants play a stronger role than previous experience. Preference of feeding and oviposition by adults may not accurately reflect host suitability of immatures. These results provided important information for understanding whitefly population dynamics and dispersal among different crop systems. PMID:24146985

  19. Pyrosequencing the Bemisia tabaci Transcriptome Reveals a Highly Diverse Bacterial Community and a Robust System for Insecticide Resistance

    PubMed Central

    Wu, Qing-jun; Wang, Shao-li; Yang, Xin; Yang, Ni-na; Li, Ru-mei; Jiao, Xiao-guo; Pan, Hui-peng; Liu, Bai-ming; Su, Qi; Xu, Bao-yun; Hu, Song-nian; Zhou, Xu-guo; Zhang, You-jun

    2012-01-01

    Background Bemisia tabaci (Gennadius) is a phloem-feeding insect poised to become one of the major insect pests in open field and greenhouse production systems throughout the world. The high level of resistance to insecticides is a main factor that hinders continued use of insecticides for suppression of B. tabaci. Despite its prevalence, little is known about B. tabaci at the genome level. To fill this gap, an invasive B. tabaci B biotype was subjected to pyrosequencing-based transcriptome analysis to identify genes and gene networks putatively involved in various physiological and toxicological processes. Methodology and Principal Findings Using Roche 454 pyrosequencing, 857,205 reads containing approximately 340 megabases were obtained from the B. tabaci transcriptome. De novo assembly generated 178,669 unigenes including 30,980 from insects, 17,881 from bacteria, and 129,808 from the nohit. A total of 50,835 (28.45%) unigenes showed similarity to the non-redundant database in GenBank with a cut-off E-value of 10–5. Among them, 40,611 unigenes were assigned to one or more GO terms and 6,917 unigenes were assigned to 288 known pathways. De novo metatranscriptome analysis revealed highly diverse bacterial symbionts in B. tabaci, and demonstrated the host-symbiont cooperation in amino acid production. In-depth transcriptome analysis indentified putative molecular markers, and genes potentially involved in insecticide resistance and nutrient digestion. The utility of this transcriptome was validated by a thiamethoxam resistance study, in which annotated cytochrome P450 genes were significantly overexpressed in the resistant B. tabaci in comparison to its susceptible counterparts. Conclusions This transcriptome/metatranscriptome analysis sheds light on the molecular understanding of symbiosis and insecticide resistance in an agriculturally important phloem-feeding insect pest, and lays the foundation for future functional genomics research of the B. tabaci complex

  20. [Biotypes and phylogenetic analysis of Bemisia tabaci (Hemiptera: Aleyrodidae) in China].

    PubMed

    Xu, Li-Li; Cai, Li; Shen, Wei-Jiang; Du, Yu-Zhou

    2014-04-01

    Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) is considered taxonomically as a species complex and could cause serious damages to crops by directly feeding on phloem and/or indirectly transmission of plant viruses. In this study, biotypes and phylogenetic relationships of 33 geographic populations of B. tabaci collected from nine provinces of China in 2010 and 2011 were studied based on the mitochondrial COI gene. The results showed there were a total of six biotypes of B. tabaci (B, Q, ZHJ-1, ZHJ-3, An and Nauru) recovered in China and the geographical distribution of these six biotypes was uneven. Phylogenetic analysis showed that biotype An B. tabaci from Taiwan clustered together with Hainan biotype An populations, indicating these two geographic populations might originate from a same ancestor. In addition, biotype B B. tabaci in China had a 99% genetical similarity compared to that from France and Uganda. However, relationships of biotype Q on the phylogenetic tree were divided into two different clusters. One was occupied with the population from China and Western Mediterranean Sea countries (France and Morocco) and the other contained biotype Q populations from Eastern Mediterranean Sea countries (Israel and Turkey). Overall, the results suggested that biotype Q B. tabaci in China was genetically similar to that from Western Mediterranean Sea countries and it could be highly possible that Chinese biotype Q B. tabaci originated from Western Mediterranean Sea areas. PMID:25011310

  1. Update on the Status of Bemisia tabaci in the UK and the Use of Entomopathogenic Fungi within Eradication Programmes

    PubMed Central

    Cuthbertson, Andrew G. S.

    2013-01-01

    The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) continues to be a serious threat to crops worldwide. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. Both B and Q Bemisia biotypes are now regularly intercepted entering the UK. With increasing reports of neonicotinoid resistance in both these biotypes, it is becoming more problematic to control/eradicate. Therefore, alternative means of control are necessary. Entomopathogenic fungi (Lecanicilllium muscarium and Beauveria bassiana) offer much potential as control agents of B. tabaci within eradication programmes in the UK. PMID:26464385

  2. Biotype Characterization, Developmental Profiling, Insecticide Response and Binding Property of Bemisia tabaci Chemosensory Proteins: Role of CSP in Insect Defense

    PubMed Central

    Liu, Guoxia; Ma, Hongmei; Xie, Hongyan; Xuan, Ning; Guo, Xia; Fan, Zhongxue; Rajashekar, Balaji; Arnaud, Philippe; Offmann, Bernard; Picimbon, Jean-François

    2016-01-01

    Chemosensory proteins (CSPs) are believed to play a key role in the chemosensory process in insects. Sequencing genomic DNA and RNA encoding CSP1, CSP2 and CSP3 in the sweet potato whitefly Bemisia tabaci showed strong variation between B and Q biotypes. Analyzing CSP-RNA levels showed not only biotype, but also age and developmental stage-specific expression. Interestingly, applying neonicotinoid thiamethoxam insecticide using twenty-five different dose/time treatments in B and Q young adults showed that Bemisia CSP1, CSP2 and CSP3 were also differentially regulated over insecticide exposure. In our study one of the adult-specific gene (CSP1) was shown to be significantly up-regulated by the insecticide in Q, the most highly resistant form of B. tabaci. Correlatively, competitive binding assays using tryptophan fluorescence spectroscopy and molecular docking demonstrated that CSP1 protein preferentially bound to linoleic acid, while CSP2 and CSP3 proteins rather associated to another completely different type of chemical, i.e. α-pentyl-cinnamaldehyde (jasminaldehyde). This might indicate that some CSPs in whiteflies are crucial to facilitate the transport of fatty acids thus regulating some metabolic pathways of the insect immune response, while some others are tuned to much more volatile chemicals known not only for their pleasant odor scent, but also for their potent toxic insecticide activity. PMID:27167733

  3. Biotype Characterization, Developmental Profiling, Insecticide Response and Binding Property of Bemisia tabaci Chemosensory Proteins: Role of CSP in Insect Defense.

    PubMed

    Liu, Guoxia; Ma, Hongmei; Xie, Hongyan; Xuan, Ning; Guo, Xia; Fan, Zhongxue; Rajashekar, Balaji; Arnaud, Philippe; Offmann, Bernard; Picimbon, Jean-François

    2016-01-01

    Chemosensory proteins (CSPs) are believed to play a key role in the chemosensory process in insects. Sequencing genomic DNA and RNA encoding CSP1, CSP2 and CSP3 in the sweet potato whitefly Bemisia tabaci showed strong variation between B and Q biotypes. Analyzing CSP-RNA levels showed not only biotype, but also age and developmental stage-specific expression. Interestingly, applying neonicotinoid thiamethoxam insecticide using twenty-five different dose/time treatments in B and Q young adults showed that Bemisia CSP1, CSP2 and CSP3 were also differentially regulated over insecticide exposure. In our study one of the adult-specific gene (CSP1) was shown to be significantly up-regulated by the insecticide in Q, the most highly resistant form of B. tabaci. Correlatively, competitive binding assays using tryptophan fluorescence spectroscopy and molecular docking demonstrated that CSP1 protein preferentially bound to linoleic acid, while CSP2 and CSP3 proteins rather associated to another completely different type of chemical, i.e. α-pentyl-cinnamaldehyde (jasminaldehyde). This might indicate that some CSPs in whiteflies are crucial to facilitate the transport of fatty acids thus regulating some metabolic pathways of the insect immune response, while some others are tuned to much more volatile chemicals known not only for their pleasant odor scent, but also for their potent toxic insecticide activity. PMID:27167733

  4. The Feeding Rate of Predatory Mites on Life Stages of Bemisia tabaci Mediterranean Species

    PubMed Central

    Cuthbertson, Andrew G. S.

    2014-01-01

    The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) continues to be a serious threat to crops worldwide. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. There has recently been a shift from Middle East-Asia Minor 1 to the more chemical resistant Mediterranean species entering the UK. Predatory mites (Amblyseius swirskii, Transeius montdorensis and Typhlodromalus limonicus) were screened for their impact upon various lifestages of B. tabaci Mediterranean species. Approximately 30% of eggs were fed upon by A. swirskii following a 5 day period. Feeding rates slightly decreased for all mite species when feeding on first instar life-stages (27%, 24%, 16% respectively) and significantly decreased when feeding on second instars (8.5%, 8.5%, 8.7% respectively). Combining the two mite species (A. swirskii and T. montdorensis) increased mortality of Bemisia eggs to 36%. The potential of incorporating the mites into existing control strategies for B. tabaci is discussed. PMID:26462828

  5. The Feeding Rate of Predatory Mites on Life Stages of Bemisia tabaci Mediterranean Species.

    PubMed

    Cuthbertson, Andrew G S

    2014-01-01

    The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) continues to be a serious threat to crops worldwide. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. There has recently been a shift from Middle East-Asia Minor 1 to the more chemical resistant Mediterranean species entering the UK. Predatory mites (Amblyseius swirskii, Transeius montdorensis and Typhlodromalus limonicus) were screened for their impact upon various lifestages of B. tabaci Mediterranean species. Approximately 30% of eggs were fed upon by A. swirskii following a 5 day period. Feeding rates slightly decreased for all mite species when feeding on first instar life-stages (27%, 24%, 16% respectively) and significantly decreased when feeding on second instars (8.5%, 8.5%, 8.7% respectively). Combining the two mite species (A. swirskii and T. montdorensis) increased mortality of Bemisia eggs to 36%. The potential of incorporating the mites into existing control strategies for B. tabaci is discussed. PMID:26462828

  6. Wolbachia Has Two Different Localization Patterns in Whitefly Bemisia tabaci AsiaII7 Species.

    PubMed

    Shi, Peiqiong; He, Zhan; Li, Shaojian; An, Xuan; Lv, Ning; Ghanim, Murad; Cuthbertson, Andrew G S; Ren, Shun-Xiang; Qiu, Bao-Li

    2016-01-01

    The whitefly Bemisia tabaci is a cosmopolitan insect species complex that harbors the obligate primary symbiont Portiera aleyrodidarum and several facultative secondary symbionts including Wolbachia, which have diverse influences on the host biology. Here, for the first time, we revealed two different localization patterns of Wolbachia present in the immature and adult stages of B. tabaci AsiaII7 cryptic species. In the confined pattern, Wolbachia was restricted to the bacteriocytes, while in the scattered pattern Wolbachia localized in the bacteriocytes, haemolymph and other organs simultaneously. Our results further indicated that, the proportion of B. tabaci AsiaII7 individuals with scattered Wolbachia were significantly lower than that of confined Wolbachia, and the distribution patterns of Wolbachia were not associated with the developmental stage or sex of whitefly host. This study will provide a new insight into the various transmission routes of Wolbachia in different whitefly species. PMID:27611575

  7. Deep Sequencing-Based Transcriptome Analysis Reveals the Regulatory Mechanism of Bemisia tabaci (Hemiptera: Aleyrodidae) Nymph Parasitized by Encarsia sophia (Hymenoptera: Aphelinidae)

    PubMed Central

    Wang, Ran; Li, Fei; Zhang, Fan; Wang, Su

    2016-01-01

    The whitefly Bemisia tabaci is a genetically diverse complex with multiple cryptic species, and some are the most destructive invasive pests of many ornamentals and crops worldwide. Encarsia sophia is an autoparasitoid wasp that demonstrated high efficiency as bio-control agent of whiteflies. However, the immune mechanism of B. tabaci parasitization by E. sophia is unknown. In order to investigate immune response of B. tabaci to E. Sophia parasitization, the transcriptome of E. sophia parasitized B. tabaci nymph was sequenced by Illumina sequencing. De novo assembly generated 393,063 unigenes with average length of 616 bp, in which 46,406 unigenes (15.8% of all unigenes) were successfully mapped. Parasitization by E. sophia had significant effects on the transcriptome profile of B. tabaci nymph. A total of 1482 genes were significantly differentially expressed, of which 852 genes were up-regulated and 630 genes were down-regulated. These genes were mainly involved in immune response, development, metabolism and host signaling pathways. At least 52 genes were found to be involved in the host immune response, 33 genes were involved in the development process, and 29 genes were involved in host metabolism. Taken together, the assembled and annotated transcriptome sequences provided a valuable genomic resource for further understanding the molecular mechanism of immune response of B. tabaci parasitization by E. sophia. PMID:27332546

  8. Development of an antibody-based diagnostic method for the identification of Bemisia tabaci biotype B.

    PubMed

    Baek, Ji Hyeong; Lee, Hye Jung; Kim, Young Ho; Lim, Kook Jin; Lee, Si Hyeock; Kim, Bum Joon

    2016-07-01

    The whitefly Bemisia tabaci is a very destructive pest. B. tabaci is composed of various morphologically undistinguishable biotypes, among which biotypes B and Q, in particular, draw attention because of their wide distribution in Korea and differential potentials for insecticide resistance development. To develop a biotype-specific protein marker that can readily distinguishes biotypes B from other biotypes in the field, we established an ELISA protocol based on carboxylesterase 2 (COE2), which is more abundantly expressed in biotypes B compared with Q. Recombinant COE2 was expressed, purified and used for antibody construction. Polyclonal antibodies specific to B. tabaci COE2 [anti-COE2 pAb and deglycosylated anti-COE2 pAb (DG anti-COE2 pAb)] revealed a 3-9-fold higher reactivity to biotype B COE2 than biotype Q COE2 by Western blot and ELISA analyses. DG anti-COE2 pAb exhibited low non-specific activity, demonstrating its compatibility in diagnosing biotypes. Western blot and ELISA analyses determined that one of the 11 field populations examined was biotype B and the others were biotype Q, suggesting the saturation of biotype Q in Korea. DG anti-COE2 pAb discriminates B. tabaci biotypes B and Q with high specificity and accuracy and could be useful for the development of a B. tabaci biotype diagnosis kit for on-site field applications. PMID:27265822

  9. Global haplotype analysis of the whitefly Bemisia tabaci cryptic species Asia I in Asia.

    PubMed

    Hu, Jian; Chen, Yong-Dui; Jiang, Zhi-Lin; Nardi, Francesco; Yang, Tai-Yuan; Jin, Jie; Zhang, Zhong-Kai

    2015-04-01

    The whitefly, Bemisia tabaci (Hemiptera: Aleyrodidiae), is a cryptic species complex comprising a minimum of 24 cryptic species. Some members of this complex are important agricultural pests, causing considerable damage to vegetable as well as ornamental and horticultural crops. Asia I, one of the cryptic species of B. tabaci, is widely distributed in Asia. One hundred and sixty mitochondrial cytochrome oxidase I (COI) sequences from eight countries have been analyzed to investigate the geographic origin and current genetic structure of this cryptic species. Sixty different haplotypes were identified, with levels of genetic distances ranging from 0.001 to 0.021. A sign of possible genetic differentiation emerges from the differential distribution of dominant haplotypes in Indonesia and India compared to China. A possible ancient separation between Asia I in India and Indonesia and secondary contact in China has been hypothesized. PMID:24460161

  10. Potentiation/Antagonism of pyrethroids with organophosphate insecticides in Bemisia tabaci (Homoptera: Aleyrodidae).

    PubMed

    Ahmad, Mushtaq

    2007-06-01

    The binary mixtures of pyrethroids cypermethrin, alpha-cypermethrin, zeta-cypermethrin, bifenthrin, fenpropathrin, lambda-cyhalothrin, and deltamethrin plus organophosphates ethion, profenofos, chlorpyrifos, quinalphos, acephate, methamidophos, methyl parathion, and triazophos were evaluated on putatively resistant field populations of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) from Pakistan using a leaf-dip bioassay. Ethion exhibited good potentiation with all the pyrethroids. Quinalphos potentiated cypermethrin, fenpropathrin, and lambda-cyhalothrin but not bifenthrin. Acephate was potentiating with bifenthrin and fenpropathrin but antagonistic with zeta-cypermethrin. A potentiation effect was also found when methamidophos was mixed with bifenthrin and fenpropathrin. However, profenofos was antagonistic with cypermethrin, bifenthrin, and lambda-cyhalothrin. Similarly, bifenthrin + methyl parathion and deltamethrin + triazophos mixtures were antagonistic when tested on several populations of B. tabaci. Chlorpyrifos was antagonistic with cypermethrin but had an additive effect with fenpropathrin. PMID:17598552

  11. Genetic structure of the whitefly Bemisia tabaci populations in Colombia following a recent invasion.

    PubMed

    Díaz, Fernando; Endersby, Nancy M; Hoffmann, Ary A

    2015-08-01

    The whitefly Bemisia tabaci (Gennadius) is one of the most important pests causing economic losses in a variety of cropping systems around the world. This species was recently found in a coastal region of Colombia and has now spread inland. To investigate this invasive process, the genetic structure of B. tabaci was examined in 8 sampling locations from 2 infested regions (coastal, inland) using 9 microsatellite markers and the mitochondrial COI gene. The mitochondrial analysis indicated that only the invasive species of the B. tabaci complex Middle East-Asia Minor 1 (MEAM 1 known previously as biotype B) was present. The microsatellite data pointed to genetic differences among the regions and no isolation by distance within regions. The coastal region in the Caribbean appears to have been the initial point of invasion, while the inland region in the Southwest showed genetic variation among populations most likely reflecting founder events and ongoing changes associated with climatic and topographical heterogeneity. These findings have implications for tracking and managing B. tabaci. PMID:24753322

  12. Compatibility of the entomopathogenic fungus Lecanicillium muscarium and insecticides for eradication of sweetpotato whitefly, Bemisia tabaci.

    PubMed

    Cuthbertson, Andrew G S; Walters, Keith F A; Deppe, Carola

    2005-08-01

    The compatibility of the entomopathogenic fungus Lecanicillium muscarium and chemical insecticides used to control the second instar stages of the sweetpotato whitefly, Bemisia tabaci, was investigated. The effect on spore germination of direct exposure for 24 h to the insecticides imidacloprid, buprofezin, teflubenzuron and nicotine was determined. Only exposure to buprofezin was followed by acceptable spore germination. However, all chemicals significantly reduced spore germination when compared to a water control. Infectivity of L. muscarium in the presence of dry residues of buprofezin, teflubenzuron and nicotine (imidacloprid is a systemic pesticide) on foliage were also investigated. No significant detrimental effects on the level of control of B. tabaci was recorded when compared with fungi applied to residue free foliage on either tomato or verbena plants. Fungi in combination with imidacloprid gave higher B. tabaci mortality on verbena foliage compared to either teflubenzuron or nicotine and fungi combinations. Use of these chemical insecticides with L. muscarium in integrated control programmes for B. tabaci is discussed. PMID:16160767

  13. Species and endosymbiont diversity of Bemisia tabaci (Homoptera: Aleyrodidae) on vegetable crops in Senegal.

    PubMed

    Hélène, Delatte; Rémy, Baudin; Nathalie, Becker; Anne-Laure, Girard; Traoré, Ramatoulaye Sidebe; Jean-Michel, Lett; Bernard, Reynaud

    2015-03-01

    Bemisia tabaci-transmitted geminiviruses are one of the major threats on cassava and vegetable crops in Africa. However, to date, few studies are available on the diversity of B. tabaci and their associated endosymbionts in Africa. More than 28 species have been described in the complex of B. tabaci cryptic species; among them, 2 are invasive pests worldwide: MED and MEAM1. In order to assess the species diversity of B. tabaci in vegetable crops in Senegal, several samplings in different localities, hosts and seasons were collected and analyzed with nuclear (microsatellite) and mitochondrial (COI) markers. The bacterial endosymbiont community was also studied for each sample. Two species were detected: MED Q1 and MEAM1 B. Patterns of MED Q1 (dominance on most of the samples and sites, highest nuclear and mitochondrial diversity and broader secondary endosymbiont community: Hamiltonella, Cardinium, Wolbachia and Rickettsia), point toward a predominant resident begomovirus vector group for MED Q1 on market gardening crops. Furthermore, the lower prevalence of the second species MEAM1 B, its lower nuclear and mitochondrial diversity and a narrower secondary endosymbiont community (Hamiltonella/Rickettsia), indicate that this genetic group is exotic and results from a recent invasion in this area. PMID:24789572

  14. Pathogenicity of the entomopathogenic fungus, Lecanicillium muscarium, against the sweetpotato whitefly Bemisia tabaci under laboratory and glasshouse conditions.

    PubMed

    Cuthbertson, Andrew G S; Walters, Keith F A

    2005-11-01

    The potential for using the entomopathogenic fungus Lecanicillium muscarium to control the sweetpotato whitefly, Bemisia tabaci has been established in the laboratory by other studies. Laboratory studies however frequently overestimate the level of control achieved by biological control agents in the glasshouse. Before full-scale commercial or field development is considered, glasshouse trials are required to confirm laboratory results. Under both controlled laboratory and glasshouse conditions high mortality of second instar B. tabaci was recorded after application of L. muscarium. The potential of incorporating L. muscarium into integrated pest management strategies for the control of B. tabaci is discussed. PMID:16244900

  15. Comparison of three single-nozzle operator-carried spray applicators for whitefly (Bemisia tabaci) management on squash

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whiteflies cause problems in vegetable production on a global scale. The primary worldwide whitefly pest is Bemisia tabaci (Gennadius). Insecticides are commonly used to mitigate the whitefly problem in vegetable crops. In limited-resource crop production, operator-carried spray applicators are comm...

  16. Bemisia tabaci (Homoptera: Aleyrodidae) Instar Effects on Rate of Parasitism by Eretmocerus mundus and Encarsia pergandiella (Hymenoptera: Aphelinidae).

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were conducted to compare preference among Bemisia tabaci Gennadius, Biotype B instars for parasitization by Encarsia pergandiella Howard and Eretmocerus mundus Mercet when provided one instar only, two different instars, and four different instars simultaneously. In the single instar-choic...

  17. Introduction and Recovery of Delphastus catalinae (Coleoptera: Coccinellidae) as a predator of Bemisia tabaci (Hemiptera: Aleyrodidae) in Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci (Gennadius) (Hemiptera: Alyerodidae) is an important pest of many crops on a global scale. The use of biological control organisms such as coccinelid predators can help manage this pest. Delphastus catalinae (Horn) (Coleoptera: Coccinelidae) is an obligate predator of whiteflies, in...

  18. Infection of the whitefly Bemisia tabaci with Rickettsia spp. alters its interactions with Tomato yellow leaf curl virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous animal and plant viruses are transmitted by arthropod vectors in a persistent, circulative manner. Tomato yellow leaf curl virus (TYLCV) is transmitted by the sweet potato whitefly Bemisia tabaci. Here we report that infection with Rickettsia spp., a facultative endosymbiont of whiteflies...

  19. Population dynamics of the Bemisia tabaci B and Q biotypes as determined by microsatellite marker and mitochondrial COI sequence comparisons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The current understanding of Bemisia tabaci phylogenetics suggests that this organism exists as a cryptic species complex. This complex is composed of what are most commonly called biotypes, at least some of which appear to have pre and/or post zygotic barriers to hybridization. Numerous studies hav...

  20. Populations of predators and parasitoids of Bemisia tabaci (Hemiptera: Aleyrodidae) after the application of eight biorational insecticides in vegetable crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an important pest of vegetables and many other crops worldwide. Some insecticides may be more compatible with natural enemies for whitefly management than others. Nine biorational insecticides (based on oil, plant deri...

  1. Some cultural strategies to help manage Bemisia tabaci (Hemiptera: Aleyrodidae) and associated whitefly-viruses in vegetable crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius), is an important global pest of numerous crops as a result of its feeding and whitefly-transmitted plant viruses. To help develop a strategy to manage this pest and associated viruses in three vegetable crops in the Egyptian agricultural system, ...

  2. Pathogenicity of Isaria sp. (Hypocreales: Clavicipitaceae)against the sweetpotato whitefly B biotype, Bemisia tabaci (Hemiptera: Aleyrodidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pathogenicity of an indigenous entomopathogenic fungus, Isaria sp., found during natural epizootics on whiteflies in the Lower Rio Grande Valley of Texas, against the sweetpotato whitefly, Bemisia tabaci Gennadius biotype B, was tested under laboratory conditions (27 ºC, 70% RH and a photoperiod...

  3. Identification of the MEAM1 cryptic species of Bemisia tabaci (Hemiptera: Aleyrodidae) by loop-mediated isothermal amplification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are two major invasive cryptic species within the Bemisia tabaci cryptic species complex in Florida, called MEAM1 or biotype B, and MED or biotype Q. We used loop-mediated isothermal amplification of DNA to detect these groups. Primer sets developed in house and those previously published wer...

  4. Taxonomic Status of the Bemisia tabaci Complex (Hemiptera: Aleyrodidae) and Reassessment of the Number of Its Constituent Species

    PubMed Central

    Lee, Wonhoon; Park, Jongsun; Lee, Gwan-Seok; Lee, Seunghwan; Akimoto, Shin-ichi

    2013-01-01

    Bemisia tabaci (Hemiptera: Aleyrodidae) is one of the most important insect pests in the world. In the present study, the taxonomic status of B. tabaci and the number of species composing the B. tabaci complex were determined based on 1059 COI sequences of B. tabaci and 509 COI sequences of 153 hemipteran species. The genetic divergence within B. tabaci was conspicuously higher (on average, 11.1%) than interspecific genetic divergence within the respective genera of the 153 species (on average, 6.5%). This result indicates that B. tabaci is composed of multiple species that may belong to different genera or subfamilies. A phylogenetic tree constructed based on 212 COI sequences without duplications revealed that the B. tabaci complex is composed of a total of 31 putative species, including a new species, JpL. However, genetic divergence within six species (Asia II 1, Asia II 7, Australia, Mediterranean, New World, and Sub Saharan Africa 1) was higher than 3.5%, which has been used as a threshold of species boundaries within the B. tabaci complex. These results suggest that it is necessary to increase the threshold for species boundaries up to 4% to distinguish the constituent species in the B. tabaci complex. PMID:23675507

  5. Olfactory response of predatory Macrolophus caliginosus Wagner (Heteroptera: Miridae) to the odours host plant infested by Bemisia tabaci

    NASA Astrophysics Data System (ADS)

    Saad, Khalid A.; Roff, M. N. Mohamad; Salam, Mansour; Hanifah Mohd, Y.; Idris, A. B.

    2014-09-01

    Plant infested with herbivores, release volatile that can be used by natural enemies to locate their herbivorous prey. Laboratory studies were carried out to determine the olfactory responses of predator Macrolophus caliginosus Wagner (Heteroptera: Miridae), to chili plant infected with eggs, nymphs of Bemisia tabaci, using Y-tube olfactometer. The results shown that predator, M. caliginosus has ability to discriminate between non-infested and infested plant by B. tabaci. Moreover, the predator preferred plants with nymphs over plants with eggs. This suggested that M. caliginous uses whitefly-induced volatile as reliable indicators to distinguish between infested chili plants by nymphs, eggs and non-infested plants. These results enhance our understanding of the olfactory cues that guide foraging by M. caliginosus to plant with and without Bemisia tabaci.

  6. Effects of selected fertilizers on the life history of Bemisia tabaci (Hemiptera: Aleyrodidae) biotype B.

    PubMed

    England, K M; Sadof, C S; Cañnas, L A; Kuniyoshi, C H; Lopez, R G

    2011-04-01

    We tested the effects among a purportedly sustainable water-soluble fertilizer, a conventional water-soluble fertilizer, an alternation of these, a controlled-release fertilizer, and a clear water control on the life-history traits of sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae; =Bemisia argentifolii Bellows & Perring) biotype B reared on poinsettia (Euphorbia pulcherrima Willdenow ex Klotzch). Free amino acids in petioles were measured to estimate plant nutrient assimilation and phloem nutritional quality for B. tabaci biotype B. The sustainable fertilizer produced plants with the highest concentration of amino acids. In contrast, fecundity of whiteflies was lowest in plants treated with the sustainable fertilizer and the water control. The relationship between total amino acids in phloem and survival was significantly quadratic, with the highest survival at intermediate levels. Fecundity, however, was negatively correlated with total amino acid content of the maternal host plant. Variation in total amino acid concentration in petioles of plants treated within fertilizer treatments makes it difficult to predict whether a particular fertilizer will produce plants with enough amino acids to deleteriously affect both survivorship and fecundity and yet yield a plant of good quality. Despite this limitation, we can conclude that the use of this sustainable fertilizer will not cause increases in whitefly populations relative to plants fertilized with water-soluble and slow-release fertilizers that deliver the same level of nitrogen to the plant. PMID:21510203

  7. Endosymbiont metacommunities, mtDNA diversity and the evolution of the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex.

    PubMed

    Gueguen, Gwénaelle; Vavre, Fabrice; Gnankine, Olivier; Peterschmitt, Michel; Charif, Delphine; Chiel, Elad; Gottlieb, Yuval; Ghanim, Murad; Zchori-Fein, Einat; Fleury, Frédéric

    2010-10-01

    Bemisia tabaci, an invasive pest that causes crop damage worldwide, is a highly differentiated species complex, divided into biotypes that have mainly been defined based on mitochondrial DNA sequences. Although endosymbionts can potentially induce population differentiation, specialization and indirect selection on mtDNA, studies have largely ignored these influential passengers in B. tabaci, despite as many as seven bacterial endosymbionts have been identified. Here, we investigate the composition of the whole bacterial community in worldwide populations of B. tabaci, together with host genetic differentiation, focusing on the invasive B and Q biotypes. Among 653 individuals studied, more than 95% of them harbour at least one secondary endosymbiont, and multiple infections are very common. In addition, sequence analyses reveal a very high diversity of facultative endosymbionts in B. tabaci, with some bacterial genus being represented by more than one strain. In the B and Q biotypes, nine different strains of bacteria have been identified. The mtDNA-based phylogeny of B. tabaci also reveals a very high nucleotide diversity that partitions the two ITS clades (B and Q) into six CO1 genetic groups. Each genetic group is in linkage disequilibrium with a specific combination of endosymbionts. All together, our results demonstrate the rapid dynamics of the bacterial endosymbiont-host associations at a small evolutionary scale, questioning the role of endosymbiotic communities in the evolution of the Bemisia tabaci species complex and strengthening the need to develop a metacommunity theory of inherited endosymbionts. PMID:20723069

  8. Aphid-induced Defences in Chilli Affect Preferences of the Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae).

    PubMed

    Saad, Khalid A; Mohamad Roff, M N; Hallett, Rebecca H; Idris, A B

    2015-01-01

    The sweetpotato whitefly (WF), Bemisia tabaci, is a major pest that damages a wide range of vegetable crops in Malaysia. WF infestation is influenced by a variety of factors, including previous infestation of the host plant by other insect pests. This study investigated the effects of previous infestation of host chilli plants by the green peach aphid (Myzus persicae) on the olfactory behavioural response of B. tabaci, using free-choice bioassay with a Y-tube olfactometer. We analysed volatile organic compounds (VOCs) emitted by non-infested and M. persicae-infested chilli plants using solid-phase microextraction and gas chromatography-mass spectrometry. Our results showed that female WFs preferred non-infested to pre-infested plants. Collection and analysis of volatile compounds emitted by infested plants confirmed that there were significant increases in the production of monoterpenes (cymene; 1,8-cineole), sesquiterpenes (β-cadinene, α-copaene), and methyl salicylate (MeSA) compared to non-infested plants. Our results suggest that host plant infestation by aphids may induce production of secondary metabolites that deter B. tabaci from settling on its host plants. These results provide important information for understanding WF host selection and dispersal among crops, and also for manipulating WF behaviour to improve IPM in chilli. PMID:26334135

  9. A Bemisia tabaci midgut protein interacts with begomoviruses and plays a role in virus transmission.

    PubMed

    Rana, Vipin Singh; Popli, Sonam; Saurav, Gunjan Kumar; Raina, Harpreet Singh; Chaubey, Rahul; Ramamurthy, V V; Rajagopal, R

    2016-05-01

    Begomoviruses are a major group of plant viruses, transmitted exclusively by Bemisia tabaci (Gennadius) in a persistent circulative non-propagative manner. The information regarding molecular and cellular basis underlying Begomovirus - whitefly interaction is very scarce. Evidences have suggested that the insect gut possesses some crucial protein receptors that allow specific entry of virus into the insect haemolymph. We have performed yeast two hybrid gut cDNA expression library screening against coat protein of Tomato leaf curl New Delhi virus (ToLCV) and Cotton leaf curl Rajasthan virus (CLCuV) as bait. Midgut protein (MGP) was the common protein found interacting with both ToLCV and CLCuV. MGP was localized in whole mount B. tabaci as well as in dissected guts through confocal microscopy. Pull down and dot blot assays confirmed in vitro interaction between ToLCV/CLCuV coat protein and MGP. Immunolocalization analysis also showed colocalization of ToLCV/CLCuV particles and MGP within insect's gut. Finally, anti-MGP antibody fed B. tabaci, exhibited 70% reduction in ToLCV transmission, suggesting a supportive role for MGP in virus transmission. PMID:26488331

  10. Host selection by the autoparasitoid Encarsia pergandiella on primary (Bemisia tabaci) and secondary (Eretmocerus mundus) hosts.

    PubMed

    Zhang, Yi-Bo; Castañé, Cristina; Gabarra, Rosa; Albajes, Ramon; Wan, Fang-Hao

    2015-12-01

    In autoparasitoids, females are generally primary endoparasitoids of Hemiptera, while males are hyperparasitoids developing in or on conspecific females or other primary parasitoids. Female-host acceptance can be influenced by extrinsic and/or intrinsic factors. In this paper, we are concerned with intrinsic factors such as nutritional status, mating status, etc. We observed the behavior of Encarsia pergandiella Howard (Hymenoptera: Aphelinidae) females when parasitizing primary (3rd instar larvae of Bemisia tabaci Gennadius [Homoptera: Aleyrodidae]) and secondary hosts (3rd instar larvae and pupae of Eretmocerus mundus Mercet [Hymenoptera: Aphelinidae]) for a period of 1 h. Females had different reproductive (virgin or mated younger) and physiological (fed elder or mated elder) status. Virgin females killed a large number of secondary hosts while investing a long time per host. However, they did not feed upon them. Mated females killed a lower number of secondary hosts and host feeding was observed in both consuming primary and secondary hosts. It was common to observe host examining females of all physiological statues tested repeatedly stinging the same hosts when parasitizing, killing or rejecting them. Fed elder females parasitized more B. tabaci larvae than E. mundus larvae or pupae, while investing less time on the primary host than on the secondary host. They also parasitized more B. tabaci larvae than mated elder females, while investing less time per host. The access of females to honey allowed them to lay more eggs. PMID:24992443

  11. Transcriptomic dissection of sexual differences in Bemisia tabaci, an invasive agricultural pest worldwide

    PubMed Central

    Xie, Wen; Guo, Litao; Jiao, Xiaoguo; Yang, Nina; Yang, Xin; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2014-01-01

    Sex difference involving chromosomes and gene expression has been extensively documented. In this study, the gender difference in the sweetpotato whitefly Bemisia tabaci was investigated using Illumina-based transcriptomic analysis. Gender-based RNAseq data produced 27 Gb reads, and subsequent de novo assembly generated 93,948 transcripts with a N50 of 1,853 bp. A total of 1,351 differentially expressed genes were identified between male and female B. tabaci, and majority of them were female-biased. Pathway and GO enrichment experiments exhibited a gender-specific expression, including enriched translation in females, and enhanced structural constituent of cuticle in male whiteflies. In addition, a putative transformer2 gene (tra2) was cloned, and the structural feature and expression profile of tra2 were investigated. Sexually dimorphic transcriptome is an uncharted territory for the agricultural insect pests. Molecular understanding of sex determination in B. tabaci, an emerging invasive insect pest worldwide, will provide potential molecular target(s) for genetic pest control alternatives. PMID:24526031

  12. Extraordinary resistance to insecticides reveals exotic Q biotype of Bemisia tabaci in the New World.

    PubMed

    Dennehy, Timothy J; Degain, Benjamin A; Harpold, Virginia S; Zaborac, Marni; Morin, Shai; Fabrick, Jeffrey A; Nichols, Robert L; Brown, Judith K; Byrne, Frank J; Li, Xianchun

    2010-12-01

    A strain of the whitefly Bemisia tabaci (Gennadius) possessing unusually high levels of resistance to a wide range of insecticides was discovered in 2004 in the course of routine resistance monitoring in Arizona. The multiply resistant insects, collected from poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) plants purchased at a retail store in Tucson, were subjected to biotype analysis in three laboratories. Polyacrylamide gel electrophoresis of naphthyl esterases and sequencing of the mitochondrial cytochrome oxidase I gene (780 bp) confirmed the first detection of the Q biotype of B. tabaci in the New World. This U.S. Q biotype strain, referred to as Poinsettia'04, was highly resistant to two selective insect growth regulators, pyriproxyfen and buprofezin, and to mixtures of fenpropathrin and acephate. It was also unusually low in susceptibility to the neonicotinoid insecticides imidacloprid, acetamiprid, and thiamethoxam, relative to B biotype whiteflies. In 100 collections of whiteflies made in Arizona cotton (Gossypium spp.), vegetable, and melon (Cucumis melo L.) fields from 2001 to 2005, no Q biotypes were detected. Regions of the United States that were severely impacted by the introduction of the B biotype of B. tabaci in the 1980s would be well advised to promote measures that limit movement of the Q biotype from controlled environments into field systems and to formulate alternatives for managing this multiply-resistant biotype, in the event that it becomes more widely distributed. PMID:21309242

  13. Aphid-induced Defences in Chilli Affect Preferences of the Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)

    PubMed Central

    Saad, Khalid A.; Mohamad Roff, M. N.; Hallett, Rebecca H.; Idris, A. B.

    2015-01-01

    The sweetpotato whitefly (WF), Bemisia tabaci, is a major pest that damages a wide range of vegetable crops in Malaysia. WF infestation is influenced by a variety of factors, including previous infestation of the host plant by other insect pests. This study investigated the effects of previous infestation of host chilli plants by the green peach aphid (Myzus persicae) on the olfactory behavioural response of B. tabaci, using free-choice bioassay with a Y-tube olfactometer. We analysed volatile organic compounds (VOCs) emitted by non-infested and M. persicae-infested chilli plants using solid-phase microextraction and gas chromatography–mass spectrometry. Our results showed that female WFs preferred non-infested to pre-infested plants. Collection and analysis of volatile compounds emitted by infested plants confirmed that there were significant increases in the production of monoterpenes (cymene; 1,8-cineole), sesquiterpenes (β–cadinene, α-copaene), and methyl salicylate (MeSA) compared to non-infested plants. Our results suggest that host plant infestation by aphids may induce production of secondary metabolites that deter B. tabaci from settling on its host plants. These results provide important information for understanding WF host selection and dispersal among crops, and also for manipulating WF behaviour to improve IPM in chilli. PMID:26334135

  14. Performance of Bemisia tabaci (Genn.) Biotype B (Hemiptera: Aleyrodidae) on Weeds.

    PubMed

    Sottoriva, L D M; Lourenção, A L; Colombo, C A

    2014-12-01

    Bemisia tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) is regarded as a pest with a large number of hosts, including crops and weeds. The performance of this whitefly on seven weeds was evaluated in order to identify the most suitable host. The following weeds that are very common in intense agricultural areas in the state of São Paulo, Brazil, were selected for this study: spurge (Euphorbia heterophylla), beggarticks (Bidens pilosa), red tasselflower (Emilia sonchifolia), small-flower galinsoga (Galinsoga parviflora), pigweed (Amaranthus viridis), black nightshade (Solanum americanum), and morning glory (Ipomoea sp.). In free-choice tests, adult preference and oviposition were greatest on spurge. In contrast, morning glory was the least attractive and least oviposited plant. In assays carried out for egg-adult development, egg viability was greater than 87% over all weeds, whereas nymph viability ranged from 74 to 97%. The developmental period from egg to adult ranged from 26.7 to 49.1 days among the hosts under study. The lowest nymph density rate was observed for beggarticks and morning glory. Cluster analysis resulted in a single group formed by spurge, indicating its superiority as a host for B. tabaci biotype B. Even though the parameters evaluated indicate that spurge is the most suitable host among the weeds, all the others allow the reproduction of B. tabaci biotype B. For this reason, they should be observed during cropping and the intercrop period in areas infested by this whitefly. PMID:27194066

  15. Efficacy of the entomopathogenic nematode, Steinernema feltiae, against sweetpotato whitefly Bemisia tabaci (Homoptera: Aleyrodidae) under laboratory and glasshouse conditions.

    PubMed

    Cuthbertson, A G S; Walters, K F A; Northing, P; Luo, W

    2007-02-01

    The potential of using the entomopathogenic nematode Steinernema feltiae to control the sweetpotato whitefly Bemisia tabaci (Gennadius) has been established in previous laboratory studies. However, laboratory studies can overestimate the level of control achieved by biocontrol agents in the glasshouse. Glasshouse trials are therefore required to confirm laboratory results before full-scale commercial development is considered. Under both controlled laboratory and glasshouse conditions high mortality of second instar B. tabaci (>90% and >80%, respectively) was recorded after application of S. feltiae. The efficacy of the biocontrol agent at various application rates was also investigated, where halving the rate of S. feltiae application caused no significant reduction in B. tabaci mortality on tomato foliage. Steinernema feltiae has shown much potential for incorporation into integrated pest management strategies for the control of B. tabaci. PMID:17298677

  16. Infestation by Bemisia tabaci (Hemiptera: Aleyrodidae) and incidence of whitefly-transmitted viruses after the application of four biorational insecticides in some crops in Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a global insect pest that transmits many important plant viruses. A field study was conducted on infestation by B. tabaci and incidence of whitefly-transmitted viruses after the application of selected foliar and seed-treated biorational insecti...

  17. Transcriptomic and Proteomic Responses of Sweetpotato Whitefly, Bemisia tabaci, to Thiamethoxam

    PubMed Central

    Yang, Nina; Xie, Wen; Yang, Xin; Wang, Shaoli; Wu, Qingjun; Li, Rumei; Pan, Huipeng; Liu, Baiming; Shi, Xiaobin; Fang, Yong; Xu, Baoyun; Zhou, Xuguo; Zhang, Youjun

    2013-01-01

    Background The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is one of the most widely distributed agricultural pests. Although it has developed resistance to many registered insecticides including the neonicotinoid insecticide thiamethoxam, the mechanisms that regulate the resistance are poorly understood. To understand the molecular basis of thiamethoxam resistance, “omics” analyses were carried out to examine differences between resistant and susceptible B. tabaci at both transcriptional and translational levels. Results A total of 1,338 mRNAs and 52 proteins were differentially expressed between resistant and susceptible B. tabaci. Among them, 11 transcripts had concurrent transcription and translation profiles. KEGG analysis mapped 318 and 35 differentially expressed genes and proteins, respectively, to 160 and 59 pathways (p<0.05). Thiamethoxam treatment activated metabolic pathways (e.g., drug metabolism), in which 118 transcripts were putatively linked to insecticide resistance, including up-regulated glutathione-S-transferase, UDP glucuronosyltransferase, glucosyl/glucuronosyl transferase, and cytochrome P450. Gene Ontology analysis placed these genes and proteins into protein complex, metabolic process, cellular process, signaling, and response to stimulus categories. Quantitative real-time PCR analysis validated “omics” response, and suggested a highly overexpressed P450, CYP6CX1, as a candidate molecular basis for the mechanistic study of thiamethoxam resistance in whiteflies. Finally, enzymatic activity assays showed elevated detoxification activities in the resistant B. tabaci. Conclusions This study demonstrates the applicability of high-throughput omics tools for identifying molecular candidates related to thiamethoxam resistance in an agricultural important insect pest. In addition, transcriptomic and proteomic analyses provide a solid foundation for future functional investigations into the complex molecular mechanisms

  18. Effect of starvation on vein preference of whitefly (Bemisia tabaci) on chilli as host plant

    NASA Astrophysics Data System (ADS)

    Siti Sakinah, A.; Mohamad Roff M., N.; Idris, A. B.

    2014-09-01

    The whitefly, Bemisia tabaci (Gennadius), is a cosmopolitan pest of horticultural crops. It caused serious damaged to the plants by feeding on plant saps as direct damage and transmit virus as indirect damage. Vein preferences of both female and male whitefly (WF) on chilli plant were recorded using Dinolite, a portable microscope, under laboratory conditions. WF adults of both sexes were starved for 2 and 4 hours before used for observation while no starvation for control individual (treatment). Results showed that both female and male preferred to feed on secondary veins rather than lamina, midrib and vein. From the result of whitefly preferred target site, hopefully this information will help to improve control tactics in WF management.

  19. Investigation on some biological aspects of Chrysoperla lucasina (Chrysopidae: Neuroptera) on Bemisia tabaci in laboratory conditions.

    PubMed

    Baghdadi, A; Sharifi, F; Mirmoayedi, A

    2012-01-01

    Bemisia tabaci is one of the most important key pests of many types of cultivated plants. Lacewings (Chrysopidae: Neuroptera) are predatory insects, widely used in biological control programs. Between them green lacewing is a promising biological control agent of pests in green houses and crop fields. In this study, gravid females of the green lacewing Chrysoperla lucasina (Lacroix) were captured from Sarepolzahab ( altitude 540m, latitude 34 degrees ,14' N 46 degrees, 9' E) in western part of Iran. Collected insects were reared in a growth chamber, under experimental conditions (25 +/- 1 degrees C, 70 +/- 5% RH and a photoperiod of 16:8 L: D). Different diets were offered to larvae which consisted of a whitefly species B. tabaci, an aphid Myzus persica and also lyophilized powder of drone honeybee (Apis melifera). As different foods were used to nurish larvae, so for each diet, mean larval period were calculated, and finally means were compared to each other. Anova in MSTAT-C was used for analysis of variance, and Duncan multiple range test (DMRT) to compare between means. The results showed that larvae had maximum duration of 27 +/- 0.33 days when fed on honeybee lyophilized powder and the minimum value was 17.9 +/- 0.3 days for B. tabaci. 25 +/- 0.27 day recorded for M. persicae. Food preference of the 3rd instar larvae of green lacewing was surveyed, they showed a food preference to M. persicae, to compare with B. tabaci, as the former has a bigger body size, so more easily to be captured by the predator larvae. The 3rd instar larvae of lacewing were more voracious on preys, than the 1st or the 2nd instar larvae. Statistically speaking, there were a significantly difference when mean of different preys consumed by predator larvae were compared. We found, that when the predator larvae have fed on B. tabaci, their development time was shorter, and when arrived to adult stage, the adults showed, an improved fertility. The results indicated that the suitable prey

  20. The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci

    PubMed Central

    Shi, Xiaobin; Chen, Gong; Tian, Lixia; Peng, Zhengke; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2016-01-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA)-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV). The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles—especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles. PMID:27376280

  1. The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci.

    PubMed

    Shi, Xiaobin; Chen, Gong; Tian, Lixia; Peng, Zhengke; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2016-01-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA)-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV). The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles-especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles. PMID:27376280

  2. Biological Invasions of Geminiviruses: Case Study of TYLCV and Bemisia tabaci in Reunion Island

    PubMed Central

    Péréfarres, Frédéric; Thierry, Magali; Becker, Nathalie; Lefeuvre, Pierre; Reynaud, Bernard; Delatte, Hélène; Lett, Jean-Michel

    2012-01-01

    In the last 20 years, molecular ecology approaches have proven to be extremely useful to identify and assess factors associated with viral emerging diseases, particularly in economically and socially important tropical crops such as maize (maize streak disease) and cassava (cassava mosaic disease). Molecular ecology approaches were applied in Reunion Island to analyze the epidemic of tomato yellow leaf curl disease, which has been affecting the island since the end of the 1990s. Before the invasive biotype B (currently known as Middle East-Asia Minor 1 cryptic species) of Bemisia tabaci spread across the world, Reunion Island (South West Indian Ocean) only hosted an indigenous biotype of B. tabaci, Ms (currently known as Indian Ocean cryptic species). Wild hybrids between invasive and indigenous species were subsequently characterized over multiple generations. Endosymbiont analysis of the hybrid population indicated that matings were non-random. Similarly, while no indigenous begomoviruses have ever been reported on Reunion Island, the two main strains of one of the most damaging and emerging plant viruses in the world, the Mild and Israel strains of the Tomato yellow leaf curl virus (TYLCV-Mld and TYLCV-IL), were introduced in 1997 and 2004 respectively. While these introductions extensively modified the agricultural landscape of Reunion Island, they also provided an invaluable opportunity to study the ecological and genetic mechanisms involved in biological invasion and competition. PMID:23235470

  3. Acyl sugars and whitefly (Bemisia tabaci) resistance in segregating populations of tomato genotypes.

    PubMed

    Dias, D M; Resende, J T V; Marodin, J C; Matos, R; Lustosa, I F; Resende, N C V

    2016-01-01

    The wild tomato, Solanum pennellii, is an important source of resistance genes against tomato pests. This resistance is due to the presence of acyl sugars (AS), which are allelochemicals that have negative effects on arthropod pests. There are no commercially available tomato cultivars that exhibit significant levels of resistance to arthropod pests. Therefore, this study evaluated resistance to whitefly (Bemisia tabaci) in F2 and F2RC1 tomato genotypes with high AS levels from a cross between Solanum lycopersicum 'Redenção' and the S. pennellii accession, LA-716. Plants were exposed to B. tabaci biotype B at the pre-flowering stage. In both generations, there were significant, negative correlations between AS content and oviposition preference and nymph development. Whitefly exhibited a lower preference for oviposition and produced fewer nymphs in genotypes with high AS levels and the wild parent S. pennellii than in the low AS-level genotypes and Redenção cultivar, demonstrating that the breeding program was effective in transferring resistance to the F2 and F2RC1 generations. RVTA-2010-pl#31 and RVTA-2010-pl#94 in the F2 population are promising genotypes that produced materials with high AS levels in the F2RC1 generation (RVTA-2010-31-pl#177 and RVTA-2010-94-pl#381). PMID:27173206

  4. Challenges with managing insecticide resistance in agricultural pests, exemplisfied by the whitefly Bemisia tabaci

    PubMed Central

    Denholm, I.

    1998-01-01

    For many key agricultural pests, successful management of insecticide resistance depends not only on modifying the way that insecticides are deployed, but also on reducing the total number of treatments applied. Both approaches benefit from a knowledge of the biological characteristics of pests that promote or may retard the development of resistance. For the whitefly Bemisia tabaci (Gennadius), these factors include a haplodiploid breeding system that encourages the rapid selection and fixation of resistance genes, its breeding cycle on a succession of treated or untreated hosts, and its occurrence on and dispersal from high-value crops in greenhouses and glasshouses. These factors, in conjunction with often intensive insecticide use, have led to severe and widespread resistance that now affects several novel as well as conventional control agents. Resistance-management strategies implemented on cotton in Israel, and subsequently in south-western USA, have nonetheless so far succeeded in arresting the resistance treadmill in B. tabaci through a combination of increased chemical diversity, voluntary or mandatory restrictions on the use of key insecticides, and careful integration of chemical control with other pest-management options. In both countries, the most significant achievement has been a dramatic reduction in the number of insecticide treatments applied against whiteflies on cotton, increasing the prospect of sustained use of existing and future insecticides.

  5. Quantitative resistance against Bemisia tabaci in Solanum pennellii: Genetics and metabolomics.

    PubMed

    van den Oever-van den Elsen, Floor; Lucatti, Alejandro F; van Heusden, Sjaak; Broekgaarden, Colette; Mumm, Roland; Dicke, Marcel; Vosman, Ben

    2016-04-01

    The whitefly Bemisia tabaci is a serious threat in tomato cultivation worldwide as all varieties grown today are highly susceptible to this devastating herbivorous insect. Many accessions of the tomato wild relative Solanum pennellii show a high resistance towards B. tabaci. A mapping approach was used to elucidate the genetic background of whitefly-resistance related traits and associated biochemical traits in this species. Minor quantitative trait loci (QTLs) for whitefly adult survival (AS) and oviposition rate (OR) were identified and some were confirmed in an F2 BC1 population, where they showed increased percentages of explained variance (more than 30%). Bulked segregant analyses on pools of whitefly-resistant and -susceptible F2 plants enabled the identification of metabolites that correlate either with resistance or susceptibility. Genetic mapping of these metabolites showed that a large number of them co-localize with whitefly-resistance QTLs. Some of these whitefly-resistance QTLs are hotspots for metabolite QTLs. Although a large number of metabolite QTLs correlated to whitefly resistance or susceptibility, most of them are yet unknown compounds and further studies are needed to identify the metabolic pathways and genes involved. The results indicate a direct genetic correlation between biochemical-based resistance characteristics and reduced whitefly incidence in S. pennellii. PMID:26576823

  6. Relative amount of symbionts in Bemisia tabaci (Gennadius) Q changes with host plant and establishing the method of analyzing free amino acid in B. tabaci

    PubMed Central

    Pan, Huipeng; Su, Qi; Jiao, Xiaoguo; Zhou, Long; Liu, Baiming; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Xu, Baoyun; Zhang, YouJun

    2013-01-01

    The impact of symbionts on their insect hosts depends on their infection density. In the current study, we investigated the effects of host plants (cucumber, cabbage, and cotton) on the relative amount of symbionts Portiera and Hamiltonella in the whitefly Bemisia tabaci (Gennadius) Q. The relative amounts of symbionts in 3 host plant B. tabaci Q populations with the same genetic background were evaluated by quantitative PCR. The whiteflies of cabbage population harbored more Portiera than those of cucumber and cotton populations, and the relative amount of Portiera did not differ statistically between cotton and cucumber populations. The whiteflies of cucumber and cabbage populations harbored more Hamiltonella than that of cotton population, and the relative amount of Hamiltonella did not differ statistically between cabbage and cucumber populations, indicated that the relative amount of symbionts was significantly affected by host plant. In addition, the method of analyzing the composition of free amino acid in B. tabaci was established. Twenty-eight amino acids were detected in the B. tabaci Q population, the non-essential amino acids, such as glutamate, glutamine, alanine, proline and the essential amino acid arginine were the dominant amino acids in B. tabaci Q. PMID:23750302

  7. Monitoring changes in Bemisia tabaci (Hemiptera: Aleyrodidae) susceptibility to neonicotinoid insecticides in Arizona and California.

    PubMed

    Castle, S J; Prabhaker, N

    2013-06-01

    Bemisia tabaci (Gennadius) biotype B is a highly prolific and polyphagous whitefly that established in much of North America during the 1980s. Neonicotinoid insecticides have been fundamental in regaining control over outbreak populations of B. tabaci, but resistance threatens their sustainability. Susceptibility of B. tabaci in the southwestern United States to four neonicotinoid insecticides varied considerably across populations within each year over a 3 yr period. Using a variability ratio of highest LC50 to lowest LC50 in field-collected whitefly adults from Arizona and California, the ranges of LC50(s) across all tests within compounds were highest to imidacloprid and lowest to thiamethoxam. Patterns of susceptibility were similar among all four neonicotinoid insecticides, but the greater variability in responses to imidacloprid and significantly higher LC50(s) attained indicated higher resistance levels to imidacloprid in all field populations. Further evidence of differential toxicities of neonicotinoids was observed in multiple tests of dinotefuran against imidacloprid-resistant lab strains that yielded significant differences in the LC50(s) of dinotefuran and imidacloprid in simultaneous bioassays. To test the possibility that resistance expression in field-collected insects was sometimes masked by stressful conditions, field strains cultured in a greenhouse without insecticide exposure produced significantly higher LC50(s) to all neonicotinoids compared with LC50(s) attained directly from the field. In harsh climates such as the American southwest, resistance expression in field-collected test insects may be strongly influenced by environmental stresses such as high temperatures, overcrowding, and declining host plant quality. PMID:23865208

  8. Comparison of the Antennal Sensilla Ultrastructure of Two Cryptic Species in Bemisia tabaci

    PubMed Central

    Zhang, Xiao-Man; Wang, Su; Li, Shu; Luo, Chen; Li, Yuan-Xi; Zhang, Fan

    2015-01-01

    Bemisia tabaci is an important agricultural pest with worldwide distribution and host preference. Therefore, understanding the biology of this pest is important to devise specific pest control strategies. The antennae of herbivorous insects play an important role in the identification of hosts using plant volatiles. To understand the features of antennae in B. tabaci MEAM 1(formerly known as biotype ‘B’) and MED (formerly known as biotype ‘Q’), the morphology and distribution of the antennal sensilla were examined using scanning electron micrographs. The results showed that the average antennae length in MEAM 1 was longer than MED. No differences were observed in the number and distribution of antennal sensilla in MEAM 1 and MED antennae; each antenna had nine different types of sensilla. Both cryptic species possessed Microtrichia, Grooved surface trichodea sensilla, Chaetae sensilla, Coeloconic sensillaⅠandⅡ, Basiconic sensilla Ⅰ, Ⅱ and Ⅲ and Finger-like sensilla. This is the first report of Grooved surface trichodea sensilla and Basiconic sensilla Ⅱ on B. tabaci flies. The numbers of Chaetae sensilla were different in the females and males of MEAM 1 and MED, which females having 5 and males containing 7. The surface structure of Basiconic sensilla Ⅰ was different with MEAM 1 showing a multiple-pitted linen surface and MED showing a multiple-pitted pocking surface. Basiconic sensillaⅡ were double in one socket with the longer one having a multiple-pitted surface and the shorter one with a smooth surface. Basiconic Ⅲ and Finger-like sensillae were longer in MEAM 1 antennae than in MED antennae. Our results are expected to further the studies that link morphological characteristics to insect behavior and help devise strategies to control insect pests. PMID:25822843

  9. [Effects of calcium fertilizer on the development, survival, and feeding of B-biotype Bemisia tabaci on Euphorbia pulcherrima].

    PubMed

    Huang, Jun; Zhang, Juan; Yu, Yong-Ming; Liu, Jian-Xin; Li, Ming-Jiang; Zhu, Kai-Yuan

    2012-09-01

    This paper studied the development, survival, and feeding of B-biotype Bemisia tabaci on Euphorbia pulcherrima under the conditions of 26 +/- 1 degrees C and 60% - 80% relative humidity after applying calcium fertilizer, taking applying fresh water as the control. There existed significant differences in the developmental duration of B. tabaci between treatment applying calcium fertilizer and the control. After applying calcium fertilizer, the egg stage of B. tabaci shortened significantly, and the development from egg to adult took 20.18 days (for the control, it took 18.72 days). However, there were no significant differences in the survival rates of B. tabaci at different development stages between the two treatments. The feeding of B. tabaci on E. pulcherrima induced the plant leaf chlorophyll fluorescence parameters changed, i. e., the photochemical efficiency (Fv/Fm), photochemical quenching coefficient (q(p)), light use efficiency (alpha), maximum photosynthesis rate (rETRmax), and tolerance to light (I(k)) decreased significantly, while the non-photochemical quenching coefficient (NPQ) had a significant increase. After applying calcium fertilizer, the plant leaf photoinhibition parameter (beta), rETRmax, and I(k) had less difference with th e control. The nail polish blot observation on the lower epidermis structure of plant leaf showed that calcium fertilizer could effectively compensate the decrease in the photosynthesis of E. pulcherrima damaged by B-biotype B. tabaci. PMID:23286011

  10. Trade-offs between survival, longevity, and reproduction, and variation of survival tolerance in Mediterranean Bemisia tabaci after temperature stress.

    PubMed

    Lü, Zhi-Chuang; Wang, Yan-Min; Zhu, Shao-Guang; Yu, Hao; Guo, Jian-Ying; Wan, Fang-Hao

    2014-01-01

    The invasive Mediterranean Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) has emerged as one of the most common agricultural pests in the world. In the present study, we examined the cross-tolerance, fitness costs, and benefits of thermal tolerance and the variation in the responses of life history traits after heat-shock selection. The results showed that survival and longevity of Mediterranean B. tabaci were decreased significantly after direct or cross temperature stress and that the number of eggs per female was not reduced significantly. Furthermore, heat-shock selection dramatically increased the survival of Mediterranean B. tabaci within two generations, and it did not significantly affect the egg number per female within five generations. These results indicated that there was a trade-off between survival, longevity, and reproduction in Mediterranean B. tabaci after temperature stress. The improvement in reproduction was costly in terms of decreased survival and longevity, and there was a fitness consequence to temperature stress. In addition, heat tolerance in Mediterranean B. tabaci increased substantially after selection by heat shock, indicating a considerable variation for survival tolerance in this species. This information could help us better understand the thermal biology of Mediterranean B. tabaci within the context of climate change. PMID:25368068

  11. Insecticidal Activity of Some Reducing Sugars Against the Sweet Potato Whitefly, Bemisia tabaci, Biotype B

    PubMed Central

    Hu, Jing S.; Gelman, Dale B.; Salvucci, Michael E.; Chen, Yan P.; Blackburn, Michael B.

    2010-01-01

    The effects of 16 sugars (arabinose, cellobiose, fructose, galactose, gentiobiose, glucose, inositol, lactose, maltose, mannitol (a sugar alcohol), mannose, melibiose, ribose, sorbitol, trehalose, and xylose) on sweet potato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) survival were determined using in vitro bioassays. Of these sugars, arabinose, mannose, ribose, and xylose were strongly inhibitory to both nymphal and adult survival. When 10% mannose was added to the nymphal diet, 10.5%, 1.0%, and 0% developed to the 2nd, 3rd, and 4th instars, respectively. When 10% arabinose was added, 10.8% and 0% of the nymphs molted to the 2nd and 3rd instars, respectively. Addition of 10% xylose or ribose completely terminated B. tabaci development, preventing the molt to the 2nd instar. With decreasing sugar concentrations the inhibitory effect was significantly reduced. In tests using adults, arabinose, galactose, inositol, lactose, maltose, mannitol, mannose, melibiose, ribose, sorbitol, trehalose, and xylose significantly reduced mean day survival. Mortality rates were highest when arabinose, mannitol, mannose, ribose, or xylose was added to the diet. Mean day survival was less than 2 days when adults were fed on diet containing 10% of any one of these five sugars. When lower concentrations of sugars were used there was a decrease in mortality. Mode of action studies revealed that toxicity was not due to the inhibition of alpha glucosidase (converts sucrose to glucose and fructose) and/or trehalulose synthase (converts sucrose to trehalulose) activity. The result of agarose gel electrophoresis of RT-PCR products of bacterial endosymbionts amplified from RNA isolated from whiteflies fed with 10% arabinose, mannose, or xylose indicated that the concentration of endosymbionts in mycetomes was not affected by the toxic sugars. Experiments in which B. tabaci were fed on diets that contained radio-labeled sucrose, methionine or inulin and one or none (control) of

  12. Replication of Tomato Yellow Leaf Curl Virus in Its Whitefly Vector, Bemisia tabaci

    PubMed Central

    Pakkianathan, Britto Cathrin; Kontsedalov, Svetlana; Lebedev, Galina; Mahadav, Assaf; Zeidan, Muhammad; Czosnek, Henryk

    2015-01-01

    ABSTRACT Tomato yellow leaf curl virus (TYLCV) is a begomovirus transmitted exclusively by the whitefly Bemisia tabaci in a persistent, circulative manner. Replication of TYLCV in its vector remains controversial, and thus far, the virus has been considered to be nonpropagative. Following 8 h of acquisition on TYLCV-infected tomato plants or purified virions and then transfer to non-TYLCV-host cotton plants, the amounts of virus inside whitefly adults significantly increased (>2-fold) during the first few days and then continuously decreased, as measured by the amounts of genes on both virus DNA strands. Reported alterations in insect immune and defense responses upon virus retention led us to hypothesize a role for the immune response in suppressing virus replication. After virus acquisition, stress conditions were imposed on whiteflies, and the levels of three viral gene sequences were measured over time. When whiteflies were exposed to TYLCV and treatment with two different pesticides, the virus levels continuously increased. Upon exposure to heat stress, the virus levels gradually decreased, without any initial accumulation. Switching of whiteflies between pesticide, heat stress, and control treatments caused fluctuating increases and decreases in virus levels. Fluorescence in situ hybridization analysis confirmed these results and showed virus signals inside midgut epithelial cell nuclei. Combining the pesticide and heat treatments with virus acquisition had significant effects on fecundity. Altogether, our results demonstrate for the first time that a single-stranded DNA plant virus can replicate in its hemipteran vector. IMPORTANCE Plant viruses in agricultural crops are of great concern worldwide. Many of them are transmitted from infected to healthy plants by insects. Persistently transmitted viruses often have a complex association with their vectors; however, most are believed not to replicate within these vectors. Such replication is important, as it

  13. Gene expression profiling in the thiamethoxam resistant and susceptible B-biotype sweetpotato whitefly, Bemisia tabaci.

    PubMed

    Xie, Wen; Yang, Xin; Wang, Shao-Ii; Wu, Qing-jun; Yang, Ni-na; Li, Ru-mei; Jiao, Xiao-guo; Pan, Hui-peng; Liu, Bai-ming; Feng, Yun-tao; Xu, Bao-yun; Zhou, Xu-guo; Zhang, You-jun

    2012-01-01

    Thiamethoxam has been used as a major insecticide to control the B-biotype sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Due to its excessive use, a high level of resistance to thiamethoxam has developed worldwide over the past several years. To better understand the molecular mechanisms underlying this resistance in B. tabaci, gene profiles between the thiamethoxam-resistant and thiamethoxam-susceptible strains were investigated using the suppression subtractive hybridization (SSH) library approach. A total of 72 and 52 upand down-regulated genes were obtained from the forward and reverse SSH libraries, respectively. These expressed sequence tags (ESTs) belong to several functional categories based on their gene ontology annotation. Some categories such as cell communication, response to abiotic stimulus, lipid particle, and nuclear envelope were identified only in the forward library of thiamethoxam-resistant strains. In contrast, categories such as behavior, cell proliferation, nutrient reservoir activity, sequence-specific DNA binding transcription factor activity, and signal transducer activity were identified solely in the reverse library. To study the validity of the SSH method, 16 differentially expressed genes from both forward and reverse SSH libraries were selected randomly for further analyses using quantitative realtime PCR (qRT-PCR). The qRT-PCR results were fairly consistent with the SSH results; however, only 50% of the genes showed significantly different expression profiles between the thiamethoxam-resistant and thiamethoxam-susceptible whiteflies. Among these genes, a putative NAD-dependent methanol dehydrogenase was substantially over-expressed in the thiamethoxamresistant adults compared to their susceptible counterparts. The distributed profiles show that it was highly expressed during the egg stage, and was most abundant in the abdomen of adult females. PMID:22957505

  14. Behavioral Response of Bemisia tabaci (Hemiptera: Aleyrodidae) to 20 Plant Extracts.

    PubMed

    Emilie, Deletre; Mallent, Maelle; Menut, Chantal; Chandre, Fabrice; Martin, Thibaud

    2015-08-01

    In the Mediterranean region, the use of small-mesh netting to protect horticultural crops is an effective sustainable tool against pests. But in tropical regions, because of high humidity under the net favoring fungal development, netting with a larger mesh size has to be used, protecting crops against lepidopteran pests but not against small pests such as hemipterans, thrips, and phytophagous mites. A combination of netting with a repellent or irritant product is one possible solution, but the desire to reduce the use of synthetic chemicals and mitigate resistance issues calls for a natural alternative. The objective of this study was to evaluate the repellent, irritant, and toxic effects of nets dipped in 20 different plant extracts on Bemisia tabaci (Gennadius) adults. The repellent effect of volatile compounds was evaluated using a still-air olfactometer. The irritant effect and toxicity were evaluated with a no-choice test in tubes separated into two parts by an impregnated net. Our results showed the seven most irritant and toxic products against B. tabaci were aframomum, cinnamon, geranium, dill, citronella, litsea, and savory. The most repellent were aframomum and lemongrass, although cinnamon, geranium, and savory were also repellent at higher doses. Effects varied with the plant extract and the concentration, and effects were independent of one another, i.e., an essential oil can be irritant but not repellent, suggesting that the repellent mechanism and that behind the irritant or toxic effects is not the same. The use of repellent compounds in combination with netting as new pest control strategy is discussed. PMID:26470332

  15. Further insight into reproductive incompatibility between putative cryptic species of the Bemisia tabaci whitefly complex.

    PubMed

    Qin, Li; Pan, Li-Long; Liu, Shu-Sheng

    2016-04-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), with its global distribution and extensive genetic diversity, is now known to be a complex of over 35 cryptic species. However, a satisfactory resolution of the systematics of this species complex is yet to be achieved. Here, we designed experiments to examine reproductive compatibility among species with different levels of mitochondrial cytochrome oxidase I (mtCOI) divergence. The data show that putative species with mtCOI divergence of >8% between them consistently exhibited complete reproductive isolation. However, two of the putative species, Asia II 9 and Asia II 3, with mtCOI divergence of 4.47% between them, exhibited near complete reproductive compatibility in one direction of their cross, and partial reproductive compatibility in the other direction. Together with some recent reports on this topic from the literature, our data indicates that, while divergence in the mtCOI sequences provides a valid molecular marker for species delimitation in most clades, more genetic markers and more sophisticated molecular phylogeny will be required to achieve adequate delimitation of all species in this whitefly complex. While many attempts have been made to examine the reproductive compatibility among genetic groups of the B. tabaci complex, our study represents the first effort to conduct crossing experiments with putative species that were chosen with considerations of their genetic divergence. In light of the new data, we discuss the best strategy and protocols to conduct further molecular phylogenetic analysis and crossing trials, in order to reveal the overall pattern of reproductive incompatibility among species of this whitefly complex. PMID:27001484

  16. Gene Expression Profiling in the Thiamethoxam Resistant and Susceptible B-biotype Sweetpotato Whitefly, Bemisia tabaci

    PubMed Central

    Xie, Wen; Yang, Xin; Wang, Shao-Ii; Wu, Qing-jun; Yang, Ni-na; Li, Ru-mei; Jiao, Xiaoguo; Pan, Hui-peng; Liu, Bai-ming; Feng, Yun-tao; Xu, Bao-yun; Zhou, Xu-guo; Zhang, You-jun

    2012-01-01

    Thiamethoxam has been used as a major insecticide to control the B-biotype sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Due to its excessive use, a high level of resistance to thiamethoxam has developed worldwide over the past several years. To better understand the molecular mechanisms underlying this resistance in B. tabaci, gene profiles between the thiamethoxam-resistant and thiamethoxam-susceptible strains were investigated using the suppression subtractive hybridization (SSH) library approach. A total of 72 and 52 upand down-regulated genes were obtained from the forward and reverse SSH libraries, respectively. These expressed sequence tags (ESTs) belong to several functional categories based on their gene ontology annotation. Some categories such as cell communication, response to abiotic stimulus, lipid particle, and nuclear envelope were identified only in the forward library of thiamethoxam-resistant strains. In contrast, categories such as behavior, cell proliferation, nutrient reservoir activity, sequence-specific DNA binding transcription factor activity, and signal transducer activity were identified solely in the reverse library. To study the validity of the SSH method, 16 differentially expressed genes from both forward and reverse SSH libraries were selected randomly for further analyses using quantitative realtime PCR (qRT-PCR). The qRT-PCR results were fairly consistent with the SSH results; however, only 50% of the genes showed significantly different expression profiles between the thiamethoxam-resistant and thiamethoxam-susceptible whiteflies. Among these genes, a putative NAD-dependent methanol dehydrogenase was substantially over-expressed in the thiamethoxamresistant adults compared to their susceptible counterparts. The distributed profiles show that it was highly expressed during the egg stage, and was most abundant in the abdomen of adult females. PMID:22957505

  17. Transcriptome analysis of host-associated differentiation in Bemisia tabaci (Hemiptera: Aleyrodidae)

    PubMed Central

    Xie, Wen; Wu, Qingjun; Wang, Shaoli; Jiao, Xiaoguo; Guo, Litao; Zhou, Xuguo; Zhang, Youjun

    2014-01-01

    Host-associated differentiation is one of the driving forces behind the diversification of phytophagous insects. In this study, host induced transcriptomic differences were investigated in the sweetpotato whitefly Bemisia tabaci, an invasive agricultural pest worldwide. Comparative transcriptomic analyses using coding sequence (CDS), 5′ and 3′ untranslated regions (UTR) showed that sequence divergences between the original host plant, cabbage, and the derived hosts, including cotton, cucumber and tomato, were 0.11–0.14%, 0.19–0.26%, and 0.15–0.21%, respectively. In comparison to the derived hosts, 418 female and 303 male transcripts, respectively, were up-regulated in the original cabbage strain. Among them, 17 transcripts were consistently up-regulated in both female and male whiteflies originated from the cabbage host. Specifically, two ESTs annotated as Cathepsin B or Cathepsin B-like genes were significantly up-regulated in the original cabbage strain, representing a transcriptomic response to the dietary challenges imposed by the host shifting. Results from our transcriptome analysis, in conjunction with previous reports documenting the minor changes in their reproductive capacity, insecticide susceptibility, symbiotic composition and feeding behavior, suggest that the impact of host-associated differentiation in whiteflies is limited. Furthermore, it is unlikely the major factor contributing to their rapid range expansion/invasiveness. PMID:25540625

  18. Biotype expression and insecticide response of Bemisia tabaci chemosensory protein-1.

    PubMed

    Liu, Guo Xia; Xuan, Ning; Chu, Dong; Xie, Hong Yan; Fan, Zhong Xue; Bi, Yu Ping; Picimbon, Jean-François; Qin, Yu Chuan; Zhong, Su Ting; Li, Yao Fa; Gao, Zhan Lin; Pan, Wen Liang; Wang, Guo Ying; Rajashekar, Balaji

    2014-03-01

    Chemosensory proteins (CSPs) are a group of small soluble proteins found so far exclusively in arthropod species. These proteins act in chemical communication and perception. In this study, a gene encoding the Type 1 CSP (BtabCSP1) from the agricultural pest Bemisia tabaci (whitefly) was analyzed to understand sequence variation and expression specificity in different biotypes. Sequence analysis of BtabCSP1 showed significant differences between the two genetically characterized biotypes, B and Q. The B-biotype had a larger number of BtabCSP1 mutations than the Q-biotype. Similar to most other CSPs, BtabCSP1 was more expressed in the head than in the rest of the body. One-step RT-PCR and qPCR analysis on total messenger RNA showed that biotype-Q had higher BtabCSP1 expression levels than biotype-B. Females from a mixed field-population had high levels of BtabCSP1 expression. The interaction of BtabCSP1 with the insecticide thiamethoxam was investigated by analyzing the BtabCSP1 expression levels following exposure to the neonicotinoid, thiamethoxam, in a time/dose-response study. Insecticide exposure increased BtabCSP1 expression (up to tenfold) at 4 and 24 h following 50 or 100 g/ml treatments. PMID:24478049

  19. Computational Insights into the Different Resistance Mechanism of Imidacloprid versus Dinotefuran in Bemisia tabaci.

    PubMed

    Meng, Xiaoqing; Zhu, Chengchun; Feng, Yue; Li, Weihua; Shao, Xusheng; Xu, Zhiping; Cheng, Jiagao; Li, Zhong

    2016-02-17

    Insecticide resistance is a critical problem for pest control and management. For Bemisia tabaci, striking high metabolic resistance (generally conferred by CYP6CM1) was observed for imidacloprid (IMI) and most other neonicotinoid members. However, dinotefuran (DIN) displayed very low resistance factors, which indicated distinct metabolic properties. Here, molecular modeling methods were applied to explore the different resistance features of IMI versus DIN within the Q type of CYP6CM1. It was found that Arg225 played crucial roles in the binding of IMI-CYP6CM1vQ with a cation-π interaction and two stable H-bonds; however, such interactions were all absent in the DIN-CYP6CM1vQ system. The stable binding of IMI with CYP6CM1vQ would facilitate the following metabolic reaction, while the weak binding of DIN might disable its potential metabolism, which should be an important factor for their distinct resistance levels. The findings might facilitate future design of the antiresistance neonicotinoid molecules. PMID:26817991

  20. Bemisia tabaci Q carrying tomato yellow leaf curl virus strongly suppresses host plant defenses

    PubMed Central

    Shi, Xiaobin; Pan, Huipeng; Zhang, Hongyi; Jiao, Xiaoguo; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Fang, Yong; Chen, Gong; Zhou, Xuguo; Zhang, Youjun

    2014-01-01

    The concurrence of tomato yellow leaf curl virus (TYLCV) with the spread of its vector Bemisia tabaci Q rather than B in China suggests a more mutualistic relationship between TYLCV and Q. Here, we investigated the hypothesis that viruliferous B and Q have different effects on plant defenses. We found the fecundity of nonviruliferous B, nonviruliferous Q, viruliferous Q and viruliferous B was 11.080, 12.060, 10.760, and 11.220 respectively on plants previously attacked by the other biotype, however, on their respective noninfested control leaves fecundity was 12.000, 10.880, 9.760, and 8.020 respectively. Only viruliferous B had higher fecundity on viruliferous Q-infested plants than on control plants. The longevity of viruliferous B showed the same phenomenon. At 1 d infestion, the jasmonic acid content in leaves noninfested and in leaves infested with nonviruliferous B, nonviruliferous Q, viruliferous B and viruliferous Q was 407.000, 281.333, 301.333, 266.667 and 134.000 ng/g FW, respectively. The JA content was lowest in viruliferous Q-infested leaves. The proteinase inhibitor activity and expression of JA-related upstream gene LOX and downstream gene PI II showed the same trend. The substantial suppression of host defenses by Q carrying TYLCV probably enhances the spread of Q and TYLCV in China. PMID:24912756

  1. Bioactivity of Indigenous Medicinal Plants against the Cotton Whitefly, Bemisia tabaci

    PubMed Central

    Hammad, E. Abou-Fakhr; Zeaiter, A.; Saliba, N.; Talhouk, S.

    2014-01-01

    Forty-one methanol extracts of 28 indigenous medicinal plant species were tested for their insecticidal bioactivity against cotton whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), adults and second nymphal instars under controlled conditions. This study is within a bioprospection context, in the form of utilizing local plant species as an alternative in sustainable agriculture development. Eighteen and nine plant extracts caused a significant decrease in number of live adult and nymphal whiteflies, respectively, compared to the control. This is the first report for the potential effect on survival of insects for 22 out of 28 tested medicinal plant species. Whole plant extracts of Ranunculus myosuroudes Boiss. and Kotschy (Ranunculaceae), Achillea damascena L. (Asteraceae), and Anthemis hebronica Boiss. and Kotschy (Asteraceae) and leaf extracts of Verbascum leptostychum DC. (Scrophulariaceae) and Heliotropium rotundifolium Boiss. (Borangiaceae) caused both repellent and toxic effects against the adult and second nymphal instars, respectively. Extracts of leaves and stems of Anthemis scariosa Boiss. (Asteraceae) and Calendula palestina Pers. (Asteraceae) were found to be more bioactive against the adult and nymphal instars, respectively, than extracts of other plant parts, such as flowers. Thus, the bioactive extracts of these medicinal plants have the potential to lower whitefly populations in a comprehensive pest management program in local communities, pending cultivation of these medicinal plant species. PMID:25204756

  2. Evidence for Horizontal Transmission of Secondary Endosymbionts in the Bemisia tabaci Cryptic Species Complex

    PubMed Central

    Ahmed, Muhammad Z.; De Barro, Paul J.; Ren, Shun-Xiang; Greeff, Jaco M.; Qiu, Bao-Li

    2013-01-01

    Bemisia tabaci (Hemiptera: Aleyrodidae) is a globally distributed pest composed of at least 34 morphologically indistinguishable cryptic species. At least seven species of endosymbiont have been found infecting some or all members of the complex. The origin(s) of the associations between specific endosymbionts and their whitefly hosts is unknown. Infection is normally vertical, but horizontal transmission does occur and is one way for new infections to be introduced into individuals. The relationships between the different members of the cryptic species complex and the endosymbionts have not been well explored. In this study, the phylogenies of different cryptic species of the host with those of their endosymbionts were compared. Of particular interest was whether there was evidence for both coevolution and horizontal transmission. Congruence was observed for the primary endosymbiont, Portiera aleyrodidarum, and partial incongruence in the case of two secondary endosymbionts, Arsenophonus and Cardinium and incongruence for a third, Wolbachia. The patterns observed for the primary endosymbiont supported cospeciation with the host while the patterns for the secondary endosymbionts, and especially Wolbachia showed evidence of host shifts and extinctions through horizontal transmission rather than cospeciation. Of particular note is the observation of several very recent host shift events in China between exotic invader and indigenous members of the complex. These shifts were from indigenous members of the complex to the invader as well as from the invader to indigenous relatives. PMID:23308142

  3. Sensitivity of Bemisia tabaci (Hemiptera: Aleyrodidae) to several new insecticides in China: effects of insecticide type and whitefly species, strain, and stage.

    PubMed

    Xie, Wen; Liu, Yang; Wang, Shaoli; Wu, Qingjun; Pan, Huipeng; Yang, Xin; Guo, Litao; Zhang, Youjun

    2014-01-01

    Whitefly biotypes B and Q are the two most damaging members of the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex. Control of B. tabaci (and especially of Q) has been impaired by resistance to commonly used insecticides. To find new insecticides for B. tabaci management in China, we investigated the sensitivity of eggs, larvae, and adults of laboratory strains of B and Q (named Lab-B and Lab-Q) and field strains of Q to several insecticides. For eggs, larvae, and adults of B. tabaci and for six insecticides (cyantraniliprole, chlorantraniliprole, pyriproxyfen, buprofezin, acetamiprid, and thiamethoxam), LC50 values were higher for Lab-Q than for Lab-B; avermectin LC50 values, however, were low for adults of both Lab-Q and Lab-B. Based on the laboratory results, insecticides were selected to test against eggs, larvae, and adults of four field strains of B. tabaci Q. Although the field strains differed in their sensitivity to the insecticides, the eggs and larvae of all strains were highly sensitive to cyantraniliprole, and the adults of all strains were highly sensitive to avermectin. The eggs, larvae, and adults of B. tabaci Q were generally more resistant than those of B. tabaci B to the tested insecticides. B. tabaci Q eggs and larvae were sensitive to cyantraniliprole and pyriproxyfen, whereas B. tabaci Q adults were sensitive to avermectin. Field trials should be conducted with cyantraniliprole, pyriproxyfen, and avermectin for control of B. tabaci Q and B in China. PMID:25434040

  4. Role of the Insect Supervectors Bemisia tabaci and Frankliniella occidentalis in the Emergence and Global Spread of Plant Viruses.

    PubMed

    Gilbertson, Robert L; Batuman, Ozgur; Webster, Craig G; Adkins, Scott

    2015-11-01

    Emergence of insect-transmitted plant viruses over the past 10-20 years has been disproportionately driven by two so-called supervectors: the whitefly, Bemisia tabaci, and the Western flower thrips, Frankliniella occidentalis. High rates of reproduction and dispersal, extreme polyphagy, and development of insecticide resistance, together with human activities, have made these insects global pests. These supervectors transmit a diversity of plant viruses by different mechanisms and mediate virus emergence through local evolution, host shifts, mixed infections, and global spread. Associated virus evolution involves reassortment, recombination, and component capture. Emergence of B. tabaci-transmitted geminiviruses (begomoviruses), ipomoviruses, and torradoviruses has led to global disease outbreaks as well as multiple paradigm shifts. Similarly, F. occidentalis has mediated tospovirus host shifts and global dissemination and the emergence of pollen-transmitted ilarviruses. The plant virus-supervector interaction offers exciting opportunities for basic research and global implementation of generalized disease management strategies to reduce economic and environmental impacts. PMID:26958907

  5. The Dynamics and Environmental Influence on Interactions Between Cassava Brown Streak Disease and the Whitefly, Bemisia tabaci.

    PubMed

    Jeremiah, S C; Ndyetabula, I L; Mkamilo, G S; Haji, S; Muhanna, M M; Chuwa, C; Kasele, S; Bouwmeester, H; Ijumba, J N; Legg, J P

    2015-05-01

    Cassava brown streak disease (CBSD) is currently the most significant virus disease phenomenon affecting African agriculture. In this study, we report results from the most extensive set of field data so far presented for CBSD in Africa. From assessments of 515 farmers' plantings of cassava, incidence in the Coastal Zone of Tanzania (46.5% of plants; 87% of fields affected) was higher than in the Lake Zone (22%; 34%), but incidences for both zones were greater than previous published records. The whitefly vector, Bemisia tabaci, was more abundant in the Lake Zone than the Coastal Zone, the reverse of the situation reported previously, and increased B. tabaci abundance is driving CBSD spread in the Lake Zone. The altitudinal "ceiling" previously thought to restrict the occurrence of CBSD to regions <1,000 masl has been broken as a consequence of the greatly increased abundance of B. tabaci in mid-altitude areas. Among environmental variables analyzed, minimum temperature was the strongest determinant of CBSD incidence. B. tabaci in the Coastal and Lake Zones responded differently to environmental variables examined, highlighting the biological differences between B. tabaci genotypes occurring in these regions and the superior adaptation of B. tabaci in the Great Lakes region both to cassava and low temperature conditions. Regression analyses using multi-country data sets could be used to determine the potential environmental limits of CBSD. Approaches such as this offer potential for use in the development of predictive models for CBSD, which could strengthen country- and continent-level CBSD pandemic mitigation strategies. PMID:25585059

  6. Rapid accumulation and low degradation: key parameters of Tomato yellow leaf curl virus persistence in its insect vector Bemisia tabaci

    PubMed Central

    Becker, Nathalie; Rimbaud, Loup; Chiroleu, Frédéric; Reynaud, Bernard; Thébaud, Gaël; Lett, Jean-Michel

    2015-01-01

    Of worldwide economic importance, Tomato yellow leaf curl virus (TYLCV, Begomovirus) is responsible for one of the most devastating plant diseases in warm and temperate regions. The DNA begomoviruses (Geminiviridae) are transmitted by the whitefly species complex Bemisia tabaci. Although geminiviruses have long been described as circulative non-propagative viruses, observations such as long persistence of TYLCV in B. tabaci raised the question of their possible replication in the vector. We monitored two major TYLCV strains, Mild (Mld) and Israel (IL), in the invasive B. tabaci Middle East-Asia Minor 1 cryptic species, during and after the viral acquisition, within two timeframes (0–144 hours or 0–20 days). TYLCV DNA was quantified using real-time PCR, and the complementary DNA strand of TYLCV involved in viral replication was specifically quantified using anchored real-time PCR. The DNA of both TYLCV strains accumulated exponentially during acquisition but remained stable after viral acquisition had stopped. Neither replication nor vertical transmission were observed. In conclusion, our quantification of the viral loads and complementary strands of both Mld and IL strains of TYLCV in B. tabaci point to an efficient accumulation and preservation mechanism, rather than to a dynamic equilibrium between replication and degradation. PMID:26625871

  7. Three Members of the Bemisia tabaci (Hemiptera: Aleyrodidae) Cryptic Species Complex Occur Sympatrically in Argentine Horticultural Crops.

    PubMed

    Alemandri, V; Vaghi Medina, C G; Dumón, A D; Argüello Caro, E B; Mattio, M F; García Medina, S; López Lambertini, P M; Truol, G

    2015-04-01

    The whitefly, Bemisia tabaci (Gennadius), is a cryptic species complex that attacks >600 different species of plants and transmits several plant viruses causing severe economic losses. Until 2010, the B. tabaci complex comprised 24 distinct putative species. Recently, at least 15 new species have been reported. The objective of this study was to identify B. tabaci species present in bean, melon, and tomato crops in Argentina by applying phylogenetic analyses and pairwise comparison of genetic distances of mitochondrial cytochrome c oxidase subunit I (mtCOI) sequences. The 39 proposed whitefly species were identified with both analyses, and the presence in Argentina of one indigenous species, New World 2 (NW2), and two introduced species, Middle East-Asia Minor one (MEAM1) and Mediterranean, was confirmed. Common bean crop presented the three whitefly species detected, with NW2, MEAM1, and Mediterranean being present all together under field conditions. Also, Mediterranean was the only species identified in tomato, whereas MEAM1 was found in melon. To the best of our knowledge, Mediterranean is a recent invasive species in open-field agriculture in the American continent and in greenhouse tomato in Argentina. Additionally, we provide the first report of MEAM1 in common bean and melon. These findings raise several questions on the future scenario of B. tabaci and the viruses it transmits in Argentina. PMID:26470151

  8. Molecular cloning of the sex-related gene PSI in Bemisia tabaci and its alternative splicing properties.

    PubMed

    Liu, Yating; Xie, Wen; Yang, Xin; Guo, Litao; Wang, Shaoli; Wu, Qingjun; Yang, Zezhong; Zhou, Xuguo; Zhang, Youjun

    2016-04-15

    The P-element somatic inhibitor (PSI) is gene known to regulate the transcription of doublesex (dsx) when transformer (tra) is absent in Bombyx mori. In this study, we identified and characterized a PSI homolog in Bemisia tabaci (BtPSI). BtPSI cDNA had a total length of 5700 bp and contained a predicted open reading frame (ORF) of 2208 nucleotides encoding for 735 amino acids. Multiple sequence alignments of the common regions of PSI proteins from B. tabaci and five other insect species revealed a high degree of sequence conservation. BtPSI is expressed in all stages of B. tabaci development, and expression did not significantly differ between female and male adult. A total of 92 BtPSI isoforms (78 in female and 22 in male) were identified, and a marker indicating the female-specific form was found. These results increase the understanding of genes that may determine sex in B. tabaci and provide a foundation for research on the sex determination mechanism in this insect. PMID:26773355

  9. Rapid accumulation and low degradation: key parameters of Tomato yellow leaf curl virus persistence in its insect vector Bemisia tabaci.

    PubMed

    Becker, Nathalie; Rimbaud, Loup; Chiroleu, Frédéric; Reynaud, Bernard; Thébaud, Gaël; Lett, Jean-Michel

    2015-01-01

    Of worldwide economic importance, Tomato yellow leaf curl virus (TYLCV, Begomovirus) is responsible for one of the most devastating plant diseases in warm and temperate regions. The DNA begomoviruses (Geminiviridae) are transmitted by the whitefly species complex Bemisia tabaci. Although geminiviruses have long been described as circulative non-propagative viruses, observations such as long persistence of TYLCV in B. tabaci raised the question of their possible replication in the vector. We monitored two major TYLCV strains, Mild (Mld) and Israel (IL), in the invasive B. tabaci Middle East-Asia Minor 1 cryptic species, during and after the viral acquisition, within two timeframes (0-144 hours or 0-20 days). TYLCV DNA was quantified using real-time PCR, and the complementary DNA strand of TYLCV involved in viral replication was specifically quantified using anchored real-time PCR. The DNA of both TYLCV strains accumulated exponentially during acquisition but remained stable after viral acquisition had stopped. Neither replication nor vertical transmission were observed. In conclusion, our quantification of the viral loads and complementary strands of both Mld and IL strains of TYLCV in B. tabaci point to an efficient accumulation and preservation mechanism, rather than to a dynamic equilibrium between replication and degradation. PMID:26625871

  10. Inoculation of tomato plants with rhizobacteria enhances the performance of the phloem-feeding insect Bemisia tabaci

    PubMed Central

    Shavit, Roee; Ofek-Lalzar, Maya; Burdman, Saul; Morin, Shai

    2013-01-01

    In their natural environment, plants experience multiple biotic interactions and respond to this complexity in an integrated manner. Therefore, plant responses to herbivory are flexible and depend on the context and complexity in which they occur. For example, plant growth promoting rhizobacteria (PGPR) can enhance plant growth and induce resistance against microbial pathogens and herbivorous insects by a phenomenon termed induced systemic resistance (ISR). In the present study, we investigated the effect of tomato (Solanum lycopersicum) pre-inoculation with the PGPR Pseudomonas fluorescens WCS417r, on the performance of the generalist phloem-feeding insect Bemisia tabaci. Based on the ability of P. fluorescens WCS417r to prime for ISR against generalists chewing insects and necrotrophic pathogens, we hypothesized that pre-inoculated plants will strongly resist B. tabaci infestation. In contrast, we discovered that the pre-inoculation treatment increased the tomato plant suitability for B. tabaci which was emphasized both by faster developmental rate and higher survivability of nymph stages on pre-inoculated plants. Our molecular and chemical analyses suggested that the phenomenon is likely to be related to: (I) the ability of the bacteria to reduce the activity of the plant induced defense systems; (II) a possible manipulation by P. fluorescens of the plant quality (in terms of suitability for B. tabaci) through an indirect effect on the rhizosphere bacterial community. The contribution of our study to the pattern proposed for other belowground rhizobacteria and mycorrhizal fungi and aboveground generalist phloem-feeders is discussed. PMID:23964283

  11. An EPG study of the probing behavior of adult Bemisia tabaci biotype Q (Hemiptera: Aleyrodidae) following exposure to cyantraniliprole.

    PubMed

    Civolani, Stefano; Cassanelli, Stefano; Chicca, Milvia; Rison, Jean L; Bassi, Andrea; Alvarez, Juan M; Annan, I Billy; Parrella, Giuseppe; Giorgini, Massimo; Fano, Elisa Anna

    2014-06-01

    Cyantraniliprole is a novel insecticide for control of multiple chewing and sucking insect pest species including the sweetpotato whitefly Bemisia tabaci (Gennadius), which is one of the most important polyphagous pests in tropical, subtropical, and Mediterranean regions. This study aims to evaluate the effects of cyantraniliprole on the probing behavior of B. tabaci on tomato. Electrical penetration graph data indicated that on plants treated with cyantraniliprole (foliar application), adult whiteflies of the genetic variant Q2 were not able to reach the phloem and consequently did not perform the activities represented by E1 and E2 waveforms, i.e., phloem salivation (during which inoculation of geminiviruses occurs) and phloem sap ingestion (during which geminiviruses are acquired by the whiteflies), respectively. The complete failure of B. tabaci biotype Q adults to feed from the phloem of tomato plants treated with cyantraniliprole could be explained by rapid cessation of ingestion because of the mode of action of this insecticide. Overall, these findings indicated that cyantraniliprole might represent a useful new tool for producers to protect tomato plants from damage by B. tabaci. PMID:25026647

  12. Response of Bemisia tabaci Genn. (Hemiptera: Aleyrodidae) biotype B to genotypes of pepper Capsicum annuum (Solanales: Solanaceae).

    PubMed

    Ballina-Gomez, H; Ruiz-Sanchez, E; Chan-Cupul, W; Latournerie-Moreno, L; Hernández-Alvarado, L; Islas-Flores, I; Zuñiga-Aguilar, J J

    2013-04-01

    Bemisia tabaci Genn. biotype B is a widely distributed plant pest that represents one of the major constraints for horticultural crop production. The purpose of the present work was to evaluate the oviposition preference, survivorship, and development of B. tabaci biotype B on semi-cultivated genotypes of Capsicum annuum from southeast Mexico. In free-choice experiments to evaluate the oviposition preference, lower number of eggs laid by B. tabaci biotype B was observed in the genotypes Maax and Xcat´ik relative to that in the commercial genotype Parado. Egg hatchability was significantly lower in Pico Paloma, Bolita, Blanco, Chawa, Payaso, and Xcat´ik than in the rest of the genotypes, including the commercial genotype Jalapeño. Likewise, survivorship of nymphs was significantly lower in Pico Paloma, Bolita, and Blanco than in the remaining genotypes. Nymph developmental time and the period of development from egg to adult were the shortest in Amaxito. Therefore, sources of resistance to B. tabaci biotype B by antibiosis (accumulation of plant defense compounds) might be found in the semi-cultivated genotypes Pico Paloma, Bolita, and Blanco. PMID:23949756

  13. Reference Gene Selection for qRT-PCR Analysis in the Sweetpotato Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)

    PubMed Central

    Li, Rumei; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Yang, Nina; Yang, Xin; Pan, Huipeng; Zhou, Xiaomao; Bai, Lianyang; Xu, Baoyun; Zhou, Xuguo; Zhang, Youjun

    2013-01-01

    Background Accurate evaluation of gene expression requires normalization relative to the expression of reliable reference genes. Expression levels of “classical” reference genes can differ, however, across experimental conditions. Although quantitative real-time PCR (qRT-PCR) has been used extensively to decipher gene function in the sweetpotato whitefly Bemisia tabaci, a world-wide pest in many agricultural systems, the stability of its reference genes has rarely been validated. Results In this study, 15 candidate reference genes from B. tabaci were evaluated using two Excel-based algorithms geNorm and Normfinder under a diverse set of biotic and abiotic conditions. At least two reference genes were selected to normalize gene expressions in B. tabaci under experimental conditions. Specifically, for biotic conditions including host plant, acquisition of a plant virus, developmental stage, tissue (body region of the adult), and whitefly biotype, ribosomal protein L29 was the most stable reference gene. In contrast, the expression of elongation factor 1 alpha, peptidylprolyl isomerase A, NADH dehydrogenase, succinate dehydrogenase complex subunit A and heat shock protein 40 were consistently stable across various abiotic conditions including photoperiod, temperature, and insecticide susceptibility. Conclusion Our finding is the first step toward establishing a standardized quantitative real-time PCR procedure following the MIQE (Minimum Information for publication of Quantitative real time PCR Experiments) guideline in an agriculturally important insect pest, and provides a solid foundation for future RNA interference based functional study in B. tabaci. PMID:23308130

  14. Implication of the Bacterial Endosymbiont Rickettsia spp. in Interactions of the Whitefly Bemisia tabaci with Tomato yellow leaf curl virus

    PubMed Central

    Kliot, Adi; Cilia, Michelle; Czosnek, Henryk

    2014-01-01

    ABSTRACT Numerous animal and plant viruses are transmitted by arthropod vectors in a persistent, circulative manner. Tomato yellow leaf curl virus (TYLCV) is transmitted by the sweet potato whitefly Bemisia tabaci. We report here that infection with Rickettsia spp., a facultative endosymbiont of whiteflies, altered TYLCV-B. tabaci interactions. A B. tabaci strain infected with Rickettsia acquired more TYLCV from infected plants, retained the virus longer, and exhibited nearly double the transmission efficiency compared to an uninfected B. tabaci strain with the same genetic background. Temporal and spatial antagonistic relationships were discovered between Rickettsia and TYLCV within the whitefly. In different time course experiments, the levels of virus and Rickettsia within the insect were inversely correlated. Fluorescence in situ hybridization analysis of Rickettsia-infected midguts provided evidence for niche exclusion between Rickettsia and TYLCV. In particular, high levels of the bacterium in the midgut resulted in higher virus concentrations in the filter chamber, a favored site for virus translocation along the transmission pathway, whereas low levels of Rickettsia in the midgut resulted in an even distribution of the virus. Taken together, these results indicate that Rickettsia, by infecting the midgut, increases TYLCV transmission efficacy, adding further insights into the complex association between persistent plant viruses, their insect vectors, and microorganism tenants that reside within these insects. IMPORTANCE Interest in bacterial endosymbionts in arthropods and many aspects of their host biology in agricultural and human health systems has been increasing. A recent and relevant studied example is the influence of Wolbachia on dengue virus transmission by mosquitoes. In parallel with our recently studied whitefly-Rickettsia-TYLCV system, other studies have shown that dengue virus levels in the mosquito vector are inversely correlated with

  15. Gene transcript changes associated with Bemisia tabaci Biotype B induced tomato irregular ripening disorder identified using microarray technology and Q-RT-PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tomato irregular ripening is a disorder manifested in the fruit as a result of silver leaf whitefly (otherwise known as the B biotype of Bemisia tabaci) feeding on leaf phloem of tomato. This physiological disorder has significant economic impact in commercial tomato production; however, little is k...

  16. Establishment of papaya banker plant system for Parasitoid, Encarsia sophia (Hymenoptera: Aphilidae) against Bemisia tabaci (Hemiptera: Aleyrodidae) in greenhouse tomato production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The silverleaf whitefly, Bemisia tabaci biotype B (Gennadius) (Hemiptera:Aleyrodidae), is a key pest of tomato (Solanum lycopersicum L.) and other vegetable crops worldwide. To combat this pest, a non-crop banker plant system was evaluated that employs a parasitoid, Encarsia sophia (Girault & Dodd) ...

  17. Population genetics of Bemisia tabaci biotypes B and Q from the Mediterranean and the U.S. inferred using microsatellite markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci is composed of several biotypes, some of which appear to have pre and/or post zygotic barriers to hybridization. Numerous studies have been performed to determine the geographical distribution of different biotypes, but little is known about the gene flow within and among biotypes. R...

  18. Yellow Sticky Trap Catches of Parasitoids of Bemisia tabaci (Hemiptera: Aleyrodidae) in Vegetable Crops and Their Relationship to In-field Populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We examined the relationship of yellow sticky trap captures of Bemisia tabaci (Gennadius) biotype ‘B’ parasitoids to the local population of parasitoids as measured by leaf samples of parasitized whiteflies and mass-release of parasitoids. Traps were placed in experimental collard and cowpea field ...

  19. Intraguild predation on Eretmocerus nr emiratus, a parasitoid of Bemisia tabaci by three generalist predators with implications for estimating the level and impact of parasitism.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intraguild predation is pervasive in many managed and unmanaged ecosystems. Both generalist predators and aphelinid parasitoids attack Bemisia tabaci on cotton in the southwestern USA. Free-choice and no-choice laboratory assays were conducted to quantify prey consumption patterns and preference by ...

  20. Transcriptome analysis of Bemisia tabaci during tomato yellow leaf curl virus acquisition and ribonucleic acid interference to manage whitefly-transmitted viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 300 viruses are transmitted by the whitefly, Bemisia tabaci, with 90% of them belonging to the genus, Begomovirus. Begomoviruses are obligately transmitted by whiteflies to a wide range of agriculture crops, resulting in billions of dollars lost annually, while jeopardizing food security worldw...

  1. Comparative transcriptome analysis in Bemisia tabaci in response to tomato yellow leaf curl virus and development of ribonucleic acid interference to manage whitefly-transmitted viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The whitefly, Bemisia tabaci transmits over 300 plant viruses, with the majority of them belonging to the Begomovirus genus. Begomoviruses are obligately transmitted to a wide range of agriculture crops, resulting in the loss of billions of dollars annually, while jeopardizing food security worldwid...

  2. Pre shipping dip treatments using soap, natural oils, and Isaria fumosorosea: potential biopesticides for mitigating the spread of whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) invasive insects on ornamental plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The whitefly Bemisia tabaci (Hemiptera: Aleyodidae) is an invasive insect pest affecting different crops including vegetables, fruits, cereals, and ornamentals. The efficacy of some products such as commercial soap, natural oils and Preferal® (based on the entomopathogenic fungus Isaria fumosorosea ...

  3. Genetic Networking of the Bemisia tabaci Cryptic Species Complex Reveals Pattern of Biological Invasions

    PubMed Central

    De Barro, Paul; Ahmed, Muhammad Z.

    2011-01-01

    Background A challenge within the context of cryptic species is the delimitation of individual species within the complex. Statistical parsimony network analytics offers the opportunity to explore limits in situations where there are insufficient species-specific morphological characters to separate taxa. The results also enable us to explore the spread in taxa that have invaded globally. Methodology/Principal Findings Using a 657 bp portion of mitochondrial cytochrome oxidase 1 from 352 unique haplotypes belonging to the Bemisia tabaci cryptic species complex, the analysis revealed 28 networks plus 7 unconnected individual haplotypes. Of the networks, 24 corresponded to the putative species identified using the rule set devised by Dinsdale et al. (2010). Only two species proposed in Dinsdale et al. (2010) departed substantially from the structure suggested by the analysis. The analysis of the two invasive members of the complex, Mediterranean (MED) and Middle East – Asia Minor 1 (MEAM1), showed that in both cases only a small number of haplotypes represent the majority that have spread beyond the home range; one MEAM1 and three MED haplotypes account for >80% of the GenBank records. Israel is a possible source of the globally invasive MEAM1 whereas MED has two possible sources. The first is the eastern Mediterranean which has invaded only the USA, primarily Florida and to a lesser extent California. The second are western Mediterranean haplotypes that have spread to the USA, Asia and South America. The structure for MED supports two home range distributions, a Sub-Saharan range and a Mediterranean range. The MEAM1 network supports the Middle East - Asia Minor region. Conclusion/Significance The network analyses show a high level of congruence with the species identified in a previous phylogenetic analysis. The analysis of the two globally invasive members of the complex support the view that global invasion often involve very small portions of the available

  4. Transgenic Cotton-Fed Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Affects the Parasitoid Encarsia desantisi Viggiani (Hymenoptera: Aphelinidae) Development.

    PubMed

    Pessoa, R; Rossi, G D; Busoli, A C

    2016-02-01

    Cotton cultivars expressing Cry proteins are widely used to control lepidopteran pests. The effects of transgenic plants containing insecticidal Cry proteins on non-target species must be comprehended for a better and rational use of this technology for pest management. We investigated the influence of the Bt cotton cultivars NuOPAL and FM 975 on biological parameters of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), a non-target pest of Bt cotton cultivars and on its parasitoid Encarsia desantisi Viggiani (Hymenoptera: Aphelinidae). The experiments were conducted in a climatized room, and the non-transgenic near isolines were used for rearing whiteflies as control hosts. The effects of the Bt cotton cultivars on the period of embryonic and larval development and the percentage of adult emergence of B. tabaci were assessed. The period required for embryonic, larval, and pupal development and the percentage of emergence and longevity of E. desantisi females were determined using Bt cotton-fed and non-Bt cotton-fed B. tabaci as hosts. Both Bt cotton cultivars resulted in a decrease of approximately 20% of adult emergence of B. tabaci. Differently, an increase of approximately 10% of adult emergence of E. desantisi was observed for parasitoids that used hosts fed with both Bt cotton cultivars. However, female parasitoid longevity decreased when their hosts were fed on Bt cotton cultivars. Our data suggest that the use of Bt cotton cultivars in association with the biological control agent E. desantisi could be functional for the management of B. tabaci in Bt cotton crops. PMID:26431703

  5. Differential expression patterns among heat-shock protein genes and thermal responses in the whitefly Bemisia tabaci (MEAM 1).

    PubMed

    Díaz, Fernando; Orobio, Rony F; Chavarriaga, Paul; Toro-Perea, Nelson

    2015-08-01

    There is convincing evidence that heat-shock proteins (HSP) are upregulated by stress conditions in insects; however, the relative contribution of each HSP gene to the heat-shock response remains unclear. Here we considered the whitefly Bemisia tabaci (MEAM 1), a phloem feeder and invasive species whose molecular stress response is an important mechanism for overcoming heat stress. We assessed the expression of the hsp23, 40, 70 and 90 genes at the mRNA level when submitted to heat shocks of 40 and 44°C/1h (control at 25°C). For this, we evaluated a set of available and suitable reference genes in order to perform data normalization using the real-time polymerase chain reaction (qRT-PCR) technique, and then confirmed the production of HSP70 protein based on Western blot. Results were compared with the hardening capacity of B. tabaci, measured by fitness components as a response to heat shocks, using 40°C as the induction temperature. Three of the four genes (hsp23, 70 and 90) were upregulated by heat stress at mRNA, showing differential expression patterns. Hsp70 expression was confirmed at the protein level. Hardening significantly increased fitness following heat stress, suggesting that HSPs may contribute to hardening capacity in B. tabaci. Potential role of each gene in the heat-shock response for whiteflies is discussed. PMID:26267515

  6. Pathogenicity of Isaria fumosorosea to Bemisia tabaci, with some observations on the fungal infection process and host immune response.

    PubMed

    Tian, Jing; Diao, Hongliang; Liang, Li; Hao, Chi; Arthurs, Steven; Ma, Ruiyan

    2015-09-01

    Isaria fumosorosea is an important pathogen of whiteflies, and is used as a mycoinsecticide against this pest in many regions of the world. We quantified the pathogenicity of the Chinese isolate IF-1106 against different life stages of sweetpotato whitefly, Bemisia tabaci, on cucumber plants, and describe the infection process and aspects of the host immunological response in the laboratory. The second instar was the most susceptible life stage to infection, with mortality rates at 10(7)conidia/ml ≈83% after 7d. Scanning electron microscopy was used to monitor morphological aspects of the infection process. The following stages were observed; conidia adhered on the cuticle of B. tabaci and began to germinate within 6h of inoculation, appressoria development after 24h, germ tube penetration within 48h, emergent hyphae within 72h, secondary conidiogenesis within 96h with mass hyphal proliferation occurring on cadavers within 120h. The activities of endogenous enzymes were evaluated from host homogenate at various intervals post infection. Three enzymes associated with antioxidant activity [superoxide dismutase (SOD), perioxidase (POD), and catalase (CAT)], and two with detoxification [glutathione S-transferase (GSTs) and carboxylesterase (CarE)] were apparently upregulated in second instars infected by I. fumosorosea. Enzyme activities reached peak values at 48-60h post infection, then decreased to significantly lower than controls in 84h as mycosis occurred. Our results provide new insights into the pathogenicity and potential physiological response of B. tabaci to this fungal isolate. PMID:26264671

  7. Only a minority of broad-range detoxification genes respond to a variety of phytotoxins in generalist Bemisia tabaci species.

    PubMed

    Halon, Eyal; Eakteiman, Galit; Moshitzky, Pnina; Elbaz, Moshe; Alon, Michal; Pavlidi, Nena; Vontas, John; Morin, Shai

    2015-01-01

    Generalist insect can utilize two different modes for regulating their detoxification genes, the constitutive mode and the induced mode. Here, we used the Bemisia tabaci sibling species MEAM1 and MED, as a model system for studying constitutive and induced detoxification resistance and their associated tradeoffs. B. tabaci adults were allowed to feed through membranes for 24 h on diet containing only sucrose or sucrose with various phytotoxins. Quantitative real-time PCR analyses of 18 detoxification genes, indicated that relatively few transcripts were changed in both the MEAM1 and MED species, in response to the addition of phytotoxins to the diet. Induced transcription of detoxification genes only in the MED species, in response to the presence of indole-3-carbinol in the insect's diet, was correlated with maintenance of reproductive performance in comparison to significant reduction in performance of the MEAM1 species. Three genes, COE2, CYP6-like 5 and BtGST2, responded to more than one compound and were highly transcribed in the insect gut. Furthermore, functional assays showed that the BtGST2 gene encodes a protein capable of interacting with both flavonoids and glucosinolates. In conclusion, several detoxification genes were identified that could potentially be involved in the adaptation of B. tabaci to its host plants. PMID:26655836

  8. Competitive Ability and Fitness Differences between Two Introduced Populations of the Invasive Whitefly Bemisia tabaci Q in China

    PubMed Central

    Fang, Yi-Wei; Liu, Ling-Yun; Zhang, Hua-Li; Jiang, De-Feng; Chu, Dong

    2014-01-01

    Background Our long-term field survey revealed that the Cardinium infection rate in Bemisia tabaci Q (also known as biotype Q) population was low in Shandong, China over the past few years. We hypothesize that (1) the Cardinium-infected (C+) B. tabaci Q population cannot efficiently compete with the Cardinium-uninfected (C−) B. tabaci Q population; (2) no reproductive isolation may have occurred between C+ and C−; and (3) the C− population has higher fitness than the C+ population. Methodology and Results To reveal the differences in competitive ability and fitness between the two introduced populations (C+ and C−), competition between C+ and C− was examined over several generations. Subsequently, the reproductive isolation between C+ and C− was studied by crossing C+ with C− individuals, and the fitnesses of C+ and C− populations were compared using a two-sex life table method. Our results demonstrate that the competitive ability of the C+ whiteflies was weaker than that of C−. There is that no reproductive isolation occurred between the two populations and the C− population had higher fitness than the C+ population. Conclusion The competitive ability and fitness differences of two populations may explain why C− whitefly populations have been dominant during the past few years in Shandong, China. However, the potential role Cardinium plays in whitefly should be further explored. PMID:24945699

  9. Only a minority of broad-range detoxification genes respond to a variety of phytotoxins in generalist Bemisia tabaci species

    PubMed Central

    Halon, Eyal; Eakteiman, Galit; Moshitzky, Pnina; Elbaz, Moshe; Alon, Michal; Pavlidi, Nena; Vontas, John; Morin, Shai

    2015-01-01

    Generalist insect can utilize two different modes for regulating their detoxification genes, the constitutive mode and the induced mode. Here, we used the Bemisia tabaci sibling species MEAM1 and MED, as a model system for studying constitutive and induced detoxification resistance and their associated tradeoffs. B. tabaci adults were allowed to feed through membranes for 24 h on diet containing only sucrose or sucrose with various phytotoxins. Quantitative real-time PCR analyses of 18 detoxification genes, indicated that relatively few transcripts were changed in both the MEAM1 and MED species, in response to the addition of phytotoxins to the diet. Induced transcription of detoxification genes only in the MED species, in response to the presence of indole-3-carbinol in the insect’s diet, was correlated with maintenance of reproductive performance in comparison to significant reduction in performance of the MEAM1 species. Three genes, COE2, CYP6-like 5 and BtGST2, responded to more than one compound and were highly transcribed in the insect gut. Furthermore, functional assays showed that the BtGST2 gene encodes a protein capable of interacting with both flavonoids and glucosinolates. In conclusion, several detoxification genes were identified that could potentially be involved in the adaptation of B. tabaci to its host plants. PMID:26655836

  10. Transcriptome profiling of the whitefly Bemisia tabaci reveals stage-specific gene expression signatures for thiamethoxam resistance

    PubMed Central

    Yang, N; Xie, W; Jones, CM; Bass, C; Jiao, X; Yang, X; Liu, B; Li, R; Zhang, Y

    2013-01-01

    Bemisia tabaci has developed high levels of resistance to many insecticides including the neonicotinoids and there is strong evidence that for some compounds resistance is stage-specific. To investigate the molecular basis of B. tabaci resistance to the neonicotinoid thiamethoxam we used a custom whitefly microarray to compare gene expression in the egg, nymph and adult stages of a thiamethoxam-resistant strain (TH-R) with a susceptible strain (TH-S). Gene ontology and bioinformatic analyses revealed that in all life stages many of the differentially expressed transcripts encoded enzymes involved in metabolic processes and/or metabolism of xenobiotics. Several of these are candidate resistance genes and include the cytochrome P450 CYP6CM1, which has been shown to confer resistance to several neonicotinoids previously, a P450 belonging to the Cytochrome P450s 4 family and a glutathione S-transferase (GST) belonging to the sigma class. Finally several ATP-binding cassette transporters of the ABCG subfamily were highly over-expressed in the adult stage of the TH-R strain and may play a role in resistance by active efflux. Here, we evaluated both common and stage-specific gene expression signatures and identified several candidate resistance genes that may underlie B. tabaci resistance to thiamethoxam. PMID:23889345

  11. Mixed release of two parasitoids and a polyphagous ladybird as a potential strategy to control the tobacco whitefly Bemisia tabaci

    PubMed Central

    Tan, Xiaoling; Hu, Nana; Zhang, Fan; Ramirez-Romero, Ricardo; Desneux, Nicolas; Wang, Su; Ge, Feng

    2016-01-01

    A mixed species release of parasitoids is used to suppress outbreaks of tobacco whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae); however, this biocontrol may be inhibited by interspecific interactions. We investigated the effects of mixed releases of natural enemies of B. tabaci on predation rates, parasite performance and adult parasitoid emergence under greenhouse conditions. We tested the polyphagous predatory ladybird Harmonia axyridis (Coleoptera: Coccinellidae) and two whitefly-specific parasitoids, namely Encarsia formosa and Encarsia sophia (both, Hymenoptera: Aphelinidae). Harmonia axyridis exhibited the lowest rates of predation when released with each parasitoid than with both parasitoid species together and showed a significant preference for non-parasitized nymphs as prey. Both E. formosa and E. sophia parasitized more B. tabaci when released with the ladybird than when the wasps were released either alone or mixed with the other parasitoid. We also found that the presence of H. axyridis significantly reduced adult parasitoid emergence; the highest rate of adult emergence was obtained with parasitoids released alone. Our results indicate that different combinations of natural enemies can influence observed rates of predation, parasitism, and parasitoid emergence. Therefore, the combination of natural enemies to be used for a particular biological control program should depend on the specific objectives. PMID:27312174

  12. Mixed release of two parasitoids and a polyphagous ladybird as a potential strategy to control the tobacco whitefly Bemisia tabaci.

    PubMed

    Tan, Xiaoling; Hu, Nana; Zhang, Fan; Ramirez-Romero, Ricardo; Desneux, Nicolas; Wang, Su; Ge, Feng

    2016-01-01

    A mixed species release of parasitoids is used to suppress outbreaks of tobacco whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae); however, this biocontrol may be inhibited by interspecific interactions. We investigated the effects of mixed releases of natural enemies of B. tabaci on predation rates, parasite performance and adult parasitoid emergence under greenhouse conditions. We tested the polyphagous predatory ladybird Harmonia axyridis (Coleoptera: Coccinellidae) and two whitefly-specific parasitoids, namely Encarsia formosa and Encarsia sophia (both, Hymenoptera: Aphelinidae). Harmonia axyridis exhibited the lowest rates of predation when released with each parasitoid than with both parasitoid species together and showed a significant preference for non-parasitized nymphs as prey. Both E. formosa and E. sophia parasitized more B. tabaci when released with the ladybird than when the wasps were released either alone or mixed with the other parasitoid. We also found that the presence of H. axyridis significantly reduced adult parasitoid emergence; the highest rate of adult emergence was obtained with parasitoids released alone. Our results indicate that different combinations of natural enemies can influence observed rates of predation, parasitism, and parasitoid emergence. Therefore, the combination of natural enemies to be used for a particular biological control program should depend on the specific objectives. PMID:27312174

  13. Bioassay evaluation of the entomopathogenic fungi, Beauveria bassaina Vuellemin against eggs and nymphs of Bemisia tabaci Gennadius (Homoptera: Aleyrodidae).

    PubMed

    Al-Deghairi, Mohammad A

    2008-06-15

    This study was carried out to determine the lethal effect of the entomopathogenic fungi, Beauveria bassaina Vuell. on eggs, young and old nymphs of the whitefly, Bemisia tabaci Genn. Mortality percentage was significantly differed based on stage of B. tabaci and conidial concentrations of B. bassina. Average of the infection level to insect was very low particularly in eggs with only 4.49%, even with higher conidial concentrations (6 x 10(6) conidia mL(-1)). Whereas, it was higher with 1st and 2nd instars (42.045%) and 3rd and 4th instars (35.93%). Three parameters was assessed with B. tabaci eggs, namely; egg infection, egg hatchability and crawlers emergence. Egg mortality percentages averaged 1.2, 4.27 and 8.0% with fungal concentration 2 x 10(6), 4 x 10(6) and 6 x 10(6) conidia mL(-1), respectively. Daily infection percentages were varied depend upon the conidial concentration where the highest infection rate of eggs was occurred with 6 x 10(6), followed by 4 x 10(6) conidia mL(-1). Egg hatch was very high, while the mortality among the emerged crawlers was neglectable compared with the check. Efficiency of B. bassaina on whitefly nymphs also was varied based on the insect instar and fungal concentration. Mortality percentages were obviously higher to young nymphs (1st and 2nd instars) than to older ones (3rd and 4th instars). The results indicated that nymphs were highly susceptible to fungal treatment compared with eggs. Additionally, pathogenicity and virulence of B. bassaina against B. tabaci immatures was not indicated by LC50 only, but also, by the time in days (LT50) required to achieve 50% mortality of an insect. PMID:18819641

  14. Lethal and Inhibitory Activities of Plant-Derived Essential Oils Against Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) Biotype B in Tomato.

    PubMed

    Fanela, T L M; Baldin, E L L; Pannuti, L E R; Cruz, P L; Crotti, A E M; Takeara, R; Kato, M J

    2016-04-01

    The silverleaf whitefly Bemisia tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) is one of the most severe tomato pests in the world. The damage caused by this insect may compromise up to 100% of crop production, and management of this pest has relied on spraying of synthetic insecticides. However, due to the environmental issues associated with this practice, alternative methods such as the use of botanical pesticides are now used as a strategy of integrated pest management (IPM). We evaluated the effects of essential oils of five plant species on B. tabaci biotype B in tomato and demonstrate that the essential oils (0.5%) of Piper callosum (PC-EO), Adenocalymma alliaceum (AA-EO), Pelargonium graveolens (PG-EO), and Plectranthus neochilus (PN-EO) inhibit the settlement and oviposition of B. tabaci biotype B adults in tomato plants. In fumigation tests, A. alliaceum (AA-EO) at 0.4 μL/L of air after 72 h and 0.1 μL/L of air after 6 h was the most effective against nymphs and adults of B. tabaci biotype B, respectively. The major chemical constituents of PC-EO were identified as being safrole (29.3%), α-pinene (19.2%), and β-pinene (14.3%), whereas diallyl trisulfide (66.9%) and diallyl disulfide (23.3%) were the major compounds identified in AA-EO. This is the first report on the reduction of oviposition by the use of P. callosum (PC-EO) and A. alliaceum (AA-EO). In addition, the fumigant effect of A. alliaceum (AA-EO) on nymphs and adults has also been reported here for the first time. PMID:26712319

  15. Densities of Eggs and Nymphs and Percent Parasitism of Bemisia tabaci (Hemiptera: Aleyrodidae) on Common Weeds in West Central Florida

    PubMed Central

    Smith, Hugh A.; Nagle, Curtis A.; Evans, Gregory A.

    2014-01-01

    The density of eggs and nymphs of Bemisia tabaci (Gennadius) biotype B and the percent parasitism of the nymphs were measured from specimens collected on nine species of weeds, commonly found in west central Florida during the spring and summer of 2012 and 2013. The weeds were direct seeded in 2012 and grown as transplants in 2013 for Randomized Complete Block design experiments. The leaf area of each whole-plant sample was measured and the B. tabaci density parameters were converted to numbers per 100 cm2. In June and July, 2013, whole-plant samples became too large to examine entirely, thus a representative portion of a plant totaling about 1000 cm2 was sampled. Egg and nymph densities and percent parasitism varied greatly among weed species, and were higher overall in 2012 than in 2013. The highest densities of eggs and nymphs were measured on Abutilon theophrasti, Cassia obtusifolia and Emilia fosbergii each year. Lower densities of immature B. tabaci were measured on most dates for Amaranthus retroflexus, Bidens alba, Ipomoea lacunosa, Sesbania exaltata and Sida acuta. Nymph to egg ratios of 1:4 were observed on A. theophrasti and S. exaltata in 2012, while less than one nymph per ten eggs was observed overall on A. retroflexus, E. fosbergii and I. lacunosa. In 2012, parasitism rates of 32.3% were measured for B. alba, 23.4% for C. obtusifolia and 17.5% for S. acuta. Of the 206 parasitoids reared out over two seasons, 96.6% were Encarsia spp. and the remainder Eretmocerus spp. The role of weeds in managing B. tabaci is discussed. PMID:26462945

  16. Densities of Eggs and Nymphs and Percent Parasitism of Bemisia tabaci (Hemiptera: Aleyrodidae) on Common Weeds in West Central Florida.

    PubMed

    Smith, Hugh A; Nagle, Curtis A; Evans, Gregory A

    2014-01-01

    The density of eggs and nymphs of Bemisia tabaci (Gennadius) biotype B and the percent parasitism of the nymphs were measured from specimens collected on nine species of weeds, commonly found in west central Florida during the spring and summer of 2012 and 2013. The weeds were direct seeded in 2012 and grown as transplants in 2013 for Randomized Complete Block design experiments. The leaf area of each whole-plant sample was measured and the B. tabaci density parameters were converted to numbers per 100 cm². In June and July, 2013, whole-plant samples became too large to examine entirely, thus a representative portion of a plant totaling about 1000 cm² was sampled. Egg and nymph densities and percent parasitism varied greatly among weed species, and were higher overall in 2012 than in 2013. The highest densities of eggs and nymphs were measured on Abutilon theophrasti, Cassia obtusifolia and Emilia fosbergii each year. Lower densities of immature B. tabaci were measured on most dates for Amaranthus retroflexus, Bidens alba, Ipomoea lacunosa, Sesbania exaltata and Sida acuta. Nymph to egg ratios of 1:4 were observed on A. theophrasti and S. exaltata in 2012, while less than one nymph per ten eggs was observed overall on A. retroflexus, E. fosbergii and I. lacunosa. In 2012, parasitism rates of 32.3% were measured for B. alba, 23.4% for C. obtusifolia and 17.5% for S. acuta. Of the 206 parasitoids reared out over two seasons, 96.6% were Encarsia spp. and the remainder Eretmocerus spp. The role of weeds in managing B. tabaci is discussed. PMID:26462945

  17. Transient receptor potential is essential for high temperature tolerance in invasive Bemisia tabaci Middle East Asia minor 1 cryptic species.

    PubMed

    Lü, Zhi-Chuang; Li, Qian; Liu, Wan-Xue; Wan, Fang-Hao

    2014-01-01

    Temperature is an important factor in affecting population dynamics and diffusion distribution of organisms. Alien species can successfully invade and colonize to various temperature environments, and one of important reasons is that alien species have a strong resistance to stress temperature. Recently, researchers have focused on the mechanisms of temperature sensing to determine the sensing and regulation mechanisms of temperature adaptation. The transient receptor potential (TRP) is one of the key components of an organism's temperature perception system. TRP plays important roles in perceiving temperature, such as avoiding high temperature, low temperature and choosing the optimum temperature. To assess high temperature sensation and the heat resistance role of the TRP gene, we used 3' and 5' rapid-amplification of cDNA ends to isolate the full-length cDNA sequence of the TRP gene from Bemisia tabaci (Gennadius) MEAM1 (Middle East Asia Minor 1), examined the mRNA expression profile under various temperature conditions, and identified the heat tolerance function. This is the first study to characterize the TRP gene of invasive B. tabaci MEAM1 (MEAM1 BtTRP). The full-length cDNA of MEAM1 BtTRP was 3871 bp, and the open reading frames of BtTRP was 3501 bp, encoding 1166 amino acids. Additionally, the BtTRP mRNA expression level was significantly increased at 35°C. Furthermore, compared with control treatments, the survival rate of B. tabaci MEAM1 adults was significantly decreased under high temperature stress conditions after feeding with dsRNA BtTRP. Collectively, these results showed that MEAM1 BtTRP is a key element in sensing high temperature and plays an essential role in B. tabaci MEAM1 heat tolerance ability. Our data improved our understanding of the mechanism of temperature sensation in B. tabaci MEAM1 at the molecular level and could contribute to the understanding of the thermal biology of B. tabaci MEAM1 within the context of global climate change

  18. Elimination of Arsenophonus and decrease in the bacterial symbionts diversity by antibiotic treatment leads to increase in fitness of whitefly, Bemisia tabaci.

    PubMed

    Raina, Harpreet Singh; Rawal, Vagisha; Singh, Shama; Daimei, Guisuibou; Shakarad, Mallikarjun; Rajagopal, Raman

    2015-06-01

    Bemisia tabaci is an invasive agricultural pest with more than 24 genetic groups harboring different bacterial endosymbionts categorized into obligatory and facultative endosymbionts. Arsenophonus is one of the facultative endosymbionts prevalent in B. tabaci of Indian sub-continent. Not much is known about the functional role of this endosymbiont in its host. Some studies have revealed its involvement in virus transmission by B. tabaci, but how it effects the biology of B. tabaci is unknown. In this study, tetracycline was used to eliminate Arsenophonus from B. tabaci to study its effects with regard to development and other fitness parameters. Bacteria specific 16S Polymerase chain reaction (PCR) was used to ascertain Arsenophonus absence with differential effects on other secondary endosymbionts present in B. tabaci. Our results revealed that Arsenophonus negative (A(-)) whiteflies had more fecundity, increased juvenile developmental time, increased nymphal survival and increased adult life span as compared to control (A(+)) whiteflies. Thus, our results demonstrate that A(+) whiteflies have lesser fitness as compared to A(-) whiteflies. These observations give a new insight about the probable role of Arsenophonus in B. tabaci, that need to be explored further. PMID:25801610

  19. Salicylic acid is required for Mi-1-mediated resistance of tomato to whitefly Bemisia tabaci, but not for basal defense to this insect pest.

    PubMed

    Rodríguez-Álvarez, C I; López-Climent, M F; Gómez-Cadenas, A; Kaloshian, I; Nombela, G

    2015-10-01

    Plant defense to pests or pathogens involves global changes in gene expression mediated by multiple signaling pathways. A role for the salicylic acid (SA) signaling pathway in Mi-1-mediated resistance of tomato (Solanum lycopersicum) to aphids was previously identified and its implication in the resistance to root-knot nematodes is controversial, but the importance of SA in basal and Mi-1-mediated resistance of tomato to whitefly Bemisia tabaci had not been determined. SA levels were measured before and after B. tabaci infestation in susceptible and resistant Mi-1-containing tomatoes, and in plants with the NahG bacterial transgene. Tomato plants of the same genotypes were also screened with B. tabaci (MEAM1 and MED species, before known as B and Q biotypes, respectively). The SA content in all tomato genotypes transiently increased after infestation with B. tabaci albeit at variable levels. Whitefly fecundity or infestation rates on susceptible Moneymaker were not significantly affected by the expression of NahG gene, but the Mi-1-mediated resistance to B. tabaci was lost in VFN NahG plants. Results indicated that whiteflies induce both SA and jasmonic acid accumulation in tomato. However, SA has no role in basal defense of tomato against B. tabaci. In contrast, SA is an important component of the Mi-1-mediated resistance to B. tabaci in tomato. PMID:26032615

  20. GLOBAL RELATIONSHIPS OF BEMISIA TABACI (HEMIPTERA: ALEYRODIDAE) REVEALED USING BAYESIAN ANALYSIS OF MITOCHONDRIAL COI DNA SEQUENCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Global phylogenetic relationships of the major races of B. tabaci remain unresolved thus a Bayesian phylogenetic technique was utilized to elucidate affinities. All COI DNA sequence data available in Genbank for B. tabaci world-wide (369 specimens) were obtained and the first well resolved phylogen...

  1. Aqueous extracts of some medicinal plants are as toxic as Imidacloprid to the sweet potato whitefly, Bemisia tabaci.

    PubMed

    Ateyyat, Mazen A; Al-Mazra'awi, Mohammad; Abu-Rjai, Talal; Shatnawi, Mohamad A

    2009-01-01

    Aqueous extracts of nine plants, known to have medicinal activity, were tested for their toxicity against the sweet potato whitefly, Bemisia tabaci Genn. (Homoptera: Aleurodidae) compared to the toxicity of the insecticide, Imidacloprid. Extracts of Lepidiuim sativum L. (Brassicales: Brassicaceae) killed 71 % of early stage nymphs, which was not significantly different from mortality caused by Imidacloprid. Treatment of pupae with three plant extracts, L. sativum, Achillea biebersteinii L. (Asterales: Asteraceae), or Retama raetam (Forssk.) Webb and Berthel (Fabales: Fabaceae) prevented adult development, and treatment with R. raetam extract killed adults, at levels that were not significantly different from Imidacloprid. None of the other plants showed significant toxicity. However extracts of four plants, Pimpinella anisum L. (Apiales: Apiaceae), Galium longifolium (Sibth. and SM.) (Gentianales: Rubiaceae), R. raetam and Ballota undulata Bentham (Lamiales: Lamiaceae) had a repellent effect. PMID:19613450

  2. A Primary Screening and Applying of Plant Volatiles as Repellents to Control Whitefly Bemisia tabaci (Gennadius) on Tomato.

    PubMed

    Du, Wenxiao; Han, Xiaoqing; Wang, Yubo; Qin, Yuchuan

    2016-01-01

    With the goal of finding a new way to reduce population densities of Bemisia tabaci biotype Q in greenhouses, seven repellent volatile chemicals and their combinations were screened. The mixture of DLCO (D-limonene, citral and olive oil (63:7:30)) had a better cost performance(SC50 = 22.59 mg/ml)to repel whiteflies from settling than the other mixtures or single chemicals. In the greenhouse, in both the choice test and the no-choice tests, the number of adult whiteflies that settled on 1% DLCO-treated tomato plants was significantly lower than those settling on the control plants for the different exposure periods (P < 0.01). In the choice test, the egg amount on the treated tomato plants was significantly lower (P < 0.01) than that on the control plants, but there was no significant difference (P > 0.05) between the number of eggs on treated and control plants in the no-choice test. Compared with the controls, 1% DLCO did not cause significantly statistic mortality rates (P > 0.05) out of different living stages of B. tabaci. The tests for evaluating the repellent efficacy, showed that a slow-releasing bottle containing the mixture had a period of efficacy of 29 days, and the application of this mixture plus a yellow board used as a push-pull strategy in the greenhouse was also effective. PMID:26907368

  3. A Primary Screening and Applying of Plant Volatiles as Repellents to Control Whitefly Bemisia tabaci (Gennadius) on Tomato

    NASA Astrophysics Data System (ADS)

    Du, Wenxiao; Han, Xiaoqing; Wang, Yubo; Qin, Yuchuan

    2016-02-01

    With the goal of finding a new way to reduce population densities of Bemisia tabaci biotype Q in greenhouses, seven repellent volatile chemicals and their combinations were screened. The mixture of DLCO (D-limonene, citral and olive oil (63:7:30)) had a better cost performance(SC50 = 22.59 mg/ml)to repel whiteflies from settling than the other mixtures or single chemicals. In the greenhouse, in both the choice test and the no-choice tests, the number of adult whiteflies that settled on 1% DLCO-treated tomato plants was significantly lower than those settling on the control plants for the different exposure periods (P < 0.01). In the choice test, the egg amount on the treated tomato plants was significantly lower (P < 0.01) than that on the control plants, but there was no significant difference (P > 0.05) between the number of eggs on treated and control plants in the no-choice test. Compared with the controls, 1% DLCO did not cause significantly statistic mortality rates (P > 0.05) out of different living stages of B. tabaci. The tests for evaluating the repellent efficacy, showed that a slow-releasing bottle containing the mixture had a period of efficacy of 29 days, and the application of this mixture plus a yellow board used as a push-pull strategy in the greenhouse was also effective.

  4. Transmission of Tomato Yellow Leaf Curl Virus by Bemisia tabaci as Affected by Whitefly Sex and Biotype

    PubMed Central

    Ning, Wenxi; Shi, Xiaobin; Liu, Baiming; Pan, Huipeng; Wei, Wanting; Zeng, Yang; Sun, Xinpei; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Cheng, Jiaxu; Peng, Zhengke; Zhang, Youjun

    2015-01-01

    Bemisia tabaci is a serious pest of vegetables and other crops worldwide. The most damaging and predominant B. tabaci biotypes are B and Q, and both are vectors of tomato yellow leaf curl virus (TYLCV). Previous research has shown that Q outperforms B in many respects but comparative research is lacking on the ability of B and Q to transmit viruses. In the present study, we tested the hypothesis that B and Q differ in their ability to transmit TYLCV and that this difference helps explain TYLCV outbreaks. We compared the acquisition, retention, and transmission of TYLCV by B and Q females and males. We found that Q females are more efficient than Q males, B females, and B males at TYLCV acquisition and transmission. Although TYLCV acquisition and transmission tended to be greater for B females than B males, the differences were not statistically significant. Based on electrical penetration graphs determination of phloem sap ingestion parameters, females fed better than males, and Q females fed better than Q males, B females, or B males. These results are consistent with the occurrences of TYLCV outbreaks in China, which have been associated with the spread of Q rather than B. PMID:26021483

  5. Transmission of Tomato Yellow Leaf Curl Virus by Bemisia tabaci as Affected by Whitefly Sex and Biotype.

    PubMed

    Ning, Wenxi; Shi, Xiaobin; Liu, Baiming; Pan, Huipeng; Wei, Wanting; Zeng, Yang; Sun, Xinpei; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Cheng, Jiaxu; Peng, Zhengke; Zhang, Youjun

    2015-01-01

    Bemisia tabaci is a serious pest of vegetables and other crops worldwide. The most damaging and predominant B. tabaci biotypes are B and Q, and both are vectors of tomato yellow leaf curl virus (TYLCV). Previous research has shown that Q outperforms B in many respects but comparative research is lacking on the ability of B and Q to transmit viruses. In the present study, we tested the hypothesis that B and Q differ in their ability to transmit TYLCV and that this difference helps explain TYLCV outbreaks. We compared the acquisition, retention, and transmission of TYLCV by B and Q females and males. We found that Q females are more efficient than Q males, B females, and B males at TYLCV acquisition and transmission. Although TYLCV acquisition and transmission tended to be greater for B females than B males, the differences were not statistically significant. Based on electrical penetration graphs determination of phloem sap ingestion parameters, females fed better than males, and Q females fed better than Q males, B females, or B males. These results are consistent with the occurrences of TYLCV outbreaks in China, which have been associated with the spread of Q rather than B. PMID:26021483

  6. A Primary Screening and Applying of Plant Volatiles as Repellents to Control Whitefly Bemisia tabaci (Gennadius) on Tomato

    PubMed Central

    Du, Wenxiao; Han, Xiaoqing; Wang, Yubo; Qin, Yuchuan

    2016-01-01

    With the goal of finding a new way to reduce population densities of Bemisia tabaci biotype Q in greenhouses, seven repellent volatile chemicals and their combinations were screened. The mixture of DLCO (D-limonene, citral and olive oil (63:7:30)) had a better cost performance(SC50 = 22.59 mg/ml)to repel whiteflies from settling than the other mixtures or single chemicals. In the greenhouse, in both the choice test and the no-choice tests, the number of adult whiteflies that settled on 1% DLCO-treated tomato plants was significantly lower than those settling on the control plants for the different exposure periods (P < 0.01). In the choice test, the egg amount on the treated tomato plants was significantly lower (P < 0.01) than that on the control plants, but there was no significant difference (P > 0.05) between the number of eggs on treated and control plants in the no-choice test. Compared with the controls, 1% DLCO did not cause significantly statistic mortality rates (P > 0.05) out of different living stages of B. tabaci. The tests for evaluating the repellent efficacy, showed that a slow-releasing bottle containing the mixture had a period of efficacy of 29 days, and the application of this mixture plus a yellow board used as a push-pull strategy in the greenhouse was also effective. PMID:26907368

  7. Identification and characterization of two phospholipid hydroperoxide glutathione peroxidase genes from the Mediterranean species of the whitefly Bemisia tabaci complex.

    PubMed

    Jiu, Min; Li, Jun-Min; Gao, Xian-Long; Wang, Lun-Ji; Wang, Xiao-Wei; Liu, Shu-Sheng

    2015-05-01

    Phospholipid hydroperoxide glutathione peroxidases (PHGPXs) are essential enzymes of the cellular antioxidant defense system during insect-plant interactions. However, little attention has been devoted to the functional characterization of PHGXPs in the whitefly Bemisia tabaci. Here, we report the identification and characterization of two PHGPX genes, designated as BtQ-PHGPX1 and BtQ-PHGPX2 from the Mediterranean species of the B. tabaci complex. Sequence analysis indicated that the length of BtQ-PHGPX1 is of 942 bp with a 729 bp open-reading frame (ORF) encoding 242 amino acids, and BtQ-PHGPX2 is of 699 bp with a 567 bp ORF encoding 188 amino acids. Sequence alignment analysis showed that BtQ-PHGPX1 and BtQ-PHGPX2 shared high similarity with other known PHGPXs. The NVASXCGXT, FPCNQFXXQEPG, and IKWNFXKFLV surrounded the reactive cysteine, glutamine, and tryptophan residues, respectively. Recombinant BtQ-PHGPX1 and BtQ-PHGPX2 were overexpressed in Escherichia coli and purified. quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis with whiteflies of different development stages showed that the mRNA levels of BtQ-PHGPX2 were significantly higher in larvae than in other stages. The mRNA levels of BtQ-PHGPX2 were significantly higher than BtQ-PHGPX1 during all the developmental stages. The mRNA levels of BtQ-PHGPX1 and BtQ-PHGPX2 in female adults were relatively higher than in male adults. The expression of BtQ-PHGPX1 and BtQ-PHGPX2 was induced by the insecticide imidacloprid. These results suggest that BtQ-PHGPX1 and BtQ-PHGPX2 may participate in detoxification of oxidative hazards in B. tabaci. PMID:25639712

  8. Tri-Tek (Petroleum Horticultural Oil) and Beauveria bassiana: Use in Eradication Strategies for Bemisia tabaci Mediterranean Species in UK Glasshouses

    PubMed Central

    Cuthbertson, Andrew G. S.; Collins, Debbie A.

    2015-01-01

    The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a pest of global importance on both outdoor and glasshouse crops. To date, B. tabaci has not become established in the UK. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. Mediterranean species is now the most prevalent Bemisia species entering the UK. Increasing neonicotinoid resistance is becoming increasingly widespread and problematic with this species. As a result, this continues to pose problems for eradication strategies. The current study investigates the efficacy of Tri-Tek (a petroleum horticultural oil awaiting UK registration) and the fungus Beauveria bassiana to act as control agents against Mediterranean species in UK glasshouses. Tri-Tek provided 100% egg mortality compared to 74% for B. bassiana. When tested against second instar larvae, mortalities of 69% and 65% respectively were achieved. Both products can be successfully “tank-mixed”. A tank-mix application provided 95.5% mortality of second instar larvae under glasshouse conditions. The potential integration of both products into current Bemisia eradication strategies in UK glasshouses is discussed. PMID:26463071

  9. Tri-Tek (Petroleum Horticultural Oil) and Beauveria bassiana: Use in Eradication Strategies for Bemisia tabaci Mediterranean Species in UK Glasshouses.

    PubMed

    Cuthbertson, Andrew G S; Collins, Debbie A

    2015-01-01

    The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a pest of global importance on both outdoor and glasshouse crops. To date, B. tabaci has not become established in the UK. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. Mediterranean species is now the most prevalent Bemisia species entering the UK. Increasing neonicotinoid resistance is becoming increasingly widespread and problematic with this species. As a result, this continues to pose problems for eradication strategies. The current study investigates the efficacy of Tri-Tek (a petroleum horticultural oil awaiting UK registration) and the fungus Beauveria bassiana to act as control agents against Mediterranean species in UK glasshouses. Tri-Tek provided 100% egg mortality compared to 74% for B. bassiana. When tested against second instar larvae, mortalities of 69% and 65% respectively were achieved. Both products can be successfully "tank-mixed". A tank-mix application provided 95.5% mortality of second instar larvae under glasshouse conditions. The potential integration of both products into current Bemisia eradication strategies in UK glasshouses is discussed. PMID:26463071

  10. Use of honeydew production to determine reduction in feeding by Bemisia tabaci (Hemiptera: Aleyrodidae) adults when exposed to cyantraniliprole and imidacloprid treatments.

    PubMed

    Cameron, Rachel; Lang, Edward B; Alvarez, Juan Manuel

    2014-04-01

    Bemisia tabaci (Gennadius) whitefly populations produce economically important damage to crops by their direct feeding and also by transmitting plant viruses. Although there are several methods to reduce B. tabaci damage, most growers rely on the use of insecticides to decrease populations of this pest. Insecticides that reduce feeding of whitefly adults may also reduce the transmission of viruses that are harmful to crop plants. However, demonstrating the feeding reduction has proved challenging. In this study, water-sensitive paper was used to determine whitefly adult feeding, indirectly through honeydew production, when insects were placed on insecticide-treated and untreated plants. Plant treatments with two formulations of cyantraniliprole (Cyazypyr) showed a reduction in the amount of honeydew produced by B. tabaci adults equivalent to imidacloprid. The reduction in the amount of honeydew produced indicates reduced insect feeding and the possibility for a reduction in virus transmission. Plant treatments with two formulations of cyantraniliprole also resulted in higher mortality than imidacloprid. PMID:24772533

  11. Age-specific interaction between the parasitoid, Encarsia formosa and its host, the silverleaf whitefly, Bemisia tabaci (Strain B)

    PubMed Central

    Hu, Jing S.; Gelman, Dale B.; Blackburn, Michael B.

    2003-01-01

    The effect of hostage, the instar of Bemisia tabaci (Gennadius) parasitized, on the growth and development of Encarsia formosa (Gahan) was studied. E. formosa was able to parasitize and complete its life cycle no matter which instar of B. tabaci (Strain B), [also identified as B. argentifolii (Bellows and Perring)], was provided for oviposition, but parasitoid development was significantly slower when 1st or 2nd instar B. tabaci rather than 3rd or 4th instars were parasitized. Host age influenced the day on which E. formosa nymphs hatching from eggs was first observed. Mean embryonic development was significantly longer when 1st (5.4 days) rather than 2nd, 3rd or 4th instars (4.1, 3.4 and 3.5 days, respectively) were parasitized. The duration of the 1st instar parasitoid and the pupa, but not the 2nd or 3rd instar parasitoid, were also significantly greater when 1st instars were parasitized than when older host instars were parasitized. Interestingly, no matter which instar was parasitized, the parasitoid did not molt to the 3rd instar until the 4th instar host had reached a depth of about 0.23 mm (Stage 4–5) and had initiated the nymphal-adult molt and adult development. Histological studies revealed that whitefly eye and wing structures had either disintegrated or were adult in nature whenever a 3rd instar parasitoid was present. It appears, then, that the molt of the parasitoid to its last instar is associated with the host whitefly's nymphal-adult molt. However, the initiation of the host's final molt, while a prerequisite for the parasitoid's 2nd–3rd instar molt, did not necessarily trigger this molt. In contrast to its significant effect on various aspects of parasitoid development, host instar did not significantly influence the mean size of the parasitoid larva, pupa, or adult. Larval and pupal length and adult head width were similar for all parasitoids, regardless of which host instar was parasitized as was adult longevity. Adult parasitoid emergence

  12. Use of fluorescence, a novel technique to determine reduction in Bemisia tabaci (Hemiptera: Aleyrodidae) nymph feeding when exposed to Benevia and other insecticides.

    PubMed

    Cameron, Rachel; Lang, Edward B; Annan, I Billy; Portillo, Hector E; Alvarez, Juan M

    2013-04-01

    The sweet potato whitefly, Bemisia tabaci (Gennadius), is an economically important pest in the United States and other countries. Growers in many places rely on the use of insecticides to reduce populations of B. tabaci. However, insecticides may take a few days to cause B. tabaci mortality and some do not reduce feeding before death. Earlier reduction of feeding of whiteflies would decrease the physiological effects on plants, reduce the production of sooty mold and potentially reduce the transmission of viruses. Measuring the reduction in feeding after the exposure of B. tabaci to an insecticide has proven difficult. This series of laboratory experiments demonstrate the usefulness of fluorescence in determining B. tabaci feeding cessation. Fluorescein sodium salt is systemically transported in the xylem from the roots to the plant leaves and absorbed by B. tabaci nymphs feeding on these plants. Nymphs start fluorescing shortly after the cotton plant root system is submerged in the fluorescein sodium salt. Using this novel technique, the effect of three insecticides with different modes of action, cyantraniliprole, imidacloprid, and spirotetramat on B. tabaci was evaluated and compared to determine reduction in feeding. Results indicate that B. tabaci nymphs feeding on a plant treated with Benevia have a significant reduction of feeding when compared with nymphs feeding on plants treated with imidacloprid or spirotetramat. Both Benevia and spirotetramat caused significant nymphal mortality by 48 h after exposure. This novel technique will be useful to demonstrate the feeding cessation or reduction in feeding produced by different insecticides in several sucking insect groups. PMID:23786044

  13. Detection of Cucurbit chlorotic yellows virus from Bemisia tabaci captured on sticky traps using reverse transcription loop-mediated isothermal amplification (RT-LAMP) and simple template preparation.

    PubMed

    Okuda, Mitsuru; Okuda, Shiori; Iwai, Hisashi

    2015-09-01

    Cucurbit chlorotic yellows virus (CCYV) of the genus Crinivirus within the family Closteroviridae is an emerging infectious agent of cucurbits leading to severe disease and significant economic losses. Effective detection and identification methods for this virus are urgently required. In this study, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed to detect CCYV from its vector Bemisia tabaci. LAMP primer sets to detect CCYV were evaluated for their sensitivity and specificity, and a primer set designed from the HSP70h gene with corresponding loop primers were selected. The RT-LAMP assay was applied to detect CCYV from viruliferous B. tabaci trapped on sticky traps. A simple extraction procedure using RNAsecure™ was developed for template preparation. CCYV was detected in all of the B. tabaci 0, 1, 7 and 14 days after they were trapped. Although the rise of turbidity was delayed in reactions using RNA from B. tabaci trapped for 7 and 14 days compared with those from 0 and 1 day, the DNA amplification was sufficient to detect CCYV in all of the samples. These findings therefore present a simple template preparation method and an effective RT-LAMP assay, which can be easily and rapidly performed to monitor CCYV-viruliferous B. tabaci in the field. PMID:25912723

  14. The suitability of biotypes Q and B of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) at different nymphal instars as hosts for Encarsia formosa Gahan (Hymenoptera: Aphelinidae).

    PubMed

    Liu, Xin; Zhang, Youjun; Xie, Wen; Wu, Qingjun; Wang, Shaoli

    2016-01-01

    Encarsia formosa Gahan (Hymenoptera: Aphelinidae) is a solitary endoparasitoid that is commercially reared and released for augmentative biological control of whiteflies infesting greenhouse crops. In most areas in China, the invasive and destructive whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype Q has replaced B. tabaci biotype B and has become dominant between the two. A better understanding of the suitability of different nymphal instars of B. tabaci biotypes Q and B as hosts for E. formosa is needed to improve the use of this parasitoid for biological control. Parasitism of the four nymphal instars of B. tabaci biotypes Q and B by the commercial strain of E. formosa mass reared on Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) was assessed in the laboratory. The results indicated that E. formosa parasitized and successfully developed on all instars of both biotypes but performed best on the 3rd instar of B. tabaci biotype B and on the 2nd, 3rd, and 4th instars of B. tabaci biotype Q. The host-feeding rate of the adult parasitoid was generally higher on nymphal instars of B. tabaci biotype Q than on the corresponding nymphal instars of biotype B and was significantly higher on the 2nd and 3rd instars. For both whitefly biotypes, the parasitoid's immature developmental period was the longest on the 1st instar, intermediate on the 2nd and 3rd instars, and the shortest on the 4th instar. The parasitoid emergence rate was significantly lower on the 1st instar than on the other three instars and did not significantly differ between B. tabaci biotype B and biotype Q. Offspring longevity was greater on the 3rd and 4th instars than on the 1st instar and did not significantly differ between the two B. tabaci biotypes. The results indicate that commercially-produced E. formosa can parasitize all instars of B. tabaci biotypes B and Q, making this parasitoid a promising tool for the management of the two biotypes of B. tabaci present in

  15. The suitability of biotypes Q and B of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) at different nymphal instars as hosts for Encarsia formosa Gahan (Hymenoptera: Aphelinidae)

    PubMed Central

    Liu, Xin; Zhang, Youjun; Xie, Wen; Wu, Qingjun

    2016-01-01

    Encarsia formosa Gahan (Hymenoptera: Aphelinidae) is a solitary endoparasitoid that is commercially reared and released for augmentative biological control of whiteflies infesting greenhouse crops. In most areas in China, the invasive and destructive whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype Q has replaced B. tabaci biotype B and has become dominant between the two. A better understanding of the suitability of different nymphal instars of B. tabaci biotypes Q and B as hosts for E. formosa is needed to improve the use of this parasitoid for biological control. Parasitism of the four nymphal instars of B. tabaci biotypes Q and B by the commercial strain of E. formosa mass reared on Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) was assessed in the laboratory. The results indicated that E. formosa parasitized and successfully developed on all instars of both biotypes but performed best on the 3rd instar of B. tabaci biotype B and on the 2nd, 3rd, and 4th instars of B. tabaci biotype Q. The host-feeding rate of the adult parasitoid was generally higher on nymphal instars of B. tabaci biotype Q than on the corresponding nymphal instars of biotype B and was significantly higher on the 2nd and 3rd instars. For both whitefly biotypes, the parasitoid’s immature developmental period was the longest on the 1st instar, intermediate on the 2nd and 3rd instars, and the shortest on the 4th instar. The parasitoid emergence rate was significantly lower on the 1st instar than on the other three instars and did not significantly differ between B. tabaci biotype B and biotype Q. Offspring longevity was greater on the 3rd and 4th instars than on the 1st instar and did not significantly differ between the two B. tabaci biotypes. The results indicate that commercially-produced E. formosa can parasitize all instars of B. tabaci biotypes B and Q, making this parasitoid a promising tool for the management of the two biotypes of B. tabaci present

  16. Multiple forms of vector manipulation by a plant-infecting virus: Bemisia tabaci and tomato yellow leaf curl virus.

    PubMed

    Liu, Baiming; Preisser, Evan L; Chu, Dong; Pan, Huipeng; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Zhou, Xuguo; Zhang, Youjun

    2013-05-01

    For many insect-vectored plant viruses, the relationship between feeding behavior and vector competence may prove integral to an understanding of the epidemiology of the resulting plant disease. While plant-infecting viruses are well known to change host plant physiology in a way that makes them more attractive to vectors, viral manipulation of the vectors themselves has only recently been reported. Previous research suggested that the rapid spread of Tomato yellow leaf curl virus (TYLCV) throughout China has been facilitated by its primary vector, the whitefly Bemisia tabaci. We conducted two experiments testing the impact of TYLCV infection of the host plant (tomato) and vector (B. tabaci biotypes B and Q) on whitefly feeding behavior. Whiteflies of biotypes B and Q both appeared to find TYLCV-infected plants more attractive, probing them more quickly and having a greater number of feeding bouts; this did not, however, alter the total time spent feeding. Viruliferous whiteflies fed more readily than uninfected whiteflies and spent more time salivating into sieve tube elements. Because vector salivation is essential for viral transmission, this virally mediated alteration of behavior should provide TYLCV a direct fitness benefit. This is the first report of such manipulation by a nonpropagative virus that belongs to an exclusively plant-infecting family of viruses (Geminiviridae). In the context of previous research showing that feeding on TYLCV-infected plants harms biotype B but helps biotype Q, the fact that both biotypes were equally affected by TYLCV also suggests that the virus may alter the biotype B-biotype Q competitive interaction in favor of biotype Q. PMID:23408638

  17. Tomato Pathogenesis-related Protein Genes are Expressed in Response to Trialeurodes vaporariorum and Bemisia tabaci Biotype B Feeding

    PubMed Central

    Puthoff, David P.; Holzer, Frances M.; Perring, Thomas M.

    2010-01-01

    The temporal and spatial expression of tomato wound- and defense-response genes to Bemisia tabaci biotype B (the silverleaf whitefly) and Trialeurodes vaporariorum (the greenhouse whitefly) feeding were characterized. Both species of whiteflies evoked similar changes in tomato gene expression. The levels of RNAs for the methyl jasmonic acid (MeJA)- or ethylene-regulated genes that encode the basic β-1,3-glucanase (GluB), basic chitinase (Chi9), and Pathogenesis-related protein-1 (PR-1) were monitored. GluB and Chi9 RNAs were abundant in infested leaves from the time nymphs initiated feeding (day 5). In addition, GluB RNAs accumulated in apical non-infested leaves. PR-1 RNAs also accumulated after whitefly feeding. In contrast, the ethylene- and salicylic acid (SA)-regulated Chi3 and PR-4 genes had RNAs that accumulated at low levels and GluAC RNAs that were undetectable in whitefly-infested tomato leaves. The changes in Phenylalanine ammonia lyase5 (PAL5) were variable; in some, but not all infestations, PAL5 RNAs increased in response to whitefly feeding. PAL5 RNA levels increased in response to MeJA, ethylene, and abscisic acid, and declined in response to SA. Transcripts from the wound-response genes, leucine aminopeptidase (LapA1) and proteinase inhibitor 2 (pin2), were not detected following whitefly feeding. Furthermore, whitefly infestation of transgenic LapA1:GUS tomato plants showed that whitefly feeding did not activate the LapA1 promoter, although crushing of the leaf lamina increased GUS activity up to 40 fold. These studies indicate that tomato plants perceive B. tabaci and T. vaporariorum in a manner similar to baterical pathogens and distinct from tissue-damaging insects. PMID:20927641

  18. Multiple Forms of Vector Manipulation by a Plant-Infecting Virus: Bemisia tabaci and Tomato Yellow Leaf Curl Virus

    PubMed Central

    Liu, Baiming; Preisser, Evan L.; Chu, Dong; Pan, Huipeng; Xie, Wen; Wang, Shaoli; Wu, Qingjun

    2013-01-01

    For many insect-vectored plant viruses, the relationship between feeding behavior and vector competence may prove integral to an understanding of the epidemiology of the resulting plant disease. While plant-infecting viruses are well known to change host plant physiology in a way that makes them more attractive to vectors, viral manipulation of the vectors themselves has only recently been reported. Previous research suggested that the rapid spread of Tomato yellow leaf curl virus (TYLCV) throughout China has been facilitated by its primary vector, the whitefly Bemisia tabaci. We conducted two experiments testing the impact of TYLCV infection of the host plant (tomato) and vector (B. tabaci biotypes B and Q) on whitefly feeding behavior. Whiteflies of biotypes B and Q both appeared to find TYLCV-infected plants more attractive, probing them more quickly and having a greater number of feeding bouts; this did not, however, alter the total time spent feeding. Viruliferous whiteflies fed more readily than uninfected whiteflies and spent more time salivating into sieve tube elements. Because vector salivation is essential for viral transmission, this virally mediated alteration of behavior should provide TYLCV a direct fitness benefit. This is the first report of such manipulation by a nonpropagative virus that belongs to an exclusively plant-infecting family of viruses (Geminiviridae). In the context of previous research showing that feeding on TYLCV-infected plants harms biotype B but helps biotype Q, the fact that both biotypes were equally affected by TYLCV also suggests that the virus may alter the biotype B-biotype Q competitive interaction in favor of biotype Q. PMID:23408638

  19. Potential of entomopathogenic fungus, Isaria fumosorosea to protect potted ornamental plants against Bemisia tabaci during shipping

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of entomopathogenic fungus Isaria fumosoroesa has been evaluated under abiotic conditions similar to those typical for shipping of ornamental plants. When applied to a synchronized population of B. tabaci L4 nymphs on poinsettias, I. fumosorosea induced mortality even in regime of low t...

  20. Effects of Host Sex, Plant Species, and Putative Host Species on the Prevalence of Wolbachia in Natural Populations of Bemisia tabaci (Hemiptera: Aleyrodidae): A Modified Nested PCR Study.

    PubMed

    Ji, Han-Le; Qi, Lan-Da; Hong, Xiao-Yue; Xie, Hong-Fang; Li, Yuan-Xi

    2015-02-01

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a globally distributed pest. One of the key endosymbionts in B. tabaci is Wolbachia, an α-proteobacterium implicated in many important biological processes. Previous studies indicated that the infection frequency of Wolbachia in Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED) varied greatly among populations in different areas. However, little is known about the factors that influence the prevalence of Wolbachia in B. tabaci. In this paper, 25 field populations were collected from different locations in China, and 1,161 individuals were screened for the presence of Wolbachia using a nested polymerase chain reaction (PCR)-based method, which targets the wsp gene, to confirm Wolbachia infection status. The prevalence of Wolbachia ranged from 1.54 to 66.67% within the 25 field populations, and the infection frequency of Wolbachia was affected significantly by the putative species of B. tabaci. The infection frequency (51.55%) of Wolbachia was significantly greater in native species than in the MED (25.65%) and MEAM1 (14.37%). With the exception of host plant, all factors, including putative species, geographic location, and the sex of the host, affected the Wolbachia infection frequency in whiteflies. Six Wolbachia strains were found and clustered into four distinct clades upon phylogenetic analyses. Furthermore, Wolbachia in B. tabaci have close relationships with those from other host species, including Liriomyza trifolii (Burgess), Sogatella furcifera (Horvath), Nilaparvata lugens (Stål), and Culex pipiens L. The results demonstrated the variation and diversity of Wolbachia in B. tabaci field populations, and that the application of nested PCR extended our knowledge of Wolbachia infection in B. tabaci, especially in invasive whiteflies. PMID:26470122

  1. Rapid genetic turnover in populations of the insect pest Bemisia tabaci Middle East: Asia Minor 1 in an agricultural landscape.

    PubMed

    Dinsdale, A; Schellhorn, N A; De Barro, P; Buckley, Y M; Riginos, C

    2012-10-01

    Organisms differ greatly in dispersal ability, and landscapes differ in amenability to an organism's movement. Thus, landscape structure and heterogeneity can affect genetic composition of populations. While many agricultural pests are known for their ability to disperse rapidly, it is unclear how fast and over what spatial scale insect pests might respond to the temporally dynamic agricultural landscapes they inhabit. We used population genetic analyses of a severe crop pest, a member of the Bemisia tabaci (Hemiptera: Sternorrhyncha: Aleyrodoidea: Aleyrodidea) cryptic species complex known as Middle East-Asia Minor 1 (commonly known as biotype B), to estimate spatial and temporal genetic diversity over four months of the 2006-2007 summer growing season. We examined 559 individuals from eight sites, which were scored for eight microsatellite loci. Temporal genetic structure greatly exceeded spatial structure. There was significant temporal change in local genetic composition from the beginning to the end of the season accompanied by heterozygote deficits and inbreeding. This temporal structure suggests entire cohorts of pests can occupy a large and variable agricultural landscape but are rapidly replaced. These rapid genetic fluctuations reinforce the concept that agricultural landscapes are dynamic mosaics in time and space and may contribute to better decisions for pest and insecticide resistance management. PMID:22420748

  2. Comparison of transmission of Papaya leaf curl China virus among four cryptic species of the whitefly Bemisia tabaci complex.

    PubMed

    Guo, Tao; Guo, Qi; Cui, Xi-Yun; Liu, Yin-Quan; Hu, Jian; Liu, Shu-Sheng

    2015-01-01

    Begomoviruses are transmitted by cryptic species of the whitefly Bemisia tabaci complex, often in a species-specific manner. Papaya leaf curl China virus (PaLCuCNV) has been recorded to infect several crops including papaya, tomato and tobacco in China. To help assess the risks of spread of this virus, we compared the acquisition, retention and transmission of PaLCuCNV among four species of whiteflies, Middle East-Asia Minor 1 (MEAM1), Mediterranean (MED), Asia 1 and Asia II 7. All four species of whiteflies are able to acquire, retain and transmit the virus, but with different levels of efficiency. Transmission tests using tomato as the host plant showed that MEAM1 transmitted PaLCuCNV with substantially higher efficiency than did MED, Asia 1 and Asia II 7. Furthermore, accumulation of PaLCuCNV in the whiteflies was positively associated with its efficiency of transmitting the virus. Altogether, these findings indicate that MEAM1 is the most efficient vector for PaLCuCNV in the four species of whiteflies, and suggest that risks of PaLCuCNV pandemics are high in regions where MEAM1 occurs. PMID:26486606

  3. New Insecticides for Management of Tomato Yellow Leaf Curl, a Virus Vectored by the Silverleaf Whitefly, Bemisia tabaci

    PubMed Central

    Smith, H. A.; Giurcanu, M. C.

    2014-01-01

    Greenhouse studies using a randomized complete block design were carried out to evaluate the effect of six insecticides on transmission of Tomato yellow leaf curl virus (TYLCV) by the silverleaf whitefly, Bemisia tabaci biotype B Gennadius (Hemiptera: Aleyrodidae) to tomato, Lycopersicon esculentum (Miller) (Solanales: Solanaceae), seedlings that were inoculated with whiteflies from a TYLCV colony in cages 3, 7, or 14 d after treatment with insecticide. The purpose was to reveal differences in residual efficacy of four materials that are nearing registration for use on tomato—cyazypyr, flupyradifurone, pyrafluquinazon, and sulfoxaflor—and to compare them with two established insecticides, pymetrozine and a zeta-cypermethrin/bifenthrin combination. Differences in efficacy were expected because these six materials represent five distinct modes of action and both contact and systemic materials. Percentage of tomato seedlings expressing virus symptoms tended to be lowest in seedlings treated with flupyradifurone. The zeta-cypermethrin/bifenthrin insecticide demonstrated comparable efficacy to flupyradifurone in some trials at 3 and 7 d after treatment inoculations, but not the 14 d after treatment inoculation. Pyrafluquinazon was not statistically different from cyazypyr or sulfoxaflor in percentage of plants with virus symptoms in any trial. Percentage virus in the cyazypyr and sulfoxaflor treatments was not statistically different in the 3 and 7 d after treatment inoculations. Among seedlings treated with insecticide, percentage with virus symptoms tended to be highest in the seedlings treated with pymetrozine. PMID:25368089

  4. The Whitefly Bemisia tabaci Knottin-1 Gene Is Implicated in Regulating the Quantity of Tomato Yellow Leaf Curl Virus Ingested and Transmitted by the Insect.

    PubMed

    Hariton Shalev, Aliza; Sobol, Iris; Ghanim, Murad; Liu, Shu-Sheng; Czosnek, Henryk

    2016-01-01

    The whitefly Bemisia tabaci is a major pest to agricultural crops. It transmits begomoviruses, such as Tomato yellow leaf curl virus (TYLCV), in a circular, persistent fashion. Transcriptome analyses revealed that B. tabaci knottin genes were responsive to various stresses. Upon ingestion of tomato begomoviruses, two of the four knottin genes were upregulated, knot-1 (with the highest expression) and knot-3. In this study, we examined the involvement of B. tabaci knottin genes in relation to TYLCV circulative transmission. Knottins were silenced by feeding whiteflies with knottin dsRNA via detached tomato leaves. Large amounts of knot-1 transcripts were present in the abdomen of whiteflies, an obligatory transit site of begomoviruses in their circulative transmission pathway; knot-1 silencing significantly depleted the abdomen from knot-1 transcripts. Knot-1 silencing led to an increase in the amounts of TYLCV ingested by the insects and transmitted to tomato test plants by several orders of magnitude. This effect was not observed following knot-3 silencing. Hence, knot-1 plays a role in restricting the quantity of virions an insect may acquire and transmit. We suggest that knot-1 protects B. tabaci against deleterious effects caused by TYLCV by limiting the amount of virus associated with the whitefly vector. PMID:27455309

  5. The Whitefly Bemisia tabaci Knottin-1 Gene Is Implicated in Regulating the Quantity of Tomato Yellow Leaf Curl Virus Ingested and Transmitted by the Insect

    PubMed Central

    Hariton Shalev, Aliza; Sobol, Iris; Ghanim, Murad; Liu, Shu-Sheng; Czosnek, Henryk

    2016-01-01

    The whitefly Bemisia tabaci is a major pest to agricultural crops. It transmits begomoviruses, such as Tomato yellow leaf curl virus (TYLCV), in a circular, persistent fashion. Transcriptome analyses revealed that B. tabaci knottin genes were responsive to various stresses. Upon ingestion of tomato begomoviruses, two of the four knottin genes were upregulated, knot-1 (with the highest expression) and knot-3. In this study, we examined the involvement of B. tabaci knottin genes in relation to TYLCV circulative transmission. Knottins were silenced by feeding whiteflies with knottin dsRNA via detached tomato leaves. Large amounts of knot-1 transcripts were present in the abdomen of whiteflies, an obligatory transit site of begomoviruses in their circulative transmission pathway; knot-1 silencing significantly depleted the abdomen from knot-1 transcripts. Knot-1 silencing led to an increase in the amounts of TYLCV ingested by the insects and transmitted to tomato test plants by several orders of magnitude. This effect was not observed following knot-3 silencing. Hence, knot-1 plays a role in restricting the quantity of virions an insect may acquire and transmit. We suggest that knot-1 protects B. tabaci against deleterious effects caused by TYLCV by limiting the amount of virus associated with the whitefly vector. PMID:27455309

  6. Temporal changes of symbiont density and host fitness after rifampicin treatment in a whitefly of the Bemisia tabaci species complex.

    PubMed

    Shan, Hong-Wei; Zhang, Chang-Rong; Yan, Ting-Ting; Tang, Hai-Qin; Wang, Xiao-Wei; Liu, Shu-Sheng; Liu, Yin-Quan

    2016-04-01

    Microbial symbionts are essential or important partners to phloem-feeding insects. Antibiotics have been used to selectively eliminate symbionts from their host insects and establish host lines with or without certain symbionts for investigating functions of the symbionts. In this study, using the antibiotic rifampicin we attempted to selectively eliminate certain symbionts from a population of the Middle East-Asia Minor 1 whitefly of the Bemisia tabaci species complex, which harbors the primary symbiont "Candidatus Portiera aleyrodidarum" and two secondary symbionts "Candidatus Hamiltonella defensa" and Rickettsia. Neither the primary nor the secondary symbionts were completely depleted in the adults (F0) that fed for 48 h on a diet treated with rifampicin at concentrations of 1-100 μg/mL. However, both the primary and secondary symbionts were nearly completely depleted in the offspring (F1) of the rifampicin-treated adults. Although the F1 adults produced some eggs (F2), most of the eggs failed to hatch and none of them reached the second instar, and consequently the rifampicin-treated whitefly colony vanished at the F2 generation. Interestingly, quantitative polymerase chain reaction assays showed that in the rifampicin-treated whiteflies, the density of the primary symbiont was reduced at an obviously slower pace than the secondary symbionts. Mating experiments between rifampicin-treated and untreated adults demonstrated that the negative effects of rifampicin on host fitness were expressed when the females were treated by the antibiotic, and whether males were treated or not by the antibiotic had little contribution to the negative effects. These observations indicate that with this whitefly population it is not feasible to selectively eliminate the secondary symbionts using rifampicin without affecting the primary symbiont and establish host lines for experimental studies. However, the extinction of the whitefly colony at the second generation after

  7. Genetic diversity and geographic distribution of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) genotypes associated with cassava in East Africa

    PubMed Central

    Mugerwa, Habibu; Rey, Marie E C; Alicai, Titus; Ateka, Elijah; Atuncha, Hellen; Ndunguru, Joseph; Sseruwagi, Peter

    2012-01-01

    The genetic variability of whitefly (Bemisia tabaci) species, the vectors of cassava mosaic begomoviruses (CMBs) in cassava growing areas of Kenya, Tanzania, and Uganda, was investigated through comparison of partial sequences of the mitochondria cytochrome oxidase I (mtCOI) DNA in 2010/11. Two distinct species were obtained including sub-Saharan Africa 1 (SSA1), comprising of two sub-clades (I and II), and a South West Indian Ocean Islands (SWIO) species. Among the SSA1, sub-clade I sequences shared a similarity of 97.8–99.7% with the published Uganda 1 genotypes, and diverged by 0.3–2.2%. A pairwise comparison of SSA1 sub-clade II sequences revealed a similarity of 97.2–99.5% with reference southern Africa genotypes, and diverged by 0.5–2.8%. The SSA1 sub-clade I whiteflies were widely distributed in East Africa (EA). In comparison, the SSA1 sub-clade II whiteflies were detected for the first time in the EA region, and occurred predominantly in the coast regions of Kenya, southern and coast Tanzania. They occurred in low abundance in the Lake Victoria Basin of Tanzania and were widespread in all four regions in Uganda. The SWIO species had a sequence similarity of 97.2–97.7% with the published Reunion sequence and diverged by 2.3–2.8%. The SWIO whiteflies occurred in coast Kenya only. The sub-Saharan Africa 2 whitefly species (Ug2) that was associated with the severe CMD pandemic in Uganda was not detected in our study. PMID:23170210

  8. Investigation of the genetic diversity of an invasive whitefly (Bemisia tabaci) in China using both mitochondrial and nuclear DNA markers.

    PubMed

    Chu, D; Gao, C S; De Barro, P; Wan, F H; Zhang, Y J

    2011-08-01

    It is often considered that reduced genetic variation due to bottlenecks and founder effects limits the capacity for species to establish in new environments and subsequently spread. The recent invasion (during the past five years) of an alien whitefly, one member of Bemisia tabaci cryptic species complex, referred to as Mediterranean (herein referred to as Q-type) in Shandong Province, China, provides an ideal opportunity to study the changes in genetic variation between its home range in the Mediterranean region and its invasion range. Using both the mitochondrial cytochrome oxidase I (mtCOI) and nuclear (microsatellite) DNA, we show that Q in Shandong likely originated in the western Mediterranean. We also found that the haplotype diversity was low compared with its presumed geographic origin, whereas microsatellite allele diversity showed no such decline. A key factor in invasions is the establishment of females and so bottleneck and founder events can lead to a very rapid and considerable loss of mitochondrial diversity. The lack of haplotype diversity in Shandong supports the interpretation that, at one or more points between the western Mediterranean and China, the invading Q lost haplotype diversity, most probably through the serial process of establishment and redistribution through trade in ornamental plants. However, the loss in haplotype diversity does not necessarily mean that nuclear allelic diversity should also decline. Provided females can mate freely with whichever males are available, allelic diversity can be maintained or even increased relative to the origin of the invader. Our findings may offer some explanation to the apparent paradox between the concept of reduced genetic variation limiting adaptation to new environments and the observed low diversity in successful invaders. PMID:21320364

  9. Binding of insecticidal lectin Colocasia esculenta tuber agglutinin (CEA) to midgut receptors of Bemisia tabaci and Lipaphis erysimi provides clues to its insecticidal potential.

    PubMed

    Roy, Amit; Gupta, Sumanti; Hess, Daniel; Das, Kali Pada; Das, Sampa

    2014-07-01

    The insecticidal potential of Galanthus nivalis agglutinin-related lectins against hemipterans has been experimentally proven. However, the basis behind the toxicity of these lectins against hemipterans remains elusive. The present study elucidates the molecular basis behind insecticidal efficacy of Colocasia esculenta tuber agglutinin (CEA) against Bemisia tabaci and Lipaphis erysimi. Confocal microscopic analyses highlighted the binding of 25 kDa stable homodimeric lectin to insect midgut. Ligand blots followed by LC MS/MS analyses identified binding partners of CEA as vacuolar ATP synthase and sarcoplasmic endoplasmic reticulum type Ca(2+) ATPase from B. tabaci, and ATP synthase, heat shock protein 70 and clathrin heavy chain assembly protein from L. erysimi. Internalization of CEA into hemolymph was confirmed by Western blotting. Glycoprotein nature of the receptors was identified through glycospecific staining. Deglycosylation assay indicated the interaction of CEA with its receptors to be probably glycan mediated. Surface plasmon resonance analysis revealed the interaction kinetics between ATP synthase of B. tabaci with CEA. Pathway prediction study based on Drosophila homologs suggested the interaction of CEA with insect receptors that probably led to disruption of cellular processes causing growth retardation and loss of fecundity of target insects. Thus, the present findings strengthen our current understanding of the entomotoxic potentiality of CEA, which will facilitate its future biotechnological applications. PMID:24753494

  10. A novel Wolbachia strain from the rice moth Corcyra cephalonica induces reproductive incompatibility in the whitefly Bemisia tabaci: sequence typing combined with phenotypic evidence.

    PubMed

    Hu, Hong-Yan; Li, Zheng-Xi

    2015-06-01

    Wolbachia are a group of maternally inherited bacteria frequently found in arthropods and filarial nematodes. They have recently attracted attention for their ecological roles in manipulating host reproduction, their potential use in biological control of pest insects and medical significance. Classification of Wolbachia strains is currently solely based on molecular methods. However, the strains even with identical sequence types may induce different host phenotypes. Here we isolated a Wolbachia strain from the rice moth Corcyra cephalonica (designated as wCcep_B_BJ), which was shown to share multilocus sequence typing and Wolbachia surface protein hypervariable region profiles with a cytoplasmic incompatibility (CI)-inducing strain in supergroup B, but the phenotype wCcep_B_BJ may induce needs to be determined. We thus transinfected it into the whitefly Bemisia tabaci harbouring an A-Wolbachia through nymphal microinjection. Fluorescent in situ hybridization demonstrated that wCcep_B_BJ was successfully transinfected into B. tabaci and transmitted to offspring through host eggs. Reciprocal cross showed that wCcep_B_BJ induced a strong bidirectional CI in the transinfected host without imposing a significant cost on female fecundity. Our results suggest that wCcep_B_BJ may be a promising strain for biocontrol of B. tabaci, an important agricultural pest insect. PMID:25683566

  11. Infection of Bacterial Endosymbionts in Insects: A Comparative Study of Two Techniques viz PCR and FISH for Detection and Localization of Symbionts in Whitefly, Bemisia tabaci

    PubMed Central

    Raina, Harpreet Singh; Singh, Ambika; Popli, Sonam; Pandey, Neeti; Rajagopal, Raman

    2015-01-01

    Bacterial endosymbionts have been associated with arthropods and large number of the insect species show interaction with such bacteria. Different approaches have been used to understand such symbiont- host interactions. The whitefly, Bemisia tabaci, a highly invasive agricultural pest, harbors as many as seven different bacterial endosymbionts. These bacterial endosymbionts are known to provide various nutritional, physiological, environmental and evolutionary benefits to its insect host. In this study, we have tried to compare two techniques, Polymerase chain reaction (PCR) and Flourescence in situ Hybridisation (FISH) commonly used for identification and localization of bacterial endosymbionts in B. tabaci as it harbors one of the highest numbers of endosymbionts which have helped it in becoming a successful global invasive agricultural pest. The amplified PCR products were observed as bands on agarose gel by electrophoresis while the FISH samples were mounted on slides and observed under confocal microscope. Analysis of results obtained by these two techniques revealed the advantages of FISH over PCR. On a short note, performing FISH, using LNA probes proved to be more sensitive and informative for identification as well as localization of bacterial endosymbionts in B. tabaci than relying on PCR. This study would help in designing more efficient experiments based on much reliable detection procedure and studying the role of endosymbionts in insects. PMID:26287997

  12. Invasive mechanism and management strategy of Bemisia tabaci (Gennadius) biotype B: progress report of 973 Program on invasive alien species in China.

    PubMed

    Wan, FangHao; Zhang, GuiFen; Liu, ShuSheng; Luo, Chen; Chu, Dong; Zhang, YouJun; Zang, LianSheng; Jiu, Min; Lü, ZhiChuang; Cui, XuHong; Zhang, LiPing; Zhang, Fan; Zhang, QingWen; Liu, WanXue; Liang, Pei; Lei, ZhongRen; Zhang, YongJun

    2009-01-01

    Bemisia tabaci (Gennadius) biotype B, called a "superbug", is one of the most harmful biotypes of this species complex worldwide. In this report, the invasive mechanism and management of B. tabaci biotype B, based on our 5-year studies, are presented. Six B. tabaci biotypes, B, Q, ZHJ1, ZHJ2, ZHJ3 and FJ1, have been identified in China. Biotype B dominates the other biotypes in many regions of the country. Genetic diversity in biotype B might be induced by host plant, geographical conditions, and/or insecticidal application. The activities of CarE (carboxylesterase) and GSTs (glutathione-S-transferase) in biotype B reared on cucumber and squash were greater than on other host plants, which might have increased its resistance to insecticides. The higher activities of detoxification enzymes in biotype B might be induced by the secondary metabolites in host plants. Higher adaptive ability of biotype B adults to adverse conditions might be linked to the expression of heat shock protein genes. The indigenous B. tabaci biotypes were displaced by the biotype B within 225 d. The asymmetric mating interactions and mutualism between biotype B and begomoviruses via its host plants speed up widespread invasion and displacement of other biotypes. B. tabaci biotype B displaced Trialeurodes vaporariorum (Westwood) after 4-7 generations under glasshouse conditions. Greater adaptive ability of the biotype B to adverse conditions and its rapid population increase might be the reasons of its successful displacement of T. vaporariorum. Greater ability of the biotype B to switch to different host plants may enrich its host plants, which might enable it to better compete with T. vaporariorum. Native predatory natural enemies possess greater ability to suppress B. tabaci under field conditions. The kairomones in the 3rd and 4th instars of biotype B may provide an important stimulus in host searching and location by its parasitoids. The present results provide useful information in

  13. Leaf Morphological Characters Can Be a Factor for Intra-Varietal Preference of Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) among Eggplant Varieties.

    PubMed

    Hasanuzzaman, Abu Tayeb Mohammad; Islam, Md Nazrul; Zhang, Yi; Zhang, Chen-Yang; Liu, Tong-Xian

    2016-01-01

    The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) MEAM1, is considered a serious pest of horticultural and many other crops. While eggplant (Solanum melongena) is one of the most favored host plants, the whiteflies exhibit preferences among different varieties. We hypothesized that certain morphological leaf characteristics of different varieties, like leaf trichome density, trichome length, leaf lamina thickness and leaf color, may affect whitefly landing, feeding and oviposition. In this study, we investigated the variation in leaf morphological characters among selected eggplant varieties and evaluated the effect of these leaf characteristics in rendering eggplant varieties either susceptible or resistant to B. tabaci. We evaluated eight eggplant varieties in choice feeding tests, and we found that the varieties JinSheng Zilongchangqie (JSZ) and H149 were the highly preferred varieties with the highest numbers of whitefly adults and eggs. Significantly lower numbers of whitefly adult eggs were found on the resistant variety Tuo Lu Bamu (TLB). The varieties JinGuangbo Luqie (JGL), JinGuangbo Ziquanqie (JGZ), DaYang Ziguanqie (DYZ), QinXing Ziguanqie (QXZ), and QinXing Niuxinqie (QXN) were moderately favored by B. tabaci. Leaf trichome density, trichome length and leaf lamina thickness were positively correlated with numbers of whitefly adults and eggs. B. tabaci was less attracted to the leaves that reflect long and middle wavelength light (higher R and G values) than to the bright green leaves (medium G value), but the short wavelength light (higher B value) had no significant effect on whitefly preference. The degree of hue had a positive effect, and saturation and brightness had a negative effect on whitefly attraction. PMID:27081849

  14. Leaf Morphological Characters Can Be a Factor for Intra-Varietal Preference of Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) among Eggplant Varieties

    PubMed Central

    Zhang, Yi; Zhang, Chen-Yang; Liu, Tong-Xian

    2016-01-01

    The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) MEAM1, is considered a serious pest of horticultural and many other crops. While eggplant (Solanum melongena) is one of the most favored host plants, the whiteflies exhibit preferences among different varieties. We hypothesized that certain morphological leaf characteristics of different varieties, like leaf trichome density, trichome length, leaf lamina thickness and leaf color, may affect whitefly landing, feeding and oviposition. In this study, we investigated the variation in leaf morphological characters among selected eggplant varieties and evaluated the effect of these leaf characteristics in rendering eggplant varieties either susceptible or resistant to B. tabaci. We evaluated eight eggplant varieties in choice feeding tests, and we found that the varieties JinSheng Zilongchangqie (JSZ) and H149 were the highly preferred varieties with the highest numbers of whitefly adults and eggs. Significantly lower numbers of whitefly adult eggs were found on the resistant variety Tuo Lu Bamu (TLB). The varieties JinGuangbo Luqie (JGL), JinGuangbo Ziquanqie (JGZ), DaYang Ziguanqie (DYZ), QinXing Ziguanqie (QXZ), and QinXing Niuxinqie (QXN) were moderately favored by B. tabaci. Leaf trichome density, trichome length and leaf lamina thickness were positively correlated with numbers of whitefly adults and eggs. B. tabaci was less attracted to the leaves that reflect long and middle wavelength light (higher R and G values) than to the bright green leaves (medium G value), but the short wavelength light (higher B value) had no significant effect on whitefly preference. The degree of hue had a positive effect, and saturation and brightness had a negative effect on whitefly attraction. PMID:27081849

  15. Evaluation of Interspecific Interaction Between Encarsia lutea and Eretomocerus near mundus, the Parasitoids of Cotton Whitefly (Bemisia tabaci) with Host Plants Density Levels and Preference

    NASA Astrophysics Data System (ADS)

    Arshad Ullah, Muhammad; Abbasi, Khalida Hamid; Bano, Saadia; Khanum, Saeeda

    `Studies were carried out at CABI Biosciences Pakistan Centre, Rawalpindi to evaluate the effects of host plants and insects with host density levels and preference by both these species, i.e., Encarsia lutea and Eretomocerus separately as well as together in competitive situation. Preference of density levels by both parasitoids species showed that density level 20 (cotton leaf disc with 20 Bemisia tabaci nymphs and pupae) was contributed more (42%) preference than other density levels (5, 10, 40, 60 and 80). Different density levels had highly significant effect on settlement time of both species separately while in competitive situation the settlement time of both species was not significantly different from each other on different treatments.

  16. Extensive settlement of the invasive MEAM1 population of Bemisia tabaci (Hemiptera: Aleyrodidae) in the Caribbean and rare detection of indigenous populations.

    PubMed

    Muñiz, Y; Granier, M; Caruth, C; Umaharan, P; Marchal, C; Pavis, C; Wicker, E; Martínez, Y; Peterschmitt, M

    2011-10-01

    Bemisia tabaci populations belonging to Middle East-Asia Minor one (MEAM1) and Mediterranean (MED) groups (formerly biotype B and Q, respectively) have spread throughout the world. Although the introduction of MEAM1 is documented from several Caribbean islands, it is generally not known whether MED has also been introduced; whether indigenous populations have survived; and if in the affirmative, to which group(s) they belonged. Whiteflies were collected from seven islands on various plant species. The prevalence of MEAM1 and non-MEAM1 individuals was assessed using a microsatellite approach validated with sequences of the mitochondrial cytochrome oxidase I (mtCOI) gene. Of the 262 samples tested, 247 exhibited the MEAM1 pattern, whereas none showed the MED pattern. The mtCOI gene was partially sequenced from a sample of individuals exhibiting MEAM1 (n = 15) and non-MEAM1 patterns (n = 8) and compared with type sequences. The 15 individuals exhibiting the MEAM1 pattern were confirmed to belong to MEAM1. Of the eight individuals representative of the six non-MEAM1 patterns, two belonged to the indigenous New World (NW) group of B. tabaci (NW), one belonged to a distinct species of Bemisia, and five belonged to MEAM1. One individual belonging to NW exhibited 99.9% nucleotide identity with a NW individual from Puerto Rico. The other was identified as the most divergent individual of the North and Central American genetic cluster. We conclude that a highly homogenous MEAM1 population has extensively settled in the Caribbean and that heterogeneous NW populations were still detectable although severely displaced. PMID:22251711

  17. Potential of two populations of Amblyseius swirskii (Acari: Phytoseiidae) for the control of Bemisia tabaci biotype B (Hemiptera: Aleyrodidae) in Brazil.

    PubMed

    Cavalcante, Ana Cristina Cerqueira; Borges, Lucas Rosa; Lourenção, André Luiz; de Moraes, Gilberto José

    2015-12-01

    Predatory mites of the family Phytoseiidae are commercialized in European and North American countries for the control of whiteflies (Insecta: Aleyrodidae). Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is one of the predators used for that purpose. This predator is not found in Brazil and in many other countries, but its introduction could promote biological control of Bemisia tabaci (Gennadius) biotype B (silverleaf whitefly) in those countries. The aim of this study was to compare two populations of A. swirskii as predators of eggs of B. tabaci of two different ages, as well as the acceptance of those populations for other food types [eggs of Tetranychus urticae Koch; larvae and protonymphs of Aleuroglyphus ovatus (Troupeau) (Astigmatina: Acaridae) and cattail pollen (Typha domingensis Persoon)]. One of the populations of A. swirskii was collected in the Republic of Benin, in tropical Africa, and the other was commercially available in The Netherlands. The comparison was done to evaluate the population with better potential for practical use, and to determine food types that could be used for mass rearing the predator. Experiments were conducted at 28 ± 1 °C, 80 ± 10 % relative humidity and 12 h photophase. Both populations were able to oviposit when fed eggs of B. tabaci, but the Netherlands population showed higher oviposition rate (2.3 and 1.6 times higher on young and older eggs, respectively). Higher predation rates were observed for eggs up to 24 h of age in comparison with older eggs. Aleuroglyphus ovatus proved to be a promising prey for possible mass rearing of this predator in Brazil, where that astigmatic mite is found naturally when pollen was used as food, no significant difference was observed for oviposition rate between populations. The results suggested a higher potential of the Netherlands population of A. swirskii for the control of B. tabaci biotype B in this country for augmentative biological control, with the possible use of

  18. Release and recovery of exotic parasitoids of Bemisia tabaci in the Lower Rio Grande Valley of Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An intensive field program was conducted in the subtropical Lower Rio Grande Valley of Texas (LRGV) to evaluate the establishment of the imported parasitoids of B. tabaci. Thirty populations/species of Eretmocerus and Encarsia parasitoids were mass reared for field release in multiple agricultural c...

  19. SEASONAL ECOLOGY OF BEMISIA TABACI IN ARIZONA: LOW TEMPERATURE AND HOST PLANT EFFECTS ON FIELD POPULATIONS AND ASSOCIATED MORTALITY FACTORS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The current ongoing study has examined seasonality and mortality patterns of B. tabaci on different hosts during the year. Plots of six representative host plants (broccoli, cantaloupe, cotton, alfalfa, Lantana and various weeds) were established at the Yuma, Maricopa and Marana Agricultural Centers...

  20. Development of a lateral flow test to detect metabolic resistance in Bemisia tabaci mediated by CYP6CM1, a cytochrome P450 with broad spectrum catalytic efficiency.

    PubMed

    Nauen, Ralf; Wölfel, Katharina; Lueke, Bettina; Myridakis, Antonis; Tsakireli, Dimitra; Roditakis, Emmanouil; Tsagkarakou, Anastasia; Stephanou, Euripides; Vontas, John

    2015-06-01

    Cotton whitefly, Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae) is a major sucking pest in many agricultural and horticultural cropping systems globally. The frequent use of insecticides of different mode of action classes resulted in populations resisting treatments used to keep numbers under economic damage thresholds. Recently it was shown that resistance to neonicotinoids such as imidacloprid is linked to the over-expression of CYP6CM1, a cytochrome P450 monooxygenase detoxifying imidacloprid and other neonicotinoid insecticides when recombinantly expressed in insect cells. However over-expression of CYP6CM1 is also known to confer cross-resistance to pymetrozine, an insecticide not belonging to the chemical class of neonicotinoids. In addition we were able to demonstrate by LC-MS/MS analysis the metabolisation of pyriproxyfen by recombinantly expressed CYP6CM1. Based on our results CYP6CM1 is one of the most versatile detoxification enzymes yet identified in a pest of agricultural importance, as it detoxifies a diverse range of chemical classes used to control whiteflies. Therefore we developed a field-diagnostic antibody-based lateral flow assay which detects CYP6CM1 protein at levels providing resistance to neonicotinoids and other insecticides. The ELISA based test kit can be used as a diagnostic tool to support resistance management strategies based on the alternation of different modes of action of insecticides. PMID:26047106

  1. Effectiveness of Cyantraniliprole for Managing Bemisia tabaci (Hemiptera: Aleyrodidae) and Interfering with Transmission of Tomato Yellow Leaf Curl Virus on Tomato.

    PubMed

    Caballero, Rafael; Schuster, David J; Peres, Natalia A; Mangandi, Jozer; Hasing, Tomas; Trexler, Fred; Kalb, Steve; Portillo, Héctor E; Marçon, Paula C; Annan, I B

    2015-06-01

    Cyantraniliprole is the second xylem-systemic active ingredient in the new anthranilic diamide class. Greenhouse (2006), growth chamber (2007), and field studies (2009-2010) were conducted to determine the efficacy of cyantraniliprole for managing Bemisia tabaci (Gennadius) biotype B and in interfering with transmission of tomato yellow leaf curl virus (TYLCV) by this whitefly. Cyantraniliprole applied as soil treatments (200 SC) or foliar sprays (100 OD) provided excellent adult whitefly control, TYLCV suppression, and reduced oviposition and nymph survival, comparable to current standards. The positive results observed in these greenhouse experiments with a high level of insect pressure (10× the field threshold of one adult per plant) and disease pressure (five adults per plant, with a high level of confidence that TYLCV virulent adults were used), indicate a great potential for cyantraniliprole to be used in a whitefly management program. Field evaluations of soil drench treatments confirmed the suppression of TYLCV transmission demonstrated in the greenhouse studies. Field studies in 2009 and 2010 showed that cyantraniliprole (200 SC) provided TYLCV suppression for 2 wk after a drench application, when using a susceptible (2009) or imidacloprid-tolerant (2010) whitefly population. Cyantraniliprole was demonstrated to be a promising tool for management of TYLCV in tomato production, which is very difficult and expensive, and which has limited options. The integration of cyantraniliprole into a resistance management program will help to ensure the continued sustainability of this and current insecticides used for the management of insect vectors, including whiteflies and the TYLCV they spreads. PMID:26470209

  2. Viral infection of tobacco plants improves performance of Bemisia tabaci but more so for an invasive than for an indigenous biotype of the whitefly.

    PubMed

    Liu, Jian; Li, Meng; Li, Jun-min; Huang, Chang-jun; Zhou, Xue-ping; Xu, Fang-cheng; Liu, Shu-sheng

    2010-01-01

    The ecological effects of plant-virus-vector interactions on invasion of alien plant viral vectors have been rarely investigated. We examined the transmission of Tomato yellow leaf curl China virus (TYLCCNV) by the invasive Q biotype and the indigenous ZHJ2 biotype of the whitefly Bemisia tabaci, a plant viral vector, as well as the influence of TYLCCNV-infection of plants on the performance of the two whitefly biotypes. Both whitefly biotypes were able to acquire viruses from infected plants and retained them in their bodies, but were unable to transmit them to either tobacco or tomato plants. However, when the Q biotype fed on tobacco plants infected with TYLCCNV, its fecundity and longevity were increased by 7- and 1-fold, respectively, compared to those of the Q biotype fed on uninfected tobacco plants. When the ZHJ2 biotype fed on virus-infected plants, its fecundity and longevity were increased by only 2- and 0.5-fold, respectively. These data show that the Q biotype acquired higher beneficial effects from TYLCCNV-infection of tobacco plants than the ZHJ2 biotype. Thus, the Q biotype whitefly may have advantages in its invasion and displacement of the indigenous ZHJ2 biotype. PMID:20043350

  3. [Genetic variability of the Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae) in vegetable crops in São Luís, state of Maranhão, Brazil].

    PubMed

    Da Silva, Maria C; De Lemos, Raimunda N S; Lima, Luzia H C; Gourlart Filho, Luiz R; Pereira, Silma R F

    2009-01-01

    The RAPD technique is widely used to investigate the distinct genetic characteristics of the complex Bemisia tabaci (Gennadius), which is currently constituted of approximately 41 biotypes. The objective of this research was to characterize populations of whitefly collected in crops of agricultural producing areas in São Luís, MA, like okra, beans and pepper, using RAPD molecular markers. Females from nine whitefly populations were analyzed and compared with B. tabaci biotype B taken from poinsettia culture of Embrapa Genetic Resources and Biotechnology (Brasília, DF). Twelve out of the 20 primers tested produced specific band patterns suitable to confirm that the evaluated specimens belong to the biotype B of B. tabaci, despite the high percentage of detected polymorphism. The analysis of the 96 RAPD molecular markers generated indicated that the populations on okra, beans and pepper were grouped according to the host cultures, sharing 80, 76 and 45% of genetic similarity, respectively, when compared with the control population of B. tabaci biotype B. A lower selective pressure was observed with the population of whitefly collected on pepper and minor genetic variability in the whitefly populations collected on okra and bean, when compared with the control population. PMID:20098922

  4. Evaluation of Bioinsecticides for Management of Bemisia tabaci (Hemiptera: Aleyrodidae) and the Effect on the Whitefly Predator Delphastus catalinae (Coleoptera: Coccinellidae) in Organic Squash.

    PubMed

    Razze, Janine M; Liburd, Oscar E; Nuessly, Gregg S; Samuel-Foo, Michelle

    2016-08-01

    Organic zucchini squash is a high-value vegetable crop in Florida and potential exists to expand its production throughout the state. A lack of knowledge on the effectiveness of organic products and their integration with natural enemies is an important constraint to the regulation of pest populations in organic squash production in Florida. The objectives of this study were to evaluate the effect of insecticides labeled for organic production that can be used for management of Bemisia tabaci (Gennadius) biotype B, on organically grown squash; and to determine the effects of the most efficient insecticides on a key natural enemy, Delphastus catalinae (Horn). Experiments were conducted in the greenhouse in exclusion cages. The first experiment compared the effects of four bioinsecticides on whitefly densities. Insecticides include 1) AzaSol (azadirachtin), 2) PyGanic EC 1.4 (pyrethrin), 3) M-Pede (insecticidal soap), and 4) Entrust (spinosad). The second experiment investigated the effects of bioinsecticides on D. catalinae Treatment effectiveness was evaluated 1, 3, and 5 d posttreatment. PyGanic and M-Pede were highly effective in controlling whitefly populations on organic squash, while moderate control was provided by AzaSol and there was no control provided by Entrust. PyGanic and M-Pede treatments reduced D. catalinae populations when adults were released 1 d post pesticide application. However, when adults were released 5 d post application, there was no reduction. The importance of using bioinsecticides in combination with natural enemies to regulate pest populations in organic cropping systems is discussed. PMID:27247302

  5. Virion Stability Is Important for the Circulative Transmission of Tomato Yellow Leaf Curl Sardinia Virus by Bemisia tabaci, but Virion Access to Salivary Glands Does Not Guarantee Transmissibility▿ †

    PubMed Central

    Caciagli, Piero; Medina Piles, Vicente; Marian, Daniele; Vecchiati, Manuela; Masenga, Vera; Mason, Giovanna; Falcioni, Tania; Noris, Emanuela

    2009-01-01

    The capsid protein (CP) of the monopartite begomovirus Tomato yellow leaf curl Sardinia virus (TYLCSV), family Geminiviridae, is indispensable for plant infection and vector transmission. A region between amino acids 129 and 152 is critical for virion assembly and insect transmissibility. Two previously described mutants, one with a double Q129P Q134H mutation (PNHD) and another with a further D152E change (PNHE), were found nontransmissible (NT). Another NT mutant with a single N130D change (QDQD) was retrieved from a new mutational analysis. In this study, these three NT mutants and the wild-type (wt) virus were compared in their relationships with the whitefly vector Bemisia tabaci and the nonvector Trialeurodes vaporariorum. Retention kinetics of NT mutants were analyzed by quantitative dot blot hybridization in whiteflies fed on infected plants. The QDQD mutant, whose virions appeared nongeminate following purification, was hardly detectable in either whitefly species at any sampling time. The PNHD mutant was acquired and circulated in both whitefly species for up to 10 days, like the wt virus, while PNHE circulated in B. tabaci only. Using immunogold labeling, both PNHD and PNHE CPs were detected in B. tabaci salivary glands (SGs) like the wt virus, while no labeling was found in any whitefly tissue with the QDQD mutant. Significant inhibition of transmission of the wt virus was observed after prior feeding of the insects on plants infected with the PNHE mutant, but not on plants infected with the other mutants. Virion stability and ability to cross the SG barrier are necessary for TYLCSV transmission, but interactions with molecular components inside the SGs are also critical for transmissibility. PMID:19321611

  6. Fumigant toxicity of summer savory and lemon balm oil constituents and efficacy of spray formulations containing the oils to B- and neonicotinoid-resistant Q-biotypes of Bemisia tabaci (Homoptera: Aleyrodidae).

    PubMed

    Chae, Song-Hwa; Kim, Soon-Il; Yeon, Seong Hum; Perumalsamy, Haribalan; Ahn, Young-Joon

    2014-02-01

    An assessment was made of the fumigant toxicity of 36 constituents from lemon balm oil (LBO) and summer savory oil (SSO) and another additional nine previously identified compounds of the oils, as well as of the control efficacy of four experimental spray formulations containing individual oils (0.5 and 0.1% sprays) and spinosad 10% suspension concentrate (SC) to females from B- and neonicotinoid-resistant Q-biotypes of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae). Based on 24-h LC50 values, Q-biotype females (0.20 microg/cm3) were 40 times less susceptible to dichlorvos than B-biotype females (0.005 microg/cm3). Thymol (LC50, 0.35 microg/cm3) and carvacrol (0.56 microg/cm3) were the most toxic compounds toward Q-biotype females, followed by (1S)-(-)-borneol, alpha-terpineol, nerol, linalool, and carvone (1.06-1.38 microg/cm3). The toxicity of these compounds was virtually identical toward both biotype females, indicating that the terpenoids and the insecticides (neonicotinoids and dichlorvos) do not share a common mode of action or elicit cross-resistance. The 0.5% spray of LBO, SSO, and spinosad 10% SC resulted in >90% mortality toward both biotype females. Global efforts to reduce the level of toxic synthetic insecticides in the agricultural environment justify further studies on LBO- and SSO-derived materials as potential contact-action fumigants for the control of B. tabaci populations. PMID:24665712

  7. Efficacy of insecticide rotations and their impact on populations of the ‘B’ and ‘Q’ biotypes of Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In our trial, we tested rotations of different chemistries in controlling ‘B’ and ‘Q’ whiteflies in a caged environment. Three main objectives were studied during the trial. The first: to determine efficacy of different treatment rotations on a mixed population of Bemisia. Second, to determine the s...

  8. Bemisia: bionomics and management of a global pest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bemisia tabaci has distinguished itself from the more than 1000 whitefly species in the world by it adaptability, persistence and potential to damage a wide range of agricultural and horticultural crops in all six of the world’s inhabited continents. B. tabaci inflicts plant damage through direct f...

  9. Bemisia tabaci-infested tomato plants show a phase-specific pattern of photosynthetic gene expression indicative of disrupted electron flow leading to photo-oxidation and plant death

    PubMed Central

    Estrada-Hernández, María Gloria

    2009-01-01

    A suppression-subtractive-hybridization (SSH) strategy led to the identification of several genes whose expression was differentially modified in response to different larval phases present during the infestation process of tomato plants (Solanum lycopersicum) by virus-free whitefly Bemisia tabaci (Bt). The findings regarding photosynthetic gene expression were in accordance to previous studies reporting altered patterns of expression as a result of insect herbivory. However, the examination, in this study, of four stages of larval Bt development permitted the detection of phase-dependent changes in gene expression which appeared to target specific photosynthetic complexes. Thus, an upregulation of photosystem II genes in the latter two phases of Bt development contrasted with a general repression of genes belonging to the three other photosynthetic complexes, in addition to a number of genes coding for proteins associated with the oxygen evolving complex and the Calvin cycle. We propose that the contrasting pattern of expression led to an over-excitation of PSII and consequent oxidative damage, as suggested by the concomitant upregulation of oxidative stress genes, and could have contributed to the wide-spread necrosis observed in Bt-infested tomato plants at late stages of the plant-insect interaction. PMID:19826216

  10. Inundative Field Releases and Evaluation of Three Predators for Bemisia tabasi (Hemiptera: Aleyrodidae) Management in Three Vegetable Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a global pest on numerous crops, including vegetables. Weekly inundative releases of a coccinellid predator (Coccinella undecimpunctata L.), a mirid predator [Macrophillus caliginosus (Wagner)] and a neuropteran predator [Chrysoperla carnea S...

  11. A complete mitochondrial DNA genome derived from a Chinese population of the Bemisia afer species complex (Hemiptera: Aleyrodidae).

    PubMed

    Wang, Hua-Ling; Zhang, Zhen; Bing, Xiao-Li; Liu, Yin-Quan; Liu, Shu-Sheng; Wang, Xiao-Wei

    2016-09-01

    We report here the sequence of a complete mitochondrial genome (mitogenome) of a population of Bemisia afer species complex, which was collected from Abutilonaviecnnae gaerner at LinYi, Shan Dong province of China (hereafter B. afer_China_Ag) (GenBank accession number: KR819174). The mitogenome of B. afer_China_Ag is 15 300 bp and contains 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and 2 control regions. The content and arrangement of mitochondrial genes of B. afer_China_Ag exhibit remarkable differences from the mitogenome of a B. afer population collected from African cassava (KF734668). Phylogenetic analyses based on 13 protein-coding genes support the close relationship of the two sequenced B. afer mitogenomes and confirm the species status of our specimen. PMID:26218308

  12. Habitat management for the establishment of Bemisia natural enemies. Chapter 15 in: Biological Control of Bemisia: a Review of the Interagency Research and Implementation Program in the United States, 1992-2001

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During outbreaks of sweetpotato whitefly, Bemisia tabaci biotype B, in the 1990s in the southwestern United States, it was recognized that conservation biological control could play a key role in the establishment of newly introduced whitefly parasitoids. However, many Bemisia host plants in desert...

  13. A draft genome sequence and functional screen reveals the repertoire of type III secreted proteins of Pseudomonas syringae pathovar tabaci 11528

    PubMed Central

    Studholme, David J; Ibanez, Selena Gimenez; MacLean, Daniel; Dangl, Jeffery L; Chang, Jeff H; Rathjen, John P

    2009-01-01

    Background Pseudomonas syringae is a widespread bacterial pathogen that causes disease on a broad range of economically important plant species. Pathogenicity of P. syringae strains is dependent on the type III secretion system, which secretes a suite of up to about thirty virulence 'effector' proteins into the host cytoplasm where they subvert the eukaryotic cell physiology and disrupt host defences. P. syringae pathovar tabaci naturally causes disease on wild tobacco, the model member of the Solanaceae, a family that includes many crop species as well as on soybean. Results We used the 'next-generation' Illumina sequencing platform and the Velvet short-read assembly program to generate a 145X deep 6,077,921 nucleotide draft genome sequence for P. syringae pathovar tabaci strain 11528. From our draft assembly, we predicted 5,300 potential genes encoding proteins of at least 100 amino acids long, of which 303 (5.72%) had no significant sequence similarity to those encoded by the three previously fully sequenced P. syringae genomes. Of the core set of Hrp Outer Proteins that are conserved in three previously fully sequenced P. syringae strains, most were also conserved in strain 11528, including AvrE1, HopAH2, HopAJ2, HopAK1, HopAN1, HopI, HopJ1, HopX1, HrpK1 and HrpW1. However, the hrpZ1 gene is partially deleted and hopAF1 is completely absent in 11528. The draft genome of strain 11528 also encodes close homologues of HopO1, HopT1, HopAH1, HopR1, HopV1, HopAG1, HopAS1, HopAE1, HopAR1, HopF1, and HopW1 and a degenerate HopM1'. Using a functional screen, we confirmed that hopO1, hopT1, hopAH1, hopM1', hopAE1, hopAR1, and hopAI1' are part of the virulence-associated HrpL regulon, though the hopAI1' and hopM1' sequences were degenerate with premature stop codons. We also discovered two additional HrpL-regulated effector candidates and an HrpL-regulated distant homologue of avrPto1. Conclusion The draft genome sequence facilitates the continued development of P

  14. Biology and management of Bemisia whitefly vectors of cassava virus pandemics in Africa.

    PubMed

    Legg, James P; Shirima, Rudolph; Tajebe, Lensa S; Guastella, Devid; Boniface, Simon; Jeremiah, Simon; Nsami, Elibariki; Chikoti, Patrick; Rapisarda, Carmelo

    2014-10-01

    Cassava mosaic disease and cassava brown streak disease are caused by viruses transmitted by Bemisia tabaci and affect approximately half of all cassava plants in Africa, resulting in annual production losses of more than $US 1 billion. A historical and current bias towards virus rather than vector control means that these diseases continue to spread, and high Bemisia populations threaten future virus spread even if the extant strains and species are controlled. Progress has been made in parts of Africa in replicating some of the successes of integrated Bemisia control programmes in the south-western United States. However, these management efforts, which utilise chemical insecticides that conserve the Bemisia natural enemy fauna, are only suitable for commercial agriculture, which presently excludes most cassava cultivation in Africa. Initiatives to strengthen the control of B. tabaci on cassava in Africa need to be aware of this limitation, and to focus primarily on control methods that are cheap, effective, sustainable and readily disseminated, such as host-plant resistance and biological control. A framework based on the application of force multipliers is proposed as a means of prioritising elements of future Bemisia control strategies for cassava in Africa. PMID:24706604

  15. Remote sensing for detecting and mapping whitefly (Bemisia tabaci) infestations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Remote sensing technology has long been used for detecting insect infestations on agricultural crops. With recent advances in remote sensing sensors and other spatial information technologies such as Global Position Systems (GPS) and Geographic Information Systems (GIS), remote sensing is finding mo...

  16. Transmission of Sweet Potato Leaf Curl Virus by Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato, Ipomoea batatas (L.) Lam. (Solanales: Convolvulaceae), is an important world food crop, and Asia is the focal production region. Because it is vegetatively propagated, sweetpotato is especially prone to accumulate infections by several viruses. Sweet potato leaf curl virus (SPLCV) (ss...

  17. The Evolution of Genomic Instability in the Obligate Endosymbionts of Whiteflies

    PubMed Central

    Sloan, Daniel B.; Moran, Nancy A.

    2013-01-01

    Many insects depend on ancient associations with intracellular bacteria to perform essential metabolic functions. These endosymbionts exhibit striking examples of convergence in genome architecture, including a high degree of structural stability that is not typical of their free-living counterparts. However, the recently sequenced genome of the obligate whitefly endosymbiont Portiera revealed features that distinguish it from other ancient insect associates, such as a low gene density and the presence of perfectly duplicated sequences. Here, we report the comparative analysis of Portiera genome sequences both within and between host species. In one whitefly lineage (Bemisia tabaci), we identify large-scale structural polymorphisms in the Portiera genome that exist even within individual insects. This variation is likely mediated by recombination across identical repeats that are maintained by gene conversion. The complete Portiera genome sequence from a distantly related whitefly host (Trialeurodes vaporarium) confirms a history of extensive genome rearrangement in this ancient endosymbiont. Using gene-order-based phylogenetic analysis, we show that the majority of rearrangements have occurred in the B. tabaci lineage, coinciding with an increase in the rate of nucleotide substitutions, a proliferation of short tandem repeats (microsatellites) in intergenic regions, and the loss of many widely conserved genes involved in DNA replication, recombination, and repair. These results indicate that the loss of recombinational machinery is unlikely to be the cause of the extreme structural conservation that is generally observed in obligate endosymbiont genomes and that large, repetitive intergenic regions are an important substrate for genomic rearrangements. PMID:23542079

  18. Diversity and evolution of the Wolbachia endosymbionts of Bemisia (Hemiptera: Aleyrodidae) whiteflies

    PubMed Central

    Bing, Xiao-Li; Xia, Wen-Qiang; Gui, Jia-Dong; Yan, Gen-Hong; Wang, Xiao-Wei; Liu, Shu-Sheng

    2014-01-01

    Wolbachia is the most prevalent symbiont described in arthropods to date. Wolbachia can manipulate host reproduction, provide nutrition to insect hosts and protect insect hosts from pathogenic viruses. So far, 13 supergroups of Wolbachia have been identified. The whitefly Bemisia tabaci is a complex containing more than 28 morphologically indistinguishable cryptic species. Some cryptic species of this complex are invasive. In this study, we report a comprehensive survey of Wolbachia in B. tabaci and its relative B. afer from 1658 insects representing 54 populations across 13 provinces of China and one state of Australia. Based on the results of PCR or sequencing of the 16S rRNA gene, the overall rates of Wolbachia infection were 79.6% and 0.96% in the indigenous and invasive Bemisia whiteflies, respectively. We detected a new Wolbachia supergroup by sequencing five molecular marker genes including 16S rRNA, groEL, gltA, hcpA, and fbpA genes. Data showed that many protein-coding genes have limitations in detecting and classifying newly identified Wolbachia supergroups and thus raise a challenge to the known Wolbachia MLST standard analysis system. Besides, the other Wolbachia strains detected from whiteflies were clustered into supergroup B. Phylogenetic trees of whitefly mitochondrial cytochrome oxidase subunit I and Wolbachia multiple sequencing typing genes were not congruent. In addition, Wolbachia was also detected outside the special bacteriocytes in two cryptic species by fluorescence in situ hybridization, indicating the horizontal transmission of Wolbachia. Our results indicate that members of Wolbachia are far from well explored. PMID:25077022

  19. Improved DNA barcoding method for Bemisia tabaci and related Aleyrodidae: Development of universal and Bemisia tabaci biotype-specific mitochondrial cytochrome c oxidase I polymerase chain reaction primers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whitefly is the common name of heteropteran insects that comprise the Aleyrodidae family composed of over 160 genera and 1500 different species. The mitochondrial cytochome c oxidase I (mtCOI) sequence has been used extensively in whitefly phylogenetic comparisons and in biotype identification of th...

  20. Evaluation of mustard plants and other products to control sweetpotato whitefly, Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major insect pest of vegetables and horticultural crops in the southeast US is the sweetpotato whitefly.Scientists at the USDA-Agriculture Research Service, Center for Veterinary Entomology, Gainesaville, Florida, evaluated the effect of giant red mustard plants and commercial products to control ...

  1. Temperature stress, anti-oxidative enzyme activity and virus acquisition in Bemisia tabaci (Hemiptera: Aleyrodidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In most eukaryotic systems, antioxidants provide protection when cells are exposed to stressful environmental conditions. Antioxidants, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase, function in a stepwise series with SOD initially preventing oxidative damage by conve...

  2. Response of Bemisia tabaci (Hemiptera: Aleyrodidae) to vapor pressure deficit: Oviposition, immature survival and body size

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ambient temperature is an abiotic factor that has been studied extensively in insect biology and population dynamics while relatively little investigations have been carried out on the impact of ambient moisture. Whiteflies cause major agricultural problems in environments ranging from arid to humi...

  3. LAMP (Loop-mediated isothermal amplification of DNA) - A technique for biotype discrimination in Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Loop-mediated isothermal amplification of DNA (LAMP) can amplify a target DNA sequence at a constant temperature in about 1 hour. LAMP technology has great potential for agricultural applications because of the need for rapid and inexpensive diagnoses. Assays based on LAMP technology are well suited...

  4. Baseline Susceptibilities of B- and Q-biotype Bemisia tabaci to anthranilic diamides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development of pyriproxyfen and neonicotinoid resistance in the B biotype whitefly and recent introduction of the Q biotype are threatening the current whitefly management programs in Arizona. Whether the novel anthranilic diamides chlorantraniliprole and cyantraniliprole can be integrated into the ...

  5. Temperature stress effects in Bemisia tabaci (Hemiptera: Aleyrodidae) type B whiteflies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxidative stress occurs in response to changes in the redox equilibiurm, which may be caused by increases in reactive oxygen species (ROS), a decrease in antioxidant protection or failure of cells to repair oxidative damage. ROS are either free radicals, reactive molecules containing oxygen atoms or...

  6. Effect of yellow flowers on abundance of Bemisia tabaci (Hemiptera: Aleyrodidae) on plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whiteflies are major pests of agricultural crops around the world. Many factors are known to impact the population dynamics of whiteflies. This group of insects is well known to be attracted to the color yellow. Thus, yellow traps are used to monitor or control whiteflies in greenhouse and field ...

  7. Relationship of Bemisia tabaci adult mortalities and population control to imidacloprid concentrations in cantaloupes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Decision-making in chemical pest management typically depends upon information concerning how well a candidate pesticide performs against a particular pest species in a particular crop environment. The principal source of such information has traditionally been accumulated field efficacy data produ...

  8. Investigating the Q invasion of Bemisia tabaci in Florida: Current status and update

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three separate Q haplotypes within Florida were discovered that could be used to associate populations known to be related by grower and plant type thereby tracking distribution routes. We determined that biotype Q entered Florida through at least two separate introductions. In-depth analysis of ins...

  9. Field evaluation of Bemisia parasitoids in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two methods were employed to assess the potential of candidate parasitoid species/strains to parasitize B. tabaci under field conditions in Texas. Sleeve cage evaluations were conducted in kale, cantaloupe melons, and cotton in 1994–1995. In kale, the highest parasitism rates were observed for two s...

  10. In silico prediction of cotton (Gossypium hirsutum) encoded microRNAs targets in the genome of Cotton leaf curl Allahabad virus

    PubMed Central

    Shweta; Khan, Jawaid A

    2014-01-01

    Cotton leaf curl Allahabad virus (CLCuAV) belongs to genus Begomovirus, family Geminiviridae. It has single stranded monopartite DNA genome transmitted by whitefly (Bemisia tabaci). MicroRNAs (miRNAs) belong to class of endogeneous small RNAs which suppress expression of genes following cleavage or translational inhibition of target messenger RNAs. They are demonstrated to be involved in a number of plant processes such as, development, biotic and abiotic stresses. Employing in silico approach, high scoring miRNA-target pairs satisfying rules of minimum free energy and maximum complementarity were selected to investigate if they possess the potential to bind the genome CLCuAV. Our results revealed that miRNA species viz., ghr-miR2950 can target all the viral genes, ghr-miR408 targets overlapping transcripts of AC1 and AC2 genes; while ghr-miR394 and ghr-miR395a and miR395d could bind overlapping transcripts of AC1 and AC4 genes. This is the first report of prediction of cotton miRNAs which have the potential to target CLCuAV genes including AC1 and AC4, involved in viral replication and gene silencing suppression, respectively. PMID:24966530

  11. LIFE HISTORY OF DELPHASTUS CATALINAE: A PREDATOR OF BEMISIA ARGENTIFOLII

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immature development and reproductive life history of Delphastus catalinae (Coleoptera: Coccinellidae) feeding on Bemisia argentifolii (Homoptera: Aleyrodidae) immatures was studied at three constant temperatures: 22, 26 and 30 ºC. Development rates and lower temperature threshold temperatures (T0) ...

  12. First report of Bemisia tabaci biotype Q in Costa Rica and detection of viruliferous whiteflies in greenhouses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whiteflies are a complex that comprises multiple species and biotypes or races which are capable of affecting crops by phloem feeding, virus transmission and promotion of fungal colonization. The distribution of these pests is worldwide. In Costa Rica, a country located in the tropics, the most prob...

  13. Whitefly (Bemisia tabaci) transmitted Squash vein yellowing virus (SqVYV): a component of Watermelon Vine Decline in South Florida.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watermelon production has been greatly impacted in South Florida since 2003 when symptoms were first observed of a severe watermelon vine decline (WVD) that killed plants as the crop approached first harvest (Roberts et. al., 2005; Huber 2006). Since 2003, watermelon plants have been affected in ea...

  14. Climate Change: Life history adaptation by a global whitefly, Bemisia tabaci, with rising temperature and carbon dioxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Climate change can have direct and indirect impacts on living organisms. A rise in ambient temperature and elevated carbon dioxide (CO2) concentrations due to global warming may have assorted impacts on arthropods such as altered life cycles, altered reproductive patterns, and change...

  15. Relative influence of plant quality and natural enemies on the seasonal dynamics of bemisia tabaci (Hemiptera: Aleyrodidae) in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The abundance and distribution of insect herbivores is determined by, among other things, plant quality and natural enemies. These two factors vary temporally and spatially, subsequently affecting seasonal population dynamics. The relative influence of plant quality and natural enemies on the season...

  16. Evolution and homoplasy at the Bem6 microsatellite locus in three sweetpotato whitefly (Bemisia tabaci) cryptic species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The evolution of individual microsatellite loci is often complex and homoplasy is common but often goes undetected. Sequencing alleles at a microsatellite locus can provide a more complete picture of the common evolutionary mechanisms occurring at that locus and can reveal cases of homoplasy. Within...

  17. Homopteran vector biomarkers for efficient circulative plant virus transmission are conserved in multiple aphid species and the whitefly Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant viruses in the families Luteoviridae and Geminiviridae are phloem restricted and are transmitted in a persistent, circulative manner by homopteran insects. Using fluorescence 2-D difference gel electrophoresis to compare the proteomes of genotypes in an F2 population of S. graminum that segre...

  18. Fourth International Bemisia Workshop International Whitefly Genomics Workshop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invited speakers from around the world presented research and management tactics conducted in their respective geographic regions and areas of expertise. Sessions were arranged with a slate of invited speakers followed by discussion, comments, and questions. Attendance was truly international with m...

  19. Enhanced symbiotic nitrogen fixation with P. syringae pv tabaci

    SciTech Connect

    Langston-Unkefer, P.J.; Knight, T.J. New Mexico State Univ., Las Cruces ); Sengupta-Gopalan, C. )

    1989-04-01

    Infestation of legumes such as alfalfa and soybeans with the plant pathogen Pseudomonas syringae pv. tabaci is accompanied by increased plant growth, nodulation, overall nitrogen fixation, and total assimilated nitrogen. These effects are observed only in plants infested with Tox{sup +} pathogen; the toxin is tabtoxinine-{beta}-lactam, an active site-directed irreversible inhibitor of glutamine synthetase. The key to the legumes survival of this treatment is the insensitivity of the nodule-specific form of glutamine synthetase to the toxin. As expected, significant changes are observed in ammonia assimilation in these plants. The biochemical and molecular biological consequences of this treatment are being investigated.

  20. Detection of Gene Flow from Sexual to Asexual Lineages in Thrips tabaci (Thysanoptera: Thripidae).

    PubMed

    Li, Xiao-Wei; Wang, Ping; Fail, Jozsef; Shelton, Anthony M

    2015-01-01

    Populations of Thrips tabaci are known to have two sympatric but genetically isolated reproductive modes, arrhenotoky (sexual reproduction) and thelytoky (asexual reproduction). Herein, we report behavioral, ecological and genetic studies to determine whether there is gene flow between arrhenotokous and thelytokous T. tabaci. We did not detect significant preference by arrhenotokous males to mate with females of a particular reproductive mode, nor did we detect significant behavioral differences between arrhenotokous males mated with arrhenotokous or thelytokous females in their pre-copulation, copulation duration and mating frequency. Productive gene transfer resulting from the mating between the two modes was experimentally confirmed. Gene transfer from arrhenotokous T. tabaci to thelytokous T. tabaci was further validated by confirmation of the passage of the arrhenotokous male-originated nuclear gene (histone H3 gene) allele to the F2 generation. These behavioral, ecological and genetic studies confirmed gene transfer from the sexual arrhenotokous mode to the asexual thelytokous mode of T. tabaci in the laboratory. These results demonstrate that asexual T. tabaci populations may acquire genetic variability from sexual populations, which could offset the long-term disadvantage of asexual reproduction. PMID:26375283

  1. Detection of Gene Flow from Sexual to Asexual Lineages in Thrips tabaci (Thysanoptera: Thripidae)

    PubMed Central

    Li, Xiao-Wei; Wang, Ping; Fail, Jozsef; Shelton, Anthony M.

    2015-01-01

    Populations of Thrips tabaci are known to have two sympatric but genetically isolated reproductive modes, arrhenotoky (sexual reproduction) and thelytoky (asexual reproduction). Herein, we report behavioral, ecological and genetic studies to determine whether there is gene flow between arrhenotokous and thelytokous T. tabaci. We did not detect significant preference by arrhenotokous males to mate with females of a particular reproductive mode, nor did we detect significant behavioral differences between arrhenotokous males mated with arrhenotokous or thelytokous females in their pre-copulation, copulation duration and mating frequency. Productive gene transfer resulting from the mating between the two modes was experimentally confirmed. Gene transfer from arrhenotokous T. tabaci to thelytokous T. tabaci was further validated by confirmation of the passage of the arrhenotokous male-originated nuclear gene (histone H3 gene) allele to the F2 generation. These behavioral, ecological and genetic studies confirmed gene transfer from the sexual arrhenotokous mode to the asexual thelytokous mode of T. tabaci in the laboratory. These results demonstrate that asexual T. tabaci populations may acquire genetic variability from sexual populations, which could offset the long-term disadvantage of asexual reproduction. PMID:26375283

  2. Metabolic coevolution in the bacterial symbiosis of whiteflies and related plant sap-feeding insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In animals dependent on intracellular bacteria with very small genomes, the host cell is adapted to support the function of its bacterial symbionts, but the molecular basis of these adaptations is poorly understood. We investigated the metabolic coevolution between the whitefly Bemisia tabaci and th...

  3. Metablic Coevolution in the bacterial symbiosis of whiteflies and related plant sap-feeding insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In animals dependent on intracellular bacteria with very small genomes, the host cell is adapted to support the function of its bacterial symbionts, but the molecular basis of these adaptations is poorly understood. We investigated the metabolic coevolution between the whitefly Bemisia tabaci and th...

  4. Seasonal Changes in Thrips tabaci Population Structure in Two Cultivated Hosts

    PubMed Central

    Nault, Brian A.; Kain, Wendy C.; Wang, Ping

    2014-01-01

    Thrips tabaci is a major pest of high-value vegetable crops and understanding its population genetics will advance our knowledge about its ecology and management. Mitochondrial cytochrome oxidase subunit I (COI) gene sequence was used as a molecular marker to analyze T. tabaci populations from onion and cabbage fields in New York. Eight COI haplotypes were identified in 565 T. tabaci individuals collected from these fields. All T. tabaci were thelytokous and genetically similar to those originating from hosts representing seven plant families spanning five continents. The most dominant haplotype was NY-HT1, accounting for 92 and 88% of the total individuals collected from onion fields in mid-summer in 2005 and 2007, respectively, and 100 and 96% of the total in early fall in 2005 and 2007, respectively. In contrast, T. tabaci collected from cabbage fields showed a dynamic change in population structure from mid-summer to early fall. In mid-summer, haplotype NY-HT2 was highly abundant, accounting for 58 and 52% of the total in 2005 and 2007, respectively, but in early fall it decreased drastically to 15 and 7% of the total in 2005 and 2007, respectively. Haplotype NY-HT1 accounted for 12 and 46% of the total in cabbage fields in mid-summer of 2005 and 2007, respectively, but became the dominant haplotype in early fall accounting for 81 and 66% of the total in 2005 and 2007, respectively. Despite the relative proximity of onion and cabbage fields in the western New York landscape, T. tabaci populations differed seasonally within each cropping system. Differences may have been attributed to better establishment of certain genotypes on specific hosts or differing colonization patterns within these cropping systems. Future studies investigating temporal changes in T. tabaci populations on their major hosts in these ecosystems are needed to better understand host-plant utilization and implications for population management. PMID:24992484

  5. Temporal Effects of a Begomovirus Infection and Host Plant Resistance on the Preference and Development of an Insect Vector, Bemisia tabaci, and Implications for Epidemics

    PubMed Central

    Legarrea, Saioa; Barman, Apurba; Marchant, Wendy; Diffie, Stan; Srinivasan, Rajagopalbabu

    2015-01-01

    Persistent plant viruses, by altering phenotypic and physiological traits of their hosts, could modulate the host preference and fitness of hemipteran vectors. A majority of such modulations increase vector preference for virus-infected plants and improve vector fitness, ultimately favouring virus spread. Nevertheless, it remains unclear how these virus-induced modulations on vectors vary temporally, and whether host resistance to the pathogen influences such effects. This study addressed the two questions using a Begomovirus-whitefly-tomato model pathosystem. Tomato yellow leaf curl virus (TYLCV) -susceptible and TYLCV-resistant tomato genotypes were evaluated by whitefly-mediated transmission assays. Quantitative PCR revealed that virus accumulation decreased after an initial spike in all genotypes. TYLCV accumulation was less in resistant than in susceptible genotypes at 3, 6, and 12 weeks post inoculation (WPI). TYLCV acquisition by whiteflies over time from resistant and susceptible genotypes was also consistent with virus accumulation in the host plant. Furthermore, preference assays indicated that non-viruliferous whiteflies preferred virus-infected plants, whereas viruliferous whiteflies preferred non-infected plants. However, this effect was prominent only with the susceptible genotype at 6 WPI. The development of whiteflies on non-infected susceptible and resistant genotypes was not significantly different. However, developmental time was reduced when a susceptible genotype was infected with TYLCV. Together, these results suggest that vector preference and development could be affected by the timing of infection and by host resistance. These effects could play a crucial role in TYLCV epidemics. PMID:26529402

  6. Reduction of viral load in whitefly (Bemisia tabaci Gen.) feeding on RNAi-mediated bean golden mosaic virus resistant transgenic bean plants.

    PubMed

    de Paula, Nayhanne T; de Faria, Josias C; Aragão, Francisco J L

    2015-12-01

    The RNAi concept was explored to silence the rep gene from the bean golden mosaic virus (BGMV) and a genetically modified (GM) bean immune to the virus was previously generated. We investigated if BGMV-viruliferous whiteflies would reduce viral amount after feeding on GM plants. BGMV DNA amount was significantly reduced in whiteflies feeding in GM-plants (compared with insects feeding on non-GM plants) for a period of 4 and 8 days in 52% and 84% respectively. PMID:26297125

  7. Effect of three irrigation methods on incidences of Bemisia tabaci (Hemiptera: Aleyrodidae) and some whitefly-transmitted viruses in four vegetable crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whiteflies and whitefly-transmitted viruses cause major agricultural problems in environments ranging from arid to humid climates. Experiments were conducted to assess the effect of some cultural irrigation practices (drip, furrow and sprinkler) on the population of the sweetpotato whitefly, Bemisi...

  8. Effects of temperature and culture media on vegetative growth of an entomopathogenic fungus Isaria sp. (Hympcreales: Clavicipitaceae) naturally affecting the whitefly, Bemisia tabaci in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of temperature and mycological media on mycelial growth and estimates of spore production of the newly discovered entomopathogenic fungus Isaria poprawskii sp. nov. were investigated. The general response of daily radial growth of I. poprawskii as a function of temperature fits a linear...

  9. Draft Genome Sequence of Antagonistic Agent Lysobacter antibioticus 13-6

    PubMed Central

    Zhou, Lihong; Li, Miao; Yang, Jun; Wei, Lanfang

    2014-01-01

    Lysobacter antibioticus 13-6, isolated from the roots of Chinese cabbage, effectively controls the pathogens Plasmodiophora brassicae, Xanthomonas oryzae pv. oryzicola, X. oryzae pv. oryzae, Xanthomonas axonopodis pv. dieffenbachiae, and Pseudomonas syringae pv. tabaci. We report the first draft genome sequence of the L. antibioticus species in China. PMID:25301638

  10. Draft Genome Sequence of Antagonistic Agent Lysobacter antibioticus 13-6.

    PubMed

    Zhou, Lihong; Li, Miao; Yang, Jun; Wei, Lanfang; Ji, Guanghai

    2014-01-01

    Lysobacter antibioticus 13-6, isolated from the roots of Chinese cabbage, effectively controls the pathogens Plasmodiophora brassicae, Xanthomonas oryzae pv. oryzicola, X. oryzae pv. oryzae, Xanthomonas axonopodis pv. dieffenbachiae, and Pseudomonas syringae pv. tabaci. We report the first draft genome sequence of the L. antibioticus species in China. PMID:25301638

  11. Mass-rearing Bemisia parasitoids for support of classical and augmentative biological control programs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of efficient mass-rearing systems for Bemisia parasitoids was crucial for the implementation of the classical and augmentative biological control programs for this exotic pest. Early work relied on adapting methods for the production of Encarsia formosa (Gahan) for the greenhouse whi...

  12. Early detection and mass trapping of frankliniella occidentalis and thrips tabaci in vegetable crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Western flower thrips, Frankliniella occidentalis Pergande and onion thrips, Thrips tabaci Lindeman, are economic pest insects of head lettuce, Lactuca sativa L. and dehydrator onions, Allium cepa L., in the Imperial Valley, California. Sticky traps were evaluated as potential detection and monitor...

  13. Effects of Bt cotton on Thrips tabaci (Thysanoptera: Thripidae) and its predator, Orius insidiosus (Hemiptera: Anthocoridae).

    PubMed

    Kumar, Rishi; Tian, Jun-Ce; Naranjo, Steven E; Shelton, Anthony M

    2014-06-01

    Laboratory studies were conducted to investigate tritrophic transfer of insecticidal Cry proteins from transgenic cotton to an herbivore and its predator, and to examine effects of these proteins on the predator's development, survival, and reproduction. Cry1Ac and Cry2Ab proteins from the bacterium Bacillus thuringiensis (Bt) produced in Bollgard-II (BG-II, Event 15985) cotton plants were acquired by Thrips tabaci Lindeman (Thysanoptera: Thripidae), an important sucking pest of cotton, and its generalist predator, Orius insidiosus (Say) (Hemiptera: Anthocoridae). The average protein titers in BG-II cotton leaves were 1,256 and 43,637 ng Cry1Ac and Cry2Ab per gram fresh leaf tissue, respectively. At the second trophic level, larvae of T. tabaci reared on BG-II cotton for 48-96 h had 22.1 and 2.1% of the Cry1Ac and Cry2Ab levels expressed in leaves, respectively. At the third trophic level, O. insidiosus that fed on T. tabaci larvae had 4.4 and 0.3% of the Cry1Ac and Cry2Ab protein levels, respectively, expressed in BG-II plants. O. insidiosus survivorship, time of nymphal development, adult weight, preoviposition and postoviposition periods, fecundity, and adult longevity were not adversely affected owing to consumption of T. tabaci larvae that had fed on BG-II cotton compared with non-Bt cotton. Our results indicate that O. insidiosus, a common predator of T. tabaci, is not harmed by BG-II cotton when exposed to Bt proteins through its prey. Thus, O. insidiosus can continue to provide important biological control services in the cotton ecosystem when BG-II cotton is used to control primary lepidopteran pests. PMID:25026649

  14. Thrips tabaci Population Genetic Structure and Polyploidy in Relation to Competency as a Vector of Tomato Spotted Wilt Virus

    PubMed Central

    Jacobson, Alana L.; Booth, Warren; Vargo, Edward L.; Kennedy, George G.

    2013-01-01

    Knowledge of population-level genetic differences can help explain variation among populations of insect vectors in their role in the epidemiology of specific viruses. Variation in competency to transmit Tomato spotted wilt virus (TSWV) that exists among populations of Thrips tabaci has been associated with the presence of cryptic species that exhibit different modes of reproduction and host ranges. However, recent findings suggest that vector competency of T. tabaci at any given location depends on the thrips and virus populations that are present. This study characterizes the population genetic structure of T. tabaci collected from four locations in North Carolina and examines the relationship between population genetic structure and variation in TSWV transmission by T. tabaci. Mitochondrial COI sequence analysis revealed the presence of two genetically distinct groups with one characterized by thelytokous, parthenogenetic reproduction and the other by arrhenotokous, sexual reproduction. Using a set of 11 microsatellite markers that we developed to investigate T. tabaci population genetic structure, we identified 17 clonal groups and found significant genetic structuring among the four NC populations that corresponded to the geographic locations where the populations were collected. Application of microsatellite markers also led to the discovery of polyploidy in this species. All four populations contained tetraploid individuals, and three contained both diploid and tetraploid individuals. Analysis of variation in transmission ofTSWV among isofemale lines initiated with individuals used in this study revealed that ‘clone assignment,’ ‘virus isolate’ and their interaction significantly influenced vector competency. These results highlight the importance of interactions between specific T. tabaci clonal types and specific TSWV isolates underlying transmission of TSWV by T. tabaci. PMID:23365671

  15. Colonization of Onions by Endophytic Fungi and Their Impacts on the Biology of Thrips tabaci

    PubMed Central

    Muvea, Alexander M.; Meyhöfer, Rainer; Subramanian, Sevgan; Poehling, Hans-Michael; Ekesi, Sunday; Maniania, Nguya K.

    2014-01-01

    Endophytic fungi, which live within host plant tissues without causing any visible symptom of infection, are important mutualists that mediate plant–herbivore interactions. Thrips tabaci (Lindeman) is one of the key pests of onion, Allium cepa L., an economically important agricultural crop cultivated worldwide. However, information on endophyte colonization of onions, and their impacts on the biology of thrips feeding on them, is lacking. We tested the colonization of onion plants by selected fungal endophyte isolates using two inoculation methods. The effects of inoculated endophytes on T. tabaci infesting onion were also examined. Seven fungal endophytes used in our study were able to colonize onion plants either by the seed or seedling inoculation methods. Seed inoculation resulted in 1.47 times higher mean percentage post-inoculation recovery of all the endophytes tested as compared to seedling inoculation. Fewer thrips were observed on plants inoculated with Clonostachys rosea ICIPE 707, Trichoderma asperellum M2RT4, Trichoderma atroviride ICIPE 710, Trichoderma harzianum 709, Hypocrea lixii F3ST1 and Fusarium sp. ICIPE 712 isolates as compared to those inoculated with Fusarium sp. ICIPE 717 and the control treatments. Onion plants colonized by C. rosea ICIPE 707, T. asperellum M2RT4, T. atroviride ICIPE 710 and H. lixii F3ST1 had significantly lower feeding punctures as compared to the other treatments. Among the isolates tested, the lowest numbers of eggs were laid by T. tabaci on H. lixii F3ST1 and C. rosea ICIPE 707 inoculated plants. These results extend the knowledge on colonization of onions by fungal endophytes and their effects on Thrips tabaci. PMID:25254657

  16. Specific Insect-Virus Interactions Are Responsible for Variation in Competency of Different Thrips tabaci Isolines to Transmit Different Tomato Spotted Wilt Virus Isolates

    PubMed Central

    Jacobson, Alana L.; Kennedy, George G.

    2013-01-01

    Local adaptation between sympatric host and parasite populations driven by vector genetics appears to be a factor that influences dynamics of disease epidemics and evolution of insect-vectored viruses. Although T. tabaci is the primary vector of Tomato spotted wilt virus (TSWV) in some areas of the world, it is not an important vector of this economically important plant virus in many areas where it occurs. Previous studies suggest that genetic variation of thrips populations, virus isolates, or both are important factors underlying the localized importance of this species as a vector of TSWV. This study was undertaken to quantify variation in transmissibility of TSWV isolates by T. tabaci, in the ability of T. tabaci to transmit isolates of TSWV, and to examine the possibility that genetic interactions and local adaptation contribute to the localized nature of this species as a vector of TSWV. Isofemale lines of Thrips tabaci from multiple locations were tested for their ability to transmit multiple TSWV isolates collected at the same and different locations as the thrips. Results revealed that the probability of an isofemale line transmitting TSWV varied among virus isolates, and the probability of an isolate being transmitted varied among isofemale lines. These results indicate that the interaction of T. tabaci and TSWV isolate genetic determinants underlie successful transmission of TSWV by T. tabaci. Further analysis revealed sympatric vector-virus pairing resulted in higher transmission than allopatric pairing, which suggests that local adaptation is occurring between T. tabaci and TSWV isolates. PMID:23358707

  17. Self-protection of Pseudomonas syringae pv. "tabaci" from its toxin, tabtoxinine-beta-lactam.

    PubMed Central

    Knight, T J; Durbin, R D; Langston-Unkefer, P J

    1987-01-01

    An extracellular toxin, tabtoxinine-beta-lactam (T beta L), is produced by Pseudomonas syringae pv. "tabaci." This toxin irreversibly inhibits its target, glutamine synthetase; yet P. syringae pv. "tabaci" retains significant amounts of glutamine synthetase activity during toxin production in culture. As part of our investigation of the self-protection of P. syringae pv. "tabaci," we compared the effects of T beta L on Tox+ (T beta L-producing, insensitive to T beta L) and Tox- (T beta L nonproducing, sensitive to T beta L) strains. The extent of protection afforded to the Tox- strain when induced to adenylylate glutamine synthetase was tested. We concluded that an additional protection mechanism was required. A detoxification activity was found in the Tox+ strain which opens the beta-lactam ring of T beta L to produce the inactive, open-chain form, tabtoxinine. Whole cells of the Tox+ strain incubated for 24 h with [14C]T beta L (0.276 mumol/3 X 10(10) cells) contained [14C]tabtoxinine (0.056 mumol), and the medium contained T beta L (0.226 mumol). Extracts of spheroplasts of the Tox+ stain also converted T beta L to tabtoxinine, whereas extracts of the Tox- strain did not alter T beta L. The conversion was time dependent and stoichiometric and was destroyed by boiling for 30 min or by the addition of 5 mM EDTA. Penicillin, a possible substrate and competitive inhibitor of this lactamase activity, inhibited the conversion of T beta L to tabtoxinine. Periplasmic fluid did not catalyze the conversion of T beta L. PMID:3571155

  18. Self-protection of Pseudomonas syringae pv. tabaci from its toxin, tabtoxinine-. beta. -lactam

    SciTech Connect

    Knight, T.J.; Durbin, R.D.; Langston-Unkefer, P.J.

    1987-05-01

    An extracellular toxin, tabtoxinine-..beta..-lactam (T..beta..L), is produced by Pseudomonas syringae pv. tabaci. This toxin irreversibly inhibits its target, glutamine synthetase; yet P. syringae pv. tabaci retains significant amounts of glutamine synthetase activity during toxin production in culture. As part of our investigation of the self-protection of P. syringae pv. tabaci, the authors compared the effects of T..beta..L on Tox/sup +/ (T..beta..L-producing, insensitive to T..beta..L) and Tox/sup -/ (T..beta..L nonproducing, sensitive to T..lambda..) strains. The extent of protection afforded to the Tox/sup -/ strain when induced to adenylylate glutamine synthetase was tested. It was concluded that an additional protection mechanism was required. A detoxification activity was found in the Tox/sup +/ strain which opens the epsilon-lactam ring to T..beta..L to produce the inactive, open-chain form, tabtoxinine. Whole cells of the Tox/sup +/ strain incubated for 24 h with (/sup 14/C)T..beta..L (0.276 ..mu..mol/3 x 10/sup 10/ cells) contained (/sup 14/C)tabtoxinine (0.056 ..mu..mol), and the medium contained T..beta..L (0.226 ..mu..mol). Extracts of spheroplasts of the Tox/sup +/ stain also converted T..beta..L to tabtoxinine, whereas extracts of the Tox/sup -/ strain did not alter T..beta..L. The conversion was time dependent and stoichiometric and was destroyed by boiling for 30 min or by the addition of 5mM EDTA. Penicillin, a possible substrate and competitive inhibitor of this lactamase activity, inhibited the conversion of T..lambda.. to tabtoxinine. Periplasmic fluid did not catalyze the conversion of T..beta..L.

  19. Foreign exploration for insect natural enemies of Bemisia for use in biological control in the USA: A successful program

    Technology Transfer Automated Retrieval System (TEKTRAN)

    European Biological Control Laboratory scientists (USDA-ARS) and collaborators sent 130 shipments of Bemisia species and natural enemies from 28 countries to the Mission Biological Control Laboratory (MBCL) in Mission Texas.More than 235 collections resulted in 13 species of parasitoids and several ...

  20. Expression of the Tomato Pto Gene in Tobacco Enhances Resistance to Pseudomonas syringae pv tabaci Expressing avrPto.

    PubMed Central

    Thilmony, R. L.; Chen, Z.; Bressan, R. A.; Martin, G. B.

    1995-01-01

    The Pto gene encodes a serine-threonine kinase that confers resistance in tomato to Pseudomonas syringae pv tomato strains expressing the avirulence gene avrPto. We examined the ability of Pto to function in tobacco, a species that is sexually incompatible with tomato. Evidence that a heterologous Pto-like signal transduction pathway is present in tobacco was suggested by the fact that tobacco line Wisconsin-38 exhibits a hypersensitive response after infection with P. syringae pv tabaci expressing avrPto. We introduced a Pto transgene into cultivar Wisconsin-38 and assessed the ability of transformed plants to further inhibit growth of the P. s. tabaci strain expressing avrPto. The Pto-transformed tobacco plants exhibited a significant increase in resistance to the avirulent P. s. tabaci strain compared with wild-type tobacco as indicated by (1) more rapid development of a hypersensitive resistance response at high inoculum concentrations (108 colony-forming units per mL); (2) lessened severity of disease symptoms at moderate inoculum concentrations (106 and 107 colony-forming units per mL); and (3) reduced growth of avirulent P. s. tabaci in inoculated leaves. The results indicate that essential components of a Pto-mediated signal transduction pathway are conserved in tobacco and should prompt examination of resistance gene function across even broader taxonomic distances. PMID:12242354

  1. Thrips tabaci (Thysanoptera: Thripidae) and Iris yellow spot virus associated with onion transplants, onion volunteers, and weeds in Colorado

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thrips tabaci infestation was determined on onion transplants received in Colorado during March and April from out of state sources (Imperial Valley, near Phoenix Arizona, and southern Texas) during 2004 to 2008. In the five years of the study, 50% to 100% of the transplant lots sampled were found ...

  2. Evaluation of onion germplasm for resistance to Iris yellow spot (Iris yellow spot virus) and onion thrips, Thrips tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Onion (Allium cepa L.) is the most economically important monocot outside of the grasses. This important crop suffers severe damage from onion thrips (Thrips tabaci), a cosmopolitan and polyphagous insect pest. In addition to direct feeding damages, onion thrips has emerged as the principal vector o...

  3. Transmission of Pantoea ananatis and P. agglomerans, causal agents of center rot of onion (Allium cepa), by onion thrips (Thrips tabaci) through feces.

    PubMed

    Dutta, B; Barman, A K; Srinivasan, R; Avci, U; Ullman, D E; Langston, D B; Gitaitis, R D

    2014-08-01

    Frankliniella fusca, the tobacco thrips, has been shown to acquire and transmit Pantoea ananatis, one of the causal agents of the center rot of onion. Although Thrips tabaci, the onion thrips, is a common pest of onions, its role as a vector of P. ananatis has been unknown. The bacterium, P. agglomerans, is also associated with the center rot of onion, but its transmission by thrips has not been previously investigated. In this study, we investigated the relationship of T. tabaci with P. ananatis and P. agglomerans. Surface-sterilized T. tabaci were provided with various acquisition access periods (AAP) on onion leaves inoculated with either P. ananatis or P. agglomerans. A positive exponential relationship was observed between thrips AAP duration and P. ananatis (R² = 0.967; P = 0.023) or P. agglomerans acquisition (R² = 0.958; P = 0.017). Transmission experiments conducted with T. tabaci adults indicated that 70% of the seedlings developed center rot symptoms 15 days after inoculation. Immunofluorescence microscopy with antibodies specific to P. ananatis revealed that the bacterium was localized only in the gut of T. tabaci adults. Mechanical inoculation of onion seedlings with fecal rinsates alone produced center rot but not with salivary secretions. Together these results suggested that T. tabaci could efficiently transmit P. ananatis and P. agglomerans. PMID:24548212

  4. Arsenophonus GroEL Interacts with CLCuV and Is Localized in Midgut and Salivary Gland of Whitefly B. tabaci

    PubMed Central

    Rana, Vipin Singh; Kumar, Jitendra; Rajagopal, Raman

    2012-01-01

    Cotton leaf curl virus (CLCuV) (Gemininiviridae: Begomovirus) is the causative agent of leaf curl disease in cotton plants (Gossypium hirsutum). CLCuV is exclusively transmitted by the whitefly species B. tabaci (Gennadius) (Hemiptera: Alerodidae). B. tabaci contains several biotypes which harbor dissimilar bacterial endo-symbiotic community. It is reported that these bacterial endosymbionts produce a 63 kDa chaperon GroEL protein which binds to geminivirus particles and protects them from rapid degradation in gut and haemolymph. In biotype B, GroEL protein of Hamiltonella has been shown to interact with Tomato yellow leaf curl virus (TYLCV). The present study was initiated to find out whether endosymbionts of B. tabaci are similarly involved in CLCuV transmission in Sriganganagar (Rajasthan), an area endemic with cotton leaf curl disease. Biotype and endosymbiont diversity of B. tabaci were identified using MtCO1 and 16S rDNA genes respectively. Analysis of our results indicated that the collected B. tabaci population belong to AsiaII genetic group and harbor the primary endosymbiont Portiera and the secondary endosymbiont Arsenophonus. The GroEL proteins of Portiera and Arsenophonus were purified and in-vitro interaction studies were carried out using pull down and co-immunoprecipitation assays. In-vivo interaction was confirmed using yeast two hybrid system. In both in-vitro and in-vivo studies, the GroEL protein of Arsenophonus was found to be interacting with the CLCuV coat protein. Further, we also localized the presence of Arsenophonus in the salivary glands and the midgut of B. tabaci besides the already reported bacteriocytes. These results suggest the involvement of Arsenophonus in the transmission of CLCuV in AsiaII genetic group of B. tabaci. PMID:22900008

  5. Effect of temperature on development and reproduction of Proprioseiopsis asetus (Acari: Phytoseiidae) fed on asparagus thrips, Thrips tabaci.

    PubMed

    Huang, Jian Hua; Freed, Shoaib; Wang, Li Si; Qin, Wen Jing; Chen, Hong Fan; Qin, Hou Guo

    2014-10-01

    Thrips tabaci Lindeman (Thysanoptera: Thripidae) is one of the most important pests of asparagus in China. In this study the effects of five constant temperatures (15, 20, 25, 30 and 35 °C) on the growth, survivorship and reproduction of Proprioseiopsis asetus (Chant) (Acari: Phytoseiidae) fed on T. tabaci was examined under laboratory conditions. Development time of immatures decreased with increasing temperature. The lower egg-to-adult developmental threshold (T 0) and thermal constant (K) of P. asetus were estimated at 15.2 °C and 75.8 degree days by means of a linear model. Fertilized females fed on T. tabaci produced offspring of both sexes, whereas the offspring sex ratio [♀/(♀ + ♂)] of P. asetus at 20-35 °C was female-biased (0.68-0.78) and not significantly influenced by temperature. Survivorship during immature development was significantly influenced by temperature, and was especially low at 15 °C. Pre- and post-oviposition periods of fertilized females shortened with the increase in temperature. The longest oviposition period was 20.4 days, at 25 °C, whereas at 15 °C the mites did not reproduce. Maximum average life time fecundity and mean daily fecundity was recorded at 25 and 35 °C, respectively; the intrinsic rate of increase ranged from 0.05 (20 °C) to 0.17 (35 °C). The results indicate the capability of P. asetus to develop and reproduce at a broad range of temperatures, especially above 25 °C, which can be used for better management of T. tabaci in asparagus. PMID:24797293

  6. Genetic and host-associated differentiation within Thrips tabaci Lindeman (Thysanoptera: Thripidae) and its links to Tomato spotted wilt virus-vector competence.

    PubMed

    Westmore, G C; Poke, F S; Allen, G R; Wilson, C R

    2013-09-01

    Of eight thelytokous populations of onion thrips (Thrips tabaci) collected from potato (three populations), onion (four) or Chrysanthemum (one) hosts from various regions of Australia, only those from potato were capable of transmitting Tomato spotted wilt virus (TSWV) in controlled transmission experiments. Genetic differentiation of seven of these eight populations, and nine others not tested for TSWV vector competence, was examined by comparison of the DNA sequences of mitochondrial cytochrome oxidase subunit 1 (COI) gene. All Australian populations of T. tabaci grouped within the European 'L2' clade of Brunner et al. (2004). Within this clade the seven populations from potato, the three from onion, and the four from other hosts (Chrysanthemum, Impatiens, lucerne, blackberry nightshade) clustered as three distinct sub-groupings characterised by source host. Geographical source of thrips populations had no influence on genetic diversity. These results link genetic differentiation of thelytokous T. tabaci to source host and to TSWV vector capacity for the first time. PMID:23632893

  7. Pathogenicity of Aschersonia spp. against whiteflies Bemisia argentifolii and Trialeurodes vaporariorum.

    PubMed

    Meekes, Ellis T M; Fransen, Joanne J; van Lenteren, Joop C

    2002-09-01

    Entomopathogenic fungi of the genus Aschersonia are specific for whitefly and scale insects. They can be used as biological control agents against silverleaf whitefly, Bemisia argentifolii and greenhouse whitefly, Trialeurodes vaporariorum. Forty-four isolates of Aschersonia spp. were tested for their ability to sporulate and germinate on semi-artificial media and to infect insect hosts. Seven isolates sporulated poorly (less than 1x10(7) conidia/dry weight) and 10 were not able to infect either of the whitefly species. Several isolates were able to produce capilliconidia. Infection level was not correlated with germination on water agar. After a selection based on spore production and infection, virulence of 31 isolates was evaluated on third instar nymphs of both whitefly species on poinsettia (Euphorbia pulcherrima). Whitefly infection levels varied between 2 and 70%, and infection percentages of B. argentifolii correlated with that of T. vaporariorum. However, mortality was higher for T. vaporariorum than for B. argentifolii, as a result of a higher 'mortality due to unknown causes.' Several isolates, among which unidentified species of Aschersonia originating from Thailand and Malaysia, A. aleyrodis from Colombia, and A. placenta from India showed high spore production on semi-artificial medium and high infection levels of both whitefly species. PMID:12417207

  8. Temporal dynamics of iris yellow spot virus and its vector, Thrips tabaci (Thysanoptera: Thripidae), in seeded and transplanted onion fields.

    PubMed

    Hsu, Cynthia L; Hoepting, Christine A; Fuchs, Marc; Shelton, Anthony M; Nault, Brian A

    2010-04-01

    Onion thrips, Thrips tabaci (Lindeman) (Thysanoptera: Thripidae), can reduce onion bulb yield and transmit iris yellow spot virus (IYSV) (Bunyaviridae: Tospovirus), which can cause additional yield losses. In New York, onions are planted using seeds and imported transplants. IYSV is not seed transmitted, but infected transplants have been found in other U.S. states. Transplants are also larger than seeded onions early in the season, and thrips, some of which may be viruliferous, may preferentially colonize larger plants. Limited information is available on the temporal dynamics of IYSV and its vector in onion fields. In 2007 and 2008, T. tabaci and IYSV levels were monitored in six seeded and six transplanted fields. We found significantly more thrips in transplanted fields early in the season, but by the end of the season seeded fields had higher levels of IYSV. The percentage of sample sites with IYSV-infected plants remained low (<12%) until August, when infection levels increased dramatically in some fields. The densities of adult and larval thrips in August and September were better predictors of final IYSV levels than early season thrips densities. For 2007 and 2008, the time onions were harvested may have been more important in determining IYSV levels than whether the onions were seeded or transplanted. Viruliferous thrips emigrating from harvested onion fields into nonharvested ones may be increasing the primary spread of IYSV in late-harvested onions. Managing T. tabaci populations before harvest, and manipulating the spatial arrangement of fields based on harvest date could mitigate the spread of IYSV. PMID:20388253

  9. Evaluating mustard as a potential companion crop for collards to control the silverleaf whitefly, Bemisia argentifolii (Hemiptera:Aleyrodidae): outdoor and olfactometer experiments.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three varieties of mustard (giant red mustard, tender green mustard and ragged leaf mustard) were evaluated as possible repellent companion crops for collards against the silverleaf whitefly, Bemisia argentifolii in outdoor potted experiments and through laboratory studies using a Y-tube olfactomete...

  10. Molecular basis of a microbe-mediated enhancement of symbiotic N/sub 2/-fixation. [Rhizobium meliloti; Pseudomonas syringae pv. tabaci

    SciTech Connect

    Unkefer, P.J.; Knight, T.J.

    1987-04-01

    Improvement of biological nitrogen fixation represents a potential source of both increased food production and decreased dependence on costly chemical fertilizer. They report the results of an investigation of the molecular basis of a unique, microbial-mediated mechanism for increased growth and nitrogen fixation rates in alfalfa. Inoculation of alfalfa plants with both Rhizobium meliloti and Pseudomonas syringae pv tabaci provides increased growth and N/sub 2/-fixation rates of alfalfa. Tabaci produces tabtoxinine-..beta..-lactam (T..beta..L), an exocellular product and glutamine synthetase (GS) inhibitor. The association of this pathogen with nodulating alfalfa plants appears to alter the normal regulation of nitrogen fixation such that nitrogenase activity is stimulated and GS activity is inhibited. Studies of the soluble amino acids in these nodules and the activities of the ammonia assimilatory enzymes indicate alternative pathways of ammonia assimilation are being employed.

  11. Whitefly transmission of the Sweet potato leaf curl virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius) is highly adaptive and polyphagous on taxonomically diverse species of plants on a global scale. This whitefly transmits numerous plant viruses, including Begomoviruses (Geminiviridae). We recently found the Sweet Potato Leaf Curl Virus (SPLCV) ...

  12. Reducing whiteflies on cucumber using intercropping with less preferred vegetables

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effectiveness of four less preferred vegetables – celery, asparagus lettuce, Malabar spinach, and edible amaranth – were investigated for suppression of two biotypes of sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) on cucumber, Cucumis sativus L. (Cucurbitaceae). Int...

  13. Molecular characterization with RAPD-PCR: Application of genetic diagnostics to biological control of the sweetpotato whitefly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The application of genetic diagnostics under the umbrella of classical taxonomy was imperative for successful development and delivery of the biological control program against the sweet potato whitefly, Bemisia tabaci Gennadius biotype B (= silverleaf whitefly, B. argentifolii Bellows and Perring)....

  14. New state record for the silverleaf whitefly parasitoid Encarsia sophia in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A hymenopteran parasitoid reared, Encarsia sophia (Girault & Dodd) (= transvena Timberlake) [Aphelinidae], from silverleaf whitefly, Bemisia tabaci (Genn.), was collected with their host remains from infested cotton, Gossypium hirsutum L., in a greenhouse and potatoes, Solanum tuberosum L., planted ...

  15. Susceptibility of ornamental pepper banker plant candidates to common greenhouse pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Susceptibility of four potential ornamental pepper banker plant candidates [Black Pearl (BP), Explosive Ember (EE), Masquerade (MA), Red Missile (RM), and a commercial pepper cultivar Blitz (BL)] were evaluated against three common greenhouse pests - Bemisia tabaci, Polyphagotarsonemus latus and Fra...

  16. Effects of selected defoliants in combination with insecticides on sweetpotato whitefly (Hemiptera: Aleyrodidae) and its parasitoids in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of two defoliants, Def (S, S, Stributylphosphorotrithioate) and Dropp (thidiazuron) alone and in combination with two commonly used insecticides, a pyrethroid, Karate (lambda-cyhalothrin) and an organophosphate, Guthion (azinphosmethyl) on sweetpotato whitefly, Bemisia tabaci Gennadius Bioty...

  17. Resistance of Citrullus Colocynthis to Whiteflies and Spidermites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The B-biotype sweetpotato whitefly (SPWF), Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), and the two-spotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae) are serious pests of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai var. lanatus) (Cucurbitaceae). United ...

  18. Molecular differences in the mitochondrial cytochrome oxidase I (mtCOI) gene and development of a species-specific marker for onion thrips, Thrips tabaci Lindeman, and melon thrips, T. palmi Karny (Thysanoptera: Thripidae), vectors of tospoviruses (Bunyaviridae).

    PubMed

    Asokan, R; Krishna Kumar, N K; Kumar, Vikas; Ranganath, H R

    2007-10-01

    A quick and developmental-stage non-limiting method of the identification of vectors of tospoviruses, such as Thrips tabaci and T. palmi, is important in the study of vector transmission, insecticide resistance, biological control, etc. Morphological identification of these thrips vectors is often a stumbling block in the absence of a specialist and limited by polymorphism, sex, stage of development, etc. Molecular identification, on the other hand, is not hampered by the above factors and can easily be followed by a non-specialist with a little training. The mitochondrial cytochrome oxidase I (mtCOI) exhibits reliable inter-species variations as compared to the other markers. In this communication, we present the differences in the mtCOI partial sequence of morphologically identified specimens of T. tabaci and T. palmi collected from onion and watermelon, respectively. Species-specific markers, identified in this study, could successfully determine T. tabaci and T. palmi, which corroborated the morphological identification. Phylogenetic analyses showed that both T. tabaci and T. palmi formed different clades as compared to the other NCBI accessions. The implication of these variations in vector efficiency has to be investigated further. The result of this investigation is useful in the quick identification of T. tabaci and T. palmi, a critical factor in understanding the epidemiology of the tospoviruses, their management and also in quarantine. PMID:17916265

  19. Efficacy of CC traps and seasonal activity of adult Bemisia argentifolii (Homoptera: Aleyrodidae) in Imperial and Palo Verde Valleys, California.

    PubMed

    Chu, C C; Henneberry, T J; Natwick, E T; Ritter, D; Birdsall, S L

    2001-02-01

    Adult whitefly Bemisia argentifolii Bellows & Perring trap (CC trap) catches were compared with suction type trap catches. CC trap catches were significantly correlated to the suction trap catches. Higher numbers of B. argentifolii adults were caught in CC traps oriented toward an untreated, B. argentifolii-infested, cotton field as compared with traps oriented toward Bermuda grass fields, farm roads, or fallow areas. CC trap catches at five heights above ground (from 0 to 120 cm) were significantly related to each other in choice and no-choice studies. CC trap catches were low in the Imperial and Palo Verde Valleys from late October to early June each of 1996, 1997, and 1998. Trap catches increased with increasing seasonal air temperatures and host availability. Trap catches were adversely affected by wind and rain. Abrupt trap catch increases of 40- to 50-fold for 1-2 d in late June to early July followed by abrupt decreases in adult catches suggest migrating activity of adults from other nearby crop sources. PMID:11233132

  20. SILVERLEAF WHITEFLY: NATIONAL RESEARCH ACTION AND TECHNOLOGY TRANSFER PLAN: FOURTH ANNUAL REVIEW OF THE SECOND 5-YEAR PLAN AND FINAL REPORT FOR 1992-2002

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Sweetpotato Whitefly, Bemisia tabaci (Gennadius) Strain B (= Silverleaf Whitefly, Bemisia argentifolii Bellows and Perring), National Research and Action Plans (1992-1997 and 1997-2002) were developed by USDA agencies (ARS, APHIS, and CSREES), state agencies, state agricultural experimental stat...

  1. Population of the Sweetpotato Whitefly in Response to Different Rates of Three Sulfur-Containing Fertilizers on Ten Vegetable Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whiteflies in the Bemisia complex are a global pest on numerous horticultural crops. The effect of production practices on the population of the B-biotype sweetpotato whitefly, Bemisia tabaci (Gennadius), is only partly understood. A study was conducted to examine the effect of different rates of ...

  2. Tissue-specific changes of glutamine synthetase activity in oats after rhizosphere infestation by Pseudomonas syringae pv. tabaci. Final report

    SciTech Connect

    Knight, T.J.; Temple, S.; Sengupta-Gopalan, C.

    1996-05-15

    Oats (Avena sativa L. lodi) tolerant of rhizosphere infestation by Pseudomonas syringae pv. tabaci when challenged by the pathogen experience tissue-specific alterations of ammonia assimilatory capabilities. Altered ammonia assimilatory potentials between root and leaf tissue result from selective inactivation of glutamine synthetase (GS) by the toxin Tabtoxinine-B-lactam (TBL). Root GS is sensitive and leaf GSs are resistant to TBL inactivation. With prolonged challenge by the pathogen root GS activity decreases but leaf GS specific activity increase. Higher leaf GS activity is due to decreased rates of degradation rather than increased GS synthesis. Higher leaf GS activity and elevated levels of GS polypeptide appear to result from a limited interaction between GS and TBL leading to the accumulation of a less active but more stable GS holoenzyme. Tolerant challenged oats besides surviving rhizosphere infestation, experience enhanced growth. A strong correlation exists between leaf GS activity and whole plant fresh weight, suggesting that tissue-specific changes in ammonia assimilatory capability provides the plant a more efficient mechanism for uptake and utilization of nitrogen.

  3. Evaluations of melon germplasm reported to exhibit host plant resistance to sweetpotato whitefly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato whitefly (MEAM1 cryptic species of Bemisia tabaci; SPWF) displaced B. tabaci biotype A in 1991 in the lower desert area of southern California and the adjoining areas of Arizona and western Mexico. The search for high-level host plant resistance to this devastating insect has been ongoin...

  4. Sweet Potato Leaf Curl Virus: Efficiency of Whitefly Transmission

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius) is a widespread pest. It is highly adaptive and feeds on taxonomically diverse species of plants. This whitefly damages plants directly by feeding on leaves, but the problem is compounded because B. tabaci is known to vector numerous plant virus...

  5. A LIGHT-EMITTING DIODE EQUIPPED CC TRAP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trap catches of adult Bemisia tabaci (Gennadius), biotype-B, and their Eretmocerus spp. and Encarsia spp. parasitoids were compared in cage studies in the greenhouse. Average catches of adult B. tabaci in CC traps were 41% of the numbers caught on 100 cm^2 yellow sticky card (YC) traps. Coating th...

  6. Evaluating plant and plant oil repellency against the sweetpotato whitefly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci is a major insect pest of vegetables world-wide. We evaluated the effect of commercial plant oils – garlic oil, hot pepper wax, and mustard oil against B. tabaci. Cucumber plants served as the control. Additional treatments included no plants or oil (clear ai...

  7. Molecular characterization with RAPD-PCR: application of genetic diagnostics to biological bontrol of the sweetpotato whitefly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 38 exotic and 2 native parasitoid populations of the sweetpotato whitefly, Bemisia tabaci biotype B, were evaluated in pre-release quarantine efficacy tests. Numbers of B. tabaci parasitized were counted in sleeve cages on cantaloupe melons (Cucumis melo‘Perlita’), cotton (Gossypium hirsu...

  8. A new species of Cales (Hymenoptera: Aphelinidae) parasitizing Bemisia pongamiae (Takahashi) (Hemiptera: Aleyrodidae) in Taiwan, with a key to world species of the Cales spenceri-group

    PubMed Central

    Shih, Yuan-Tung; Ward, Samantha E.

    2015-01-01

    Abstract Background The genus Cales has been extensively revised recently and divided into two species groups, the noacki- and spenceri-groups Mottern et al. (2010), Mottern and Heraty (2014). New information Cales motterni Polaszek, Shih & Ward sp. nov. is described from two females reared from the whitefly Bemisia pongamiae from Taiwan. The species belongs to the spenceri- group, and has a characteristic and unusual antennal clava. A key to the four species currently known from the spenceri-group is provided. PMID:26696762

  9. Influence of cover crop and intercrop systems on Bemisia argentifolli (Hemiptera: Aleyrodidae) infestation and associated squash silverleaf disorder in zucchini.

    PubMed

    Manandhar, Roshan; Hooks, Cerruti R R; Wright, Mark G

    2009-04-01

    Field experiments were conducted to evaluate the effects of cover cropping and intercropping on population densities of silverleaf whitefly, Bemisia argentifolli Bellow and Perring, and the incidence of squash silverleaf disorder (SSL) in zucchini, Cucurbita pepo L., in Oahu, HI. Two cover crops, buckwheat (BW), Fagopyrum esculentum Moench, and white clover (WC), Trifolium repens L., or sunn hemp (SH), Crotolaria juncea L., and an intercropped vegetable, okra, Abelmonchus esculentus L., were evaluated during the 2003, 2005, and 2006 growing seasons, respectively. Population densities of whiteflies and SSL severity varied during the three field experiments. In 2003, the severity of SSL and percentage of leaves displaying symptoms were significantly lower on zucchini plants in WC than BW plots throughout the crops' growth cycle. Additionally, the percentage of leaves per plant displaying SSL symptoms was significantly greater in bare-ground (BG) compared with the pooled BW and WC treatments on each inspection date. In 2005, zucchini intercropped with okra had lower numbers of adult whiteflies and resulted in significantly lower severity of SSL than pooled BW and WC treatments. During 2006, zucchini grown with SH had significantly lower numbers of all whitefly stages (i.e., egg, immature, and adult) and less SSL severity symptoms than BW. Despite these differences in whitefly numbers and SSL severity, marketable yields were not significantly lower in BW compared with WC or SH treatment plots during the study. The mechanisms underlying these results and the feasibility of using cover crops and intercrops to manage B. argentifolli and SSL are discussed. PMID:19389294

  10. Impact of Bemisia argentifolii (Homoptera: Auchenorrhyncha: Aleyrodidae) infestation and squash silverleaf disorder on zucchini yield and quality.

    PubMed

    Chen, Jiang; McAuslane, Heather J; Carle, R Bruce; Webb, Susan E

    2004-12-01

    Fruit yield and quality of zucchini, Cucurbita pepo L., plants infested with Bemisia argentifolii Bellows & Perring were evaluated in a screenhouse under spring and fall growing conditions by using closely related sister lines that were either susceptible (ZUC61) or tolerant (ZUC76-SLR) to squash silverleaf disorder. Our objective was to test separately the effects of level of whitefly infestation and expression of silverleaf symptoms on zucchini yield and quality. In a second experiment, yield and quality of fruit produced by silverleaf-tolerant zucchini genotypes incorporating two different sources of tolerance (ZUC76-SLR and ZUC33-SLR/PMR) were compared with that of 'Zucchini Elite', a silverleaf-susceptible commercial hybrid. Zucchini fruit yield was reduced in plants exposed to repeated infestations of whiteflies in spring and fall of both experiments. In addition, fruit grew to harvestable size more slowly under the highest whitefly infestations. Fruit quality was reduced at high infestations because of uneven and reduced pigmentation. The fruit yield and quality of ZUC61 and ZUC76-SLR were similarly affected by whitefly infestation despite differences in their susceptibility to squash silverleaf disorder. Fruit from infested plants showed decreased levels of chlorophyll and carotenoids causing the "blanching" of the fruit that is associated with loss of quality and reduced marketability. Leaves of infested plants of all genotypes had reduced levels of photosynthetic and photoprotectant pigments, possibly leading to reduced photosynthesis and consequently reduced yield. We conclude that feeding by high whitefly populations rather than expression of squash silverleaf disorder is responsible for yield and quality reduction in zucchini. PMID:15666769

  11. Light Suppresses Bacterial Population through the Accumulation of Hydrogen Peroxide in Tobacco Leaves Infected with Pseudomonas syringae pv. tabaci

    PubMed Central

    Cheng, Dan-Dan; Liu, Mei-Jun; Sun, Xing-Bin; Zhao, Min; Chow, Wah S.; Sun, Guang-Yu; Zhang, Zi-Shan; Hu, Yan-Bo

    2016-01-01

    Pseudomonas syringae pv. tabaci (Pst) is a hemibiotrophic bacterial pathogen responsible for tobacco wildfire disease. Although considerable research has been conducted on the tobacco plant’s tolerance to Pst, the role of light in the responses of the photosystems to Pst infection is poorly understood. This study aimed to elucidate the underlying mechanisms of the reduced photosystem damage in tobacco leaves due to Pst infection under light conditions. Compared to dark conditions, Pst infection under light conditions resulted in less chlorophyll degradation and a smaller decline in photosynthetic function. Although the maximal quantum yield of photosystem II (PSII) and the activity of the photosystem I (PSI) complex decreased as Pst infection progressed, damage to PSI and PSII after infection was reduced under light conditions compared to dark conditions. Pst was 17-fold more abundant in tobacco leaves under dark compared to light conditions at 3 days post inoculation (dpi). Additionally, H2O2 accumulated to a high level in tobacco leaves after Pst infection under light conditions; although to a lesser extent, H2O2 accumulation was also significant under dark conditions. Pretreatment with H2O2 alleviated chlorotic lesions and decreased Pst abundance in tobacco leaves at 3 dpi under dark conditions. MV pretreatment had the same effects under light conditions, whereas 3-(3,4-dichlorophenyl)-1,1-dimethylurea pretreatment aggravated chlorotic lesions and increased the Pst population. These results indicate that chlorotic symptoms and the size of the bacterial population are each negatively correlated with H2O2 accumulation. In other words, light appears to suppress the Pst population in tobacco leaves through the accumulation of H2O2 during infection. PMID:27148334

  12. Light Suppresses Bacterial Population through the Accumulation of Hydrogen Peroxide in Tobacco Leaves Infected with Pseudomonas syringae pv. tabaci.

    PubMed

    Cheng, Dan-Dan; Liu, Mei-Jun; Sun, Xing-Bin; Zhao, Min; Chow, Wah S; Sun, Guang-Yu; Zhang, Zi-Shan; Hu, Yan-Bo

    2016-01-01

    Pseudomonas syringae pv. tabaci (Pst) is a hemibiotrophic bacterial pathogen responsible for tobacco wildfire disease. Although considerable research has been conducted on the tobacco plant's tolerance to Pst, the role of light in the responses of the photosystems to Pst infection is poorly understood. This study aimed to elucidate the underlying mechanisms of the reduced photosystem damage in tobacco leaves due to Pst infection under light conditions. Compared to dark conditions, Pst infection under light conditions resulted in less chlorophyll degradation and a smaller decline in photosynthetic function. Although the maximal quantum yield of photosystem II (PSII) and the activity of the photosystem I (PSI) complex decreased as Pst infection progressed, damage to PSI and PSII after infection was reduced under light conditions compared to dark conditions. Pst was 17-fold more abundant in tobacco leaves under dark compared to light conditions at 3 days post inoculation (dpi). Additionally, H2O2 accumulated to a high level in tobacco leaves after Pst infection under light conditions; although to a lesser extent, H2O2 accumulation was also significant under dark conditions. Pretreatment with H2O2 alleviated chlorotic lesions and decreased Pst abundance in tobacco leaves at 3 dpi under dark conditions. MV pretreatment had the same effects under light conditions, whereas 3-(3,4-dichlorophenyl)-1,1-dimethylurea pretreatment aggravated chlorotic lesions and increased the Pst population. These results indicate that chlorotic symptoms and the size of the bacterial population are each negatively correlated with H2O2 accumulation. In other words, light appears to suppress the Pst population in tobacco leaves through the accumulation of H2O2 during infection. PMID:27148334

  13. Genome walking.

    PubMed

    Shapter, Frances M; Waters, Daniel L E

    2014-01-01

    Genome walking is a method for determining the DNA sequence of unknown genomic regions flanking a region of known DNA sequence. The Genome walking has the potential to capture 6-7 kb of sequence in a single round. Ideal for identifying gene promoter regions where only the coding region. Genome walking also has significant utility for capturing homologous genes in new species when there are areas in the target gene with strong sequence conservation to the characterized species. The increasing use of next-generation sequencing technologies will see the principles of genome walking adapted to in silico methods. However, for smaller projects, PCR-based genome walking will remain an efficient method of characterizing unknown flanking sequence. PMID:24243201

  14. Prophage Genomics

    PubMed Central

    Canchaya, Carlos; Proux, Caroline; Fournous, Ghislain; Bruttin, Anne; Brüssow, Harald

    2003-01-01

    The majority of the bacterial genome sequences deposited in the National Center for Biotechnology Information database contain prophage sequences. Analysis of the prophages suggested that after being integrated into bacterial genomes, they undergo a complex decay process consisting of inactivating point mutations, genome rearrangements, modular exchanges, invasion by further mobile DNA elements, and massive DNA deletion. We review the technical difficulties in defining such altered prophage sequences in bacterial genomes and discuss theoretical frameworks for the phage-bacterium interaction at the genomic level. The published genome sequences from three groups of eubacteria (low- and high-G+C gram-positive bacteria and γ-proteobacteria) were screened for prophage sequences. The prophages from Streptococcus pyogenes served as test case for theoretical predictions of the role of prophages in the evolution of pathogenic bacteria. The genomes from further human, animal, and plant pathogens, as well as commensal and free-living bacteria, were included in the analysis to see whether the same principles of prophage genomics apply for bacteria living in different ecological niches and coming from distinct phylogenetical affinities. The effect of selection pressure on the host bacterium is apparently an important force shaping the prophage genomes in low-G+C gram-positive bacteria and γ-proteobacteria. PMID:12794192

  15. Host plant pubescence: effect on silverleaf whitefly, Bemisia argentifolii, fourth instar and pharate adult dimensions and ecdysteroid titer fluctuations.

    PubMed

    Gelman, Dale B; Gerling, Dan

    2003-01-01

    The ability to generate physiologically synchronous groups of insects is vital to the performance of investigations designed to test insect responses to intrinsic and extrinsic stimuli. During a given instar, the silverleaf whitefly, Bemisia argentifolii, increase in depth but not in length or width. A staging system to identify physiologically synchronous 4th instar and pharate adult silverleaf whiteflies based on increasing body depth and the development of the adult eye has been described previously. This study determined the effect of host plant identity on ecdysteroid fluctuations during the 4th instar and pharate adult stages, and on the depth, length and width dimensions of 4th instar/pharate adult whiteflies. When grown on the pubescent-leafed green bean, tomato and poinsettia plants, these stages were significantly shorter and narrower, but attained greater depth than when grown on the glabrous-leafed cotton, collard and sweet potato plants. Thus, leaf pubescence is associated with reduced length and width dimensions, but increased depth dimensions in 4(th) instars and pharate adults. For all host plants, nymphal ecdysteroid titers peaked just prior to the initiation of adult development. However, when reared on pubescent-leafed plants, the initiation of adult development typically occurred in nymphs that had attained a depth of 0.2 to 0.25 mm (Stage 3 - 4). When reared on glabrous-leafed plants, the initiation of adult development typically occurred earlier, in nymphs that had attained a depth of only 0.15-0.18 mm (Stage 2 Old - early 3). Therefore, based on ecdysteroid concentration, it appears that Stage-2, -3 and -4/5 nymphs reared on pubescent-leafed plants are physiologically equivalent to Stage-1, -2 Young and -2 Old/3, respectively, nymphs reared on glabrous-leafed plants. The host plant affected the width but not the height of the nymphal-adult premolt ecdysteroid peak. However, leaf pubescence was not the determining factor. Thus, host plant

  16. Aquaculture Genomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genomics chapter covers the basics of genome mapping and sequencing and the current status of several relevant species. The chapter briefly describes the development and use of (cDNA, BAC, etc.) libraries for mapping and obtaining specific sequence information. Other topics include comparative ...

  17. Analysis of the nucleotide sequence of the treehopper-transmitted geminivirus, tomato pseudo-curly top virus, suggests a recombinant origin.

    PubMed

    Briddon, R W; Bedford, I D; Tsai, J H; Markham, P G

    1996-05-15

    The genome of tomato pseudo-curly top virus (TPCTV), originating from Florida, has been cloned and sequenced. TPCTV is the only geminivirus identified with a vector specificity which falls outside the Cicadellidae (leafhoppers) and Aleyrodidae (whiteflies). Infectivity of the cloned viral genome was demonstrated by Agrobacterium-mediated inoculation of several host species. Progeny virus was transmissible by the treehopper vector of TPCTV, Micrutalis malleifera (Fowler). The genome of TPCTV shows features typical of both subgroups I and III genera of the family Geminiviridae. The coat protein of TPCTV, although distinct from all previously characterized geminiviruses, exhibits features more akin to the leafhopper-transmitted geminiviruses than those transmissible by the whitefly Bemisia tabaci Genn. The relationship of TPCTV to other geminiviruses, particularly beet curly top virus, is discussed in relation to the possible evolutionary origins of this virus. PMID:8638404

  18. Antarctic Genomics

    PubMed Central

    Clarke, Andrew; Cockell, Charles S.; Convey, Peter; Detrich III, H. William; Fraser, Keiron P. P.; Johnston, Ian A.; Methe, Barbara A.; Murray, Alison E.; Peck, Lloyd S.; Römisch, Karin; Rogers, Alex D.

    2004-01-01

    With the development of genomic science and its battery of technologies, polar biology stands on the threshold of a revolution, one that will enable the investigation of important questions of unprecedented scope and with extraordinary depth and precision. The exotic organisms of polar ecosystems are ideal candidates for genomic analysis. Through such analyses, it will be possible to learn not only the novel features that enable polar organisms to survive, and indeed thrive, in their extreme environments, but also fundamental biological principles that are common to most, if not all, organisms. This article aims to review recent developments in Antarctic genomics and to demonstrate the global context of such studies. PMID:18629155

  19. Incidence and characterization of resistance to pyrethroid and organophosphorus insecticides in Thrips tabaci (Thysanoptera: Thripidae) in onion fields in Isfahan, Iran.

    PubMed

    Nazemi, A; Khajehali, J; Van Leeuwen, T

    2016-05-01

    Onion thrips, Thrips tabaci Lindeman, is the main pest of onion-growing fields in Isfahan and is mainly controlled by frequently spraying several insecticides. To investigate the resistance status and mechanisms, the susceptibility of ten field populations collected from Isfahan onion-growing regions were tested to several currently used pesticides. Resistance to the tested insecticides was observed in most populations when compared with the susceptible reference population. Enhanced detoxification, implicated by the use of inhibitors of major metabolic detoxification enzymes, was observed in the populations resistant to profenofos and chlorpyrifos. In the deltamethrin resistant populations, the amino acid substitution T929I was detected in the voltage gated sodium channel, which is known to confer pyrethroid resistance. These data are a first step towards more efficient resistance management tactics through early detection of resistant onion thrips in Iran. PMID:27017878

  20. Genomic Testing

    MedlinePlus

    ... Working Group Independent Web site Informing the effective integration of genomics into health practice—Lynch syndrome ACCE Model for Evaluating Genetic Tests Recommendations by the EGAPP Working Group Top of ... ...

  1. Genome databases

    SciTech Connect

    Courteau, J.

    1991-10-11

    Since the Genome Project began several years ago, a plethora of databases have been developed or are in the works. They range from the massive Genome Data Base at Johns Hopkins University, the central repository of all gene mapping information, to small databases focusing on single chromosomes or organisms. Some are publicly available, others are essentially private electronic lab notebooks. Still others limit access to a consortium of researchers working on, say, a single human chromosome. An increasing number incorporate sophisticated search and analytical software, while others operate as little more than data lists. In consultation with numerous experts in the field, a list has been compiled of some key genome-related databases. The list was not limited to map and sequence databases but also included the tools investigators use to interpret and elucidate genetic data, such as protein sequence and protein structure databases. Because a major goal of the Genome Project is to map and sequence the genomes of several experimental animals, including E. coli, yeast, fruit fly, nematode, and mouse, the available databases for those organisms are listed as well. The author also includes several databases that are still under development - including some ambitious efforts that go beyond data compilation to create what are being called electronic research communities, enabling many users, rather than just one or a few curators, to add or edit the data and tag it as raw or confirmed.

  2. Listeria Genomics

    NASA Astrophysics Data System (ADS)

    Cabanes, Didier; Sousa, Sandra; Cossart, Pascale

    The opportunistic intracellular foodborne pathogen Listeria monocytogenes has become a paradigm for the study of host-pathogen interactions and bacterial adaptation to mammalian hosts. Analysis of L. monocytogenes infection has provided considerable insight into how bacteria invade cells, move intracellularly, and disseminate in tissues, as well as tools to address fundamental processes in cell biology. Moreover, the vast amount of knowledge that has been gathered through in-depth comparative genomic analyses and in vivo studies makes L. monocytogenes one of the most well-studied bacterial pathogens. This chapter provides an overview of progress in the exploration of genomic, transcriptomic, and proteomic data in Listeria spp. to understand genome evolution and diversity, as well as physiological aspects of metabolism used by bacteria when growing in diverse environments, in particular in infected hosts.

  3. Genome Informatics

    PubMed Central

    Winslow, Raimond L.; Boguski, Mark S.

    2005-01-01

    This article reviews recent advances in genomics and informatics relevant to cardiovascular research. In particular, we review the status of (1) whole genome sequencing efforts in human, mouse, rat, zebrafish, and dog; (2) the development of data mining and analysis tools; (3) the launching of the National Heart, Lung, and Blood Institute Programs for Genomics Applications and Proteomics Initiative; (4) efforts to characterize the cardiac transcriptome and proteome; and (5) the current status of computational modeling of the cardiac myocyte. In each instance, we provide links to relevant sources of information on the World Wide Web and critical appraisals of the promises and the challenges of an expanding and diverse information landscape. PMID:12750305

  4. Whither genomics?

    PubMed Central

    Murray, Andrew W

    2000-01-01

    The flood of data from genome-wide analysis is transforming biology. We need to develop new, interdisciplinary approaches to convert these data into information about the components and structures of individual biological pathways and to use the resulting information to yield knowledge about general principles that explain the functions and evolution of life. PMID:11104516

  5. Metabolic Coevolution in the Bacterial Symbiosis of Whiteflies and Related Plant Sap-Feeding Insects

    PubMed Central

    Luan, Jun-Bo; Chen, Wenbo; Hasegawa, Daniel K.; Simmons, Alvin M.; Wintermantel, William M.; Ling, Kai-Shu; Fei, Zhangjun; Liu, Shu-Sheng; Douglas, Angela E.

    2015-01-01

    Genomic decay is a common feature of intracellular bacteria that have entered into symbiosis with plant sap-feeding insects. This study of the whitefly Bemisia tabaci and two bacteria (Portiera aleyrodidarum and Hamiltonella defensa) cohoused in each host cell investigated whether the decay of Portiera metabolism genes is complemented by host and Hamiltonella genes, and compared the metabolic traits of the whitefly symbiosis with other sap-feeding insects (aphids, psyllids, and mealybugs). Parallel genomic and transcriptomic analysis revealed that the host genome contributes multiple metabolic reactions that complement or duplicate Portiera function, and that Hamiltonella may contribute multiple cofactors and one essential amino acid, lysine. Homologs of the Bemisia metabolism genes of insect origin have also been implicated in essential amino acid synthesis in other sap-feeding insect hosts, indicative of parallel coevolution of shared metabolic pathways across multiple symbioses. Further metabolism genes coded in the Bemisia genome are of bacterial origin, but phylogenetically distinct from Portiera, Hamiltonella and horizontally transferred genes identified in other sap-feeding insects. Overall, 75% of the metabolism genes of bacterial origin are functionally unique to one symbiosis, indicating that the evolutionary history of metabolic integration in these symbioses is strongly contingent on the pattern of horizontally acquired genes. Our analysis, further, shows that bacteria with genomic decay enable host acquisition of complex metabolic pathways by multiple independent horizontal gene transfers from exogenous bacteria. Specifically, each horizontally acquired gene can function with other genes in the pathway coded by the symbiont, while facilitating the decay of the symbiont gene coding the same reaction. PMID:26377567

  6. Metabolic Coevolution in the Bacterial Symbiosis of Whiteflies and Related Plant Sap-Feeding Insects.

    PubMed

    Luan, Jun-Bo; Chen, Wenbo; Hasegawa, Daniel K; Simmons, Alvin M; Wintermantel, William M; Ling, Kai-Shu; Fei, Zhangjun; Liu, Shu-Sheng; Douglas, Angela E

    2015-09-01

    Genomic decay is a common feature of intracellular bacteria that have entered into symbiosis with plant sap-feeding insects. This study of the whitefly Bemisia tabaci and two bacteria (Portiera aleyrodidarum and Hamiltonella defensa) cohoused in each host cell investigated whether the decay of Portiera metabolism genes is complemented by host and Hamiltonella genes, and compared the metabolic traits of the whitefly symbiosis with other sap-feeding insects (aphids, psyllids, and mealybugs). Parallel genomic and transcriptomic analysis revealed that the host genome contributes multiple metabolic reactions that complement or duplicate Portiera function, and that Hamiltonella may contribute multiple cofactors and one essential amino acid, lysine. Homologs of the Bemisia metabolism genes of insect origin have also been implicated in essential amino acid synthesis in other sap-feeding insect hosts, indicative of parallel coevolution of shared metabolic pathways across multiple symbioses. Further metabolism genes coded in the Bemisia genome are of bacterial origin, but phylogenetically distinct from Portiera, Hamiltonella and horizontally transferred genes identified in other sap-feeding insects. Overall, 75% of the metabolism genes of bacterial origin are functionally unique to one symbiosis, indicating that the evolutionary history of metabolic integration in these symbioses is strongly contingent on the pattern of horizontally acquired genes. Our analysis, further, shows that bacteria with genomic decay enable host acquisition of complex metabolic pathways by multiple independent horizontal gene transfers from exogenous bacteria. Specifically, each horizontally acquired gene can function with other genes in the pathway coded by the symbiont, while facilitating the decay of the symbiont gene coding the same reaction. PMID:26377567

  7. Citrus Genomics

    PubMed Central

    Talon, Manuel; Gmitter Jr., Fred G.

    2008-01-01

    Citrus is one of the most widespread fruit crops globally, with great economic and health value. It is among the most difficult plants to improve through traditional breeding approaches. Currently, there is risk of devastation by diseases threatening to limit production and future availability to the human population. As technologies rapidly advance in genomic science, they are quickly adapted to address the biological challenges of the citrus plant system and the world's industries. The historical developments of linkage mapping, markers and breeding, EST projects, physical mapping, an international citrus genome sequencing project, and critical functional analysis are described. Despite the challenges of working with citrus, there has been substantial progress. Citrus researchers engaged in international collaborations provide optimism about future productivity and contributions to the benefit of citrus industries worldwide and to the human population who can rely on future widespread availability of this health-promoting and aesthetically pleasing fruit crop. PMID:18509486

  8. Ancient genomics

    PubMed Central

    Der Sarkissian, Clio; Allentoft, Morten E.; Ávila-Arcos, María C.; Barnett, Ross; Campos, Paula F.; Cappellini, Enrico; Ermini, Luca; Fernández, Ruth; da Fonseca, Rute; Ginolhac, Aurélien; Hansen, Anders J.; Jónsson, Hákon; Korneliussen, Thorfinn; Margaryan, Ashot; Martin, Michael D.; Moreno-Mayar, J. Víctor; Raghavan, Maanasa; Rasmussen, Morten; Velasco, Marcela Sandoval; Schroeder, Hannes; Schubert, Mikkel; Seguin-Orlando, Andaine; Wales, Nathan; Gilbert, M. Thomas P.; Willerslev, Eske; Orlando, Ludovic

    2015-01-01

    The past decade has witnessed a revolution in ancient DNA (aDNA) research. Although the field's focus was previously limited to mitochondrial DNA and a few nuclear markers, whole genome sequences from the deep past can now be retrieved. This breakthrough is tightly connected to the massive sequence throughput of next generation sequencing platforms and the ability to target short and degraded DNA molecules. Many ancient specimens previously unsuitable for DNA analyses because of extensive degradation can now successfully be used as source materials. Additionally, the analytical power obtained by increasing the number of sequence reads to billions effectively means that contamination issues that have haunted aDNA research for decades, particularly in human studies, can now be efficiently and confidently quantified. At present, whole genomes have been sequenced from ancient anatomically modern humans, archaic hominins, ancient pathogens and megafaunal species. Those have revealed important functional and phenotypic information, as well as unexpected adaptation, migration and admixture patterns. As such, the field of aDNA has entered the new era of genomics and has provided valuable information when testing specific hypotheses related to the past. PMID:25487338

  9. Genomic Imprinting

    PubMed Central

    Bajrami, Emirjeta; Spiroski, Mirko

    2016-01-01

    BACKGROUND: Genomic imprinting is the inheritance out of Mendelian borders. Many of inherited diseases and human development violates Mendelian law of inheritance, this way of inheriting is studied by epigenetics. AIM: The aim of this review is to analyze current opinions and options regarding to this way of inheriting. RESULTS: Epigenetics shows that gene expression undergoes changes more complex than modifications in the DNA sequence; it includes the environmental influence on the gametes before conception. Humans inherit two alleles from mother and father, both are functional for the majority of the genes, but sometimes one is turned off or “stamped” and doesn’t show in offspring, that gene is imprinted. Imprinting means that that gene is silenced, and gene from other parent is expressed. The mechanisms for imprinting are still incompletely defined, but they involve epigenetic modifications that are erased and then reset during the creation of eggs and sperm. Genomic imprinting is a process of silencing genes through DNA methylation. The repressed allele is methylated, while the active allele is unmethylated. The most well-known conditions include Prader-Willi syndrome, and Angelman syndrome. Both of these syndromes can be caused by imprinting or other errors involving genes on the long arm of chromosome 15. CONCLUSIONS: Genomic imprinting and other epigenetic mechanisms such as environment is shown that plays role in offspring neurodevelopment and autism spectrum disorder. PMID:27275355

  10. Virus infection of a weed increases vector attraction to and vector fitness on the weed

    PubMed Central

    Chen, Gong; Pan, Huipeng; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Fang, Yong; Shi, Xiaobin; Zhang, Youjun

    2013-01-01

    Weeds are important in the ecology of field crops, and when crops are harvested, weeds often become the main hosts for plant viruses and their insect vectors. Few studies, however, have examined the relationships between plant viruses, vectors, and weeds. Here, we investigated how infection of the weed Datura stramonium L. by tomato yellow leaf curl virus (TYLCV) affects the host preference and performance of the TYLCV vector, Bemisia tabaci (Gennadius) Q. The results of a choice experiment indicated that B. tabaci Q preferentially settled and oviposited on TYLCV-infected plants rather than on healthy plants. In addition, B. tabaci Q performed better on TYLCV-infected plants than on healthy plants. These results demonstrate that TYLCV is indirectly mutualistic to B. tabaci Q. The mutually beneficial interaction between TYLCV and B. tabaci Q may help explain the concurrent outbreaks of TYLCV and B. tabaci Q in China. PMID:23872717

  11. Two years research on efficiency of two intercrops, birdsfoot trefoil and summer savory, to reduce damage caused by onion thrips(Thrips tabaci Lindeman, Thysanoptera, Thripidae) on leek.

    PubMed

    Gombac, P; Trdan, S

    2012-01-01

    In 2009 and 2011, a field experiment was carried out at the Laboratory Field at the Biotechnical Faculty in Ljubljana, Slovenia, with the aim to investigate suitability of two intercrops, birdsfoot trefoil (Lotus corniculatus L) and summer savory (Satureja hortensis L.), for reducing damage caused by onion thrips (Thrips tabaci Lindeman) on leek (Allium porrum L.). Four leek cultivars--'Columbus', 'Forrest', 'Lancelot' and 'Lincoln'--were used in the research (Bejo Zaden B.V., Netherlands). In both years, the mean index of damage caused by feeding of the pest on the leek leaves increased from the first evaluation (13 July 2009 and 18 June 2011) in both treatments with intercrops and in control treatment (without intercrop). Leek grown with birdsfoot trefoil as intercrop was in both years statistically the least damaged from thrips. Also summer savory was efficient in the same context in comparison with control treatment. In year 2009 cultivar 'Lancelot' was the least damaged in all treatments, and in year 2011 'Lancelot' and 'Forrest'. In both years intercrop and cultivar also had a significant influence on the yield of leek. The highest yield was obtained on the control plots, meanwhile birdsfoot trefoil and summer savory were pretty competitive and yield of leek grown with them as intercrops was therefore significantly lower. PMID:23885428

  12. Characterization of dapB, a gene required by Pseudomonas syringae pv. tabaci BR2.024 for lysine and tabtoxinine-beta-lactam biosynthesis.

    PubMed Central

    Liu, L; Shaw, P D

    1997-01-01

    The dapB gene, which encodes L-2,3-dihydrodipicolinate reductase, the second enzyme of the lysine branch of the aspartic amino acid family, was cloned and sequenced from a tabtoxin-producing bacterium, Pseudomonas syringae pv. tabaci BR2.024. The deduced amino acid sequence shared 60 to 90% identity to known dapB gene products from gram-negative bacteria and 19 to 21% identity to the dapB products from gram-positive bacteria. The consensus sequence for the NAD(P)H binding site [(V/I)(A/G)(V/I)XGXXGXXG)] and the proposed substrate binding site (HHRHK) were conserved in the polypeptide. A BR2.024 dapB mutant is a diaminopimelate auxotroph and tabtoxin negative. The addition of a mixture of L-,L-, D,D-, and meso-diaminopimelate to defined media restored growth but not tabtoxin production. Cloned DNA fragments containing the parental dapB gene restored the ability to grow in defined media and tabtoxin production to the dapB mutant. These results indicate that the dapB gene is required for both lysine and tabtoxin biosynthesis, thus providing the first genetic evidence that the biosynthesis of tabtoxin proceeds in part along the lysine biosynthetic pathway. These data also suggest that L-2,3,4,5-tetrahydrodipicolinate is a common intermediate for both lysine and tabtoxin biosynthesis. PMID:8990304

  13. A possible role for acetylated intermediates in diaminopimelate and tabtoxinine-beta-lactam biosynthesis in Pseudomonas syringae pv. tabaci BR2.024.

    PubMed Central

    Liu, L; Shaw, P D

    1997-01-01

    The deduced product of an open reading frame (ORF3) located in the tabtoxinine-beta-lactam (T beta L) biosynthetic region of Pseudomonas syringae pv. tabaci BR2.024 (BR2.024) has significant sequence homology to the dapD products of other bacteria. dapD encodes L-2,3,4,5-tetrahydrodipicolinate succinyl coenzyme A succinyltransferase (THDPA-ST), an enzyme in the diaminopimelate (DAP) and lysine biosynthetic pathway. Complementation studies, in vitro transcription-translation experiments, and enzymatic assays indicated that ORF3 encodes a product with THDPA-ST activity in Escherichia coli dapD mutant beta 274. However, a BR2.024 mutant with an insert in ORF3 was prototrophic, and only basal THDPA-ST activity was detected in extracts of both parent and mutant. This finding suggested that ORF3 was not required for DAP biosynthesis and that it did not encode a product with THDPA-ST activity. The results of enzymatic studies, indicating that BR2.024 uses acetylated intermediates for DAP biosynthesis, are consistent with the hypothesis that BR2.024 does not need THDPA-ST for DAP biosynthesis. The ORF3 mutant produced reduced levels of tabtoxin, indicating that ORF3 may have a role in T beta L biosynthesis. We have named the gene tabB and have proposed a possible function for the gene product. PMID:9294453

  14. Tomato yellow leaf curl virus confronts host degradation by sheltering in small/midsized protein aggregates.

    PubMed

    Gorovits, Rena; Fridman, Lilia; Kolot, Mikhail; Rotem, Or; Ghanim, Murad; Shriki, Oz; Czosnek, Henryk

    2016-02-01

    Tomato yellow leaf curl virus (TYLCV) is a begomovirus transmitted by the whitefly Bemisia tabaci to tomato and other crops. TYLCV proteins are endangered by the host defenses. We have analyzed the capacity of the tomato plant and of the whitefly insect vector to degrade the six proteins encoded by the TYLCV genome. Tomato and whitefly demonstrated the highest proteolytic activity in the fractions containing soluble proteins, less-in large protein aggregates; a significant decrease of TYLCV proteolysis was detected in the intermediate-sized aggregates. All the six TYLCV proteins were differently targeted by the cytoplasmic and nuclear degradation machineries (proteases, ubiquitin 26S proteasome, autophagy). TYLCV could confront host degradation by sheltering in small/midsized aggregates, where viral proteins are less exposed to proteolysis. Indeed, TYLCV proteins were localized in aggregates of various sizes in both host organisms. This is the first study comparing degradation machinery in plant and insect hosts targeting all TYLCV proteins. PMID:26654789

  15. Genomes on ice.

    PubMed

    Parkhill, Julian

    2016-03-01

    This month's Genome Watch discusses the analysis of a Helicobacter pylori genome from the preserved Copper-Age mummy known as the Iceman and how ancient genomes shed light on the history of bacterial pathogens. PMID:26853114

  16. Whole Genome Sequencing

    MedlinePlus

    ... you want to learn. Search form Search Whole Genome Sequencing You are here Home Testing & Services Testing ... the full story, click here . What is whole genome sequencing? Whole genome sequencing is the mapping out ...

  17. Ensembl Genomes 2016: more genomes, more complexity.

    PubMed

    Kersey, Paul Julian; Allen, James E; Armean, Irina; Boddu, Sanjay; Bolt, Bruce J; Carvalho-Silva, Denise; Christensen, Mikkel; Davis, Paul; Falin, Lee J; Grabmueller, Christoph; Humphrey, Jay; Kerhornou, Arnaud; Khobova, Julia; Aranganathan, Naveen K; Langridge, Nicholas; Lowy, Ernesto; McDowall, Mark D; Maheswari, Uma; Nuhn, Michael; Ong, Chuang Kee; Overduin, Bert; Paulini, Michael; Pedro, Helder; Perry, Emily; Spudich, Giulietta; Tapanari, Electra; Walts, Brandon; Williams, Gareth; Tello-Ruiz, Marcela; Stein, Joshua; Wei, Sharon; Ware, Doreen; Bolser, Daniel M; Howe, Kevin L; Kulesha, Eugene; Lawson, Daniel; Maslen, Gareth; Staines, Daniel M

    2016-01-01

    Ensembl Genomes (http://www.ensemblgenomes.org) is an integrating resource for genome-scale data from non-vertebrate species, complementing the resources for vertebrate genomics developed in the context of the Ensembl project (http://www.ensembl.org). Together, the two resources provide a consistent set of programmatic and interactive interfaces to a rich range of data including reference sequence, gene models, transcriptional data, genetic variation and comparative analysis. This paper provides an update to the previous publications about the resource, with a focus on recent developments. These include the development of new analyses and views to represent polyploid genomes (of which bread wheat is the primary exemplar); and the continued up-scaling of the resource, which now includes over 23 000 bacterial genomes, 400 fungal genomes and 100 protist genomes, in addition to 55 genomes from invertebrate metazoa and 39 genomes from plants. This dramatic increase in the number of included genomes is one part of a broader effort to automate the integration of archival data (genome sequence, but also associated RNA sequence data and variant calls) within the context of reference genomes and make it available through the Ensembl user interfaces. PMID:26578574

  18. Ensembl genomes 2016: more genomes, more complexity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ensembl Genomes (http://www.ensemblgenomes.org) is an integrating resource for genome-scale data from non-vertebrate species, complementing the resources for vertebrate genomics developed in the context of the Ensembl project (http://www.ensembl.org). Together, the two resources provide a consistent...

  19. Ensembl Genomes 2016: more genomes, more complexity

    PubMed Central

    Kersey, Paul Julian; Allen, James E.; Armean, Irina; Boddu, Sanjay; Bolt, Bruce J.; Carvalho-Silva, Denise; Christensen, Mikkel; Davis, Paul; Falin, Lee J.; Grabmueller, Christoph; Humphrey, Jay; Kerhornou, Arnaud; Khobova, Julia; Aranganathan, Naveen K.; Langridge, Nicholas; Lowy, Ernesto; McDowall, Mark D.; Maheswari, Uma; Nuhn, Michael; Ong, Chuang Kee; Overduin, Bert; Paulini, Michael; Pedro, Helder; Perry, Emily; Spudich, Giulietta; Tapanari, Electra; Walts, Brandon; Williams, Gareth; Tello–Ruiz, Marcela; Stein, Joshua; Wei, Sharon; Ware, Doreen; Bolser, Daniel M.; Howe, Kevin L.; Kulesha, Eugene; Lawson, Daniel; Maslen, Gareth; Staines, Daniel M.

    2016-01-01

    Ensembl Genomes (http://www.ensemblgenomes.org) is an integrating resource for genome-scale data from non-vertebrate species, complementing the resources for vertebrate genomics developed in the context of the Ensembl project (http://www.ensembl.org). Together, the two resources provide a consistent set of programmatic and interactive interfaces to a rich range of data including reference sequence, gene models, transcriptional data, genetic variation and comparative analysis. This paper provides an update to the previous publications about the resource, with a focus on recent developments. These include the development of new analyses and views to represent polyploid genomes (of which bread wheat is the primary exemplar); and the continued up-scaling of the resource, which now includes over 23 000 bacterial genomes, 400 fungal genomes and 100 protist genomes, in addition to 55 genomes from invertebrate metazoa and 39 genomes from plants. This dramatic increase in the number of included genomes is one part of a broader effort to automate the integration of archival data (genome sequence, but also associated RNA sequence data and variant calls) within the context of reference genomes and make it available through the Ensembl user interfaces. PMID:26578574

  20. Funding Opportunity: Genomic Data Centers

    Cancer.gov

    Funding Opportunity CCG, Funding Opportunity Center for Cancer Genomics, CCG, Center for Cancer Genomics, CCG RFA, Center for cancer genomics rfa, genomic data analysis network, genomic data analysis network centers,

  1. Intra- and interspecific competition between western flower thrips and sweetpotato whitefly.

    PubMed

    Wu, Qing-Jun; Hou, Wen-Jie; Li, Fei; Xu, Bao-Yun; Xie, Wen; Wang, Shao-Li; Zhang, You-Jun

    2014-01-01

    The western flower thrips, Frankliniella occidentalis (Pergande), and the sweetpotato whitefly, Bemisia tabaci (Gennadius), are both invasive insect pests and are present in most of the same agricultural crops without a clear dominance of either species. Here, intra- and interspecific competition in B. tabaci and F. occidentalis was determined under controlled experiments. The results showed that intraspecific competition was distinct in F. occidentalis and that the co-occurrence of B. tabaci had a strong effect on F. occidentalis, resulting in a decrease in oviposition. Significant intraspecific competition was found in B. tabaci, and the coexistence of F. occidentalis had limited effect on the oviposition of B. tabaci. In a selective host plant preference experiment, both F. occidentalis and B. tabaci preferred eggplants most, followed by cucumbers and tomatoes. On cucumber plants, B. tabaci was predominant, whereas on eggplant and tomato plants, F. occidentalis and B. tabaci exhibited comparative competitive abilities during the initial stage. However, over time, higher numbers of B. tabaci than that of F. occidentalis were found on the two host plants. Our in vitro and potted plant experiments indicate that B. tabaci is competitively superior to F. occidentalis, which might help to explain their differential distribution patterns in China. PMID:25480973

  2. Enabling functional genomics with genome engineering

    PubMed Central

    Hilton, Isaac B.; Gersbach, Charles A.

    2015-01-01

    Advances in genome engineering technologies have made the precise control over genome sequence and regulation possible across a variety of disciplines. These tools can expand our understanding of fundamental biological processes and create new opportunities for therapeutic designs. The rapid evolution of these methods has also catalyzed a new era of genomics that includes multiple approaches to functionally characterize and manipulate the regulation of genomic information. Here, we review the recent advances of the most widely adopted genome engineering platforms and their application to functional genomics. This includes engineered zinc finger proteins, TALEs/TALENs, and the CRISPR/Cas9 system as nucleases for genome editing, transcription factors for epigenome editing, and other emerging applications. We also present current and potential future applications of these tools, as well as their current limitations and areas for future advances. PMID:26430154

  3. Exploring Other Genomes: Bacteria.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    2001-01-01

    Points out the importance of genomes other than the human genome project and provides information on the identified bacterial genomes Pseudomonas aeuroginosa, Leprosy, Cholera, Meningitis, Tuberculosis, Bubonic Plague, and plant pathogens. Considers the computer's use in genome studies. (Contains 14 references.) (YDS)

  4. Navigating yeast genome maintenance with functional genomics.

    PubMed

    Measday, Vivien; Stirling, Peter C

    2016-03-01

    Maintenance of genome integrity is a fundamental requirement of all organisms. To address this, organisms have evolved extremely faithful modes of replication, DNA repair and chromosome segregation to combat the deleterious effects of an unstable genome. Nonetheless, a small amount of genome instability is the driver of evolutionary change and adaptation, and thus a low level of instability is permitted in populations. While defects in genome maintenance almost invariably reduce fitness in the short term, they can create an environment where beneficial mutations are more likely to occur. The importance of this fact is clearest in the development of human cancer, where genome instability is a well-established enabling characteristic of carcinogenesis. This raises the crucial question: what are the cellular pathways that promote genome maintenance and what are their mechanisms? Work in model organisms, in particular the yeast Saccharomyces cerevisiae, has provided the global foundations of genome maintenance mechanisms in eukaryotes. The development of pioneering genomic tools inS. cerevisiae, such as the systematic creation of mutants in all nonessential and essential genes, has enabled whole-genome approaches to identifying genes with roles in genome maintenance. Here, we review the extensive whole-genome approaches taken in yeast, with an emphasis on functional genomic screens, to understand the genetic basis of genome instability, highlighting a range of genetic and cytological screening modalities. By revealing the biological pathways and processes regulating genome integrity, these analyses contribute to the systems-level map of the yeast cell and inform studies of human disease, especially cancer. PMID:26323482

  5. Genome Maps, a new generation genome browser.

    PubMed

    Medina, Ignacio; Salavert, Francisco; Sanchez, Rubén; de Maria, Alejandro; Alonso, Roberto; Escobar, Pablo; Bleda, Marta; Dopazo, Joaquín

    2013-07-01

    Genome browsers have gained importance as more genomes and related genomic information become available. However, the increase of information brought about by new generation sequencing technologies is, at the same time, causing a subtle but continuous decrease in the efficiency of conventional genome browsers. Here, we present Genome Maps, a genome browser that implements an innovative model of data transfer and management. The program uses highly efficient technologies from the new HTML5 standard, such as scalable vector graphics, that optimize workloads at both server and client sides and ensure future scalability. Thus, data management and representation are entirely carried out by the browser, without the need of any Java Applet, Flash or other plug-in technology installation. Relevant biological data on genes, transcripts, exons, regulatory features, single-nucleotide polymorphisms, karyotype and so forth, are imported from web services and are available as tracks. In addition, several DAS servers are already included in Genome Maps. As a novelty, this web-based genome browser allows the local upload of huge genomic data files (e.g. VCF or BAM) that can be dynamically visualized in real time at the client side, thus facilitating the management of medical data affected by privacy restrictions. Finally, Genome Maps can easily be integrated in any web application by including only a few lines of code. Genome Maps is an open source collaborative initiative available in the GitHub repository (https://github.com/compbio-bigdata-viz/genome-maps). Genome Maps is available at: http://www.genomemaps.org. PMID:23748955

  6. Genome Maps, a new generation genome browser

    PubMed Central

    Medina, Ignacio; Salavert, Francisco; Sanchez, Rubén; de Maria, Alejandro; Alonso, Roberto; Escobar, Pablo; Bleda, Marta; Dopazo, Joaquín

    2013-01-01

    Genome browsers have gained importance as more genomes and related genomic information become available. However, the increase of information brought about by new generation sequencing technologies is, at the same time, causing a subtle but continuous decrease in the efficiency of conventional genome browsers. Here, we present Genome Maps, a genome browser that implements an innovative model of data transfer and management. The program uses highly efficient technologies from the new HTML5 standard, such as scalable vector graphics, that optimize workloads at both server and client sides and ensure future scalability. Thus, data management and representation are entirely carried out by the browser, without the need of any Java Applet, Flash or other plug-in technology installation. Relevant biological data on genes, transcripts, exons, regulatory features, single-nucleotide polymorphisms, karyotype and so forth, are imported from web services and are available as tracks. In addition, several DAS servers are already included in Genome Maps. As a novelty, this web-based genome browser allows the local upload of huge genomic data files (e.g. VCF or BAM) that can be dynamically visualized in real time at the client side, thus facilitating the management of medical data affected by privacy restrictions. Finally, Genome Maps can easily be integrated in any web application by including only a few lines of code. Genome Maps is an open source collaborative initiative available in the GitHub repository (https://github.com/compbio-bigdata-viz/genome-maps). Genome Maps is available at: http://www.genomemaps.org. PMID:23748955

  7. Two host clades, two bacterial arsenals: evolution through gene losses in facultative endosymbionts.

    PubMed

    Rollat-Farnier, Pierre-Antoine; Santos-Garcia, Diego; Rao, Qiong; Sagot, Marie-France; Silva, Francisco J; Henri, Hélène; Zchori-Fein, Einat; Latorre, Amparo; Moya, Andrés; Barbe, Valérie; Liu, Shu-Sheng; Wang, Xiao-Wei; Vavre, Fabrice; Mouton, Laurence

    2015-03-01

    Bacterial endosymbiosis is an important evolutionary process in insects, which can harbor both obligate and facultative symbionts. The evolution of these symbionts is driven by evolutionary convergence, and they exhibit among the tiniest genomes in prokaryotes. The large host spectrum of facultative symbionts and the high diversity of strategies they use to infect new hosts probably impact the evolution of their genome and explain why they undergo less severe genomic erosion than obligate symbionts. Candidatus Hamiltonella defensa is suitable for the investigation of the genomic evolution of facultative symbionts because the bacteria are engaged in specific relationships in two clades of insects. In aphids, H. defensa is found in several species with an intermediate prevalence and confers protection against parasitoids. In whiteflies, H. defensa is almost fixed in some species of Bemisia tabaci, which suggests an important role of and a transition toward obligate symbiosis. In this study, comparisons of the genome of H. defensa present in two B. tabaci species (Middle East Asia Minor 1 and Mediterranean) and in the aphid Acyrthosiphon pisum revealed that they belong to two distinct clades and underwent specific gene losses. In aphids, it contains highly virulent factors that could allow protection and horizontal transfers. In whiteflies, the genome lost these factors and seems to have a limited ability to acquire genes. However it contains genes that could be involved in the production of essential nutrients, which is consistent with a primordial role for this symbiont. In conclusion, although both lineages of H. defensa have mutualistic interactions with their hosts, their genomes follow distinct evolutionary trajectories that reflect their phenotype and could have important consequences on their evolvability. PMID:25714744

  8. Genomic Encyclopedia of Fungi

    SciTech Connect

    Grigoriev, Igor

    2012-08-10

    Genomes of fungi relevant to energy and environment are in focus of the Fungal Genomic Program at the US Department of Energy Joint Genome Institute (JGI). Its key project, the Genomics Encyclopedia of Fungi, targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts), and explores fungal diversity by means of genome sequencing and analysis. Over 150 fungal genomes have been sequenced by JGI to date and released through MycoCosm (www.jgi.doe.gov/fungi), a fungal web-portal, which integrates sequence and functional data with genome analysis tools for user community. Sequence analysis supported by functional genomics leads to developing parts list for complex systems ranging from ecosystems of biofuel crops to biorefineries. Recent examples of such parts suggested by comparative genomics and functional analysis in these areas are presented here.

  9. JGI Fungal Genomics Program

    SciTech Connect

    Grigoriev, Igor V.

    2011-03-14

    Genomes of energy and environment fungi are in focus of the Fungal Genomic Program at the US Department of Energy Joint Genome Institute (JGI). Its key project, the Genomics Encyclopedia of Fungi, targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts), and explores fungal diversity by means of genome sequencing and analysis. Over 50 fungal genomes have been sequenced by JGI to date and released through MycoCosm (www.jgi.doe.gov/fungi), a fungal web-portal, which integrates sequence and functional data with genome analysis tools for user community. Sequence analysis supported by functional genomics leads to developing parts list for complex systems ranging from ecosystems of biofuel crops to biorefineries. Recent examples of such 'parts' suggested by comparative genomics and functional analysis in these areas are presented here

  10. Genomics and Health Impact Update

    MedlinePlus

    ... Genomics in Practice Newborn Screening Pharmacogenomics Reproductive Health Tools and Databases About the Genomics & Health Impact Update The Office of Public Health Genomics provides updated and credible ...

  11. Integrating sequence, evolution and functional genomics in regulatory genomics

    PubMed Central

    Vingron, Martin; Brazma, Alvis; Coulson, Richard; van Helden, Jacques; Manke, Thomas; Palin, Kimmo; Sand, Olivier; Ukkonen, Esko

    2009-01-01

    With genome analysis expanding from the study of genes to the study of gene regulation, 'regulatory genomics' utilizes sequence information, evolution and functional genomics measurements to unravel how regulatory information is encoded in the genome. PMID:19226437

  12. Genomic Data Commons | Office of Cancer Genomics

    Cancer.gov

    The NCI’s Center for Cancer Genomics launches the Genomic Data Commons (GDC), a unified data sharing platform for the cancer research community. The mission of the GDC is to enable data sharing across the entire cancer research community, to ultimately support precision medicine in oncology.

  13. Harvesting rice's dispensable genome.

    PubMed

    Wing, Rod A

    2015-01-01

    A rapid and cost-effective approach has been developed to harvest and map the dispensable genome, that is, population-level natural sequence variation within a species that is not present in static genome assemblies. PMID:26429765

  14. Libraries for genomic SELEX.

    PubMed Central

    Singer, B S; Shtatland, T; Brown, D; Gold, L

    1997-01-01

    An increasing number of proteins are being identified that regulate gene expression by binding specific nucleic acidsin vivo. A method termed genomic SELEX facilitates the rapid identification of networks of protein-nucleic acid interactions by identifying within the genomic sequences of an organism the highest affinity sites for any protein of the organism. As with its progenitor, SELEX of random-sequence nucleic acids, genomic SELEX involves iterative binding, partitioning, and amplification of nucleic acids. The two methods differ in that the variable region of the nucleic acid library for genomic SELEX is derived from the genome of an organism. We have used a quick and simple method to construct Escherichia coli, Saccharomyces cerevisiae, and human genomic DNA PCR libraries that can be transcribed with T7 RNA polymerase. We present evidence that the libraries contain overlapping inserts starting at most of the positions within the genome, making these libraries suitable for genomic SELEX. PMID:9016629

  15. Genomic Data Commons launches

    Cancer.gov

    The Genomic Data Commons (GDC), a unified data system that promotes sharing of genomic and clinical data between researchers, launched today with a visit from Vice President Joe Biden to the operations center at the University of Chicago.

  16. GENOMICS AND ENVIRONMENTAL RESEARCH

    EPA Science Inventory

    The impact of recently developed and emerging genomics technologies on environmental sciences has significant implications for human and ecological risk assessment issues. The linkage of data generated from genomics, transcriptomics, proteomics, metabalomics, and ecology can be ...

  17. Dynamics of the endosymbiont Rickettsia in an insect pest.

    PubMed

    Cass, Bodil N; Yallouz, Rachel; Bondy, Elizabeth C; Mozes-Daube, Netta; Horowitz, A Rami; Kelly, Suzanne E; Zchori-Fein, Einat; Hunter, Martha S

    2015-07-01

    A new heritable bacterial association can bring a fresh set of molecular capabilities, providing an insect host with an almost instantaneous genome extension. Increasingly acknowledged as agents of rapid evolution, inherited microbes remain underappreciated players in pest management programs. A Rickettsia bacterium was tracked sweeping through populations of an invasive whitefly provisionally described as the "B" or "MEAM1" of the Bemisia tabaci species complex, in the southwestern USA. In this population, Rickettsia provides strong fitness benefits and distorts whitefly sex ratios under laboratory conditions. In contrast, whiteflies in Israel show few apparent fitness benefits from Rickettsia under laboratory conditions, only slightly decreasing development time. A survey of B. tabaci B samples revealed the distribution of Rickettsia across the cotton-growing regions of Israel and the USA. Thirteen sites from Israel and 22 sites from the USA were sampled. Across the USA, Rickettsia frequencies were heterogeneous among regions, but were generally very high, whereas in Israel, the infection rates were lower and declining. The distinct outcomes of Rickettsia infection in these two countries conform to previously reported phenotypic differences. Intermediate frequencies in some areas in both countries may indicate a cost to infection in certain environments or that the frequencies are in flux. This suggests underlying geographic differences in the interactions between bacterial symbionts and this serious agricultural pest. PMID:25626393

  18. Exploiting the genome

    SciTech Connect

    Block, S.; Cornwall, J.; Dyson, F.; Koonin, S.; Lewis, N.; Schwitters, R.

    1998-09-11

    In 1997, JASON conducted a DOE-sponsored study of the human genome project with special emphasis on the areas of technology, quality assurance and quality control, and informatics. The present study has two aims: first, to update the 1997 Report in light of recent developments in genome sequencing technology, and second, to consider possible roles for the DOE in the ''post-genomic" era, following acquisition of the complete human genome sequence.

  19. A new and potentially damaging whitefly-transmitted virus of cucurbits was found this fall 2014 in Imperial County, CA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new virus that appears to be related to but distinct from Squash vein yellowing virus (SqVYV), a Bemisia tabaci-transmitted ipomovirus (family Potyviridae) that occurs in Florida was found in fall 2014 in Imperial County, CA infecting pumpkin and melon plants and exhibiting symptoms of stunting an...

  20. Use of Reflective Plastic Mulch and Insecticide Sprays to Manage Viral Watermelon Vine Decline in Florida, 2007

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watermelon vine decline (WVD) caused by squash vein yellowing virus (SqVYV) is a new and emerging disease in southwest and west central Florida. The virus is transmitted by the silver-leaf whitefly (Bemisia tabaci). Experiments were conducted during the fall of 2007 in Immokalee, FL, to determine t...

  1. Persistent, circulative transmission of begomoviruses by whitefly vectors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Begomoviruses comprise an emerging and economically important group of plant viruses exclusively transmitted by the sweetpotato whitefly Bemisia tabaci in many regions of the world. The past twenty years have witnessed significant progress in studying the molecular interactions between members of th...

  2. Host plant resistance in melon (Cucumis melo L.) to sweetpotato whitefly in California and Arizona

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato whitefly (MEAM1 cryptic species of Bemisia tabaci; SPWF) feeding severely impacts fall season melon yield and quality in the lower deserts of California and Arizona. Melon accessions PI 313970 and TGR 1551 (PI 482420) have been reported to exhibit host plant resistance (HPR) to SPWF. Pot...

  3. Trap catches of the sweetpotato whitefly (Homoptera: Aleyrodidae) in the Imperial Valley, Caiifornia, from 1996 to 2002

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An outbreak of the sweetpotato whitefly, Bemisia tabaci (Gennadius), biotype B occurred in the Imperial Valley, California in 1991. The insects destroyed melon crops and seriously damaged other vegetables, ornamentals and row crops. As a result of the need for sampling technology, we developed a w...

  4. The effect of time of whitefly infestation and plant nutrition on the development of tomato irregular ripening disorder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tomato irregular ripening (TIR) is a physiological plant disorder caused by Bemisia tabaci biotype B feeding on foliage and resulting in incomplete ripening of longitudinal sections of fruit.Our objective was to determine the effect of time of whitefly infestation and plant nutrition on the developm...

  5. THE Q-BIOTYPE WHITEFLY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2004, the Q-biotype of the sweetpotato whitefly, Bemisia tabaci, was identified in the U.S. for the first time. The level of insecticide resistance to pyriproxyfen (Distance) and imidacloprid (Marathon) of the Q-biotype was higher than any U.S. population of B-biotype whiteflies (silverleaf white...

  6. The effect of time of sweetpotato whitefly infestation on plant nutrition and development of tomato irregular ripening disorder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tomato irregular ripening (TIR) disorder is associated with Bemisia tabaci biotype B feeding and is characterized by incomplete ripening of longitudinal sections of fruit. Our objective was to determine the effect of time of whitefly infestation on plant nutrition and the development of tomato irreg...

  7. Determining the role of ethylene biosynthesis in the development of tomato irregular ripening disorder using microarray technology and rt-real time PCR.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whiteflies, Bemisia tabaci biotype B, are associated with a plant physiological disorder termed tomato irregular ripening. Symptoms of tomato irregular ripening disorder do not appear on tomato foliage where whitefly feed, but appear as an uneven fruit color development during ripening in tomato. Th...

  8. Tracking disease and insect pests using Smartphone technology: a new approach for regional (and local) pest management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tomato yellow leaf curl virus (TYLCV) is vectored by the silverleaf whitefly (Bemisia tabaci biotype B) and was first detected in south Florida in 1997. The virus has spread widely in Florida and is responsible for millions of dollars of lost production. Anlaysis of data from a comprehensive, multi-...

  9. Q-BIOTYPE WHITEFLY: A TIME FOR ACTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grower’s who have been watching the news are aware that, earlier this spring, an agricultural frenzy threatened to develop following the discovery of the Q-Biotype whitefly (Bemisia tabaci) by Dr. Tim Dennehy at the University of Arizona. The cotton industry in Arizona and California was alarmed, Ar...

  10. Companion and refuge plants to control insect pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: The sweetpotato whitefly, Bemisia tabaci and aphids are major pests of crops in the southeast USA. An environmentally-friendly management strategy is “push-pull” technology which combines the use of repellent (“push”) and trap crops (“pull”) for insect pest control. The repellent crop,...

  11. Release of ‘Beniquez’ White Bean (Phaseolus vulgaris L.) Cultivar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bean golden yellow mosaic virus (BGYMV), a whitefly [Bemisia tabaci (Gennadius)]-transmitted begomovirus, can cause significant reductions in common bean (Phaseolus vulgaris L.) seed yield when susceptible bean cultivars are planted in Central America and the Caribbean. Bean common mosaic virus (BCM...

  12. Sweet Potato Leaf Curl Virus: Virus Reservoir in Species of Wild Morning Glory

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent increases in populations of the Sweetpotato leaf curl virus (SPLCV) vector, the sweetpotato whitefly, Bemisia tabaci (Gennadius), led to a dramatic increase in the disease in sweetpotato (Ipomoea batatas). Knowledge of crop or weed species that occur in sweetpotato growing areas and can serv...

  13. OKRA-LEAF AS A POTENTIAL FOR WHITEFLY CONTROL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We compared smooth-leaf okra- and normal-leaf upland cotton (Gossypium hirsutum L.) cultivars for susceptibility to colonization by Bemisia tabaci (Gennadius) biotype B. Seven field studies were conducted, five at Holtville, CA and two at Maricopa, AZ during 1996 to 2000. Okra-leaf cultivars as a gr...

  14. Release of ‘XRAV-40-4’ black bean (Phaseolus vulgaris L.) cultivar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Black bean (Phaseolus vulgaris L.) production in the lowlands of Central America and the Caribbean is threatened by viral diseases. Bean golden yellow mosaic virus (BGYMV), a whitefly [Bemisia tabaci (Gennadius)]-transmitted begomovirus, can cause significant reduction in common bean seed yield when...

  15. Immature development of Eretmocerus mundus (Hymenoptera: Aphelinidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development from egg to pupation was followed for the wasp Eretmocerus mundus parasitizing the whitefly Bemisia tabaci. This, first time study covered the histological developments and changes that the different parasitoid and host tissues have undergone during parasitism. In this work we eluci...

  16. Q-BIOTYPE WHITEFLY UPDATE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a new version of an old pest that is now appearing in ornamental production facilities. In 2005, a new biotype of the sweetpotato whitefly, Bemisia tabaci was identified by a team of scientists from the Universities of California and Arizona. A population of whiteflies was collected from p...

  17. Partial leaf chemical profiles of a desert watermelon species (Citrullus colocynthis) and heirloom watermelon cultivars (Citrullus lanatus var. lanatus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whiteflies [Bemisia tabaci (Gennadius)] and aphids [Aphis gossypii Glover and Myzus persicae (Sulzer)] are serious threats to watermelon by direct feeding and by transmitting viruses of important virus diseases. The desert watermelon Citrullus colocynthis (L.) has been shown to exhibit resistance t...

  18. Tritrophic interaction among host plants, whiteflies, and parasitoids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory experiments were conducted to compare effects of cotton, bean, sweet potato, and tomato on the mortality and development of Bemisia tabaci (Gennadius) biotype B, Traileurodes abutilonea (Haldeman), and T. vaporariorum (Westwood) and on the key biological parameters of an exotic parasitoid...

  19. Establishment and impact of exotic aphelinid parasitoids in Arizona: A life table approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A large multi-institutional, interagency classical biological control program was initiated in the early 1990s to combat the invasion of the B biotype of Bemisia tabaci into the USA. This large program was successful in the discovery, importation, rearing and release of more than 30 species/strains...

  20. Whitefly-transmitted viruses: cultural strategies in vegetable crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whitefly-transmitted viruses are important problems in agriculture on a global scale. The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a notable vector because of the extensive number of viruses that it transmits and the extensive number of host plants that it feeds on. To help develop str...

  1. Management of Whitefly Populations for the Control of Watermelon Vine Decline in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field studies were designed to confirm that a new ipomovirus, Squash vein yellowing virus (SqVYV), causes watermelon vine decline (WVD) in Florida and is transmitted by the silverleaf whitefly Bemisia tabaci (Biotype “B”). Two field studies were conducted in 2006 at SWFREC, Immokalee, FL, in the sp...

  2. Efficient Regeneration and Selection of Virus-free Sweetpotato Plants from Sweet Potato Leaf Curl Virus Infected Materials and Their Effects on Yields in Field Trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweet potato leaf curl virus (SPLCV) is an emerging virus disease in sweetpotato (Ipomoea batata) in the U.S. The incidence of SPLCV infection on sweetpotato increased dramatically in recent years due to the explosion of whitefly, Bemisia tabaci (Gennadius) populations. Among several sweetpotato v...

  3. Papaya is not a host for Tomato Yellow Leaf Curl Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The economic value of tomato production is threatened by tomato yellow leaf-curl virus TYLCV and its vector, the silverleaf whitefly Bemisia tabaci biotype B (Gennadius) (Hemiptera: Aleyrodidae). Use of papaya Carica papaya L. as a banker plant for a whitefly parasitoid shows promise as a whitefly m...

  4. Push-pull strategies against insect pests of vegetables

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We conduct research on use of a combination of appropriate companion crops (i.e., “push-pull” intercropping) with natural enemy refuges to enhance the effectiveness of biological control agents in suppressing populations of the invasive whitefly, Bemisia tabaci. We continue to identify plants or p...

  5. Host plant resistance in melon to sweetpotato whitefly in California and Arizona

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato whitefly biotype B (MEAM1 cryptic species of Bemisia tabaci; SPWF) feeding severely impacts fall season melon (Cucumis melo L.) yield and quality in the lower deserts of California and Arizona. Melon accessions PI 313970 and TGR 1551 (PI 482420) have been reported to exhibit host plant r...

  6. Biotype investigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article gives the background to the recent invasion of the USA by the Q biotype Bemisia tabaci. It also describes recent results comparing the efficacy of insecticides against the B and Q biotypes of this important pest whitefly. Both biotypes are controllable with pesticides, although there ar...

  7. Effects of Silver Plastic Mulch and Chemical Treatments on Development of Whitefly-Transmitted Viral Watermelon Vine Decline in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watermelon vine decline (WVD) in Florida is caused by the whitefly (Bemisia tabaci) transmitted virus called Squash vein yellowing virus (SqVYV, family: Potyviridae). WVD has been a major limiting factor in watermelon (Citrullus lanatus) production in south west and west central Florida for the pas...

  8. Resistance for watermelon (Citrullus lanatus var. lanatus) against whiteflies (Hemiptera: Aleyrodidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is an important global pest with and an extensive host range. Watermelon (Citrullus lanatus var. lanatus) is among the crops damaged by this pest. Host plant resistance is the foundation for the management of crops pests in general. ...

  9. Combining Reflective Mulch and Host Plant Resistance for Sweetpotato Whitefly (Hemiptera: Aleyrodidae) Management in Watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to evaluate the use of reflective mulch and host plant resistance for the management of the B-biotype sweetpotato whitefly, Bemisia tabaci (Gennadius), in watermelon [Citrullus lanatus var. lanatus (Thunberg) Matsum & Nakai]. Whitefly abundance data were collected under both g...

  10. Whitefly Transmission of a New Virus Infecting Cucurbits in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A virus isolated from squash collected in Hillsborough County, FL in 2003, which was subsequently determined to be an ipomovirus, was transmitted by the silverleaf whitefly, Bemisia tabaci B strain in laboratory experiments. The virus was acquired by whiteflies after a 3-h access period on infected ...

  11. Whitefly transmission of Sweet potato leaf curl virus in sweetpotato germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato, Ipomoea batatas (L.) Lam., is among an extensive number of plant species attacked by Bemisia tabaci (Gennadius). Because this important world food crop is vegetatively propagated, it can conveniently accumulate infections by several viruses. Sweet potato leaf curl virus (SPLCV) (ssDNA...

  12. Establishment and Impact of Exotic Aphelinid Parasitoids in Arizona: A Life Table Approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A large multi-institutional, interagency classical biological control program was initiated in the early 1990s to combat the invasion of the B biotype of Bemisia tabaci into the US. This large program was successful in the discovery, importation, rearing and release of >30 species/strains of aphelin...

  13. Transcriptomics-guided development of RNA interference strategies to manage whiteflies: a globally distributed vector of crop viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 300 viruses are transmitted by the whitefly, Bemisia tabaci, with 90% of them belonging to the genus, Begomovirus. Begomoviruses are exclusively transmitted by whiteflies to a range of agriculture crops, resulting in billions of dollars lost annually, while jeopardizing food security worldwide....

  14. EFFECTS OF APPLAUD AND KNACK ON SWEETPOTATO WHITEFLY (SPW) NYMPH MORTALITY AND ADULT AND NYMPH HONEYDEW PRODUCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato whiteflies, Bemisia tabaci (Gennadius) produce honeydew that results in cotton lint contamination causing reduced lint processing efficiency. The insect growth regulators, Applaud® and Knack®, provide effective control of SPW on cotton by interfering with their reproduction and developm...

  15. Whiteflies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whiteflies have long been considered a major pest of ornamentals. Before 1986, the primary pest species was the greenhouse whitefly until Bemisia tabaci was found attacking an array of ornamental plants in Florida greenhouses. The Q biotype was detected in Arizona in 2004 and is problematic because ...

  16. Differentiating and controlling whiteflies: The Q-biotype is a manageable pest and is not an insurmountable problem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article provides an update on the Q biotype Bemisia tabaci presence in the USA, and offers control options in the form of a table of suitable chemical insecticides. The importance of resistance in this pest is discussed, and the authors provide efficacy data for several insecticides that can be...

  17. Monitoring the U.S Ornamental Industries B's and Q's

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biotype “Q” of Bemisia tabaci was first detected in the United States on poinsettias from a southwest retail outlet in Arizona during December 2004. During the past 20 months, biotype Q has been detected in 22 states and appears to be spreading. Although indistinguishable in appearance from silverle...

  18. Whitefly management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whiteflies have long been considered a major pest of ornamentals. Until Bemisia tabaci (biotype B) was found attacking an array of ornamental plants in Florida greenhouses in 1986, the primary pest species was the greenhouse whitefly. The Q biotype was introduced in 2004 and has since spread to 25 s...

  19. Survey of Natural Enemies of the Sweetpotato Whitefly (Hemiptera: Aleyrodidae) in Ten Vegetable Crops in Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a worldwide pest in diverse agroecosystems. There are numerous species of predators and parasitoids that are associated with this pest. Climate and species of vegetation can dramatically affect the distribution and incidence of these natural...

  20. Recessive resistance to Cucurbit yellow stunting disorder virus in melon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cucurbit yellow stunting disorder virus (CYSDV) reduces melon (Cucumis melo L.) fruit quality and yield in many parts of the world. CYSDV and its vector, sweetpotato whitefly (MEAM1 cryptic species of Bemisia tabaci; SPWF) are a devastating combination in the Sonoran Desert areas of California and A...

  1. Potential sources of whitefly (Hemiptera: Aleyrodidae) resistance in desert watermelon (Citrullus colocynthis) germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selection for host plant resistance and incorporation of natural resistance into cultivars is a fundamental strategy to control insects and diseases in an environmentally-sensitive manner, and may help reduce reliance on synthetic pesticides. The sweetpotato whitefly, Bemisia tabaci (Gennadius), is...

  2. Effect of Reflective Plastic Mulch and Insecticide Sprays on Viral Watermelon Vine Decline in Florida, 2009

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watermelon vine decline (WVD) caused by Squash vein yellowing virus (SqVYV) is a new and emerging disease in southwest and west central Florida that is transmitted by the silver-leaf whitefly (Bemisia tabaci). Symptoms of WVD typically manifest as sudden decline of vines at harvest time or one to t...

  3. QTL Mapping of Whitefly Resistance in Soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whitefly Bemisia tabaci (Gennadius) is one of the most damaging insects attacking crops in the world. In soybean [Glycine max (L.) Merr.], in addition to causing plant stress and reduced seed size, they also can be vectors of viruses, e.g. soybean crinkle mosaic, and soybean dwarf mosaic. Resistance...

  4. Isaria poprawskii sp. nov. (Hypocreales: Cordycipitacae), a new entomopathogenic fungus from Texas affecting sweet potato whitefly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Isaria poprawskii is described as a new entomopathogenic species similar to Isaria javanica (=Paecilomyces javanicus). It was discovered ont he sweet potato whitefly, Bemisia tabaci biotype B in the Lower Rio Grande Valley of Texas (LRGV), USA. Morphological and DNA examinations indicated the dist...

  5. Developing resistance for watermelon against whiteflies (Hemiptera: Aleyrodidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host plant resistance is a fundamental component of crop sustainability. The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is a key pest of many crops around the world. It is adaptive to its environment and feeds on an impressive (over 1,000) number of plant species. Watermelon (Cit...

  6. Management of watermelon vine decline in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Squash vein yellowing virus (SqVYV), the causal agent of watermelon vine decline (WVD) in Florida, is vectored by the silverleaf whitefly Bemisia tabaci (Biotype “B”). Watermelon plants mechanically inoculated at different growth stages from transplant to fruit formation with SqVYV developed WVD sy...

  7. COMPARATIVE GENOMICS IN LEGUMES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The legume plant family will soon include three sequenced genomes. The majority of the gene-containing portions of the model legumes Medicago truncatula and Lotus japonicus have been sequenced in clone-by-clone projects, and the sequencing of the soybean genome is underway in a whole-genome shotgun ...

  8. Whole Genome Selection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whole genome selection (WGS) is an approach to using DNA markers that are distributed throughout the entire genome. Genes affecting most economically-important traits are distributed throughout the genome and there are relatively few that have large effects with many more genes with progressively sm...

  9. Effects of Host Plant Factors on the Bacterial Communities Associated with Two Whitefly Sibling Species

    PubMed Central

    Su, Ming-Ming; Guo, Lei; Tao, Yun-Li; Zhang, You-Jun; Wan, Fang-Hao; Chu, Dong

    2016-01-01

    Background Although discrepancy in the specific traits and ecological characteristics of Bemisia tabaci between species are partially attributed to the B. tabaci-associated bacteria, the factors that affect the diversity of B. tabaci-associated bacteria are not well-understood. We used the metagenomic approach to characterize the B. tabaci-associated bacterial community because the approach is an effective tool to identify the bacteria. Methodology and Results To investigate the effects of the host plant and a virus, tomato yellow leaf curl virus (TYLCV), on the bacterial communities of B. tabaci sibling species B and Q, we analyzed the bacterial communities associated with whitefly B and Q collected from healthy cotton, healthy tomato, and TYLCV-infected tomato. The analysis used miseq-based sequencing of a variable region of the bacterial 16S rDNA gene. For the bacteria associated with B. tabaci, we found that the influence of the host plant species was greater than that of the whitefly cryptic species. With further analysis of host plants infected with the TYLCV, the virus had no significant effects on the B. tabaci-associated bacterial community. Conclusions The effects of different plant hosts and TYLCV-infection on the diversity of B. tabaci-associated bacterial communities were successfully analyzed in this study. To explain why B. tabaci sibling species with different host ranges differ in performance, the analysis of the bacterial community may be essential to the explanation. PMID:27008327

  10. A Homologue of the 3-Oxoacyl-(Acyl Carrier Protein) Synthase III Gene Located in the Glycosylation Island of Pseudomonas syringae pv. tabaci Regulates Virulence Factors via N-Acyl Homoserine Lactone and Fatty Acid Synthesis▿

    PubMed Central

    Taguchi, Fumiko; Ogawa, Yujiro; Takeuchi, Kasumi; Suzuki, Tomoko; Toyoda, Kazuhiro; Shiraishi, Tomonori; Ichinose, Yuki

    2006-01-01

    Pseudomonas syringae pv. tabaci 6605 possesses a genetic region involved in flagellin glycosylation. This region is composed of three open reading frames: orf1, orf2, and orf3. Our previous study revealed that orf1 and orf2 encode glycosyltransferases; on the other hand, orf3 has no role in posttranslational modification of flagellin. Although the function of Orf3 remained unclear, an orf3 deletion mutant (Δorf3 mutant) had reduced virulence on tobacco plants. Orf3 shows significant homology to a 3-oxoacyl-(acyl carrier protein) synthase III in the fatty acid elongation cycle. The Δorf3 mutant had a significantly reduced ability to form acyl homoserine lactones (AHLs), which are quorum-sensing molecules, suggesting that Orf3 is required for AHL synthesis. In comparison with the wild-type strain, swarming motility, biosurfactant production, and tolerance to H2O2 and antibiotics were enhanced in the Δorf3 mutant. A scanning electron micrograph of inoculated bacteria on the tobacco leaf surface revealed that there is little extracellular polymeric substance matrix surrounding the cells in the Δorf3 mutant. The phenotypes of the Δorf3 mutant and an AHL synthesis (ΔpsyI) mutant were similar, although the mutant-specific characteristics were more extreme in the Δorf3 mutant. The swarming motility of the Δorf3 mutant was greater than that of the ΔpsyI mutant. This was attributed to the synergistic effects of the overproduction of biosurfactants and/or alternative fatty acid metabolism in the Δorf3 mutant. Furthermore, the amounts of iron and biosurfactant seem to be involved in biofilm development under quorum-sensing regulation in P. syringae pv. tabaci 6605. PMID:17028280

  11. Genomics and functional genomics with haloarchaea.

    PubMed

    Soppa, J; Baumann, A; Brenneis, M; Dambeck, M; Hering, O; Lange, C

    2008-09-01

    The first haloarchaeal genome was published in 2000 and today five genome sequences are available. Transcriptome and proteome analyses have been established for two and three haloarchaeal species, respectively, and more than 20 studies using these functional genomic approaches have been published in the last two years. These studies gave global overviews of metabolic regulation (aerobic and anaerobic respiration, phototrophy, carbon source usage), stress response (UV, X-rays, transition metals, osmotic and temperature stress), cell cycle-dependent transcript level regulation, and transcript half-lives. The only translatome analysis available for any prokaryotic species revealed that 10 and 20% of all transcripts are translationally regulated in Haloferax volcanii and Halobacterium salinarum, respectively. Very effective methods for the construction of in frame deletion mutants have been established recently for haloarchaea and are intensively used to unravel the biological roles of genes in this group. Bioinformatic analyses include both cross-genome comparisons as well as integration of genomic data with experimental results. The first systems biology approaches have been performed that used experimental data to construct predictive models of gene expression and metabolism, respectively. In this contribution the current status of genomics, functional genomics, and molecular genetics of haloarchaea is summarized and selected examples are discussed. PMID:18493745

  12. Chromium and Genomic Stability

    PubMed Central

    Wise, Sandra S.; Wise, John Pierce

    2014-01-01

    Many metals serve as micronutrients which protect against genomic instability. Chromium is most abundant in its trivalent and hexavalent forms. Trivalent chromium has historically been considered an essential element, though recent data indicate that while it can have pharmacological effects and value, it is not essential. There are no data indicating that trivalent chromium promotes genomic stability and, instead may promote genomic instability. Hexavalent chromium is widely accepted as highly toxic and carcinogenic with no nutritional value. Recent data indicate that it causes genomic instability and also has no role in promoting genomic stability. PMID:22192535

  13. The Genomic Medicine Game.

    PubMed

    Tran, Elvis; de Andrés-Galiana, Enrique J; Benitez, Sonia; Martin-Sanchez, Fernando; Lopez-Campos, Guillermo H

    2016-01-01

    With advancements in genomics technology, health care has been improving and new paradigms of medicine such as genomic medicine have evolved. The education of clinicians, researchers and students to face the challenges posed by these new approaches, however, has been often lagging behind. From this the Genomic Medicine Game, an educational tool, was created for the purpose of conceptualizing the key components of Genomic Medicine. A number of phenotype-genotype associations were found through a literature review, which was used to be a base for the concepts the Genomic Medicine Game would focus on. Built in Java, the game was successfully tested with promising results. PMID:27577486

  14. Microbial genomic taxonomy.

    PubMed

    Thompson, Cristiane C; Chimetto, Luciane; Edwards, Robert A; Swings, Jean; Stackebrandt, Erko; Thompson, Fabiano L

    2013-01-01

    A need for a genomic species definition is emerging from several independent studies worldwide. In this commentary paper, we discuss recent studies on the genomic taxonomy of diverse microbial groups and a unified species definition based on genomics. Accordingly, strains from the same microbial species share >95% Average Amino Acid Identity (AAI) and Average Nucleotide Identity (ANI), >95% identity based on multiple alignment genes, <10 in Karlin genomic signature, and > 70% in silico Genome-to-Genome Hybridization similarity (GGDH). Species of the same genus will form monophyletic groups on the basis of 16S rRNA gene sequences, Multilocus Sequence Analysis (MLSA) and supertree analysis. In addition to the established requirements for species descriptions, we propose that new taxa descriptions should also include at least a draft genome sequence of the type strain in order to obtain a clear outlook on the genomic landscape of the novel microbe. The application of the new genomic species definition put forward here will allow researchers to use genome sequences to define simultaneously coherent phenotypic and genomic groups. PMID:24365132

  15. The Bluejay genome browser.

    PubMed

    Soh, Jung; Gordon, Paul M K; Sensen, Christoph W

    2012-03-01

    The Bluejay genome browser is a stand-alone visualization tool for the multi-scale viewing of annotated genomes and other genomic elements. Bluejay allows users to customize display features to suit their needs, and produces publication-quality graphics. Bluejay provides a multitude of ways to interrelate biological data at the genome scale. Users can load gene expression data into a genome display for expression visualization in context. Multiple genomes can be compared concurrently, including time series expression data, based on Gene Ontology labels. External, context-sensitive biological Web Services are linked to the displayed genomic elements ad hoc for in-depth genomic data analysis and interpretation. Users can mark multiple points of interest in a genome by creating waypoints, and exploit them for easy navigation of single or multiple genomes. Using this comprehensive visual environment, users can study a gene not just in relation to its genome, but also its transcriptome and evolutionary origins. Written in Java, Bluejay is platform-independent and is freely available from http://bluejay.ucalgary.ca. PMID:22389011

  16. Bacterial Genome Instability

    PubMed Central

    Darmon, Elise

    2014-01-01

    SUMMARY Bacterial genomes are remarkably stable from one generation to the next but are plastic on an evolutionary time scale, substantially shaped by horizontal gene transfer, genome rearrangement, and the activities of mobile DNA elements. This implies the existence of a delicate balance between the maintenance of genome stability and the tolerance of genome instability. In this review, we describe the specialized genetic elements and the endogenous processes that contribute to genome instability. We then discuss the consequences of genome instability at the physiological level, where cells have harnessed instability to mediate phase and antigenic variation, and at the evolutionary level, where horizontal gene transfer has played an important role. Indeed, this ability to share DNA sequences has played a major part in the evolution of life on Earth. The evolutionary plasticity of bacterial genomes, coupled with the vast numbers of bacteria on the planet, substantially limits our ability to control disease. PMID:24600039

  17. UCSC genome browser tutorial.

    PubMed

    Zweig, Ann S; Karolchik, Donna; Kuhn, Robert M; Haussler, David; Kent, W James

    2008-08-01

    The University of California Santa Cruz (UCSC) Genome Bioinformatics website consists of a suite of free, open-source, on-line tools that can be used to browse, analyze, and query genomic data. These tools are available to anyone who has an Internet browser and an interest in genomics. The website provides a quick and easy-to-use visual display of genomic data. It places annotation tracks beneath genome coordinate positions, allowing rapid visual correlation of different types of information. Many of the annotation tracks are submitted by scientists worldwide; the others are computed by the UCSC Genome Bioinformatics group from publicly available sequence data. It also allows users to upload and display their own experimental results or annotation sets by creating a custom track. The suite of tools, downloadable data files, and links to documentation and other information can be found at http://genome.ucsc.edu/. PMID:18514479

  18. Variations in genome mass.

    PubMed

    Wachtel, S S; Tiersch, T R

    1993-02-01

    1. Genome size varies considerably among vertebrates, ranging from less than 1 pg to more than 200 pg; the amount of DNA differing among individuals in a population can equal the amount in the entire structural gene complement. 2. Recent technological advances permit evaluation of genome size variation at several levels including sub-chromosomal, chromosomal and cellular. 3. Genome size variation may also be viewed from taxonomic levels, and across evolutionary time frames. 4. As sources of genome size variation are identified and studied, the conundrum of the C-value paradox (lack of correlations among genome size, genomic complexity and phylogenetic status of organisms) may prove to be more apparent than real. 5. For example, the limited and relatively constant genome size of avians may be related to the physiological constraints of flight. PMID:8462275

  19. Genomics of sorghum.

    PubMed

    Paterson, Andrew H

    2008-01-01

    Sorghum (Sorghum bicolor (L.) Moench) is a subject of plant genomics research based on its importance as one of the world's leading cereal crops, a biofuels crop of high and growing importance, a progenitor of one of the world's most noxious weeds, and a botanical model for many tropical grasses with complex genomes. A rich history of genome analysis, culminating in the recent complete sequencing of the genome of a leading inbred, provides a foundation for invigorating progress toward relating sorghum genes to their functions. Further characterization of the genomes other than Saccharinae cereals may shed light on mechanisms, levels, and patterns of evolution of genome size and structure, laying the foundation for further study of sugarcane and other economically important members of the group. PMID:18483564

  20. The tiniest tiny genomes.

    PubMed

    Moran, Nancy A; Bennett, Gordon M

    2014-01-01

    Starting in 2006, surprisingly tiny genomes have been discovered from numerous bacterial symbionts of insect hosts. Despite their size, each retains some genes that enable provisioning of limiting nutrients or other capabilities required by hosts. Genome sequence analyses show that genome reduction is an ongoing process, resulting in a continuum of sizes, with the smallest genome currently known at 112 kilobases. Genome reduction is typical in host-restricted symbionts and pathogens, but the tiniest genomes are restricted to symbionts required by hosts and restricted to specialized host cells, resulting from long coevolution with hosts. Genes are lost in all functional categories, but core genes for central informational processes, including genes encoding ribosomal proteins, are mostly retained, whereas genes underlying production of cell envelope components are especially depleted. Thus, these entities retain cell-like properties but are heavily dependent on coadaptation of hosts, which continuously evolve to support the symbionts upon which they depend. PMID:24995872

  1. Querying genomic databases

    SciTech Connect

    Baehr, A.; Hagstrom, R.; Joerg, D.; Overbeek, R.

    1991-09-01

    A natural-language interface has been developed that retrieves genomic information by using a simple subset of English. The interface spares the biologist from the task of learning database-specific query languages and computer programming. Currently, the interface deals with the E. coli genome. It can, however, be readily extended and shows promise as a means of easy access to other sequenced genomic databases as well.

  2. Genome Aliquoting Revisited

    NASA Astrophysics Data System (ADS)

    Warren, Robert; Sankoff, David

    We prove that the genome aliquoting problem, the problem of finding a recent polyploid ancestor of a genome, with breakpoint distance can be solved in polynomial time. We propose an aliquoting algorithm that is a 2-approximation for the genome aliquoting problem with double cut and join distance, improving upon the previous best solution to this problem, Feijão and Meidanis' 4-approximation algorithm.

  3. Physician Assistant Genomic Competencies.

    PubMed

    Goldgar, Constance; Michaud, Ed; Park, Nguyen; Jenkins, Jean

    2016-09-01

    Genomic discoveries are increasingly being applied to the clinical care of patients. All physician assistants (PAs) need to acquire competency in genomics to provide the best possible care for patients within the scope of their practice. In this article, we present an updated version of PA genomic competencies and learning outcomes in a framework that is consistent with the current medical education guidelines and the collaborative nature of PAs in interprofessional health care teams. PMID:27490287

  4. Filarial and Wolbachia genomics.

    PubMed

    Scott, A L; Ghedin, E; Nutman, T B; McReynolds, L A; Poole, C B; Slatko, B E; Foster, J M

    2012-01-01

    Filarial nematode parasites, the causative agents for a spectrum of acute and chronic diseases including lymphatic filariasis and river blindness, threaten the well-being and livelihood of hundreds of millions of people in the developing regions of the world. The 2007 publication on a draft assembly of the 95-Mb genome of the human filarial parasite Brugia malayi- representing the first helminth parasite genome to be sequenced - has been followed in rapid succession by projects that have resulted in the genome sequencing of six additional filarial species, seven nonfilarial nematode parasites of animals and nearly 30 plant parasitic and free-living species. Parallel to the genomic sequencing, transcriptomic and proteomic projects have facilitated genome annotation, expanded our understanding of stage-associated gene expression and provided a first look at the role of epigenetic regulation of filarial genomes through microRNAs. The expansion in filarial genomics will also provide a significant enrichment in our knowledge of the diversity and variability in the genomes of the endosymbiotic bacterium Wolbachia leading to a better understanding of the genetic principles that govern filarial-Wolbachia mutualism. The goal here is to provide an overview of the trends and advances in filarial and Wolbachia genomics. PMID:22098559

  5. Fungal Genomics Program

    SciTech Connect

    Grigoriev, Igor

    2012-03-12

    The JGI Fungal Genomics Program aims to scale up sequencing and analysis of fungal genomes to explore the diversity of fungi important for energy and the environment, and to promote functional studies on a system level. Combining new sequencing technologies and comparative genomics tools, JGI is now leading the world in fungal genome sequencing and analysis. Over 120 sequenced fungal genomes with analytical tools are available via MycoCosm (www.jgi.doe.gov/fungi), a web-portal for fungal biologists. Our model of interacting with user communities, unique among other sequencing centers, helps organize these communities, improves genome annotation and analysis work, and facilitates new larger-scale genomic projects. This resulted in 20 high-profile papers published in 2011 alone and contributing to the Genomics Encyclopedia of Fungi, which targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts). Our next grand challenges include larger scale exploration of fungal diversity (1000 fungal genomes), developing molecular tools for DOE-relevant model organisms, and analysis of complex systems and metagenomes.

  6. Genomics of Clostridium tetani.

    PubMed

    Brüggemann, Holger; Brzuszkiewicz, Elzbieta; Chapeton-Montes, Diana; Plourde, Lucile; Speck, Denis; Popoff, Michel R

    2015-05-01

    Genomic information about Clostridium tetani, the causative agent of the tetanus disease, is scarce. The genome of strain E88, a strain used in vaccine production, was sequenced about 10 years ago. One additional genome (strain 12124569) has recently been released. Here we report three new genomes of C. tetani and describe major differences among all five C. tetani genomes. They all harbor tetanus-toxin-encoding plasmids that contain highly conserved genes for TeNT (tetanus toxin), TetR (transcriptional regulator of TeNT) and ColT (collagenase), but substantially differ in other plasmid regions. The chromosomes share a large core genome that contains about 85% of all genes of a given chromosome. The non-core chromosome comprises mainly prophage-like genomic regions and genes encoding environmental interaction and defense functions (e.g. surface proteins, restriction-modification systems, toxin-antitoxin systems, CRISPR/Cas systems) and other fitness functions (e.g. transport systems, metabolic activities). This new genome information will help to assess the level of genome plasticity of the species C. tetani and provide the basis for detailed comparative studies. PMID:25638019

  7. Between two fern genomes.

    PubMed

    Sessa, Emily B; Banks, Jo Ann; Barker, Michael S; Der, Joshua P; Duffy, Aaron M; Graham, Sean W; Hasebe, Mitsuyasu; Langdale, Jane; Li, Fay-Wei; Marchant, D Blaine; Pryer, Kathleen M; Rothfels, Carl J; Roux, Stanley J; Salmi, Mari L; Sigel, Erin M; Soltis, Douglas E; Soltis, Pamela S; Stevenson, Dennis W; Wolf, Paul G

    2014-01-01

    Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear genome. This lack of genome sequence information significantly impedes our ability to understand and reconstruct genome evolution not only in ferns, but across all land plants. Azolla and Ceratopteris are ideal and complementary candidates to be the first ferns to have their nuclear genomes sequenced. They differ dramatically in genome size, life history, and habit, and thus represent the immense diversity of extant ferns. Together, this pair of genomes will facilitate myriad large-scale comparative analyses across ferns and all land plants. Here we review the unique biological characteristics of ferns and describe a number of outstanding questions in plant biology that will benefit from the addition of ferns to the set of taxa with sequenced nuclear genomes. We explain why the fern clade is pivotal for understanding genome evolution across land plants, and we provide a rationale for how knowledge of fern genomes will enable progress in research beyond the ferns themselves. PMID:25324969

  8. [Landscape and ecological genomics].

    PubMed

    2013-10-01

    Landscape genomics is the modern version of landscape genetics, a discipline that arose approximately 10 years ago as a combination of population genetics, landscape ecology, and spatial statistics. It studies the effects of environmental variables on gene flow and other microevolutionary processes that determine genetic connectivity and variations in populations. In contrast to population genetics, it operates at the level of individual specimens rather than at the level of population samples. Another important difference between landscape genetics and genomics and population genetics is that, in the former, the analysis of gene flow and local adaptations takes quantitative account of landforms and features of the matrix, i.e., hostile spaces that separate species habitats. Landscape genomics is a part of population ecogenomics, which, along with community genomics, is a major part of ecological genomics. One of the principal purposes of landscape genomics is the identification and differentiation of various genome-wide and locus-specific effects. The approaches and computation tools developed for combined analysis of genomic and landscape variables make it possible to detect adaptation-related genome fragments, which facilitates the planning of conservation efforts and the prediction of species' fate in response to expected changes in the environment. PMID:25508669

  9. [Landscape and ecological genomics].

    PubMed

    Tetushkin, E Ia

    2013-10-01

    Landscape genomics is the modern version of landscape genetics, a discipline that arose approximately 10 years ago as a combination of population genetics, landscape ecology, and spatial statistics. It studies the effects of environmental variables on gene flow and other microevolutionary processes that determine genetic connectivity and variations in populations. In contrast to population genetics, it operates at the level of individual specimens rather than at the level of population samples. Another important difference between landscape genetics and genomics and population genetics is that, in the former, the analysis of gene flow and local adaptations takes quantitative account of landforms and features of the matrix, i.e., hostile spaces that separate species habitats. Landscape genomics is a part of population ecogenomics, which, along with community genomics, is a major part of ecological genomics. One of the principal purposes of landscape genomics is the identification and differentiation of various genome-wide and locus-specific effects. The approaches and computation tools developed for combined analysis of genomic and landscape variables make it possible to detect adaptation-related genome fragments, which facilitates the planning of conservation efforts and the prediction of species' fate in response to expected changes in the environment. PMID:25474890

  10. Between Two Fern Genomes

    PubMed Central

    2014-01-01

    Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear genome. This lack of genome sequence information significantly impedes our ability to understand and reconstruct genome evolution not only in ferns, but across all land plants. Azolla and Ceratopteris are ideal and complementary candidates to be the first ferns to have their nuclear genomes sequenced. They differ dramatically in genome size, life history, and habit, and thus represent the immense diversity of extant ferns. Together, this pair of genomes will facilitate myriad large-scale comparative analyses across ferns and all land plants. Here we review the unique biological characteristics of ferns and describe a number of outstanding questions in plant biology that will benefit from the addition of ferns to the set of taxa with sequenced nuclear genomes. We explain why the fern clade is pivotal for understanding genome evolution across land plants, and we provide a rationale for how knowledge of fern genomes will enable progress in research beyond the ferns themselves. PMID:25324969

  11. Genomics of Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This edited book represents the 23rd symposium in the Stadler Genetics Symposia series, and the general theme of this conference was "The Genomics of Disease." The 24 national and international speakers were invited to discuss their world-class research into the advances that genomics has made on c...

  12. Genomics for Weed Science

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous genomic-based studies have provided insight to the physiological and evolutionary processes involved in developmental and environmental processes of model plants such as arabidopsis and rice. However, far fewer efforts have been attempted to use genomic resources to study physiological and ...

  13. Unlocking the bovine genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The draft genome sequence of cattle (Bos taurus) has now been analyzed by the Bovine Genome Sequencing and Analysis Consortium and the Bovine HapMap Consortium, which together represent an extensive collaboration involving more than 300 scientists from 25 different countries. ...

  14. Genetics and Genomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Good progress is being made on genetics and genomics of sugar beet, however it is in process and the tools are now being generated and some results are being analyzed. The GABI BeetSeq project released a first draft of the sugar beet genome of KWS2320, a dihaploid (see http://bvseq.molgen.mpg.de/Gen...

  15. Development of Genomic GMACE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of genomics to enhance national genetic evaluation systems of dairy cattle is quickly becoming standard practice. The current MACE procedure used by Interbull may not accommodate these new “genomically-enhanced” national evaluations. An important assumption in MACE may no longer be valid in ...

  16. GENOME OF HORSEPOX VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Here we present the genomic sequence of horsepox virus (HSPV) isolate MNR-76, an orthopoxvirus (OPV) isolated in 1976 from diseased Mongolian horses. The 212 kbp genome contained 7.5 kbp inverted terminal repeats (ITR) and lacked extensive terminal tandem repetition. HSPV contained 236 ORFs with sim...

  17. Genomic Instability and Cancer

    PubMed Central

    Yao, Yixin; Dai, Wei

    2014-01-01

    Genomic instability is a characteristic of most cancer cells. It is an increased tendency of genome alteration during cell division. Cancer frequently results from damage to multiple genes controlling cell division and tumor suppressors. It is known that genomic integrity is closely monitored by several surveillance mechanisms, DNA damage checkpoint, DNA repair machinery and mitotic checkpoint. A defect in the regulation of any of these mechanisms often results in genomic instability, which predisposes the cell to malignant transformation. Posttranslational modifications of the histone tails are closely associated with regulation of the cell cycle as well as chromatin structure. Nevertheless, DNA methylation status is also related to genomic integrity. We attempt to summarize recent developments in this field and discuss the debate of driving force of tumor initiation and progression. PMID:25541596

  18. Microbial Genomes Multiply

    NASA Technical Reports Server (NTRS)

    Doolittle, Russell F.

    2002-01-01

    The publication of the first complete sequence of a bacterial genome in 1995 was a signal event, underscored by the fact that the article has been cited more than 2,100 times during the intervening seven years. It was a marvelous technical achievement, made possible by automatic DNA-sequencing machines. The feat is the more impressive in that complete genome sequencing has now been adopted in many different laboratories around the world. Four years ago in these columns I examined the situation after a dozen microbial genomes had been completed. Now, with upwards of 60 microbial genome sequences determined and twice that many in progress, it seems reasonable to assess just what is being learned. Are new concepts emerging about how cells work? Have there been practical benefits in the fields of medicine and agriculture? Is it feasible to determine the genomic sequence of every bacterial species on Earth? The answers to these questions maybe Yes, Perhaps, and No, respectively.

  19. Phytozome Comparative Plant Genomics Portal

    SciTech Connect

    Goodstein, David; Batra, Sajeev; Carlson, Joseph; Hayes, Richard; Phillips, Jeremy; Shu, Shengqiang; Schmutz, Jeremy; Rokhsar, Daniel

    2014-09-09

    The Dept. of Energy Joint Genome Institute is a genomics user facility supporting DOE mission science in the areas of Bioenergy, Carbon Cycling, and Biogeochemistry. The Plant Program at the JGI applies genomic, analytical, computational and informatics platforms and methods to: 1. Understand and accelerate the improvement (domestication) of bioenergy crops 2. Characterize and moderate plant response to climate change 3. Use comparative genomics to identify constrained elements and infer gene function 4. Build high quality genomic resource platforms of JGI Plant Flagship genomes for functional and experimental work 5. Expand functional genomic resources for Plant Flagship genomes

  20. Genome size evolution: sizing mammalian genomes.

    PubMed

    Redi, C A; Capanna, E

    2012-01-01

    The study of genome size (GS) and its variation is so fascinating to the scientific community because it constitutes the link between the present-day analytical and molecular studies of the genome and the old trunk of the holistic and synthetic view of the genome. The GS of several taxa vary over a broad range and do not correlate with the complexity of the organisms (the C-value paradox). However, the biology of transposable elements has let us reach a satisfactory view of the molecular mechanisms that give rise to GS variation and novelties, providing a less perplexing view of the significance of the GS (C-enigma). The knowledge of the composition and structure of a genome is a pre-requisite for trying to understand the evolution of the main genome signature: its size. The radiation of mammals provides an approximately 180-million-year test case for theories of how GS evolves. It has been found from data-mining GS databases that GS is a useful cyto-taxonomical instrument at the level of orders/superorders, providing genomic signatures characterizing Monotremata, Marsupialia, Afrotheria, Xenarthra, Laurasiatheria, and Euarchontoglires. A hypothetical ancestral mammalian-like GS of 2.9-3.7 pg has been suggested. This value appears compatible with the average values calculated for the high systematic levels of the extant Monotremata (∼2.97 pg) and Marsupialia (∼4.07 pg), suggesting invasion of mobile DNA elements concurrently with the separation of the older clades of Afrotheria (∼5.5 pg) and Xenarthra (∼4.5 pg) with larger GS, leaving the Euarchontoglires (∼3.4 pg) and Laurasiatheria (∼2.8 pg) genomes with fewer transposable elements. However, the paucity of GS data (546 mammalian species sized from 5,488 living species) for species, genera, and families calls for caution. Considering that mammalian species may be vanished even before they are known, GS data are sorely needed to phenotype the effects brought about by their variation and to validate any

  1. Evolution of genome architecture.

    PubMed

    Koonin, Eugene V

    2009-02-01

    Charles Darwin believed that all traits of organisms have been honed to near perfection by natural selection. The empirical basis underlying Darwin's conclusions consisted of numerous observations made by him and other naturalists on the exquisite adaptations of animals and plants to their natural habitats and on the impressive results of artificial selection. Darwin fully appreciated the importance of heredity but was unaware of the nature and, in fact, the very existence of genomes. A century and a half after the publication of the "Origin", we have the opportunity to draw conclusions from the comparisons of hundreds of genome sequences from all walks of life. These comparisons suggest that the dominant mode of genome evolution is quite different from that of the phenotypic evolution. The genomes of vertebrates, those purported paragons of biological perfection, turned out to be veritable junkyards of selfish genetic elements where only a small fraction of the genetic material is dedicated to encoding biologically relevant information. In sharp contrast, genomes of microbes and viruses are incomparably more compact, with most of the genetic material assigned to distinct biological functions. However, even in these genomes, the specific genome organization (gene order) is poorly conserved. The results of comparative genomics lead to the conclusion that the genome architecture is not a straightforward result of continuous adaptation but rather is determined by the balance between the selection pressure, that is itself dependent on the effective population size and mutation rate, the level of recombination, and the activity of selfish elements. Although genes and, in many cases, multigene regions of genomes possess elaborate architectures that ensure regulation of expression, these arrangements are evolutionarily volatile and typically change substantially even on short evolutionary scales when gene sequences diverge minimally. Thus, the observed genome

  2. The Banana Genome Hub

    PubMed Central

    Droc, Gaëtan; Larivière, Delphine; Guignon, Valentin; Yahiaoui, Nabila; This, Dominique; Garsmeur, Olivier; Dereeper, Alexis; Hamelin, Chantal; Argout, Xavier; Dufayard, Jean-François; Lengelle, Juliette; Baurens, Franc-Christophe; Cenci, Alberto; Pitollat, Bertrand; D’Hont, Angélique; Ruiz, Manuel; Rouard, Mathieu; Bocs, Stéphanie

    2013-01-01

    Banana is one of the world’s favorite fruits and one of the most important crops for developing countries. The banana reference genome sequence (Musa acuminata) was recently released. Given the taxonomic position of Musa, the completed genomic sequence has particular comparative value to provide fresh insights about the evolution of the monocotyledons. The study of the banana genome has been enhanced by a number of tools and resources that allows harnessing its sequence. First, we set up essential tools such as a Community Annotation System, phylogenomics resources and metabolic pathways. Then, to support post-genomic efforts, we improved banana existing systems (e.g. web front end, query builder), we integrated available Musa data into generic systems (e.g. markers and genetic maps, synteny blocks), we have made interoperable with the banana hub, other existing systems containing Musa data (e.g. transcriptomics, rice reference genome, workflow manager) and finally, we generated new results from sequence analyses (e.g. SNP and polymorphism analysis). Several uses cases illustrate how the Banana Genome Hub can be used to study gene families. Overall, with this collaborative effort, we discuss the importance of the interoperability toward data integration between existing information systems. Database URL: http://banana-genome.cirad.fr/ PMID:23707967

  3. Genomic Insights into Bifidobacteria

    PubMed Central

    Lee, Ju-Hoon; O'Sullivan, Daniel J.

    2010-01-01

    Summary: Since the discovery in 1899 of bifidobacteria as numerically dominant microbes in the feces of breast-fed infants, there have been numerous studies addressing their role in modulating gut microflora as well as their other potential health benefits. Because of this, they are frequently incorporated into foods as probiotic cultures. An understanding of their full interactions with intestinal microbes and the host is needed to scientifically validate any health benefits they may afford. Recently, the genome sequences of nine strains representing four species of Bifidobacterium became available. A comparative genome analysis of these genomes reveals a likely efficient capacity to adapt to their habitats, with B. longum subsp. infantis exhibiting more genomic potential to utilize human milk oligosaccharides, consistent with its habitat in the infant gut. Conversely, B. longum subsp. longum exhibits a higher genomic potential for utilization of plant-derived complex carbohydrates and polyols, consistent with its habitat in an adult gut. An intriguing observation is the loss of much of this genome potential when strains are adapted to pure culture environments, as highlighted by the genomes of B. animalis subsp. lactis strains, which exhibit the least potential for a gut habitat and are believed to have evolved from the B. animalis species during adaptation to dairy fermentation environments. PMID:20805404

  4. Ensembl comparative genomics resources

    PubMed Central

    Muffato, Matthieu; Beal, Kathryn; Fitzgerald, Stephen; Gordon, Leo; Pignatelli, Miguel; Vilella, Albert J.; Searle, Stephen M. J.; Amode, Ridwan; Brent, Simon; Spooner, William; Kulesha, Eugene; Yates, Andrew; Flicek, Paul

    2016-01-01

    Evolution provides the unifying framework with which to understand biology. The coherent investigation of genic and genomic data often requires comparative genomics analyses based on whole-genome alignments, sets of homologous genes and other relevant datasets in order to evaluate and answer evolutionary-related questions. However, the complexity and computational requirements of producing such data are substantial: this has led to only a small number of reference resources that are used for most comparative analyses. The Ensembl comparative genomics resources are one such reference set that facilitates comprehensive and reproducible analysis of chordate genome data. Ensembl computes pairwise and multiple whole-genome alignments from which large-scale synteny, per-base conservation scores and constrained elements are obtained. Gene alignments are used to define Ensembl Protein Families, GeneTrees and homologies for both protein-coding and non-coding RNA genes. These resources are updated frequently and have a consistent informatics infrastructure and data presentation across all supported species. Specialized web-based visualizations are also available including synteny displays, collapsible gene tree plots, a gene family locator and different alignment views. The Ensembl comparative genomics infrastructure is extensively reused for the analysis of non-vertebrate species by other projects including Ensembl Genomes and Gramene and much of the information here is relevant to these projects. The consistency of the annotation across species and the focus on vertebrates makes Ensembl an ideal system to perform and support vertebrate comparative genomic analyses. We use robust software and pipelines to produce reference comparative data and make it freely available. Database URL: http://www.ensembl.org. PMID:26896847

  5. Genome instability and aging.

    PubMed

    Vijg, Jan; Suh, Yousin

    2013-01-01

    Genome instability has long been implicated as the main causal factor in aging. Somatic cells are continuously exposed to various sources of DNA damage, from reactive oxygen species to UV radiation to environmental mutagens. To cope with the tens of thousands of chemical lesions introduced into the genome of a typical cell each day, a complex network of genome maintenance systems acts to remove damage and restore the correct base pair sequence. Occasionally, however, repair is erroneous, and such errors, as well as the occasional failure to correctly replicate the genome during cell division, are the basis for mutations and epimutations. There is now ample evidence that mutations accumulate in various organs and tissues of higher animals, including humans, mice, and flies. What is not known, however, is whether the frequency of these random changes is sufficient to cause the phenotypic effects generally associated with aging. The exception is cancer, an age-related disease caused by the accumulation of mutations and epimutations. Here, we first review current concepts regarding the relationship between DNA damage, repair, and mutation, as well as the data regarding genome alterations as a function of age. We then describe a model for how randomly induced DNA sequence and epigenomic variants in the somatic genomes of animals can result in functional decline and disease in old age. Finally, we discuss the genetics of genome instability in relation to longevity to address the importance of alterations in the somatic genome as a causal factor in aging and to underscore the opportunities provided by genetic approaches to develop interventions that attenuate genome instability, reduce disease risk, and increase life span. PMID:23398157

  6. Ensembl comparative genomics resources.

    PubMed

    Herrero, Javier; Muffato, Matthieu; Beal, Kathryn; Fitzgerald, Stephen; Gordon, Leo; Pignatelli, Miguel; Vilella, Albert J; Searle, Stephen M J; Amode, Ridwan; Brent, Simon; Spooner, William; Kulesha, Eugene; Yates, Andrew; Flicek, Paul

    2016-01-01

    Evolution provides the unifying framework with which to understand biology. The coherent investigation of genic and genomic data often requires comparative genomics analyses based on whole-genome alignments, sets of homologous genes and other relevant datasets in order to evaluate and answer evolutionary-related questions. However, the complexity and computational requirements of producing such data are substantial: this has led to only a small number of reference resources that are used for most comparative analyses. The Ensembl comparative genomics resources are one such reference set that facilitates comprehensive and reproducible analysis of chordate genome data. Ensembl computes pairwise and multiple whole-genome alignments from which large-scale synteny, per-base conservation scores and constrained elements are obtained. Gene alignments are used to define Ensembl Protein Families, GeneTrees and homologies for both protein-coding and non-coding RNA genes. These resources are updated frequently and have a consistent informatics infrastructure and data presentation across all supported species. Specialized web-based visualizations are also available including synteny displays, collapsible gene tree plots, a gene family locator and different alignment views. The Ensembl comparative genomics infrastructure is extensively reused for the analysis of non-vertebrate species by other projects including Ensembl Genomes and Gramene and much of the information here is relevant to these projects. The consistency of the annotation across species and the focus on vertebrates makes Ensembl an ideal system to perform and support vertebrate comparative genomic analyses. We use robust software and pipelines to produce reference comparative data and make it freely available. Database URL: http://www.ensembl.org. PMID:26896847

  7. Center for Cancer Genomics | Office of Cancer Genomics

    Cancer.gov

    The Center for Cancer Genomics (CCG) was established to unify the National Cancer Institute's activities in cancer genomics, with the goal of advancing genomics research and translating findings into the clinic to improve the precise diagnosis and treatment of cancers. In addition to promoting genomic sequencing approach

  8. Human Genome Project

    SciTech Connect

    Block, S.; Cornwall, J.; Dally, W.; Dyson, F.; Fortson, N.; Joyce, G.; Kimble, H. J.; Lewis, N.; Max, C.; Prince, T.; Schwitters, R.; Weinberger, P.; Woodin, W. H.

    1998-01-04

    The study reviews Department of Energy supported aspects of the United States Human Genome Project, the joint National Institutes of Health/Department of Energy program to characterize all human genetic material, to discover the set of human genes, and to render them accessible for further biological study. The study concentrates on issues of technology, quality assurance/control, and informatics relevant to current effort on the genome project and needs beyond it. Recommendations are presented on areas of the genome program that are of particular interest to and supported by the Department of Energy.

  9. Genomic taxonomy of vibrios

    PubMed Central

    Thompson, Cristiane C; Vicente, Ana Carolina P; Souza, Rangel C; Vasconcelos, Ana Tereza R; Vesth, Tammi; Alves, Nelson; Ussery, David W; Iida, Tetsuya; Thompson, Fabiano L

    2009-01-01

    Background Vibrio taxonomy has been based on a polyphasic approach. In this study, we retrieve useful taxonomic information (i.e. data that can be used to distinguish different taxonomic levels, such as species and genera) from 32 genome sequences of different vibrio species. We use a variety of tools to explore the taxonomic relationship between the sequenced genomes, including Multilocus Sequence Analysis (MLSA), supertrees, Average Amino Acid Identity (AAI), genomic signatures, and Genome BLAST atlases. Our aim is to analyse the usefulness of these tools for species identification in vibrios. Results We have generated four new genome sequences of three Vibrio species, i.e., V. alginolyticus 40B, V. harveyi-like 1DA3, and V. mimicus strains VM573 and VM603, and present a broad analyses of these genomes along with other sequenced Vibrio species. The genome atlas and pangenome plots provide a tantalizing image of the genomic differences that occur between closely related sister species, e.g. V. cholerae and V. mimicus. The vibrio pangenome contains around 26504 genes. The V. cholerae core genome and pangenome consist of 1520 and 6923 genes, respectively. Pangenomes might allow different strains of V. cholerae to occupy different niches. MLSA and supertree analyses resulted in a similar phylogenetic picture, with a clear distinction of four groups (Vibrio core group, V. cholerae-V. mimicus, Aliivibrio spp., and Photobacterium spp.). A Vibrio species is defined as a group of strains that share > 95% DNA identity in MLSA and supertree analysis, > 96% AAI, ≤ 10 genome signature dissimilarity, and > 61% proteome identity. Strains of the same species and species of the same genus will form monophyletic groups on the basis of MLSA and supertree. Conclusion The combination of different analytical and bioinformatics tools will enable the most accurate species identification through genomic computational analysis. This endeavour will culminate in the birth of the online

  10. Human Genome Program

    SciTech Connect

    Not Available

    1993-01-01

    The DOE Human Genome program has grown tremendously, as shown by the marked increase in the number of genome-funded projects since the last workshop held in 1991. The abstracts in this book describe the genome research of DOE-funded grantees and contractors and invited guests, and all projects are represented at the workshop by posters. The 3-day meeting includes plenary sessions on ethical, legal, and social issues pertaining to the availability of genetic data; sequencing techniques, informatics support; and chromosome and cDNA mapping and sequencing.

  11. What Is a Genome?

    PubMed Central

    Goldman, Aaron David; Landweber, Laura F.

    2016-01-01

    The genome is often described as the information repository of an organism. Whether millions or billions of letters of DNA, its transmission across generations confers the principal medium for inheritance of organismal traits. Several emerging areas of research demonstrate that this definition is an oversimplification. Here, we explore ways in which a deeper understanding of genomic diversity and cell physiology is challenging the concepts of physical permanence attached to the genome as well as its role as the sole information source for an organism. PMID:27442251

  12. Comparative primate genomics: emerging patterns of genome content and dynamics

    PubMed Central

    Rogers, Jeffrey; Gibbs, Richard A.

    2014-01-01

    Preface Advances in genome sequencing technologies have created new opportunities for comparative primate genomics. Genome assemblies have been published for several primates, with analyses of several others underway. Whole genome assemblies for the great apes provide remarkable new information about the evolutionary origins of the human genome and the processes involved. Genomic data for macaques and other nonhuman primates provide valuable insight into genetic similarities and differences among species used as models for disease-related research. This review summarizes current knowledge regarding primate genome content and dynamics and offers a series of goals for the near future. PMID:24709753

  13. Comparative primate genomics: emerging patterns of genome content and dynamics.

    PubMed

    Rogers, Jeffrey; Gibbs, Richard A

    2014-05-01

    Advances in genome sequencing technologies have created new opportunities for comparative primate genomics. Genome assemblies have been published for various primate species, and analyses of several others are underway. Whole-genome assemblies for the great apes provide remarkable new information about the evolutionary origins of the human genome and the processes involved. Genomic data for macaques and other non-human primates offer valuable insights into genetic similarities and differences among species that are used as models for disease-related research. This Review summarizes current knowledge regarding primate genome content and dynamics, and proposes a series of goals for the near future. PMID:24709753

  14. GenomeView: a next-generation genome browser

    PubMed Central

    Abeel, Thomas; Van Parys, Thomas; Saeys, Yvan; Galagan, James; Van de Peer, Yves

    2012-01-01

    Due to ongoing advances in sequencing technologies, billions of nucleotide sequences are now produced on a daily basis. A major challenge is to visualize these data for further downstream analysis. To this end, we present GenomeView, a stand-alone genome browser specifically designed to visualize and manipulate a multitude of genomics data. GenomeView enables users to dynamically browse high volumes of aligned short-read data, with dynamic navigation and semantic zooming, from the whole genome level to the single nucleotide. At the same time, the tool enables visualization of whole genome alignments of dozens of genomes relative to a reference sequence. GenomeView is unique in its capability to interactively handle huge data sets consisting of tens of aligned genomes, thousands of annotation features and millions of mapped short reads both as viewer and editor. GenomeView is freely available as an open source software package. PMID:22102585

  15. Hymenoptera Genome Database: integrating genome annotations in HymenopteraMine

    PubMed Central

    Elsik, Christine G.; Tayal, Aditi; Diesh, Colin M.; Unni, Deepak R.; Emery, Marianne L.; Nguyen, Hung N.; Hagen, Darren E.

    2016-01-01

    We report an update of the Hymenoptera Genome Database (HGD) (http://HymenopteraGenome.org), a model organism database for insect species of the order Hymenoptera (ants, bees and wasps). HGD maintains genomic data for 9 bee species, 10 ant species and 1 wasp, including the versions of genome and annotation data sets published by the genome sequencing consortiums and those provided by NCBI. A new data-mining warehouse, HymenopteraMine, based on the InterMine data warehousing system, integrates the genome data with data from external sources and facilitates cross-species analyses based on orthology. New genome browsers and annotation tools based on JBrowse/WebApollo provide easy genome navigation, and viewing of high throughput sequence data sets and can be used for collaborative genome annotation. All of the genomes and annotation data sets are combined into a single BLAST server that allows users to select and combine sequence data sets to search. PMID:26578564

  16. Hymenoptera Genome Database: integrating genome annotations in HymenopteraMine.

    PubMed

    Elsik, Christine G; Tayal, Aditi; Diesh, Colin M; Unni, Deepak R; Emery, Marianne L; Nguyen, Hung N; Hagen, Darren E

    2016-01-01

    We report an update of the Hymenoptera Genome Database (HGD) (http://HymenopteraGenome.org), a model organism database for insect species of the order Hymenoptera (ants, bees and wasps). HGD maintains genomic data for 9 bee species, 10 ant species and 1 wasp, including the versions of genome and annotation data sets published by the genome sequencing consortiums and those provided by NCBI. A new data-mining warehouse, HymenopteraMine, based on the InterMine data warehousing system, integrates the genome data with data from external sources and facilitates cross-species analyses based on orthology. New genome browsers and annotation tools based on JBrowse/WebApollo provide easy genome navigation, and viewing of high throughput sequence data sets and can be used for collaborative genome annotation. All of the genomes and annotation data sets are combined into a single BLAST server that allows users to select and combine sequence data sets to search. PMID:26578564

  17. Vita Genomics, Inc.

    PubMed

    Shih-Hsin Wu, Lawrence; Su, Chun-Lin; Chen, Ellson

    2007-06-01

    Vita Genomics, Inc., centered in Taiwan and China, aims to be a premier genomics-based biotechnological and biopharmaceutical company in the Asia-Pacific region. The company focuses on conducting pharmacogenomics research, in vitro diagnosis product development and specialty contract research services in both genomics and pharmacogenomics fields. We are now initiating a drug rescue program designed to resurrect drugs that have failed in the previous clinical trials owing to low efficacies. This program applies pharmacogenomics approaches using biomarkers to screen subsets of patients who may respond better or avoid adverse responses to the test drugs. Vita Genomics, Inc. has envisioned itself as an important player in the healthcare industry offering advanced molecular diagnostic products and services, revolutionizing thedrug-development process and providing pharmacogenomic solutions. PMID:17559355

  18. Lophotrochozoan mitochondrial genomes

    SciTech Connect

    Valles, Yvonne; Boore, Jeffrey L.

    2005-10-01

    Progress in both molecular techniques and phylogeneticmethods has challenged many of the interpretations of traditionaltaxonomy. One example is in the recognition of the animal superphylumLophotrochozoa (annelids, mollusks, echiurans, platyhelminthes,brachiopods, and other phyla), although the relationships within thisgroup and the inclusion of some phyla remain uncertain. While much ofthis progress in phylogenetic reconstruction has been based on comparingsingle gene sequences, we are beginning to see the potential of comparinglarge-scale features of genomes, such as the relative order of genes.Even though tremendous progress is being made on the sequencedetermination of whole nuclear genomes, the dataset of choice forgenome-level characters for many animals across a broad taxonomic rangeremains mitochondrial genomes. We review here what is known aboutmitochondrial genomes of the lophotrochozoans and discuss the promisethat this dataset will enable insight into theirrelationships.

  19. Androgen receptor genomic regulation

    PubMed Central

    Jin, Hong-Jian; Kim, Jung

    2013-01-01

    The transcriptional activity of the androgen receptor (AR) is not only critical for the normal development and function of the prostate but also pivotal to the onset and progression of prostate cancer (PCa). The studies of AR transcriptional regulation were previously limited to a handful of AR-target genes. Owing to the development of various high-throughput genomic technologies, significant advances have been made in recent years. Here we discuss the discoveries of genome-wide androgen-regulated genes in PCa cell lines, animal models and tissues using expression microarray and sequencing, the mapping of genomic landscapes of AR using Combining Chromatin Immunoprecipitation (ChIP)-on-chip and ChIP-seq assays, the interplay of transcriptional cofactors in defining AR binding profiles, and the genomic regulation and AR reprogramming in advanced PCa. PMID:25237629

  20. Mouse genome database 2016

    PubMed Central

    Bult, Carol J.; Eppig, Janan T.; Blake, Judith A.; Kadin, James A.; Richardson, Joel E.

    2016-01-01

    The Mouse Genome Database (MGD; http://www.informatics.jax.org) is the primary community model organism database for the laboratory mouse and serves as the source for key biological reference data related to mouse genes, gene functions, phenotypes and disease models with a strong emphasis on the relationship of these data to human biology and disease. As the cost of genome-scale sequencing continues to decrease and new technologies for genome editing become widely adopted, the laboratory mouse is more important than ever as a model system for understanding the biological significance of human genetic variation and for advancing the basic research needed to support the emergence of genome-guided precision medicine. Recent enhancements to MGD include new graphical summaries of biological annotations for mouse genes, support for mobile access to the database, tools to support the annotation and analysis of sets of genes, and expanded support for comparative biology through the expansion of homology data. PMID:26578600

  1. The genomics of adaptation.

    PubMed

    Radwan, Jacek; Babik, Wiesław

    2012-12-22

    The amount and nature of genetic variation available to natural selection affect the rate, course and outcome of evolution. Consequently, the study of the genetic basis of adaptive evolutionary change has occupied biologists for decades, but progress has been hampered by the lack of resolution and the absence of a genome-level perspective. Technological advances in recent years should now allow us to answer many long-standing questions about the nature of adaptation. The data gathered so far are beginning to challenge some widespread views of the way in which natural selection operates at the genomic level. Papers in this Special Feature of Proceedings of the Royal Society B illustrate various aspects of the broad field of adaptation genomics. This introductory article sets up a context and, on the basis of a few selected examples, discusses how genomic data can advance our understanding of the process of adaptation. PMID:23097510

  2. Genomics and vaccine development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genomic-based approaches are driving fundamental changes in our understanding of microbiology. Comparative analysis of microbial strain is providing new insights into pathogen evolution, virulence mechanisms, and host range specificity. Most importantly, gene discovery and genetic variations can now...

  3. Platyzoan mitochondrial genomes.

    PubMed

    Wey-Fabrizius, Alexandra R; Podsiadlowski, Lars; Herlyn, Holger; Hankeln, Thomas

    2013-11-01

    Platyzoa is a putative lophotrochozoan (spiralian) subtaxon within the protostome clade of Metazoa, comprising a range of biologically diverse, mostly small worm-shaped animals. The monophyly of Platyzoa, the relationships between the putative subgroups Platyhelminthes, Gastrotricha and Gnathifera (the latter comprising at least Gnathostomulida, "Rotifera" and Acanthocephala) as well as some aspects of the internal phylogenies of these subgroups are highly debated. Here we review how complete mitochondrial (mt) genome data contribute to these debates. We highlight special features of the mt genomes and discuss problems in mtDNA phylogenies of the clade. Mitochondrial genome data seem to be insufficient to resolve the position of the platyzoan clade within the Spiralia but can help to address internal phylogenetic questions. The present review includes a tabular survey of all published platyzoan mt genomes. PMID:23274056

  4. Mouse genome database 2016.

    PubMed

    Bult, Carol J; Eppig, Janan T; Blake, Judith A; Kadin, James A; Richardson, Joel E

    2016-01-01

    The Mouse Genome Database (MGD; http://www.informatics.jax.org) is the primary community model organism database for the laboratory mouse and serves as the source for key biological reference data related to mouse genes, gene functions, phenotypes and disease models with a strong emphasis on the relationship of these data to human biology and disease. As the cost of genome-scale sequencing continues to decrease and new technologies for genome editing become widely adopted, the laboratory mouse is more important than ever as a model system for understanding the biological significance of human genetic variation and for advancing the basic research needed to support the emergence of genome-guided precision medicine. Recent enhancements to MGD include new graphical summaries of biological annotations for mouse genes, support for mobile access to the database, tools to support the annotation and analysis of sets of genes, and expanded support for comparative biology through the expansion of homology data. PMID:26578600

  5. The rise of genomics.

    PubMed

    Weissenbach, Jean

    2016-01-01

    A brief history of the development of genomics is provided. Complete sequencing of genomes of uni- and multicellular organisms is based on important progress in sequencing and bioinformatics. Evolution of these methods is ongoing and has triggered an explosion in data production and analysis. Initial analyses focused on the inventory of genes encoding proteins. Completeness and quality of gene prediction remains crucial. Genome analyses profoundly modified our views on evolution, biodiversity and contributed to the detection of new functions, yet to be fully elucidated, such as those fulfilled by non-coding RNAs. Genomics has become the basis for the study of biology and provides the molecular support for a bunch of large-scale studies, the omics. PMID:27263360

  6. Epidemiology & Genomics Research Program

    Cancer.gov

    The Epidemiology and Genomics Research Program, in the National Cancer Institute's Division of Cancer Control and Population Sciences, funds research in human populations to understand the determinants of cancer occurrence and outcomes.

  7. Genomic definition of species

    SciTech Connect

    Crkvenjakov, R.; Drmanac, R.

    1991-07-01

    The subject of this paper is the definition of species based on the assumption that genome is the fundamental level for the origin and maintenance of biological diversity. For this view to be logically consistent it is necessary to assume the existence and operation of the new law which we call genome law. For this reason the genome law is included in the explanation of species phenomenon presented here even if its precise formulation and elaboration are left for the future. The intellectual underpinnings of this definition can be traced to Goldschmidt. We wish to explore some philosophical aspects of the definition of species in terms of the genome. The point of proposing the definition on these grounds is that any real advance in evolutionary theory has to be correct in both its philosophy and its science.

  8. Molluscan Evolutionary Genomics

    SciTech Connect

    Simison, W. Brian; Boore, Jeffrey L.

    2005-12-01

    In the last 20 years there have been dramatic advances in techniques of high-throughput DNA sequencing, most recently accelerated by the Human Genome Project, a program that has determined the three billion base pair code on which we are based. Now this tremendous capability is being directed at other genome targets that are being sampled across the broad range of life. This opens up opportunities as never before for evolutionary and organismal biologists to address questions of both processes and patterns of organismal change. We stand at the dawn of a new 'modern synthesis' period, paralleling that of the early 20th century when the fledgling field of genetics first identified the underlying basis for Darwin's theory. We must now unite the efforts of systematists, paleontologists, mathematicians, computer programmers, molecular biologists, developmental biologists, and others in the pursuit of discovering what genomics can teach us about the diversity of life. Genome-level sampling for mollusks to date has mostly been limited to mitochondrial genomes and it is likely that these will continue to provide the best targets for broad phylogenetic sampling in the near future. However, we are just beginning to see an inroad into complete nuclear genome sequencing, with several mollusks and other eutrochozoans having been selected for work about to begin. Here, we provide an overview of the state of molluscan mitochondrial genomics, highlight a few of the discoveries from this research, outline the promise of broadening this dataset, describe upcoming projects to sequence whole mollusk nuclear genomes, and challenge the community to prepare for making the best use of these data.

  9. Biobanks for Genomics and Genomics for Biobanks

    PubMed Central

    Ducournau, Pascal; Gourraud, Pierre-Antoine; Pontille, David

    2003-01-01

    Biobanks include biological samples and attached databases. Human biobanks occur in research, technological development and medical activities. Population genomics is highly dependent on the availability of large biobanks. Ethical issues must be considered: protecting the rights of those people whose samples or data are in biobanks (information, autonomy, confidentiality, protection of private life), assuring the non-commercial use of human body elements and the optimal use of samples and data. They balance other issues, such as protecting the rights of researchers and companies, allowing long-term use of biobanks while detailed information on future uses is not available. At the level of populations, the traditional form of informed consent is challenged. Other dimensions relate to the rights of a group as such, in addition to individual rights. Conditions of return of results and/or benefit to a population need to be defined. With ‘large-scale biobanking’ a marked trend in genomics, new societal dimensions appear, regarding communication, debate, regulation, societal control and valorization of such large biobanks. Exploring how genomics can help health sector biobanks to become more rationally constituted and exploited is an interesting perspective. For example, evaluating how genomic approaches can help in optimizing haematopoietic stem cell donor registries using new markers and high-throughput techniques to increase immunogenetic variability in such registries is a challenge currently being addressed. Ethical issues in such contexts are important, as not only individual decisions or projects are concerned, but also national policies in the international arena and organization of democratic debate about science, medicine and society. PMID:18629026

  10. How the genome folds

    NASA Astrophysics Data System (ADS)

    Lieberman Aiden, Erez

    2012-02-01

    I describe Hi-C, a novel technology for probing the three-dimensional architecture of whole genomes by coupling proximity-based ligation with massively parallel sequencing. Working with collaborators at the Broad Institute and UMass Medical School, we used Hi-C to construct spatial proximity maps of the human genome at a resolution of 1Mb. These maps confirm the presence of chromosome territories and the spatial proximity of small, gene-rich chromosomes. We identified an additional level of genome organization that is characterized by the spatial segregation of open and closed chromatin to form two genome-wide compartments. At the megabase scale, the chromatin conformation is consistent with a fractal globule, a knot-free conformation that enables maximally dense packing while preserving the ability to easily fold and unfold any genomic locus. The fractal globule is distinct from the more commonly used globular equilibrium model. Our results demonstrate the power of Hi-C to map the dynamic conformations of whole genomes.

  11. Human Genome Annotation

    NASA Astrophysics Data System (ADS)

    Gerstein, Mark

    A central problem for 21st century science is annotating the human genome and making this annotation useful for the interpretation of personal genomes. My talk will focus on annotating the 99% of the genome that does not code for canonical genes, concentrating on intergenic features such as structural variants (SVs), pseudogenes (protein fossils), binding sites, and novel transcribed RNAs (ncRNAs). In particular, I will describe how we identify regulatory sites and variable blocks (SVs) based on processing next-generation sequencing experiments. I will further explain how we cluster together groups of sites to create larger annotations. Next, I will discuss a comprehensive pseudogene identification pipeline, which has enabled us to identify >10K pseudogenes in the genome and analyze their distribution with respect to age, protein family, and chromosomal location. Throughout, I will try to introduce some of the computational algorithms and approaches that are required for genome annotation. Much of this work has been carried out in the framework of the ENCODE, modENCODE, and 1000 genomes projects.

  12. An archaeal genomic signature

    NASA Technical Reports Server (NTRS)

    Graham, D. E.; Overbeek, R.; Olsen, G. J.; Woese, C. R.

    2000-01-01

    Comparisons of complete genome sequences allow the most objective and comprehensive descriptions possible of a lineage's evolution. This communication uses the completed genomes from four major euryarchaeal taxa to define a genomic signature for the Euryarchaeota and, by extension, the Archaea as a whole. The signature is defined in terms of the set of protein-encoding genes found in at least two diverse members of the euryarchaeal taxa that function uniquely within the Archaea; most signature proteins have no recognizable bacterial or eukaryal homologs. By this definition, 351 clusters of signature proteins have been identified. Functions of most proteins in this signature set are currently unknown. At least 70% of the clusters that contain proteins from all the euryarchaeal genomes also have crenarchaeal homologs. This conservative set, which appears refractory to horizontal gene transfer to the Bacteria or the Eukarya, would seem to reflect the significant innovations that were unique and fundamental to the archaeal "design fabric." Genomic protein signature analysis methods may be extended to characterize the evolution of any phylogenetically defined lineage. The complete set of protein clusters for the archaeal genomic signature is presented as supplementary material (see the PNAS web site, www.pnas.org).

  13. Ebolavirus comparative genomics

    DOE PAGESBeta

    Jun, Se-Ran; Leuze, Michael R.; Nookaew, Intawat; Uberbacher, Edward C.; Land, Miriam; Zhang, Qian; Wanchai, Visanu; Chai, Juanjuan; Nielsen, Morten; Trolle, Thomas; et al

    2015-07-14

    The 2014 Ebola outbreak in West Africa is the largest documented for this virus. We examine the dynamics of this genome, comparing more than one hundred currently available ebolavirus genomes to each other and to other viral genomes. Based on oligomer frequency analysis, the family Filoviridae forms a distinct group from all other sequenced viral genomes. All filovirus genomes sequenced to date encode proteins with similar functions and gene order, although there is considerable divergence in sequences between the three genera Ebolavirus, Cuevavirus, and Marburgvirus within the family Filoviridae. Whereas all ebolavirus genomes are quite similar (multiple sequences of themore » same strain are often identical), variation is most common in the intergenic regions and within specific areas of the genes encoding the glycoprotein (GP), nucleoprotein (NP), and polymerase (L). We predict regions that could contain epitope-binding sites, which might be good vaccine targets. In conclusion, this information, combined with glycosylation sites and experimentally determined epitopes, can identify the most promising regions for the development of therapeutic strategies.« less

  14. Barley Genomics: An Overview

    PubMed Central

    Sreenivasulu, Nese; Graner, Andreas; Wobus, Ulrich

    2008-01-01

    Barley (Hordeum vulgare), first domesticated in the Near East, is a well-studied crop in terms of genetics, genomics, and breeding and qualifies as a model plant for Triticeae research. Recent advances made in barley genomics mainly include the following: (i) rapid accumulation of EST sequence data, (ii) growing number of studies on transcriptome, proteome, and metabolome, (iii) new modeling techniques, (iv) availability of genome-wide knockout collections as well as efficient transformation techniques, and (v) the recently started genome sequencing effort. These developments pave the way for a comprehensive functional analysis and understanding of gene expression networks linked to agronomically important traits. Here, we selectively review important technological developments in barley genomics and related fields and discuss the relevance for understanding genotype-phenotype relationships by using approaches such as genetical genomics and association studies. High-throughput genotyping platforms that have recently become available will allow the construction of high-density genetic maps that will further promote marker-assisted selection as well as physical map construction. Systems biology approaches will further enhance our knowledge and largely increase our abilities to design refined breeding strategies on the basis of detailed molecular physiological knowledge. PMID:18382615

  15. A Review on Genomics APIs

    PubMed Central

    Swaminathan, Rajeswari; Huang, Yungui; Moosavinasab, Soheil; Buckley, Ronald; Bartlett, Christopher W.; Lin, Simon M.

    2015-01-01

    The constant improvement and falling prices of whole human genome Next Generation Sequencing (NGS) has resulted in rapid adoption of genomic information at both clinics and research institutions. Considered together, the complexity of genomics data, due to its large volume and diversity along with the need for genomic data sharing, has resulted in the creation of Application Programming Interface (API) for secure, modular, interoperable access to genomic data from different applications, platforms, and even organizations. The Genomics APIs are a set of special protocols that assist software developers in dealing with multiple genomic data sources for building seamless, interoperable applications leading to the advancement of both genomic and clinical research. These APIs help define a standard for retrieval of genomic data from multiple sources as well as to better package genomic information for integration with Electronic Health Records. This review covers three currently available Genomics APIs: a) Google Genomics, b) SMART Genomics, and c) 23andMe. The functionalities, reference implementations (if available) and authentication protocols of each API are reviewed. A comparative analysis of the different features across the three APIs is provided in the Discussion section. Though Genomics APIs are still under active development and have yet to reach widespread adoption, they hold the promise to make building of complicated genomics applications easier with downstream constructive effects on healthcare. PMID:26702340

  16. WheatGenome.info: A Resource for Wheat Genomics Resource.

    PubMed

    Lai, Kaitao

    2016-01-01

    An integrated database with a variety of Web-based systems named WheatGenome.info hosting wheat genome and genomic data has been developed to support wheat research and crop improvement. The resource includes multiple Web-based applications, which are implemented as a variety of Web-based systems. These include a GBrowse2-based wheat genome viewer with BLAST search portal, TAGdb for searching wheat second generation genome sequence data, wheat autoSNPdb, links to wheat genetic maps using CMap and CMap3D, and a wheat genome Wiki to allow interaction between diverse wheat genome sequencing activities. This portal provides links to a variety of wheat genome resources hosted at other research organizations. This integrated database aims to accelerate wheat genome research and is freely accessible via the web interface at http://www.wheatgenome.info/ . PMID:26519407

  17. GenomeVista

    SciTech Connect

    Poliakov, Alexander; Couronne, Olivier

    2002-11-04

    Aligning large vertebrate genomes that are structurally complex poses a variety of problems not encountered on smaller scales. Such genomes are rich in repetitive elements and contain multiple segmental duplications, which increases the difficulty of identifying true orthologous SNA segments in alignments. The sizes of the sequences make many alignment algorithms designed for comparing single proteins extremely inefficient when processing large genomic intervals. We integrated both local and global alignment tools and developed a suite of programs for automatically aligning large vertebrate genomes and identifying conserved non-coding regions in the alignments. Our method uses the BLAT local alignment program to find anchors on the base genome to identify regions of possible homology for a query sequence. These regions are postprocessed to find the best candidates which are then globally aligned using the AVID global alignment program. In the last step conserved non-coding segments are identified using VISTA. Our methods are fast and the resulting alignments exhibit a high degree of sensitivity, covering more than 90% of known coding exons in the human genome. The GenomeVISTA software is a suite of Perl programs that is built on a MySQL database platform. The scheduler gets control data from the database, builds a queve of jobs, and dispatches them to a PC cluster for execution. The main program, running on each node of the cluster, processes individual sequences. A Perl library acts as an interface between the database and the above programs. The use of a separate library allows the programs to function independently of the database schema. The library also improves on the standard Perl MySQL database interfere package by providing auto-reconnect functionality and improved error handling.

  18. GenomeVista

    Energy Science and Technology Software Center (ESTSC)

    2002-11-04

    Aligning large vertebrate genomes that are structurally complex poses a variety of problems not encountered on smaller scales. Such genomes are rich in repetitive elements and contain multiple segmental duplications, which increases the difficulty of identifying true orthologous SNA segments in alignments. The sizes of the sequences make many alignment algorithms designed for comparing single proteins extremely inefficient when processing large genomic intervals. We integrated both local and global alignment tools and developed a suitemore » of programs for automatically aligning large vertebrate genomes and identifying conserved non-coding regions in the alignments. Our method uses the BLAT local alignment program to find anchors on the base genome to identify regions of possible homology for a query sequence. These regions are postprocessed to find the best candidates which are then globally aligned using the AVID global alignment program. In the last step conserved non-coding segments are identified using VISTA. Our methods are fast and the resulting alignments exhibit a high degree of sensitivity, covering more than 90% of known coding exons in the human genome. The GenomeVISTA software is a suite of Perl programs that is built on a MySQL database platform. The scheduler gets control data from the database, builds a queve of jobs, and dispatches them to a PC cluster for execution. The main program, running on each node of the cluster, processes individual sequences. A Perl library acts as an interface between the database and the above programs. The use of a separate library allows the programs to function independently of the database schema. The library also improves on the standard Perl MySQL database interfere package by providing auto-reconnect functionality and improved error handling.« less

  19. Genomes to Proteomes

    SciTech Connect

    Panisko, Ellen A.; Grigoriev, Igor; Daly, Don S.; Webb-Robertson, Bobbie-Jo; Baker, Scott E.

    2009-03-01

    Biologists are awash with genomic sequence data. In large part, this is due to the rapid acceleration in the generation of DNA sequence that occurred as public and private research institutes raced to sequence the human genome. In parallel with the large human genome effort, mostly smaller genomes of other important model organisms were sequenced. Projects following on these initial efforts have made use of technological advances and the DNA sequencing infrastructure that was built for the human and other organism genome projects. As a result, the genome sequences of many organisms are available in high quality draft form. While in many ways this is good news, there are limitations to the biological insights that can be gleaned from DNA sequences alone; genome sequences offer only a bird's eye view of the biological processes endemic to an organism or community. Fortunately, the genome sequences now being produced at such a high rate can serve as the foundation for other global experimental platforms such as proteomics. Proteomic methods offer a snapshot of the proteins present at a point in time for a given biological sample. Current global proteomics methods combine enzymatic digestion, separations, mass spectrometry and database searching for peptide identification. One key aspect of proteomics is the prediction of peptide sequences from mass spectrometry data. Global proteomic analysis uses computational matching of experimental mass spectra with predicted spectra based on databases of gene models that are often generated computationally. Thus, the quality of gene models predicted from a genome sequence is crucial in the generation of high quality peptide identifications. Once peptides are identified they can be assigned to their parent protein. Proteins identified as expressed in a given experiment are most useful when compared to other expressed proteins in a larger biological context or biochemical pathway. In this chapter we will discuss the automatic

  20. Genome position specific priors for genomic prediction

    PubMed Central

    2012-01-01

    Background The accuracy of genomic prediction is highly dependent on the size of the reference population. For small populations, including information from other populations could improve this accuracy. The usual strategy is to pool data from different populations; however, this has not proven as successful as hoped for with distantly related breeds. BayesRS is a novel approach to share information across populations for genomic predictions. The approach allows information to be captured even where the phase of SNP alleles and casuative mutation alleles are reversed across populations, or the actual casuative mutation is different between the populations but affects the same gene. Proportions of a four-distribution mixture for SNP effects in segments of fixed size along the genome are derived from one population and set as location specific prior proportions of distributions of SNP effects for the target population. The model was tested using dairy cattle populations of different breeds: 540 Australian Jersey bulls, 2297 Australian Holstein bulls and 5214 Nordic Holstein bulls. The traits studied were protein-, fat- and milk yield. Genotypic data was Illumina 777K SNPs, real or imputed. Results Results showed an increase in accuracy of up to 3.5% for the Jersey population when using BayesRS with a prior derived from Australian Holstein compared to a model without location specific priors. The increase in accuracy was however lower than was achieved when reference populations were combined to estimate SNP effects, except in the case of fat yield. The small size of the Jersey validation set meant that these improvements in accuracy were not significant using a Hotelling-Williams t-test at the 5% level. An increase in accuracy of 1-2% for all traits was observed in the Australian Holstein population when using a prior derived from the Nordic Holstein population compared to using no prior information. These improvements were significant (P<0.05) using the Hotelling

  1. Berkeley Quantitative Genome Browser

    SciTech Connect

    Hechmer, Aaron

    2008-02-29

    The Berkeley Quantitative Genome Browser provides graphical browsing functionality for genomic data organized, at a minimum, by sequence and position. While supporting the annotation browsing features typical of many other genomic browsers, additional emphasis is placed on viewing and utilizing quantitative data. Data may be read from GFF, SGR, FASTA or any column delimited format. Once the data has been read into the browser's buffer, it may be searched. filtered or subjected to mathematical transformation. The browser also supplies some graphical design manipulation functionality geared towards preparing figures for presentations or publication. A plug-in mechanism enables development outside the core functionality that adds more advanced or esoteric analysis capabilities. BBrowse's development and distribution is open-source and has been built to run on Linux, OSX and MS Windows operating systems.

  2. Genomics, health, and society.

    PubMed

    Chan, Chee Khoon

    2002-01-01

    On June 27, 2001, the World Health Organization conducted hearings in Geneva for a Special Report on Genomics & Health. Initially intended as a document to address the ethical, legal, and social implications of the gathering genomics resolution (ELSI), the terms of reference of the report were significantly modified to give primary emphasis to a scientific and technological assessment of the implications of genomics for human health. The Citizens' Health Initiative, one of two NGOs invited to make submissions at these consultations, suggested that no less important than the scientific and technical assessment was a perspective which gave due attention to the social context and political economy of scientific/technological development and its deployment. The article below touches upon neglected health priorities of poor countries, intellectual property rights and patents, risk management, insurance and discrimination, and predictive (prenatal) testing, reproductive choice, and eugenics. PMID:17208760

  3. Berkeley Quantitative Genome Browser

    Energy Science and Technology Software Center (ESTSC)

    2008-02-29

    The Berkeley Quantitative Genome Browser provides graphical browsing functionality for genomic data organized, at a minimum, by sequence and position. While supporting the annotation browsing features typical of many other genomic browsers, additional emphasis is placed on viewing and utilizing quantitative data. Data may be read from GFF, SGR, FASTA or any column delimited format. Once the data has been read into the browser's buffer, it may be searched. filtered or subjected to mathematical transformation.more » The browser also supplies some graphical design manipulation functionality geared towards preparing figures for presentations or publication. A plug-in mechanism enables development outside the core functionality that adds more advanced or esoteric analysis capabilities. BBrowse's development and distribution is open-source and has been built to run on Linux, OSX and MS Windows operating systems.« less

  4. Genomics for Weed Science

    PubMed Central

    Horvath, David

    2010-01-01

    Numerous genomic-based studies have provided insight to the physiological and evolutionary processes involved in developmental and environmental processes of model plants such as arabidopsis and rice. However, far fewer efforts have been attempted to use genomic resources to study physiological and evolutionary processes of weedy plants. Genomics-based tools such as extensive EST databases and microarrays have been developed for a limited number of weedy species, although application of information and resources developed for model plants and crops are possible and have been exploited. These tools have just begun to provide insights into the response of these weeds to herbivore and pathogen attack, survival of extreme environmental conditions, and interaction with crops. The potential of these tools to illuminate mechanisms controlling the traits that allow weeds to invade novel habitats, survive extreme environments, and that make weeds difficult to eradicate have potential for both improving crops and developing novel methods to control weeds. PMID:20808523

  5. SINGLE CELL GENOME SEQUENCING

    PubMed Central

    Yilmaz, Suzan; Singh, Anup K.

    2011-01-01

    Whole genome amplification and next-generation sequencing of single cells has become a powerful approach for studying uncultivated microorganisms that represent 90–99 % of all environmental microbes. Single cell sequencing enables not only the identification of microbes but also linking of functions to species, a feat not achievable by metagenomic techniques. Moreover, it allows the analysis of low abundance species that may be missed in community-based analyses. It has also proved very useful in complementing metagenomics in the assembly and binning of single genomes. With the advent of drastically cheaper and higher throughput sequencing technologies, it is expected that single cell sequencing will become a standard tool in studying the genome and transcriptome of microbial communities. PMID:22154471

  6. Genomic Southern blot analysis.

    PubMed

    Gebbie, Leigh

    2014-01-01

    This chapter describes a detailed protocol for genomic Southern blot analysis which can be used to detect transgene or endogenous gene sequences in cereal genomes. The protocol follows a standard approach that has been shown to generate high-quality results: size fractionation of genomic DNA; capillary transfer to a nylon membrane; hybridization with a digoxigenin-labelled probe; and detection using a chemiluminescent-based system. High sensitivity and limited background are key to successful Southern blots. The critical steps in this protocol are complete digestion of the right quantity of DNA, careful handling of the membrane to avoid unnecessary background, and optimization of probe concentration and temperatures during the hybridization step. Detailed instructions on how to successfully master these techniques are provided. PMID:24243203

  7. Genomics of Volvocine Algae

    PubMed Central

    Umen, James G.; Olson, Bradley J.S.C.

    2015-01-01

    Volvocine algae are a group of chlorophytes that together comprise a unique model for evolutionary and developmental biology. The species Chlamydomonas reinhardtii and Volvox carteri represent extremes in morphological diversity within the Volvocine clade. Chlamydomonas is unicellular and reflects the ancestral state of the group, while Volvox is multicellular and has evolved numerous innovations including germ-soma differentiation, sexual dimorphism, and complex morphogenetic patterning. The Chlamydomonas genome sequence has shed light on several areas of eukaryotic cell biology, metabolism and evolution, while the Volvox genome sequence has enabled a comparison with Chlamydomonas that reveals some of the underlying changes that enabled its transition to multicellularity, but also underscores the subtlety of this transition. Many of the tools and resources are in place to further develop Volvocine algae as a model for evolutionary genomics. PMID:25883411

  8. Genomic medicine and neurology.

    PubMed

    Vance, Jeffery M; Tekin, Demet

    2011-04-01

    The application of genetics to the understanding of neurology has been highly successful over the past several decades. During the past 10 years, tools were developed to begin genetic investigations into more common disorders such as Alzheimer disease, multiple sclerosis, autism, and Parkinson disease. The era of genomic medicine now has begun and will have an increasing effect on the daily care of common neurologic diseases. Thus it is important for neurologists to have a basic understanding of genomic medicine and how it differs from the traditional clinical genetics of the past. This article provides some basic information about genomic medicine and pharmacogenetics in neurology to help neurologists to begin to adopt these principles into their practice. PMID:22810818

  9. Genomic Imprinting in Mammals

    PubMed Central

    Barlow, Denise P.

    2014-01-01

    Genomic imprinting affects a subset of genes in mammals and results in a monoallelic, parental-specific expression pattern. Most of these genes are located in clusters that are regulated through the use of insulators or long noncoding RNAs (lncRNAs). To distinguish the parental alleles, imprinted genes are epigenetically marked in gametes at imprinting control elements through the use of DNA methylation at the very least. Imprinted gene expression is subsequently conferred through lncRNAs, histone modifications, insulators, and higher-order chromatin structure. Such imprints are maintained after fertilization through these mechanisms despite extensive reprogramming of the mammalian genome. Genomic imprinting is an excellent model for understanding mammalian epigenetic regulation. PMID:24492710

  10. Resequencing rice genomes: an emerging new era of rice genomics.

    PubMed

    Huang, Xuehui; Lu, Tingting; Han, Bin

    2013-04-01

    Rice is a model system for crop genomics studies. Much of the early work on rice genomics focused on analyzing genome-wide genetic variation to further understand rice gene functions in agronomic traits and to generate data and resources for rice research. The advent of next-generation high-throughput DNA sequencing technologies and the completion of high-quality reference genome sequences have enabled the development of sequencing-based genotyping and genome-wide association studies (GWAS) that have significantly advanced rice genetics research. This has led to the emergence of a new era of rice genomics aimed at bridging the knowledge gap between genotype and phenotype in rice. These technologies have also led to pyramid breeding through genomics-assisted selection, which will be useful in breeding elite varieties suitable for sustainable agriculture. Here, we review the recent advances in rice genomics and discuss the future of this line of research. PMID:23295340

  11. Brief Guide to Genomics: DNA, Genes and Genomes

    MedlinePlus

    ... guía de genómica A Brief Guide to Genomics DNA, Genes and Genomes Deoxyribonucleic acid (DNA) is the ... and lead to a disease such as cancer. DNA Sequencing Sequencing simply means determining the exact order ...

  12. Haemonchus contortus: Genome Structure, Organization and Comparative Genomics.

    PubMed

    Laing, R; Martinelli, A; Tracey, A; Holroyd, N; Gilleard, J S; Cotton, J A

    2016-01-01

    One of the first genome sequencing projects for a parasitic nematode was that for Haemonchus contortus. The open access data from the Wellcome Trust Sanger Institute provided a valuable early resource for the research community, particularly for the identification of specific genes and genetic markers. Later, a second sequencing project was initiated by the University of Melbourne, and the two draft genome sequences for H. contortus were published back-to-back in 2013. There is a pressing need for long-range genomic information for genetic mapping, population genetics and functional genomic studies, so we are continuing to improve the Wellcome Trust Sanger Institute assembly to provide a finished reference genome for H. contortus. This review describes this process, compares the H. contortus genome assemblies with draft genomes from other members of the strongylid group and discusses future directions for parasite genomics using the H. contortus model. PMID:27238013

  13. Ebolavirus comparative genomics

    PubMed Central

    Jun, Se-Ran; Leuze, Michael R.; Nookaew, Intawat; Uberbacher, Edward C.; Land, Miriam; Zhang, Qian; Wanchai, Visanu; Chai, Juanjuan; Nielsen, Morten; Trolle, Thomas; Lund, Ole; Buzard, Gregory S.; Pedersen, Thomas D.; Wassenaar, Trudy M.; Ussery, David W.

    2015-01-01

    The 2014 Ebola outbreak in West Africa is the largest documented for this virus. To examine the dynamics of this genome, we compare more than 100 currently available ebolavirus genomes to each other and to other viral genomes. Based on oligomer frequency analysis, the family Filoviridae forms a distinct group from all other sequenced viral genomes. All filovirus genomes sequenced to date encode proteins with similar functions and gene order, although there is considerable divergence in sequences between the three genera Ebolavirus, Cuevavirus and Marburgvirus within the family Filoviridae. Whereas all ebolavirus genomes are quite similar (multiple sequences of the same strain are often identical), variation is most common in the intergenic regions and within specific areas of the genes encoding the glycoprotein (GP), nucleoprotein (NP) and polymerase (L). We predict regions that could contain epitope-binding sites, which might be good vaccine targets. This information, combined with glycosylation sites and experimentally determined epitopes, can identify the most promising regions for the development of therapeutic strategies. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). PMID:26175035

  14. Ebolavirus comparative genomics.

    PubMed

    Jun, Se-Ran; Leuze, Michael R; Nookaew, Intawat; Uberbacher, Edward C; Land, Miriam; Zhang, Qian; Wanchai, Visanu; Chai, Juanjuan; Nielsen, Morten; Trolle, Thomas; Lund, Ole; Buzard, Gregory S; Pedersen, Thomas D; Wassenaar, Trudy M; Ussery, David W

    2015-09-01

    The 2014 Ebola outbreak in West Africa is the largest documented for this virus. To examine the dynamics of this genome, we compare more than 100 currently available ebolavirus genomes to each other and to other viral genomes. Based on oligomer frequency analysis, the family Filoviridae forms a distinct group from all other sequenced viral genomes. All filovirus genomes sequenced to date encode proteins with similar functions and gene order, although there is considerable divergence in sequences between the three genera Ebolavirus, Cuevavirus and Marburgvirus within the family Filoviridae. Whereas all ebolavirus genomes are quite similar (multiple sequences of the same strain are often identical), variation is most common in the intergenic regions and within specific areas of the genes encoding the glycoprotein (GP), nucleoprotein (NP) and polymerase (L). We predict regions that could contain epitope-binding sites, which might be good vaccine targets. This information, combined with glycosylation sites and experimentally determined epitopes, can identify the most promising regions for the development of therapeutic strategies.This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). PMID:26175035

  15. Genome Size and Species Diversification

    PubMed Central

    2010-01-01

    Theoretically, there are reasons to believe that large genome size should favour speciation. Several major factors contributing to genome size, such as duplications and transposable element activity have been proposed to facilitate the formation of new species. However, it is also possible that small genome size promotes speciation. For example, selection for genome reduction may be resolved in different ways in incipient species, leading to incompatibilities. Mutations and chromosomal rearrangements may also be more stably inherited in smaller genomes. Here I review the following lines of empirical evidence bearing on this question: (i) Correlations between genome size and species richness of taxa are often negative. (ii) Fossil evidence in lungfish shows that the accumulation of DNA in the genomes of this group coincided with a reduction in species diversity. (iii) Estimates of speciation interval in mammals correlate positively with genome size. (iv) Genome reductions are inferred at the base of particular species radiations and genome expansions at the base of others. (v) Insect clades that have been increasing in diversity up to the present have smaller genomes than clades that have remained stable or have decreased in diversity. The general pattern emerging from these observations is that higher diversification rates are generally found in small-genome taxa. Since diversification rates are the net effect of speciation and extinction, large genomes may thus either constrain speciation rate, increase extinction rate, or both. I argue that some of the cited examples are unlikely to be explained by extinction alone. PMID:22140283

  16. The cancer genome

    PubMed Central

    Stratton, Michael R.; Campbell, Peter J.; Futreal, P. Andrew

    2010-01-01

    All cancers arise as a result of changes that have occurred in the DNA sequence of the genomes of cancer cells. Over the past quarter of a century much has been learnt about these mutations and the abnormal genes that operate in human cancers. We are now, however, moving into an era in which it will be possible to obtain the complete DNA sequence of large numbers of cancer genomes. These studies will provide us with a detailed and comprehensive perspective on how individual cancers have developed. PMID:19360079

  17. Methanococcus jannaschii genome: revisited

    NASA Technical Reports Server (NTRS)

    Kyrpides, N. C.; Olsen, G. J.; Klenk, H. P.; White, O.; Woese, C. R.

    1996-01-01

    Analysis of genomic sequences is necessarily an ongoing process. Initial gene assignments tend (wisely) to be on the conservative side (Venter, 1996). The analysis of the genome then grows in an iterative fashion as additional data and more sophisticated algorithms are brought to bear on the data. The present report is an emendation of the original gene list of Methanococcus jannaschii (Bult et al., 1996). By using a somewhat more updated database and more relaxed (and operator-intensive) pattern matching methods, we were able to add significantly to, and in a few cases amend, the gene identification table originally published by Bult et al. (1996).

  18. Genomic standards consortium projects.

    PubMed

    Field, Dawn; Sterk, Peter; Kottmann, Renzo; De Smet, J Wim; Amaral-Zettler, Linda; Cochrane, Guy; Cole, James R; Davies, Neil; Dawyndt, Peter; Garrity, George M; Gilbert, Jack A; Glöckner, Frank Oliver; Hirschman, Lynette; Klenk, Hans-Peter; Knight, Rob; Kyrpides, Nikos; Meyer, Folker; Karsch-Mizrachi, Ilene; Morrison, Norman; Robbins, Robert; San Gil, Inigo; Sansone, Susanna; Schriml, Lynn; Tatusova, Tatiana; Ussery, Dave; Yilmaz, Pelin; White, Owen; Wooley, John; Caporaso, Gregory

    2014-06-15

    The Genomic Standards Consortium (GSC) is an open-membership community that was founded in 2005 to work towards the development, implementation and harmonization of standards in the field of genomics. Starting with the defined task of establishing a minimal set of descriptions the GSC has evolved into an active standards-setting body that currently has 18 ongoing projects, with additional projects regularly proposed from within and outside the GSC. Here we describe our recently enacted policy for proposing new activities that are intended to be taken on by the GSC, along with the template for proposing such new activities. PMID:25197446

  19. The Brachypodium genome sequence: a resource for oat genomics research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oat (Avena sativa) is an important cereal crop used as both an animal feed and for human consumption. Genetic and genomic research on oat is hindered because it is hexaploid and possesses a large (13 Gb) genome. Diploid Avena relatives have been employed for genetic and genomic studies, but only mod...

  20. Tick Genomics: The Ixodes genome project and beyond

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ticks and mites (subphylum Chelicerata; subclass Acari) are important pests of animals and plants worldwide. The Ixodes scapularis (black-legged tick) genome sequencing project marks the beginning of the genomics era for the field of acarology. This project is the first to sequence the genome of a...