@article{pirzada_khan_opperman_affokpon_2023, title={Banana-paper seed wrap increases yam crop yield and quality in Africa}, volume={2}, ISSN={["2662-1355"]}, DOI={10.1038/s43016-023-00718-9}, journal={NATURE FOOD}, author={Pirzada, Tahira and Khan, Saad A. and Opperman, Charles H. and Affokpon, Antoine}, year={2023}, month={Feb} } @article{sohail_pirzada_guenther_barbieri_sit_menegatti_crook_opperman_khan_2023, title={Cellulose Acetate-Stabilized Pickering Emulsions: Preparation, Rheology, and Incorporation of Agricultural Active Ingredients}, volume={11}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.3c02428}, DOI={10.1021/acssuschemeng.3c02428}, abstractNote={We report the use of cellulose acetate (CA) nanoparticles (NPs) to produce oil in water Pickering emulsions. The CA NP can emulsify various oils and form stable emulsions at concentrations as low as 0.5 wt %. Rheological and microscopic analyses show evidence of interconnected NP aggregate networks between droplets. Yield stress measurements display evidence of "double" yielding. We postulate that the presence of the NP aggregates provides a secondary network between droplet clusters resulting in such behavior. We demonstrate the suitability of the emulsions as agriculture formulations by incorporating an agrochemical, abamectin (Abm), and a plant-growth-promoting microbe (PGPM) in the emulsions. Release assays exhibit sustained Abm release, promising higher efficacy at lower usage volumes. Incorporation of nonsporulating PGPM Pseudomonas simiae in the emulsions shows significantly higher microbe viability compared to controls after 70 days of storage. By demonstrating the application of CA NPs as a sustainable Pickering emulsifier, this study introduces the use of CA as a platform technology for the delivery of diverse agriculture cargos. A comprehensive evaluation of the system is articulated in a fundamental microstructure analysis and a demonstration of practical on-site attributes, including shelf-life stability and functional performance, verified through bioassays and plant growth studies.}, number={42}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Sohail, Mariam and Pirzada, Tahira and Guenther, Richard and Barbieri, Eduardo and Sit, Tim and Menegatti, Stefano and Crook, Nathan and Opperman, Charles H. and Khan, Saad A.}, year={2023}, month={Sep}, pages={15178–15191} } @article{conceicao_escobar_opperman_fourie_2023, title={Editorial: Genetics of plant-nematode interactions}, volume={14}, ISSN={["1664-462X"]}, DOI={10.3389/fpls.2023.1181564}, abstractNote={COPYRIGHT © 2023 Conceição, Escobar, Opperman and Fourie. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. TYPE Editorial PUBLISHED 16 March 2023 DOI 10.3389/fpls.2023.1181564}, journal={FRONTIERS IN PLANT SCIENCE}, author={Conceicao, Isabel Luci and Escobar, Carolina and Opperman, Charles and Fourie, Hendrika}, year={2023}, month={Mar} } @article{wang_pirzada_xie_barbieri_hossain_opperman_pal_wei_parsons_khan_2022, title={Creating hierarchically porous banana paper-metal organic framework (MOF) composites with multifunctionality}, volume={28}, ISSN={["2352-9407"]}, url={https://doi.org/10.1016/j.apmt.2022.101517}, DOI={10.1016/j.apmt.2022.101517}, abstractNote={We report a robust approach to integrate metal-organic frameworks (MOF) via vapor phase synthesis on a cost-effective and mechanically durable fibrous banana paper (BP) substrate developed from lignocellulosic biomass. The unique hollow fibrous structure of BP combined with the methodology used produces MOF-fiber composites with uniform MOF distribution and enhanced functionalities, with minimal use of organic solvents. The BP-MOF composites demonstrate a high surface area of 552 m2/g and uniform surface growth of MOF on them. Mechanical strength and bending flexibility of the substrate is well retained after the MOF growth, while the hollow tubular nature and hierarchical porosity of the BP facilitate gas diffusion. The BP-MOF composites demonstrate strong antibacterial activity with 99.2% of E.coli destroyed within the first hour of incubation. Preliminary studies with smartphone-based volatile organic compound (VOC) sensor show enhanced 1-octen-3-ol vapor absorption on BP-MOF, indicating its potential for VOC capture and sensing. We believe that the sustainable nature and flexibility of the lignocellulosic BP substrate taken together with uniform growth of MOF on the hierarchically porous BP impart impressive attributes to these composites, which can be explored in diverse applications.}, journal={APPLIED MATERIALS TODAY}, publisher={Elsevier BV}, author={Wang, Siyao and Pirzada, Tahira and Xie, Wenyi and Barbieri, Eduardo and Hossain, Oindrila and Opperman, Charles H. and Pal, Lokendra and Wei, Qingshan and Parsons, Gregory N. and Khan, Saad A.}, year={2022}, month={Aug} } @article{sohail_pirzada_opperman_khan_2022, title={Recent advances in seed coating technologies: transitioning toward sustainable agriculture}, volume={7}, ISSN={["1463-9270"]}, url={https://doi.org/10.1039/D2GC02389J}, DOI={10.1039/d2gc02389j}, abstractNote={This review provides a sustainability perspective on existing seed coating research through comparing potential agricultural benefits with the associated energy, chemical and environmental footprints.}, journal={GREEN CHEMISTRY}, publisher={Royal Society of Chemistry (RSC)}, author={Sohail, Mariam and Pirzada, Tahira and Opperman, Charles H. and Khan, Saad A.}, year={2022}, month={Jul} } @article{ochola_cortada_mwaura_tariku_christensen_ng'ang'a_hassanali_pirzada_khan_pal_et al._2022, title={Wrap-and-plant technology to manage sustainably potato cyst nematodes in East Africa}, volume={2}, ISSN={["2398-9629"]}, url={https://doi.org/10.1038/s41893-022-00852-5}, DOI={10.1038/s41893-022-00852-5}, abstractNote={AbstractRenewable eco-friendly options for crop protection are fundamental in achieving sustainable agriculture. Here, we demonstrate the use of a biodegradable lignocellulosic banana-paper matrix as a seed wrap for the protection of potato plants against potato cyst nematode (PCN), Globodera rostochiensis. Potato cyst nematodes are devastating quarantine pests of potato globally. In East Africa, G. rostochiensis has recently emerged as a serious threat to potato production. Wrapping seed potatoes within the lignocellulose banana-paper matrix substantially reduced G. rostochiensis field inoculum and increased potato yields by up to fivefold in Kenya, relative to farmer practice, whether or not impregnated with ultra-low doses of the nematicide abamectin (ABM). Markedly, ABM-treated banana paper at ~1,000 times lower than conventional recommendations reduced PCN inoculum. Assays and analyses revealed that the lignocellulose matrix disrupts parasite–host chemical signalling by adsorbing critical PCN hatching and infective juvenile host location chemicals present in potato root exudate. Recovery experiments confirmed adsorption of these host location chemicals. Our study demonstrates the use of waste organic material to sustainably manage PCN, and potentially other crop root pests, while increasing potato yields.}, journal={NATURE SUSTAINABILITY}, author={Ochola, Juliet and Cortada, Laura and Mwaura, Onesmus and Tariku, Meklit and Christensen, Shawn A. and Ng'ang'a, Margaret and Hassanali, Ahmed and Pirzada, Tahira and Khan, Saad and Pal, Lokendra and et al.}, year={2022}, month={Feb} } @article{pirzada_sohail_tripathi_farias_mathew_li_opperman_khan_2021, title={Toward Sustainable Crop Protection: Aqueous Dispersions of Biodegradable Particles with Tunable Release and Rainfastness}, volume={11}, ISSN={["1616-3028"]}, url={https://doi.org/10.1002/adfm.202108046}, DOI={10.1002/adfm.202108046}, abstractNote={AbstractFabrication of aqueous particulate dispersions of biodegradable cellulose esters (CEs) as efficient carriers of agrochemical active‐ingredients (AIs) for foliar applications, is reported. The use of different ester substituent groups on CE permits modulation of particle morphology and size, from irregular shapes (<350 nm) to spheres (≈1.1 µm diameter), while maintaining stability as supported by minimal change in zeta potential and particle size over one year. Rainfastness is tested by simulating >50 mm h−1 rainfall on coated banana and tomato leaves and silicon. Surface coverage loss as low as 9%, based on the nature of leaf and formulation, confirms the rainfastness of the formulations. Variation in the release kinetics of a model AI fluopyram from different CEs can be attributed to the particle morphology and the nature of binding between fluopyram and various CEs. Thermodynamic analysis demonstrates spontaneous binding between fluopyram and multiple sites of CEs, justifying its two‐step release from CE particles. System functionalities are corroborated via in‐vitro fungal inhibition assays demonstrating a 100% inhibition of the fungal growth. This “lab‐to‐leaf” approach of materials development involving fundamental insights and functional performance reveals CE dispersions are promising green agricultural formulations with the potential to impact a myriad of crops around the globe.}, journal={ADVANCED FUNCTIONAL MATERIALS}, publisher={Wiley}, author={Pirzada, Tahira and Sohail, Mariam and Tripathi, Anurodh and Farias, Barbara V and Mathew, Reny and Li, Chunying and Opperman, Charles H. and Khan, Saad A.}, year={2021}, month={Nov} } @misc{mathew_opperman_2020, title={Current Insights into Migratory Endoparasitism: Deciphering the Biology, Parasitism Mechanisms, and Management Strategies of Key Migratory Endoparasitic Phytonematodes}, volume={9}, ISSN={["2223-7747"]}, DOI={10.3390/plants9060671}, abstractNote={Despite their physiological differences, sedentary and migratory plant-parasitic nematodes (PPNs) share several commonalities. Functional characterization studies of key effectors and their targets identified in sedentary phytonematodes are broadly applied to migratory PPNs, generalizing parasitism mechanisms existing in distinct lifestyles. Despite their economic significance, host–pathogen interaction studies of migratory endoparasitic nematodes are limited; they have received little attention when compared to their sedentary counterparts. Because several migratory PPNs form disease complexes with other plant-pathogens, it is important to understand multiple factors regulating their feeding behavior and lifecycle. Here, we provide current insights into the biology, parasitism mechanism, and management strategies of the four-key migratory endoparasitic PPN genera, namely Pratylenchus, Radopholus, Ditylenchus, and Bursaphelenchus. Although this review focuses on these four genera, many facets of feeding mechanisms and management are common across all migratory PPNs and hence can be applied across a broad genera of migratory phytonematodes.}, number={6}, journal={PLANTS-BASEL}, author={Mathew, Reny and Opperman, Charles H.}, year={2020}, month={Jun} } @article{ochola_coyne_cortada_haukeland_ng'ang'a_hassanali_opperman_torto_2020, title={Cyst nematode bio-communication with plants: implications for novel management approaches}, ISBN={1526-4998}, DOI={10.1002/ps.6105}, abstractNote={AbstractBio‐communication occurs when living organisms interact with each other, facilitated by the exchange of signals including visual, auditory, tactile and chemical. The most common form of bio‐communication between organisms is mediated by chemical signals, commonly referred to as ‘semiochemicals’, and it involves an emitter releasing the chemical signal that is detected by a receiver leading to a phenotypic response in the latter organism. The quality and quantity of the chemical signal released may be influenced by abiotic and biotic factors. Bio‐communication has been reported to occur in both above‐ and below‐ground interactions and it can be exploited for the management of pests, such as cyst nematodes, which are pervasive soil‐borne pests that cause significant crop production losses worldwide. Cyst nematode hatching and successful infection of hosts are biological processes that are largely influenced by semiochemicals including hatching stimulators, hatching inhibitors, attractants and repellents. These semiochemicals can be used to disrupt interactions between host plants and cyst nematodes. Advances in RNAi techniques such as host‐induced gene silencing to interfere with cyst nematode hatching and host location can also be exploited for development of synthetic resistant host cultivars. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.}, journal={PEST MANAGEMENT SCIENCE}, author={Ochola, Juliet and Coyne, Danny and Cortada, Laura and Haukeland, Solveig and Ng'ang'a, Margaret and Hassanali, Ahmed and Opperman, Charles and Torto, Baldwyn}, year={2020} } @article{mathew_opperman_2019, title={The genome of the migratory nematode, Radopholus similis, reveals signatures of close association to the sedentary cyst nematodes}, volume={14}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0224391}, abstractNote={Radopholus similis, commonly known as the burrowing nematode, is an important pest of myriad crops and ornamentals including banana (Musa spp.) and Citrus spp. In order to characterize the potential role of putative effectors encoded by R. similis genes we compared predicted proteins from a draft R. similis genome with other plant-parasitic nematodes in order to define the suite of excreted/secreted proteins that enable it to function as a parasite and to ascertain the phylogenetic position of R. similis in the Tylenchida order. Identification and analysis of candidate genes encoding for key plant cell-wall degrading enzymes including GH5 cellulases, PL3 pectate lyases and GH28 polygalactouranase revealed a pattern of occurrence similar to other PPNs, although with closest phylogenetic associations to the sedentary cyst nematodes. We also observed the absence of a suite of effectors essential for feeding site formation in the cyst nematodes. Clustering of various orthologous genes shared by R. similis with other nematodes showed higher overlap with the cyst nematodes than with the root-knot or other migratory endoparasitic nematodes. The data presented here support the hypothesis that R. similis is evolutionarily closer to the cyst nematodes, however, differences in the effector repertoire delineate ancient divergence of parasitism, probably as a consequence of niche specialization. These similarities and differences further underscore distinct evolutionary relationships during the evolution of parasitism in this group of nematodes.}, number={10}, journal={PLOS ONE}, author={Mathew, Reny and Opperman, Charles H.}, year={2019}, month={Oct} } @article{tyagi_mathew_opperman_jameel_gonzalez_lucia_hubbe_pal_2018, title={High-Strength Antibacterial Chitosan–Cellulose Nanocrystal Composite Tissue Paper}, volume={35}, ISSN={0743-7463 1520-5827}, url={http://dx.doi.org/10.1021/acs.langmuir.8b02655}, DOI={10.1021/acs.langmuir.8b02655}, abstractNote={A heightened need to control the spread of infectious diseases prompted the current work in which functionalized and innovative antimicrobial tissue paper was developed with a hydrophobic spray-coating of chitosan (Ch) and cellulose nanocrystals (CNCs) composite. It was hypothesized that the hydrophobic nature of chitosan could be counterbalanced by the addition of CNC to maintain fiber formation and water absorbency. Light-weight tissue handsheets were prepared, spray-coated with Ch, CNC, and their composite coating (ChCNC), and tested for antimicrobial activity against Gram-negative bacteria Escherichia coli and a microbial sample from a human hand after using the rest room. Water absorption and strength properties were also analyzed. To activate the surface of cationized tissue paper, an oxygen/helium gas atmospheric plasma treatment was employed on the best performing antimicrobial tissue papers. The highest bactericidal activity was observed with ChCNC-coated tissue paper, inhibiting up to 98% microbial growth. Plasma treatment further improved the antimicrobial activity of the coatings. Water absorption properties were reduced with Ch but increased with CNC. This "self-disinfecting" bactericidal tissue has the potential to be one of the most innovative products for the hygiene industry because it can dry, clean, and resist the infection of surfaces simultaneously, providing significant societal benefits.}, number={1}, journal={Langmuir}, publisher={American Chemical Society (ACS)}, author={Tyagi, Preeti and Mathew, Reny and Opperman, Charles and Jameel, Hasan and Gonzalez, Ronalds and Lucia, Lucian and Hubbe, Martin and Pal, Lokendra}, year={2018}, month={Nov}, pages={104–112} } @article{guenther_lommel_opperman_sit_2018, title={Plant Virus-Based Nanoparticles for the Delivery of Agronomic Compounds as a Suspension Concentrate}, volume={1776}, ISBN={["978-1-4939-7806-9"]}, ISSN={["1940-6029"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85048246738&partnerID=MN8TOARS}, DOI={10.1007/978-1-4939-7808-3_13}, abstractNote={Nanoparticle formulations of agrichemicals may enhance their performance while simultaneously mitigating any adverse environmental effects. Red clover necrotic mosaic virus (RCNMV) is a soil-transmitted plant virus with many inherent attributes that allow it to function as a plant virus-based nanoparticle (PVN) when loaded with biologically active ingredients. Here we describe how to formulate a PVN loaded with the nematicide abamectin (Abm) beginning with the propagation of the virus through the formulation, deactivation, and characterization of the finished product.}, journal={VIRUS-DERIVED NANOPARTICLES FOR ADVANCED TECHNOLOGIES: METHODS AND PROTOCOLS}, publisher={Springer New York}, author={Guenther, Richard H. and Lommel, Steven A. and Opperman, Charles H. and Sit, Tim L.}, year={2018}, pages={203–214} } @article{holterman_karegar_mooijman_megen_elsen_vervoort_quist_karssen_decraemer_opperman_et al._2017, title={Disparate gain and loss of parasitic abilities among nematode lineages}, volume={12}, ISSN={["1932-6203"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85029856456&partnerID=MN8TOARS}, DOI={10.1371/journal.pone.0185445}, abstractNote={Plant parasitism has arisen time and again in multiple phyla, including bacteria, fungi, insects and nematodes. In most of these organismal groups, the overwhelming diversity hampers a robust reconstruction of the origins and diversification patterns of this trophic lifestyle. Being a moderately diversified phylum with ≈ 4,100 plant parasites (15% of total biodiversity) subdivided over four independent lineages, nematodes constitute a major organismal group for which the genesis of plant parasitism could be mapped. Since substantial crop losses worldwide have been attributed to less than 1% of these plant parasites, research efforts are severely biased towards this minority. With the first molecular characterisation of numerous basal and supposedly harmless plant parasites as well as their non-parasitic relatives, we were able to generate a comprehensive molecular framework that allows for the reconstruction of trophic diversification for a complete phylum. In each lineage plant parasites reside in a single taxonomic grouping (family or order), and by taking the coverage of the next lower taxonomic level as a measure for representation, 50, 67, 100 and 85% of the known diversity was included. We revealed distinct gain and loss patterns with regard to plant parasitism per se as well as host exploitation strategies between these lineages. Our map of parasitic nematode biodiversity also revealed an unanticipated time reversal in which the two most ancient lineages showed the lowest level of ecological diversification and vice versa.}, number={9}, journal={PLOS ONE}, author={Holterman, Martijn and Karegar, Akbar and Mooijman, Paul and Megen, Hanny and Elsen, Sven and Vervoort, Mariette T. W. and Quist, Casper W. and Karssen, Gerrit and Decraemer, Wilfrida and Opperman, Charles H. and et al.}, year={2017}, month={Sep} } @article{ruark_koenning_davis_opperman_lommel_mitchum_sit_2017, title={Soybean cyst nematode culture collections and field populations from North Carolina and Missouri reveal high incidences of infection by viruses}, volume={12}, ISSN={["1932-6203"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85011268632&partnerID=MN8TOARS}, DOI={10.1371/journal.pone.0171514}, abstractNote={Five viruses were previously discovered infecting soybean cyst nematodes (SCN; Heterodera glycines) from greenhouse cultures maintained in Illinois. In this study, the five viruses [ScNV, ScPV, ScRV, ScTV, and SbCNV-5] were detected within SCN greenhouse and field populations from North Carolina (NC) and Missouri (MO). The prevalence and titers of viruses in SCN from 43 greenhouse cultures and 25 field populations were analyzed using qRT-PCR. Viral titers within SCN greenhouse cultures were similar throughout juvenile development, and the presence of viral anti-genomic RNAs within egg, second-stage juvenile (J2), and pooled J3 and J4 stages suggests active viral replication within the nematode. Viruses were found at similar or lower levels within field populations of SCN compared with greenhouse cultures of North Carolina populations. Five greenhouse cultures harbored all five known viruses whereas in most populations a mixture of fewer viruses was detected. In contrast, three greenhouse cultures of similar descent to one another did not possess any detectable viruses and primarily differed in location of the cultures (NC versus MO). Several of these SCN viruses were also detected in Heterodera trifolii (clover cyst) and Heterodera schachtii (beet cyst), but not the other cyst, root-knot, or reniform nematode species tested. Viruses were not detected within soybean host plant tissue. If nematode infection with viruses is truly more common than first considered, the potential influence on nematode biology, pathogenicity, ecology, and control warrants continued investigation.}, number={1}, journal={PLOS ONE}, publisher={Public Library of Science (PLoS)}, author={Ruark, Casey L. and Koenning, Stephen R. and Davis, Eric L. and Opperman, Charles H. and Lommel, Steven A. and Mitchum, Melissa G. and Sit, Tim L.}, editor={Rao, A.L.N.Editor}, year={2017}, month={Jan} } @article{szitenberg_cha_opperman_bird_blaxter_lunt_2016, title={Genetic Drift, Not Life History or RNAi, Determine Long-Term Evolution of Transposable Elements}, volume={8}, ISSN={["1759-6653"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84995387797&partnerID=MN8TOARS}, DOI={10.1093/gbe/evw208}, abstractNote={Abstract Transposable elements (TEs) are a major source of genome variation across the branches of life. Although TEs may play an adaptive role in their host’s genome, they are more often deleterious, and purifying selection is an important factor controlling their genomic loads. In contrast, life history, mating system, GC content, and RNAi pathways have been suggested to account for the disparity of TE loads in different species. Previous studies of fungal, plant, and animal genomes have reported conflicting results regarding the direction in which these genomic features drive TE evolution. Many of these studies have had limited power, however, because they studied taxonomically narrow systems, comparing only a limited number of phylogenetically independent contrasts, and did not address long-term effects on TE evolution. Here, we test the long-term determinants of TE evolution by comparing 42 nematode genomes spanning over 500 million years of diversification. This analysis includes numerous transitions between life history states, and RNAi pathways, and evaluates if these forces are sufficiently persistent to affect the long-term evolution of TE loads in eukaryotic genomes. Although we demonstrate statistical power to detect selection, we find no evidence that variation in these factors influence genomic TE loads across extended periods of time. In contrast, the effects of genetic drift appear to persist and control TE variation among species. We suggest that variation in the tested factors are largely inconsequential to the large differences in TE content observed between genomes, and only by these large-scale comparisons can we distinguish long-term and persistent effects from transient or random changes.}, number={9}, journal={GENOME BIOLOGY AND EVOLUTION}, author={Szitenberg, Amir and Cha, Soyeon and Opperman, Charles H. and Bird, David M. and Blaxter, Mark L. and Lunt, David H.}, year={2016}, month={Sep}, pages={2964–2978} } @article{galle_opperman_kerns_2016, title={Population dynamics of Belonolaimus longicaudatus in Central North Carolina}, volume={48}, number={4}, journal={Journal of Nematology}, author={Galle, G. and Opperman, C. H. and Kerns, J. P.}, year={2016}, pages={322–323} } @article{heiken_schwarz_davis_opperman_2016, title={The Effects of fluopyram on nematodes}, volume={48}, number={4}, journal={Journal of Nematology}, author={Heiken, J. and Schwarz, M. R. and Davis, E. L. and Opperman, C. H.}, year={2016}, pages={330–331} } @article{cao_guenther_sit_lommel_opperman_willoughby_2015, title={Development of Abamectin Loaded Plant Virus Nanoparticles for Efficacious Plant Parasitic Nematode Control}, volume={7}, ISSN={1944-8244 1944-8252}, url={http://dx.doi.org/10.1021/ACSAMI.5B00940}, DOI={10.1021/ACSAMI.5B00940}, abstractNote={Plant parasitic nematodes are one of the world's major agricultural pests, causing in excess of $157 billion in worldwide crop damage annually. Abamectin (Abm) is a biological pesticide with a strong activity against a wide variety of plant parasitic nematodes. However, Abm's poor mobility in the soil compromises its nematicide performance because of the limited zone of protection surrounding the growing root system of the plant. In this study, we manipulated Abm's soil physical chemistry by encapsulating Abm within the Red clover necrotic mosaic virus (RCNMV) to produce a plant virus nanoparticle (PVN) delivery system for Abm. The transmission electron microscopic and dynamic light scattering characterization of Abm-loaded PVN (PVN(Abm)) indicated the resultant viral capsid integrity and morphology comparable to native RCNMV. In addition, the PVN(Abm) significantly increased Abm's soil mobility while enabling a controlled release strategy for Abm's bioavailability to nematodes. As a result, PVN(Abm) enlarged the zone of protection from Meloidogyne hapla root knot nematodes in the soil as compared to treating with free Abm molecules. Tomato seedlings treated with PVN(Abm) had healthier root growth and a reduction in root galling demonstrating the success of this delivery system for the increased efficacy of Abm to control nematode damage in crops.}, number={18}, journal={ACS Applied Materials & Interfaces}, publisher={American Chemical Society (ACS)}, author={Cao, Jing and Guenther, Richard H. and Sit, Tim L. and Lommel, Steven A. and Opperman, Charles H. and Willoughby, Julie A.}, year={2015}, month={May}, pages={9546–9553} } @article{cao_guenther_sit_lommel_opperman_willoughby_2016, title={Development of abamectin loaded lignocellulosic matrices for the controlled release of nematicide for crop protection}, volume={23}, ISSN={["1572-882X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84955651797&partnerID=MN8TOARS}, DOI={10.1007/s10570-015-0817-6}, number={1}, journal={CELLULOSE}, publisher={Springer Science and Business Media LLC}, author={Cao, Jing and Guenther, Richard H. and Sit, Tim L. and Lommel, Steven A. and Opperman, Charles H. and Willoughby, Julie A.}, year={2016}, month={Feb}, pages={673–687} } @article{vang_opperman_schwarz_davis_2016, title={Spirotetramat causes an arrest of nematode juvenile development}, volume={18}, ISSN={["1388-5545"]}, DOI={10.1163/15685411-00002948}, abstractNote={Spirotetramat (Movento™, Bayer CropScience) (SPT), an effective insecticide, has also demonstrated potential activity as a nematicide. No significant effects on hatching rates ofCaenorhabditis elegans,Meloidogyne incognitaorHeterodera glycineswere observed when eggs were soaked in a maximum concentration of 105 ppm of technical grade spirotetramat-enol (SPT-enol), the active form in plants. Synchronised first-stage juveniles ofC. eleganssoaked in SPT-enol concentrations as low as 30 ppm demonstrated arrested juvenile development with calculated EC95of 44-48 ppm. Single applications of formulated SPT (Movento 240SC) were applied to plant foliage at the labelled insecticidal rate of 87.6 g a.s. ha−1at 1-week intervals on soybean plants inoculated withH. glycinesor tomato plants inoculated withM. incognitain glasshouse tests. SPT consistently inhibited nematode development to reproductive maturity when applied at 1-2 weeks after inoculation. Optimal SPT application timings coincide with early stages of root infection, when nematodes are still in vulnerable juvenile stages.}, journal={NEMATOLOGY}, author={Vang, Leah E. and Opperman, Charles H. and Schwarz, Michael R. and Davis, Eric L.}, year={2016}, pages={121–131} } @article{burke_scholl_bird_schaff_colman_crowell_diener_gordon_graham_wang_et al._2015, title={The plant parasite Pratylenchus coffeae carries a minimal nematode genome}, volume={17}, ISSN={["1388-5545"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84938097712&partnerID=MN8TOARS}, DOI={10.1163/15685411-00002901}, abstractNote={Here we report the genome sequence of the lesion nematode, Pratylenchus coffeae, a significant pest of banana and other staple crops in tropical and sub-tropical regions worldwide. Initial analysis of the 19.67 Mb genome reveals 6712 protein encoding genes, the smallest number found in a metazoan, although sufficient to make a nematode. Significantly, no developmental or physiological pathways are obviously missing when compared to the model free-living nematode Caenorhabditis elegans, which possesses approximately 21 000 genes. The highly streamlined P. coffeae genome may reveal a remarkable functional plasticity in nematode genomes and may also indicate evolutionary routes to increased specialisation in other nematode genera. In addition, the P. coffeae genome may begin to reveal the core set of genes necessary to make a multicellular animal. Nematodes exhibit striking diversity in the niches they occupy, and the sequence of P. coffeae is a tool to begin to unravel the mechanisms that enable the extraordinary success of this phylum as both free-living and parasitic forms. Unlike the sedentary endoparasitic root-knot nematodes (Meloidogyne spp.), P. coffeae is a root-lesion nematode that does not establish a feeding site within the root. Because the P. coffeae nematode genome encodes fewer than half the number of genes found in the genomes of root-knot nematodes, comparative analysis to determine genes P. coffeae does not carry may help to define development of more sophisticated forms of nematode-plant interactions. The P. coffeae genome sequence may help to define timelines related to evolution of parasitism amongst nematodes. The genome of P. coffeae is a significant new tool to understand not only nematode evolution but animal biology in general.}, number={6}, journal={NEMATOLOGY}, author={Burke, Mark and Scholl, Elizabeth H. and Bird, David McK. and Schaff, Jennifer E. and Colman, Steven D. and Crowell, Randy and Diener, Stephen and Gordon, Oksana and Graham, Steven and Wang, Xinguo and et al.}, year={2015}, pages={621–637} } @article{cao_guenther_sit_opperman_lommel_willoughby_2014, title={Loading and Release Mechanism of Red Clover Necrotic Mosaic Virus Derived Plant Viral Nanoparticles for Drug Delivery of Doxorubicin}, volume={10}, ISSN={["1613-6829"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84919761332&partnerID=MN8TOARS}, DOI={10.1002/smll.201400558}, abstractNote={Loading and release mechanisms of Red clover necrotic mosaicvirus (RCNMV) derived plant viral nanoparticle (PVN) are shown for controlled delivery of the anticancer drug, doxorubicin (Dox). Previous studies demonstrate that RCNMV's structure and unique response to divalent cation depletion and re‐addition enables Dox infusion to the viral capsid through a pore formation mechanism. However, by controlling the net charge of RCNMV outer surface and accessibility of RCNMV interior cavity, tunable release of PVN is possible via manipulation of the Dox loading capacity and binding locations (external surface‐binding or internal capsid‐encapsulation) with the RCNMV capsid. Bimodal release kinetics is achieved via a rapid release of surface‐Dox followed by a slow release of encapsulated Dox. Moreover, the rate of Dox release and the amount of released Dox increases with an increase in environmental pH or a decrease in concentration of divalent cations. This pH‐responsive Dox release from PVN is controlled by Fickian diffusion kinetics where the release rate is dependent on the location of the bound or loaded active molecule. In summary, controllable release of Dox‐loaded PVNs is imparted by 1) formulation conditions and 2) driven by the capsid's pH‐ and ion‐ responsive functions in a given environment.}, number={24}, journal={SMALL}, publisher={Wiley}, author={Cao, Jing and Guenther, Richard H. and Sit, Tim L. and Opperman, Charles H. and Lommel, Steven A. and Willoughby, Julie A.}, year={2014}, month={Dec}, pages={5126–5136} } @article{bird_jones_opperman_kikuchi_danchin_2015, title={Signatures of adaptation to plant parasitism in nematode genomes}, volume={142}, ISSN={0031-1820 1469-8161}, url={http://dx.doi.org/10.1017/S0031182013002163}, DOI={10.1017/S0031182013002163}, abstractNote={SUMMARYPlant-parasitic nematodes cause considerable damage to global agriculture. The ability to parasitize plants is a derived character that appears to have independently emerged several times in the phylum Nematoda. Morphological convergence to feeding style has been observed, but whether this is emergent from molecular convergence is less obvious. To address this, we assess whether genomic signatures can be associated with plant parasitism by nematodes. In this review, we report genomic features and characteristics that appear to be common in plant-parasitic nematodes while absent or rare in animal parasites, predators or free-living species. Candidate horizontal acquisitions of parasitism genes have systematically been found in all plant-parasitic species investigated at the sequence level. Presence of peptides that mimic plant hormones also appears to be a trait of plant-parasitic species. Annotations of the few genomes of plant-parasitic nematodes available to date have revealed a set of apparently species-specific genes on every occasion. Effector genes, important for parasitism are frequently found among those species-specific genes, indicating poor overlap. Overall, nematodes appear to have developed convergent genomic solutions to adapt to plant parasitism.}, number={S1}, journal={Parasitology}, publisher={Cambridge University Press (CUP)}, author={Bird, David Mc K. and Jones, John T. and Opperman, Charles H. and Kikuchi, Taisei and Danchin, Etienne G. J.}, year={2015}, month={Feb}, pages={S71–S84} } @article{davies_rowe_manzanilla-lopez_opperman_2011, title={Re-evaluation of the life-cycle of the nematode-parasitic bacterium Pasteuria penetrans in root-knot nematodes, Meloidogyne spp.}, volume={13}, ISSN={["1388-5545"]}, DOI={10.1163/138855410x552670}, abstractNote={ Abstract Comparisons of the growth of Pasteuria penetrans in adult root-knot nematode females infected with P. penetrans dissected from the roots of tomato plants were undertaken using bright-field and scanning electron microscopy. Samples of infected females were nutritionally compromised by maintaining them in sterile saline at 30°C for different periods of time following their removal from the root system. Observations of these females maintained in saline revealed a series of growth stages of Pasteuria hitherto not documented, consisting of rhizoids, rod-like bacilli and granular masses. A new life-cycle for Pasteuria is described consisting of three phases: Phase I: attachment and germination; Phase II: rhizoid production and exponential growth; and Phase III: sporogenesis. These newly observed stages of the life cycle show a high degree of similarity to the developmental stages seen in other Bacillus spp. }, journal={NEMATOLOGY}, author={Davies, Keith G. and Rowe, Janet and Manzanilla-Lopez, Rosa and Opperman, Charles H.}, year={2011}, pages={825–835} } @article{mauchline_mohan_davies_schaff_opperman_kerry_hirsch_2010, title={A method for release and multiple strand amplification of small quantities of DNA from endospores of the fastidious bacterium Pasteuria penetrans}, volume={50}, ISSN={["0266-8254"]}, DOI={10.1111/j.1472-765x.2010.02830.x}, abstractNote={Aims:  To establish a reliable protocol to extract DNA from Pasteuria penetrans endospores for use as template in multiple strand amplification, thus providing sufficient material for genetic analyses. To develop a highly sensitive PCR‐based diagnostic tool for P. penetrans.}, number={5}, journal={LETTERS IN APPLIED MICROBIOLOGY}, author={Mauchline, T. H. and Mohan, S. and Davies, K. G. and Schaff, J. E. and Opperman, C. H. and Kerry, B. R. and Hirsch, P. R.}, year={2010}, month={May}, pages={515–521} } @article{cabrera_donohue_khalil_scholl_opperman_sonenshine_roe_2011, title={New approach for the study of mite reproduction: The first transcriptome analysis of a mite, Phytoseiulus persimilis (Acari: Phytoseiidae)}, volume={57}, ISSN={0022-1910}, url={http://dx.doi.org/10.1016/j.jinsphys.2010.09.006}, DOI={10.1016/j.jinsphys.2010.09.006}, abstractNote={Many species of mites and ticks are of agricultural and medical importance. Much can be learned from the study of transcriptomes of acarines which can generate DNA-sequence information of potential target genes for the control of acarine pests. High throughput transcriptome sequencing can also yield sequences of genes critical during physiological processes poorly understood in acarines, i.e., the regulation of female reproduction in mites. The predatory mite, Phytoseiulus persimilis, was selected to conduct a transcriptome analysis using 454 pyrosequencing. The objective of this project was to obtain DNA-sequence information of expressed genes from P. persimilis with special interest in sequences corresponding to vitellogenin (Vg) and the vitellogenin receptor (VgR). These genes are critical to the understanding of vitellogenesis, and they will facilitate the study of the regulation of mite female reproduction. A total of 12,556 contiguous sequences (contigs) were assembled with an average size of 935bp. From these sequences, the putative translated peptides of 11 contigs were similar in amino acid sequences to other arthropod Vgs, while 6 were similar to VgRs. We selected some of these sequences to conduct stage-specific expression studies to further determine their function.}, number={1}, journal={Journal of Insect Physiology}, publisher={Elsevier BV}, author={Cabrera, Ana R. and Donohue, Kevin V. and Khalil, Sayed M.S. and Scholl, Elizabeth and Opperman, Charles and Sonenshine, Daniel E. and Roe, R. Michael}, year={2011}, month={Jan}, pages={52–61} } @article{mbeunkui_scholl_opperman_goshe_bird_2010, title={Proteomic and Bioinformatic Analysis of the Root-Knot Nematode Meloidogyne hapla: The Basis for Plant Parasitism}, volume={9}, ISSN={1535-3893 1535-3907}, url={http://dx.doi.org/10.1021/pr1006069}, DOI={10.1021/pr1006069}, abstractNote={On the basis of the complete genome sequence of the root-knot nematode Melodogyne hapla, we have deduced and annotated the entire proteome of this plant-parasite to create a database of 14,420 proteins. We have made this database, termed HapPep3, available from the Superfamily repository of model organism proteomes (http://supfam.mrc-lmb.cam.ac.uk/SUPERFAMILY). To experimentally confirm the HapPep3 assignments using proteomics, we applied a data-independent LC/MS(E) analysis to M. hapla protein extracts fractionated by SDS-PAGE. A total of 516 nonredundant proteins were identified with an average of 9 unique peptides detected per protein. Some proteins, including examples with complex gene organization, were defined by more than 20 unique peptide matches, thus, providing experimental confirmation of computational predictions of intron/exon structures. On the basis of comparisons of the broad physicochemical properties of the experimental and computational proteomes, we conclude that the identified proteins reflect a true and unbiased sampling of HapPep3. Conversely, HapPep3 appears to broadly cover the protein space able to be experimentally sampled. To estimate the false discovery rate, we queried human, plant, and bacterial databases for matches to the LC/MS(E)-derived peptides, revealing fewer than 1% of matches, most of which were to highly conserved proteins. To provide a functional comparison of the acquired and deduced proteomes, each was subjected to higher order annotation, including comparisons of Gene Ontology, protein domains, signaling, and localization predictions, further indicating concordance, although those proteins that did deviate seem to be highly significant. Approximately 20% of the experimentally sampled proteome was predicted to be secreted, and thus potentially play a role at the host-parasite interface. We examined reference pathways to determine the extent of proteome similarity of M. hapla to that of the free-living nematode, Caenorhabditis elegans, revealing significant similarities and differences. Collectively, the analyzed protein set provides an initial foundation to experimentally dissect the basis of plant parasitism by M. hapla.}, number={10}, journal={Journal of Proteome Research}, publisher={American Chemical Society (ACS)}, author={Mbeunkui, Flaubert and Scholl, Elizabeth H. and Opperman, Charles H. and Goshe, Michael B. and Bird, David McK.}, year={2010}, month={Oct}, pages={5370–5381} } @article{bird_williamson_abad_mccarter_danchin_castagnone-sereno_opperman_2009, title={The Genomes of Root-Knot Nematodes}, volume={47}, ISSN={["1545-2107"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-70350221931&partnerID=MN8TOARS}, DOI={10.1146/annurev-phyto-080508-081839}, abstractNote={ Plant-parasitic nematodes are the most destructive group of plant pathogens worldwide and are extremely challenging to control. The recent completion of two root-knot nematode genomes opens the way for a comparative genomics approach to elucidate the success of these parasites. Sequencing revealed that Meloidogyne hapla, a diploid that reproduces by facultative, meiotic parthenogenesis, encodes approximately 14,200 genes in a compact, 54 Mpb genome. Indeed, this is the smallest metazoan genome completed to date. By contrast, the 86 Mbp Meloidogyne incognita genome encodes approximately 19,200 genes. This species reproduces by obligate mitotic parthenogenesis and exhibits a complex pattern of aneuploidy. The genome includes triplicated regions and contains allelic pairs with exceptionally high degrees of sequence divergence, presumably reflecting adaptations to the strictly asexual reproductive mode. Both root-knot nematode genomes have compacted gene families compared with the free-living nematode Caenorhabditis elegans, and both encode large suites of enzymes that uniquely target the host plant. Acquisition of these genes, apparently via horizontal gene transfer, and their subsequent expansion and diversification point to the evolutionary history of these parasites. It also suggests new routes to their control. }, journal={ANNUAL REVIEW OF PHYTOPATHOLOGY}, author={Bird, David McK. and Williamson, Valerie M. and Abad, Pierre and McCarter, James and Danchin, Etienne G. J. and Castagnone-Sereno, Philippe and Opperman, Charles H.}, year={2009}, pages={333–351} } @misc{bird_opperman_2009, title={The secret(ion) life of worms}, volume={10}, ISSN={["1474-760X"]}, DOI={10.1186/gb-2009-10-1-205}, abstractNote={Tandem mass spectrographic analysis of the secreted proteins of plant- and human-parasitic nematodes reveals molecular similarities that reflect the shared need to counter host defenses.}, number={1}, journal={GENOME BIOLOGY}, author={Bird, David Mck and Opperman, Charles H.}, year={2009} } @article{dhandaydham_charles_zhu_starr_huguet_cook_prosperi_opperman_2008, title={Characterization of root-knot nematode resistance in Medicago truncatula}, volume={40}, number={1}, journal={Journal of Nematology}, author={Dhandaydham, M. and Charles, L. and Zhu, H. and Starr, J. L. and Huguet, T. and Cook, D. R. and Prosperi, J. M. and Opperman, C.}, year={2008}, pages={46–54} } @article{opperman_bird_williamson_rokhsar_burke_cohn_cromer_diener_gajan_graham_et al._2008, title={Sequence and genetic map of Meloidogyne hapla: A compact nematode genome for plant parasitism}, volume={105}, ISSN={["1091-6490"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-54149092490&partnerID=MN8TOARS}, DOI={10.1073/pnas.0805946105}, abstractNote={ We have established Meloidogyne hapla as a tractable model plant-parasitic nematode amenable to forward and reverse genetics, and we present a complete genome sequence. At 54 Mbp, M. hapla represents not only the smallest nematode genome yet completed, but also the smallest metazoan, and defines a platform to elucidate mechanisms of parasitism by what is the largest uncontrolled group of plant pathogens worldwide. The M. hapla genome encodes significantly fewer genes than does the free-living nematode Caenorhabditis elegans (most notably through a reduction of odorant receptors and other gene families), yet it has acquired horizontally from other kingdoms numerous genes suspected to be involved in adaptations to parasitism. In some cases, amplification and tandem duplication have occurred with genes suspected of being acquired horizontally and involved in parasitism of plants. Although M. hapla and C. elegans diverged >500 million years ago, many developmental and biochemical pathways, including those for dauer formation and RNAi, are conserved. Although overall genome organization is not conserved, there are areas of microsynteny that may suggest a primary biological function in nematodes for those genes in these areas. This sequence and map represent a wealth of biological information on both the nature of nematode parasitism of plants and its evolution. }, number={39}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, author={Opperman, Charles H. and Bird, David M. and Williamson, Valerie M. and Rokhsar, Dan S. and Burke, Mark and Cohn, Jonathan and Cromer, John and Diener, Steve and Gajan, Jim and Graham, Steve and et al.}, year={2008}, month={Sep}, pages={14802–14807} } @article{snyder_opperman_bird_2006, title={A method for generating Meloidogyne incognita males}, volume={38}, number={2}, journal={Journal of Nematology}, author={Snyder, D. W. and Opperman, C. H. and Bird, D. M.}, year={2006}, pages={192–194} } @article{waterman_bird_opperman_2006, title={A method for isolation of Pasteuria penetrans endospores for bioassay and genomic studies}, volume={38}, number={1}, journal={Journal of Nematology}, author={Waterman, J. T. and Bird, D. M. and Opperman, C. H.}, year={2006}, pages={165–167} } @article{diener_houfek_kalat_windham_burke_opperman_dean_2005, title={Alkahest NuclearBLAST: a user-friendly BLAST management and analysis system}, volume={6}, journal={BMC Bioinformatics}, author={Diener, S. E. and Houfek, T. D. and Kalat, S. E. and Windham, D. E. and Burke, M. and Opperman, C. and Dean, R. A.}, year={2005} } @article{charles_carbone_davies_bird_burke_kerry_opperman_2005, title={Phylogenetic analysis of Pasteuria penetrans by use of multiple genetic loci}, volume={187}, ISSN={["1098-5530"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-23644445501&partnerID=MN8TOARS}, DOI={10.1128/JB.187.16.5700-5708.2005}, abstractNote={ABSTRACT Pasteuria penetrans is a gram-positive, endospore-forming eubacterium that apparently is a member of the Bacillus-Clostridium clade. It is an obligate parasite of root knot nematodes ( Meloidogyne spp.) and preferentially grows on the developing ovaries, inhibiting reproduction. Root knot nematodes are devastating root pests of economically important crop plants and are difficult to control. Consequently, P. penetrans has long been recognized as a potential biocontrol agent for root knot nematodes, but the fastidious life cycle and the obligate nature of parasitism have inhibited progress on mass culture and deployment. We are currently sequencing the genome of the Pasteuria bacterium and have performed amino acid level analyses of 33 bacterial species (including P. penetrans ) using concatenation of 40 housekeeping genes, with and without insertions/deletions (indels) removed, and using each gene individually. By application of maximum-likelihood, maximum-parsimony, and Bayesian methods to the resulting data sets, P. penetrans was found to cluster tightly, with a high level of confidence, in the Bacillus class of the gram-positive, low-G+C-content eubacteria. Strikingly, our analyses identified P. penetrans as ancestral to Bacillus spp. Additionally, all analyses revealed that P. penetrans is surprisingly more closely related to the saprophytic extremophile Bacillus haladurans and Bacillus subtilis than to the pathogenic species Bacillus anthracis and Bacillus cereus . Collectively, these findings strongly imply that P. penetrans is an ancient member of the Bacillus group. We suggest that P. penetrans may have evolved from an ancient symbiotic bacterial associate of nematodes, possibly as the root knot nematode evolved to be a highly specialized parasite of plants. }, number={16}, journal={JOURNAL OF BACTERIOLOGY}, author={Charles, L and Carbone, I and Davies, KG and Bird, D and Burke, M and Kerry, BR and Opperman, CH}, year={2005}, month={Aug}, pages={5700–5708} } @article{kojetin_thompson_benson_naylor_waterman_davies_opperman_stephenson_hoch_cavanagh_2005, title={Structural analysis of divalent metals binding to the Bacillus subtilis response regulator Spo0F: the possibility for In vitro metalloregulation in the initiation of sporulation}, volume={18}, ISSN={["1572-8773"]}, DOI={10.1007/s10534-005-4303-8}, abstractNote={The presence of a divalent metal ion in a negatively charged aspartic acid pocket is essential for phosphorylation of response regulator proteins. Here, we present metal binding studies of the Bacillus subtilis response regulator Spo0F using NMR and microESI-MS. NMR studies show that the divalent metals Ca(2+), Mg(2+) and Mn(2+) primarily bind, as expected, in the Asp pocket phosphorylation site. However, identical studies with Cu(2+) show distinct binding effects in three specific locations: (i) the Asp pocket, (ii) a grouping of charged residues at a site opposite of the Asp pocket, and (iii) on the beta 4-alpha 4 loop and the beta 5/alpha 5 interface, particularly around and including H101. microESI-MS studies stoichiometrically confirm the NMR studies and demonstrate that most divalent metal ions bind to Spo0F primarily in a 1:1 ratio. Again, in the case of Cu(2+), multiple metal-bound species are observed. Subsequent experiments reveal that Mg(2+) supports phosphotransfer between KinA and Spo0F, while Cu(2+) fails to support KinA phosphotransfer. Additionally, the presence of Cu(2+) at non-lethal concentrations in sporulation media for B. subtilis and the related organism Pasteuria penetrans was found to inhibit spore formation while continuing to permit vegetative growth. Depending on the type of divalent metal ion present, in vitro phosphorylation of Spo0F by its cognate kinase KinA can be inhibited.}, number={5}, journal={BIOMETALS}, author={Kojetin, DJ and Thompson, RJ and Benson, LM and Naylor, S and Waterman, J and Davies, KG and Opperman, CH and Stephenson, K and Hoch, JA and Cavanagh, J}, year={2005}, month={Oct}, pages={449–466} } @article{dong_barker_opperman_2005, title={Virulence genes in Heterodera glycines: Allele frequencies and ror gene groups among field isolates and inbred lines}, volume={95}, ISSN={["1943-7684"]}, DOI={10.1094/PHYTO-95-0186}, abstractNote={ Genetic variation in field populations of Heterodera glycines is a key issue for both resistance gene deployment and basic understanding of virulence-gene flow in populations. In this study, we examined phenotypically defined genes for virulence under selection from host resistance. We separated the most common H. glycines genotypes in the United States into two virulence groups, based on their reproductive abilities on the resistant soybean plant introduction (PI) 88788. These groups correspond to previously identified virulence genes in the nematode, as follows: the dominant gene in H. glycines to PI88788, and the recessive genes to PI90763 and Pickett/Peking. Virulence allele frequencies and virulence genotype frequencies of selected field isolates were investigated by testing the host range of single-female-derived lines, which were developed through single-female inoculation on the standard susceptible soybean ‘Lee 68’. By comparing virulence genotype frequencies between the original field isolates and their single-female-derived lines, we were able to determine allele frequencies in the field populations. The results suggest that tremendous variation in H. glycines virulence genes exists among field populations. Potential mechanisms of selection which could cause virulence genotype frequency increases are discussed as related to population genetics equilibrium theory. }, number={2}, journal={PHYTOPATHOLOGY}, author={Dong, K and Barker, KR and Opperman, CH}, year={2005}, month={Feb}, pages={186–191} } @misc{bird_opperman_davies_2003, title={Interactions between bacteria and plant-parasitic nematodes: now and then}, volume={33}, ISSN={["1879-0135"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0042326079&partnerID=MN8TOARS}, DOI={10.1016/S0020-7519(03)00160-7}, abstractNote={Based on genome-to-genome analyses of gene sequences obtained from plant-parasitic, root-knot nematodes (Meloidogyne spp.), it seems likely that certain genes have been derived from bacteria by horizontal gene transfer. Strikingly, a common theme underpinning the function of these genes is their apparent direct relationship to the nematodes' parasitic lifestyle. Phylogenetic analyses implicate rhizobacteria as the predominant group of 'gene donor' bacteria. Root-knot nematodes and rhizobia occupy similar niches in the soil and in roots, and thus the opportunity for genetic exchange may be omnipresent. Further, both organisms establish intimate developmental interactions with host plants, and mounting evidence suggests that the mechanisms for these interactions are shared too. We propose that the origin of parasitism in Meloidogyne may have been facilitated by acquisition of genetic material from soil bacteria through horizontal transfer, and that such events represented key steps in speciation of plant-parasitic nematodes. To further understand the mechanisms of horizontal gene transfer, and also to provide experimental tools to manipulate this promising bio-control agent, we have initiated a genomic sequence of the bacterial hyper-parasite of plant parasitic nematodes, Pasteuria penetrans. Initial data have established that P. penetrans is closely related to Bacillus spp., to the extent that considerable genome synteny is apparent. Hence, Bacillus serves as a model for Pasteuria, and vice versa.}, number={11}, journal={INTERNATIONAL JOURNAL FOR PARASITOLOGY}, author={Bird, DM and Opperman, CH and Davies, KG}, year={2003}, month={Sep}, pages={1269–1276} } @article{niblack_arelli_noel_opperman_ore_schmitt_shannon_tylka_2002, title={A revised classification scheme for genetically diverse populations of Heterodera glycines}, volume={34}, number={4}, journal={Journal of Nematology}, author={Niblack, T. L. and Arelli, P. R. and Noel, G. R. and Opperman, C. H. and Ore, J. H. and Schmitt, D. P. and Shannon, J. G. and Tylka, G. L.}, year={2002}, pages={279–288} } @article{koltai_dhandaydham_opperman_thomas_bird_2001, title={Overlapping plant signal transduction pathways induced by a parasitic nematode and a rhizobial endosymbiont}, volume={14}, ISSN={["0894-0282"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0034800333&partnerID=MN8TOARS}, DOI={10.1094/MPMI.2001.14.10.1168}, abstractNote={ Root-knot nematodes and rhizobia establish interactions with roots characterized by the de novo induction of host structures, termed giant cells and nodules, respectively. Two transcription regulators, PHAN and KNOX, required for the establishment of meristems were previously shown to be expressed in tomato giant cells. We isolated the orthologues of PHAN and KNOX (Mt-phan and Mt-knox-1) from the model legume Medicago truncatula, and established the spatial distribution of their expression in situ. We confirmed that Mt-phan and Mt-knox-1 are expressed in lateral root initials and in nematode-induced giant cells and showed that they are expressed in nodules induced by Sinorhizobium meliloti. Expression of both genes becomes spatially restricted as the nodules develop. We further examined nematode feeding sites for the expression of two genes involved in nodule formation, ccs52 (encodes a mitotic inhibitor) and ENOD40 (encodes an early, nodulation mitogen), and found transcripts of both genes to be present in and around giant cells induced in Medicago. Collectively, these results reveal common elements of host responses to mutualistic and parasitic plant endosymbionts and imply that overlapping regulatory pathways lead to giant cells and nodules. We discuss these pathways in the context of phytohormones and parallels between beneficial symbiosis and disease. }, number={10}, journal={MOLECULAR PLANT-MICROBE INTERACTIONS}, author={Koltai, H and Dhandaydham, M and Opperman, C and Thomas, J and Bird, D}, year={2001}, month={Oct}, pages={1168–1177} } @article{marin_barker_kaplan_sutton_opperman_2000, title={Development and evaluation of a standard method for screening for resistance to Radopholus similis in bananas}, volume={84}, ISSN={["0191-2917"]}, DOI={10.1094/pdis.2000.84.6.689}, abstractNote={ The description and evaluation of a standard assay method for screening for resistance of bananas to the burrowing nematode (Radopholus similis) under greenhouse conditions is presented. Seven banana genotypes, ranging from susceptible to resistant, were used to evaluate the method. Banana plants from tissue culture, grown in 0.4-liter Styrofoam cups containing sterilized sand as substrate, were maintained in the greenhouse for 4 weeks before inoculation. Two hundred burrowing nematodes, reared in monoxenic carrot-disk culture, were used as inoculum for each container. Plants were kept in the greenhouse for an additional 8 weeks at about 27°C and 80% relative humidity after inoculation. Burrowing nematodes reproduced well in the susceptible cultivars False Horn, Grande Naine, Valery, and Lacatan, whereas the reproductive fitness was very low in the resistant cultivars Pisang Jari Buaya and Yangambi. An intermediate reaction between these two groups was observed with Pisang mas. A similar trend was obtained in a follow-up field test, which indicated that the method is accurate and reliable. Assessments of total-root necrosis associated with this pathogen were also comparable between greenhouse and field conditions. However, nematode effects on the roots were more severe in the greenhouse test than in the field. In spite of low nematode reproductive fitness, root necrosis was relatively high in the two resistant cultivars tested in the greenhouse trial. }, number={6}, journal={PLANT DISEASE}, author={Marin, DH and Barker, KR and Kaplan, DT and Sutton, TB and Opperman, CH}, year={2000}, month={Jun}, pages={689–693} } @article{kaplan_thomas_frisse_sarah_stanton_speijer_marin_opperman_2000, title={Phylogenetic analysis of geographically diverse Radopholus similis via rDNA sequence reveals a monomorphic motif}, volume={32}, number={2}, journal={Journal of Nematology}, author={Kaplan, D. T. and Thomas, W. K. and Frisse, L. M. and Sarah, J. L. and Stanton, J. M. and Speijer, P. R. and Marin, D. H. and Opperman, C. H.}, year={2000}, pages={134–142} } @article{kaplan_opperman_2000, title={Reproductive strategies and karyotype of the burrowing nematode, Radopholus similis}, volume={32}, number={2}, journal={Journal of Nematology}, author={Kaplan, D. T. and Opperman, C. H.}, year={2000}, pages={126–133} } @article{marin_barker_kaplan_sutton_opperman_1999, title={Aggressiveness and damage potential of Central American and Caribbean populations of Radopholus spp. in banana}, volume={31}, number={4}, journal={Journal of Nematology}, author={Marin, D. H. and Barker, K. R. and Kaplan, D. T. and Sutton, T. B. and Opperman, C. H.}, year={1999}, pages={377–385} } @misc{conkling_opperman_acedo_song_1999, title={Nematode-resistant transgenic plants}, volume={6,008,436}, number={1999 Dec. 28}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Conkling, M. A. and Opperman, C. H. and Acedo, G. N. and Song, W.}, year={1999} } @article{marin_kaplan_opperman_1999, title={Randomly amplified polymorphic DNA differs with burrowing nematode collection site, but not with host range}, volume={31}, number={2}, journal={Journal of Nematology}, author={Marin, D. H. and Kaplan, D. T. and Opperman, C. H.}, year={1999}, pages={232–239} } @misc{bird_opperman_jones_baillie_1999, title={The Caenorhabditis elegans genome: A guide in the post genomics age}, volume={37}, ISSN={["1545-2107"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0032694561&partnerID=MN8TOARS}, DOI={10.1146/annurev.phyto.37.1.247}, abstractNote={ ▪ Abstract  The completion of the entire genome sequence of the free-living nematode, Caenorhabditis elegans is a tremendous milestone in modern biology. Not only will scientists be poring over data mined from this resource, but techniques and methodologies developed along the way have changed the way we can approach biological questions. The completion of the C. elegans genomic sequence will be of particular importance to scientists working on parasitic nematodes. In many cases, these nematode species present intractable challenges to those interested in their biology and genetics. The data already compared from parasites to the C. elegans database reveals a wealth of opportunities for parasite biologists. It is likely that many of the same genes will be present in parasites and that these genes will have similar functions. Additional information regarding differences between free-living and parasitic species will provide insight into the evolution and nature of parasitism. Finally, genetic and genomic approaches to the study of parasitic nematodes now have a clearly marked path to follow. }, number={1999}, journal={ANNUAL REVIEW OF PHYTOPATHOLOGY}, author={Bird, DM and Opperman, CH and Jones, SJM and Baillie, DL}, year={1999}, pages={247–265} } @inbook{opperman_conkling_1998, title={Bioengineering resistance to plant-parasitic nematodes}, booktitle={Plant and nematode interactions / co-eds Kenneth R. Barker, Gary A. Pederson, Gary L. Windham. Madison, Wis.: American Society of Agronomy, Inc.: Crop Science Society of America, Inc.: Soil Science Society of America, Inc., 1998.}, publisher={Madison, Wis.: American Society of Agronomy, Inc.: Crop Science Society of America, Inc.: Soil Science Society of America, Inc.}, author={Opperman, C.H. and Conkling, M.A.}, year={1998}, pages={239–250} } @article{bird_opperman_1998, title={Caenorhabditis elegans: A genetic guide to parasitic nematode biology}, volume={30}, number={3}, journal={Journal of Nematology}, author={Bird, D. M. and Opperman, C. H.}, year={1998}, pages={299–308} } @misc{conkling_opperman_taylor_1998, title={Pathogen-resistant transgenic plants}, volume={5,750,386}, number={1998 May 12}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Conkling, M. A. and Opperman, C. H. and Taylor, C. G.}, year={1998} } @misc{opperman_bird_1998, title={The soybean cyst nematode, Heterodera glycines: a genetic model system for the study of plant-parasitic nematodes}, volume={1}, ISSN={["1369-5266"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0032130137&partnerID=MN8TOARS}, DOI={10.1016/1369-5266(88)80057-8}, abstractNote={Despite advances in understanding plant responses to nematode infection, little information exists regarding parasitic mechanisms. Recently, it has become possible to perform genetic analysis of soybean cyst nematode. Integration of classic and reverse genetics and genomic approaches for the parasite, with host genetics and genomics will expand our knowledge of nematode parasitism.}, number={4}, journal={CURRENT OPINION IN PLANT BIOLOGY}, author={Opperman, CH and Bird, DM}, year={1998}, month={Aug}, pages={342–346} } @article{dong_opperman_1997, title={Genetic analysis of parasitism in the soybean cyst nematode Heterodera glycines}, volume={146}, number={4}, journal={Genetics}, author={Dong, K. and Opperman, C. H.}, year={1997}, pages={1311–1318} } @article{dong_barker_opperman_1997, title={Genetics of soybean-Heterodera glycines interactions}, volume={29}, number={4}, journal={Journal of Nematology}, author={Dong, K. and Barker, K. R. and Opperman, C. H.}, year={1997}, pages={509–522} } @article{kaplan_opperman_1997, title={Genome similarity implies that citrus-parasitic burrowing nematodes do not represent a unique species}, volume={29}, number={4}, journal={Journal of Nematology}, author={Kaplan, D. T. and Opperman, C. H.}, year={1997}, pages={430–440} } @article{kaplan_vanderspool_opperman_1997, title={Sequence tag site and host range assays demonstrate that Radopholus similis and R-citrophilus are not reproductively isolated}, volume={29}, number={4}, journal={Journal of Nematology}, author={Kaplan, D. T. and Vanderspool, M. C. and Opperman, C. H.}, year={1997}, pages={421–429} } @article{opperman_conkling_1994, title={Nematode-induced plant gene expression and related control strategies}, volume={17}, number={3}, journal={Fundamental and Applied Nematology}, author={Opperman, C. and Conkling, M. A.}, year={1994}, pages={211} } @article{opperman_taylor_conkling_1994, title={ROOT-KNOT NEMATODE-DIRECTED EXPRESSION OF A PLANT ROOT-SPECIFIC GENE}, volume={263}, ISSN={["0036-8075"]}, DOI={10.1126/science.263.5144.221}, abstractNote={ Root-knot nematodes are obligate plant parasites that induce development of an elaborate feeding site during root infection. Feeding-site formation results from a complex interaction between the pathogen and the host plant in which the nematode alters patterns of plant gene expression within the cells destined to become the feeding site. Expression of TobRB7 , a gene expressed only in tobacco roots, is induced during feeding site development. The cis-acting sequences that mediate induction by the nematode are separate from those that control normal root-specific expression. Reporter transgenes driven by the nematode-responsive promoter sequences exhibit expression exclusively in the developing feeding site. }, number={5144}, journal={SCIENCE}, author={OPPERMAN, CH and TAYLOR, CG and CONKLING, MA}, year={1994}, month={Jan}, pages={221–223} } @misc{opperman_chang_1992, title={NEMATODE ACETYLCHOLINESTERASES - MOLECULAR-FORMS AND THEIR POTENTIAL ROLE IN NEMATODE BEHAVIOR}, volume={8}, ISSN={["0169-4758"]}, DOI={10.1016/0169-4758(92)90189-9}, abstractNote={Nematode movement is reliant upon the somatic musculature that runs longitudinally along the body wall. Neuromuscular synapses occur in the ventral and dorsal cords and employ the excitatory neurotransmitter, acetylcholine (ACh), for modulation of muscle activity. Acetylcholine activity is terminated by hydrolysis by acetylcholinesterase (AChE). Here, Charles Opperman and Stella Chang discuss the molecular forms and potential role of this enzyme.}, number={12}, journal={PARASITOLOGY TODAY}, author={OPPERMAN, CH and CHANG, S}, year={1992}, month={Dec}, pages={406–411} } @article{opperman_chang_1991, title={Effects of aldicarb and fenamiphos on acetylcholinesterase and motility of Caenorhabditis elegans}, volume={23}, number={1}, journal={Journal of Nematology}, author={Opperman, C. H. and Chang, S.}, year={1991}, pages={20} } @article{opperman_chang_1990, title={Plant-parasitic nematode acetylcholinesterase inhibition by carbamate and organophosphate nematicides}, volume={22}, number={4}, journal={Journal of Nematology}, author={Opperman, C. H. and Chang, S.}, year={1990}, pages={481} }