Progress 08/01/11 to 07/31/12
Outputs
Target Audience: Target audiences are researchers in academia interested in agricultural production, industry involved in agricultural production, govenment agencies involved in regulating agricultural production, private groups interested in agriculatural production and the regulation of transgenic crops, private and government groups interested in environmental quality, and growers. Changes/Problems: No changes were made. What opportunities for training and professional development has the project provided? The project has resulted in the training and Ph.D. degrees of several students both US citizens and from abroad, and the same for postdocs. The training has been in the areas of insect rearing, insect biology and physiology, insecticide toxicology, molecular biology, insecticide resistance managment, technology transfer, molecular biology and commercialization. How have the results been disseminated to communities of interest? Results have been made available by publishing many scientific papers (see list of papers in this and previous reports), presenting these data at scientific meetings, teaching workshops at the Cotton Beltwide meetings on the use of our assay kits, developing the kits for industry partners,obtaining SBIR grants with companies to develop the technology for their applications, working with the USDA to adapt the technology into their monitoring programs, working with extension agents in most states in the SE US, providing the plates to interested parties, and patent submissions. What do you plan to do during the next reporting period to accomplish the goals? Most of our effort is aimed at finishing research and writing/submitting publications, extending the technologies to other applications, obtaining more data on our newly discovered new mechanism for Bt resistance in insects and further conducting proof of concept of the use of dsRNA for insect control. Our studies are also leading to new kits for monitoring for dsRNA resistance in insects and the discovery of cross resistance between Bt toxins and dsRNA (or siRNA).
Impacts
What was accomplished under these goals?
(a). We were successful in developing a field assay kit to detect insect resistant transgenic plant material. Unexpectedly, in the development of these kits, we discovered what appears to be two new behavioral mechanisms by which caterpillars can become resistant and likely cross resistant to almost any plant engineered for insect control. If we are correct, the use of transgenic plant technology will not only produce resistant insects but insects that will have an increased feeding rate. (b) We were successful in developing field kits to detect insect resistance for a variety of insect species and for both larval and adult insects. Unexpectedly this work was picked up by the US Navy and projects completed to develop similar technology of monitoring mosquito resistance. The work was also applied to the development of nucleic acid-based insect control and work on new insect diets; this resulted in the filing of a US patent.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Magalhaes, L.C., J. Van Kretschmar, V.M. Barlow, R.M. Roe and J.F. Walgenbach. 2012. Development of a rapid resistance monitoring bioassay for codling moth larvae. Pest. Manag. Sci. 68:883-888.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2012
Citation:
Van Kretschmar, J.G., K.V. Donohue, A.R. Cabrera, L.C. Magalhaes, C. E. Sorenson, J.S. Bacheler, S.M.S. Khalil and R.M. Roe. 2012. Illumina sequencing of green stink bug nymph and adult cDNA to identify potential RNAi targets. 2012. 2012 Beltwide Cotton Conferences, Orlando, Fla., Jan. 3-6, 2012. National Cotton Council, Memphis, TN. 1090-1096.
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Progress 08/01/07 to 07/31/12
Outputs
Target Audience: Target audiences are researchers in academia interested in agricultural production, industry involved in agricultural production, government agencies involved in regulating agricultural production, private groups interested in agricultural production and the regulation of transgenic crops, private and government groups interested in environmental quality, and growers. The work also has led to discoveries and uses of the technology outside of agriculture in the managment of mosquito resistance to insecticides. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? The project is part or all of the Ph.D. dissertations for several US and foreign students. Several postdocs (both US and foreign) have worked on this project as well. The work provided training in insect rearing, insect biology and physiology, insecticide toxicology, molecular biology, genomics, transcriptomics, insect insecticide resistance management, technology transfer and commercialization. How have the results been disseminated to communities of interest? We have published a number of scientific papers listed in the final and interim reports with the main focus being the scientific and industry community. We have also presented numerous scientific oral papers and posters at scientific meetings at the state and National level. In addition, we presented a workshop at the National Cotton Beltwide meeting supported by Cotton Inc. Furthermore, we have worked with industry through additional grants (both private and government funding) to develop the technology for other insecticides. Finally, our project involved working with extension agents in multiple states in the SE US to field test the kits. This work is now ongoing on kudzu bugs and sucking pests in general. What do you plan to do during the next reporting period to accomplish the goals? This is a final report. However, the work is continuing in that additional publications are in press, and the work is being expanded to other pests, for example mosquitoes and kudzu bug. Furthermore, the work on adult assays has resulted in a 2013 SBIR proposal on using our feeding system technologies as new methods for insect control. We have also developed ideas (proposals pending) on behavior mechanisms for Bt resistance which is being applied as well to methods using dsRNA and siRNA.
Impacts
What was accomplished under these goals?
There has been a considerable number of scientific papers published from the research directly funded by this grant. In addition, the work has resulted in new discoveries not anticipated when the proposal was written; much of this work has been published as scientific papers and one patent submission. This final report provides only the publications from 2013; previous interim reports list additional papers, and there are papers in press not provided in the final report. The work has also resulted in the Ph.D. dissertations of a number of students from the US and two students from outside of the US. There are also students in process in the Roe lab that are conducting work on this proposal subject at the time this document was prepared. Major goals in original proposal: (a) Develop a field assay kit to detect insect resistant plants of any type and measure their insecticidal activity--We were successful in developing assay kits to detect insect resistant transgenic cotton plants. This work is described in detail in the citations provided of published papers in this report and our earlier interim reports. In the conduct of this work, we also discovered what appears to be previously an unknown mechanism by which caterpillars can become resistant to cotton plants by increasing their feeding rates (paper cited in our publication output in the final report). We also found that caterpillars could detect and avoid Bt (papers cited as well). (b) Develop a field assay kit to detect insect resistance using artificial, hydrateable leaves that will be easily applicable to all insect-resistant transgenic plants being developed--We developed kits for detecting resistance to transgenic crops for both caterpillars and adult moth pests. This work was expanded from an initial focus on cotton pests to a pest of apples (codling moth; paper published). The work on lepidopteran pests in the original proposal was also expanded to green stink bugs, plant bugs, kudzu bugs and thrips (published papers cited in interim and final report). The work was also adapted by the US Navy for monitoring resistance to mosquitoes (one paper published and cited in this final report; another in press and not cited in this report). Finally, the project was expanded from protein toxins to dsRNA and siRNA for stink bugs, plant bugs, thrips and the Egyptian cotton leafworm.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Abdelall, M.F., S. Taylor, J. van Kretswchmar, S.M.S. Khalil, T.Z. Salem and R.M. Roe. 2013. Transcriptomic analysis of the larval head of Egyptian cotton leafworm. Proceedings, 2013 Beltwide Cotton Conferences, San Antonnio, Texas, Jan. 7-10, 2013. National Cotton Council, Memphis, TN. 221-226.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
van Kretschmar, J.B., A. Dhammi and R.M. Roe. 2013. New mechanism for Bt resistance in caterpillars. Proceedings, 2013 Beltwide Cotton Conferences, San Antonio, Texas, Jan. 7-10, 2013. National Cotton Council, Memphis, TN. 892-896.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
van Kretschmar, B., A.R. Cabrera, J.R. Bradley and R.M. Roe. 2013. Novel adult feeding disruption test (FDT) to detect insecticide resistance of lepidopteran pests in cotton. Pest. Manag. Sci. 69: 652-660.
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Stell, F.M., R.M. Roe, C. Arellano, L. Kennedy, H. Thornton, K. Saavedra-Rodriguez, D.M. Wesson, W.C. Black and C.S. Apperson. 2012 (on line). Proof of concept for a novel insecticide bioassay based on sugar feeding by adult Aedes aegypti (Stegomyia aegypti). Med. Vet. Ent. doi: 10.1111/j.1365-2915.2012.01048.x
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Magalhaes, L.C., J. B. van Kretschmar, K.V. Donohue and R.M. Roe. 2013. Pyrosequencing of the adult tarnished plant bug, Lygus lineolaris, and characterization of messages important in metabolism and development. Entomol. Exp. Applicata 146: 364-378.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Roe, R.M., S. Taylor, J. van Kretschmar, G.G. Kennedy, A. Dhammi, C.E. Sorenson and J.S. Bacheler. 2013. RNAi control of tobacco thrips: Illumina transcriptomics. Proceedings, 2013 Beltwide Cotton Conferences, San Antonnio, Texas, Jan. 7-10, 2013. National Cotton Council, Memphis, TN. 1185-1192.
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Progress 08/01/10 to 07/31/11
Outputs
OUTPUTS: (1)Development of an assay method for the detection of transgenic crop plants engineered for insect resistance. Different bioassay architectures were investigated in the laboratory that could be used to detect for the presence of transgenic plant material engineered for insect resistance. This effort included an examination of proof of concept of the assay method using plant material and bioassay components derived from laboratory and greenhouse research. (2) Development of an artificial cotton leaf that can be used to monitor for caterpillar resistance to the Bt toxins. Different methods were examined for the construction of an artificial plant leaf that is hydrateable, can be stored at room temperature for an extended period of time, that contains a diagnostic dose of Bt toxins as would be found in a commercial crop plant and that can be used with our feeding disruption test (FDT) technology for the routine monitoring for Bt resistance to caterpillars. This effort included an examination of proof of concept of the artificial leaf in conjunction with FDT for materials produced from the laboratory and greenhouse; and this objective was supportive of item 1, new detection system for transgenic plant materials. (3) Expanded applications of the technology. (A) The technology developed was expanded to demonstration of proof of concept for bioassays for other pests of agriculture (e.g., sucking pests like plant and stink bugs) and medically important pests (e.g., mosquitoes of importance in the US and those important in the transmission of malaria); (B) A USDA Southern Region IPM grant proposal was submitted for the use of our bioassay for managing insecticide susceptibility to a new emerging insect pest problem, the Kudzu bug; in this proposal, we describe new methods for the use of FDT for this pest; (C) Work was completed on proof of concept for FDT for different Bt toxins; and (D) FDT was developed as a screening method to evaluate potential new insecticides, i.e., chemical, small peptidic, and siRNA/dsRNA pesticides. PARTICIPANTS: The project is part of the dissertation research of five Ph.D. students in Entomology and the research of two visiting professors from Assuit University in Egypt. The technology under development has been accepted as intellectual property by North Carolina State University. So the work conducted is providing special training in technology transfer. The work is also being conducted in cooperation with Cotton Inc. and in the past with the company, Insect Diet & Rearing Research, LLC of Raleigh, NC. We also have three additional extension professors in the department of entomology at NC State University assisting with field collection of insects in support of our research. Also the work is being extended to other fields of entomology and other insect pest problems including use for the management of emerging disease problems in Africa and the US; and military applications to protect US soldiers. The most recent expansion involves cooperative agreements with professors from the University of Geogria and Clemson University to use FDT to manage the Kudzu bug pest of soybeans (research proposal in review). TARGET AUDIENCES: The target audience for the technology under development directly funded by the grant will be research and extension entomologists, Ag companies that develop plant transgenic crops, Ag consultants, and companies involved in the development and sale of Ag related diagnostics. The assays being developed have the potential of changing current practices in the monitoring of transgenic plant materials and methods used to diagnose insect resistance to transgenic plants engineered for insect resistance. Target audiences are being approached through presentations at different scientific meetings, scientific publications, IP disclosures, international cooperative research, national cooperative research, and the advancement of degrees to future experts in the field. One expansion of the project is being investigated by the US Navy for monitoring of mosquitoes for insecticide resistance. PROJECT MODIFICATIONS: No modifications made. However, the research in this grant has resulted in a number of new project initiatives for other uses of our technology and new grant funds.
Impacts
(1)Development of an assay method for the detection of transgenic crop plants engineered for insect resistanc. Proof of concept was obtained for one method for the rapid detection of any transgenic crop material that has been engineered with insect resistance. The advantage of the approach developed over that of immunochemical assays for individual insect toxins, i.e., for each Bt toxin or VIP, is that a single FDT format can be used for the detection of engineered insect resistance of any type and is not specific to a particular insect toxin or combination of toxins being used in the plant. The assay construction is technically less demanding than immunochemical or nucelic acid approaches, should have a greater shelf life, and cost less per assay than immunochemical or nucleic acid-based detection systems. Shelf life stability studies were completed showing the kit is completely stable at room temperature for six months; longer incubation times were not considered. 2) Development of an artificial cotton leaf that can be used to monitor for caterpillar resistance to the Bt toxins. A hydrateable, artificial cotton leaf was developed and studies conducted to successfully show that these artificial leaves can be used for resistance detection in caterpillars. The advantages of these artificial leaves, they should have a long shelf-life, can be stored at room temperature and are ready to use (just add a drop of water), and they can be constructed to mimic the exact toxins and toxin ratios found in current and future commercial crop plants engineered for insect control. We now have completed the field evaluation of the kit in NC using insects collected directly from wild-type populations and have further validated the technique using two Bt resistant (laboratory) tobacco budworm strains. The work is also part of the completed Ph.D. thesis of a graduate student in Entomology at North Carolina State University. Work on specific toxins in hydrateable meal pads is included in a second completed Ph.D. thesis for a student in Entomology at NCSU. The work conducted is published in a number of papers listed in previous reports and this current report. (3) An extension of this work to sucking pests of importance to agriculture was shown. The work has also been extended (i) to orchid pests (part of another Ph.D. thesis completed, (ii) used to development new protein toxins for insect control (an additional Ph.D. thesis in process), (iii) extended to resistance monitoring in mosquitoes (another Ph.D. thesis in process), and (iv) development of a model system for evaluating an insect's susceptibility to siRNA and dsRNA. The research with mosquitoes is part of a new US Navy initiative in the application of our FDTs for the protection of deployed soldiers. We have also designed FDTs for the new, emerging Kudzu bug pest in the US and have submitted a joint proposal with two additional universities for managing the chemical control of this insect using our FDT technology.
Publications
- van Kretschmar, J. B., W. D. Bailey, C. Arellano, G. D. Thompson, C. L. Sutula and R. M. Roe. 2011. Feeding disruption tests for monitoring the frequency of larval depidopteran resistance to Cry1Ac, Cry1F and Cry1Ab. Crop Protection. 30: 863-870.
- Cabrera, A. R., J. van Kretschmar, J. S. Bacheler, H. Burrack, C. E. Sorenson and R. M. Roe. 2011. Resistance monitoring of Heliiothis virescens to pyramided cotton varieties with a hydrateable, artificial cotton leaf bioassay. Crop Protection. 30: 1196-1201.
- Roe, R. M., A. R. Cabrera, H. Ezzeldin, J. B. van Kretschmar and B. W. Bissinger. 2011. Broad-spectrum biosensor for monitoring current and future transgenic plant technologies for insect control. Proceedings, 2011 Beltwide Cotton Conferences, Atlanta, Geogria, Jan. 4-7, 2011. National Cotton Council, Memphis, TN. 1153-1159.
- van Kretschmar, J. B., J. R. Bradley, A. R. Cabrera and R. M. Roe. 2011. Lepidopteran adult feeding disruption test (FDT) to detect insecticide resistance. Proceedings, 2011 Beltwide Cotton Conferences, Atlanta, Geogria, Jan. 4-7, 2011. National Cotton Council, Memphis, TN. 1010-1015.
- van Kretschmar, J. B., A. Dhammi, D. Reisig and R. M. Roe. 2011. Challenges for rearing of the stink bug: successes, failures, and RNAi screening. Proceedings, 2011 Beltwide Cotton Conferences, Atlanta, Geogria, Jan. 4-7, 2011. National Cotton Council, Memphis, TN. 1169-1175.
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Progress 08/01/09 to 07/31/10
Outputs
OUTPUTS: (1)Development of an assay method for the detection of transgenic crop plants engineered for insect resistance: Different bioassay architectures were investigated in the laboratory that could be used to detect for the presence of transgenic plant material engineered for insect resistance. This effort included an examination of proof of concept of the assay method using plant material and bioassay components derived from laboratory and greenhouse research. (2) Development of an artificial cotton leaf that can be used to monitor for caterpillar resistance to the Bt toxins: Different methods were examined for the construction of an artificial plant leaf that is hydrateable, can be stored at room temperature for an extended period of time, that contains a diagnostic dose of Bt toxins as would be found in a commercial crop plant and that can be used in conjuction with our feeding disruption test (FDT) technology for the routine monitoring for Bt resistance to caterpillars. This effort included an examination of proof of concept of the artificial leaf in conjuction with FDT for materials produced from the laboratory and greenhouse; and this objective was supportive of item 1, new detection system for transgenic plant materials. PARTICIPANTS: The project is part of the dissertation research of five Ph.D. students in Entomology and the research of two visiting professors from Assuit University in Egypt. The technology under development has been accepted as intellectual property by North Carolina State University. So the work conducted is providing special training in technology transfer. The work is also being conducted in cooperation with Cotton Inc. and in the past with the company, Insect Diet & Rearing Research, LLC of Raleigh, NC. We also have three additional extension professors in the department of entomology at NC State University assisting with field collection of insects in support of our research. Also the work is being extended to other fields of entomology and other insect pest problems including use for the management of emerging disease problems in Africa and military applications to protect US soldiers. TARGET AUDIENCES: The target audience for the technology under development directly funded by the grant will be research and extension entomologists, Ag companies that develop plant transgenic crops, Ag consultants, and companies involved in the development and sale of Ag related diagnostics. The assays being developed have the potential of changing current practices in the monitoring of transgenic plant materials and methods used to diagnose insect resistance to transgenic plants engineered for insect resistance. Target audiences are being approached through presentations at different scientific meetings, scientific publications, IP disclosures, international cooperative research, national cooperative research, and the advancement of degrees to future experts in the field. PROJECT MODIFICATIONS: No modifications made. PARTICIPANTS: This information is also described in additional detail in the discriptions of the output, impacts and new papers published. The work is part of the Ph.D. dissertations of five students in Entomology at NC State University and part of the research of two visiting scientists from Assiut University in Egypt. The work is also being conducted directly in cooperation with three extension entomologists at NC State University, has been extended to additional projects in other areas of pest management resulting in cooperative efforts with additional labs and the US military, and to the study of pest problems in other countries. The work is also part of a technology transfer effort in diagnostics and new insecticide development as well as risk assessment research for GE crops. We are also collaborating with Cotton Inc. and private companies associated with Ag applications for different aspects of implementation of the technologies being developed. Some of the effort has resulted in license agreements and follow-up research in extensions of the technology and the submission of patents. TARGET AUDIENCES: The target audiences have been extensive and can generally be classified as graduate students being trained as future experts in the field of applied and basic entomology, current applied entomologists, and research scientists in both applied and basic science. More details of target audiences are also presented in the descriptions of output, impacts and new papers published as well as the information provided under participants. PROJECT MODIFICATIONS: No major changes were made. However, many new directions for future research have been developed, even outside of the immediate direct support of the work. Our prototype kit is also now ready to be field tested and a renewal proposal request is anticipated in 2011 to accomplish this goal and use our technology to also evaluate risk for GE crop resistance to insects in the field.
Impacts
(1)Development of an assay method for the detection of transgenic crop plants engineered for insect resistance: Proof of concept was obtained for one method for the rapid detection of any transgenic crop material that has been engineered with insect resistance. The advantage of the approach developed over that of immunochemical assays for individual insect toxins, i.e., for each Bt toxin or VIP, is that a single assay can be used for the detection of engineered insect resistance of any type and is not specific to a particular insect toxin or combination of toxins being used in the plant. The assay construction is technically less demanding than immunochemical or nucelic acid approaches, should have a greater shelf life, and cost less per assay than immunochemical or nucleic acid-based detection systems. Shelf life stability studies were completed in the current reporting period showing the kit is completely stable at room temperature for six months; longer incubation times were not considered. The first draft of a manuscript was written and at the time of the filing of this report has been submitted for publication. 2) Development of an artificial cotton leaf that can be used to monitor for caterpillar resistance to the Bt toxins: A hydrateable, artificial cotton leaf was developed and studies conducted to successfully show that these artificial leaves can be used for resistance detection in caterpillars. The advantages of these artificial leaves, they should have a long shelf-life, can be stored at room temperature and are ready to use (just add a drop of water), and they can be constructed to mimic the exact toxins and toxin ratios found in current and future commercial crop plants engineered for insect control. We now have preliminary field data on the kit in NC using insects collected directly from wild-type populations (more extensive studies in this respect will be needed in the future); and have further validated the technique using two Bt resistant (laboratory) tobacco budworm strains. The work was presented at the 2010 Cotton Beltwide meetings and a paper published as part of the proceedings from this meeting. Also the first draft of a paper for journal publication has been prepared, been reviewed and is being revised for publication. The work is also part of the completed Ph.D. thesis of a graduate student in Entomology at North Carolina State University. Work on specific toxins in hydrateable meal pads is included in a second completed Ph.D. thesis for a student in Entomology at NCSU. An extension of this work to sucking pests was shown and the work published as part of the proceedings of the 2009 Cotton Beltwide meetings. The work has also been extended to orchid pests (part of another Ph.D. thesis in progress), used to development new protein toxins for insect control (an additional Ph.D. thesis in process), extended to resistance monitoring in mosquitoes (another Ph.D. thesis in process), development of a model system for evaluating an insect's susceptibility to dsRNA and research with mosquitoes is part of the US Navy's interest in the technology to protect soldiers.
Publications
- Roe, R. M., H.P. Young, T. Iwasa, C.F. Wyss, C.F. Stumpf, T.C. Sparks, G.B. Watson and J.J. Sheets. 2010. Mechanism of resistance to spinosyn in the tobacco budworm, Heliothis virescens. Pesticide Biochemistry and Physiology 96: 8-13.
- Cabrera, A.R., J. VanKretschmar, J.S. Bacheler, H.J. Burrack, C.E. Sorenson and R.M. Roe. 2010. Development of hydrateable, commercially-relevant artificial cotton leaves and assay architecture for monitoring insect resistance to Bt. Beltwide Cotton Conf., pp. 1290-1296.
- van Kretschmar, J.B., K.V. Donohue, A.R. Cabrera, L.C. Magalhaes, C.E. Sorenson, J.S. Bacheler, S.M.S. Khalil and R.M. Roe. 2010. Transcriptomics by massive parallel, pyrosequencing of the green stink bug: functional gene ontology and new targets for control. Beltwide Cotton Conf., pp. 1195-1202. (preliminary work for RNAi studies using FDT)
- Roe, R.M., K.V. Donohue, J.B. van Kretschmar and L.C. Magalhaes. 2010. Insecticidal target genes from plant bug whole body and digestive system transcriptomes. International patent publication WO 2010/141294 A1. (work aimed at using FDT for screening)
- Cabrera, A.R. 2010. Advances in resistance monitoring of agricultural pests and in the elucidation of mite reproductive physiology. Ph.D. Dissertation, NC State University.
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Progress 08/01/08 to 07/31/09
Outputs
OUTPUTS: (1)Development of an assay method for the detection of transgenic crop plants engineered for insect resistance: Different bioassay architectures were investigated in the laboratory that could be used to detect for the presence of transgenic plant material engineered for insect resistance. This effort included an examination of proof of concept of the assay method using plant material and bioassay components derived from laboratory and greenhouse research. (2) Development of an artificial cotton leaf that can be used to monitor for caterpillar resistance to the Bt toxins: Different methods were examined for the construction of an artificial plant leaf that is hydrateable, can be stored at room temperature for an extended period of time, that contains a diagnostic dose of Bt toxins as would be found in a commercial crop plant and that can be used in conjuction with our feeding disruption test (FDT) technology for the routine monitoring for Bt resistance to caterpillars. This effort included an examination of proof of concept of the artificial leaf in conjuction with FDT for materials produced from the laboratory and greenhouse. PARTICIPANTS: The project is part of the dissertation research of three Ph.D. students in Entomology and a visiting professor from Assuit, Egypt. The technology under development has been accepted as intellectual property by North Carolina State University. So the work conducted is providing special training in technology transfer to the private sector. The work is also being conducted in cooperation with Cotton Inc. and the company, Insect Diet & Rearing Research, LLC of Raleigh, NC. We also have three additional extension professors in the department of entomology at NC State University assisting with field collection of insects in support of our research. TARGET AUDIENCES: The target audience for the technology under development will be research and extension entomologists, Ag companies that develop plant transgenic crops, Ag consultants, and companies involved in the development and sale of Ag related diagnostics. The assays being developed have the potential of changing current practices in the monitoring of transgenic plant materials and methods used to diagnose insect resistance to transgenic plants engineered for insect resistance. PROJECT MODIFICATIONS: No modifications made.
Impacts
(1)Development of an assay method for the detection of transgenic crop plants engineered for insect resistance: Proof of concept was obtained for one method for the rapid detection of any transgenic crop material that has been engineered with insect resistance. The advantage of the approach developed over that of immunochemical assays for individual insect toxins, i.e., for each Bt toxin or VIP, is that a single assay can be used for the detection of engineered insect resistance of any type and is not specific to a particular insect toxin or combination of toxins being used in the plant. The assay construction is technically less demanding than immunochemical or nucelic acid approaches, should have a greater shelf life, and cost less per assay than immunochemical or nucleic acid-based detection systems. Shelf life stability studies were conducted in the current reporting period showing the kit is completely stable at room temperature for six months; longer incubation times were not considered. The first draft of a manuscript has been written and is in review to assess if additional studies are needed. 2) Development of an artificial cotton leaf that can be used to monitor for caterpillar resistance to the Bt toxins: A hydrateable, artificial cotton leaf was developed and studies conducted to successfully show that these artificial leaves can be used for resistance detection in caterpillars. The advantages of these artificial leaves, they should have a long shelf-life, can be stored at room temperature and are ready to use (just add a drop of water), and they can be constructed to mimic the exact toxins and toxin ratios found in current and future commercial crop plants engineered for insect control. In the current reporting period we have successfully field tested the kit by using insects collected directly from wild-type populations; and have further validated the technique using two Bt resistant (laboratory) tobacco budworm strains. The work was presented at the 2010 Cotton Beltwide meetings and a paper is in press as part of the proceedings from this meeting. Also the first draft of a paper for journal publication has been prepared. The work is also part of the Ph.D. thesis of a graduate student with an anticipated finishing date of Spring 2010. An extension of this work to sucking pests was shown and the work published as part of the proceedings of the 2009 Cotton Beltwide meetings.
Publications
- van Kretschmar, J. B., L. C. Magalhaes, J. Zhu, R. M. Roe and A. C. Cohen. 2009. Feasibility of a novel feeding disruption test (FDT) bioassay kit for rapid resistance detecton of sucking pests of cotton. Proceedings, 2009 Beltwide Cotton Conferences, San Antonio, Texas, January 5-8, 2009. National Cotton Council, Memphis, TN. pp. 882-892.
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Progress 08/01/07 to 07/31/08
Outputs
OUTPUTS: (1)Development of an assay method for the detection of transgenic crop plants engineered for insect resistance: Different bioassay architectures were investigated in the laboratory that could be used to detect for the presence of transgenic plant material engineered for insect resistance. This effort included an examination of proof of concept of the assay method using plant material and bioassay components derived from laboratory and greenhouse research. (2) Development of an artificial cotton leaf that can be used to monitor for caterpillar resistance to the Bt toxins: Different methods were examined for the construction of an artificial plant leaf that is hydrateable, can be stored at room temperature for an extended period of time, that contains a diagnostic dose of Bt toxins as would be found in a commercial crop plant and that can be used in conjuction with our feeding disruption test (FDT) technology for the routine monitoring for Bt resistance to caterpillars. This effort included an examination of proof of concept of the artificial leaf in conjuction with FDT for materials produced from the laboratory and greenhouse. PARTICIPANTS: The project is part of the dissertation research of two Ph.D. students in Entomology and a visiting professor from Assuit, Egypt. The technology under development has been accepted as intellectual property by North Carolina State University. So the work conducted is providing special training in technology transfer to the private sector. TARGET AUDIENCES: The target audience for the technology under development will be research and extension entomologists, Ag companies that develop plant transgenic crops, Ag consultants, and companies involved in the development and sale of Ag related diagnostics. The assays being developed have the potential of changing current practices in the monitoring of transgenic plant materials and methods used to diagnose insect resistance to transgenic plants engineered for insect resistance. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
(1)Development of an assay method for the detection of transgenic crop plants engineered for insect resistance: Proof of concept was obtained for one method for the rapid detection of any transgenic crop material that has been engineered with insect resistance. The advantage of the approach developed over that of immunochemical assays for individual insect toxins, i.e., for each Bt toxin or VIP, is that a single assay can be used for the detection of engineered insect resistance of any type and is not specific to the specific insect toxin or combination of toxins being used in the plant. The assay construction is technically less demanding than immunochemical or nucelic acid approaches, should have a greater shelf life, and cost less per assay than immunochemical or nucleic acid-based detection systems. 2) Development of an artificial cotton leaf that can be used to monitor for caterpillar resistance to the Bt toxins: A hydrateable, artificial cotton leaf was developed and studies conducted to successful show that these artificial leaves can be used for resistance detection in caterpillars. The advantages of these artificial leaves, they should have a long shelf-life, can be stored at room temperature and are ready to use (just add a drop of water), and they can be constructed to mimic the exact toxins and toxin ratios found in current and future commercial crop plants engineered for insect control.
Publications
- No publications reported this period
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