Progress 07/01/00 to 06/30/06
Outputs
Over the past several years we have advanced transgenic technology and risk mitigation on several tracks and have met and/or exceeded all objectives for this project including: (1) the development of new options for genetically engineering reproductive sterility to limit spread of transgenes; (2) the development of a new options for flowering acceleration to increase speed of breeding and research on effective sterility systems; (3) the adaptation of methods of gene transfer from agronomic crops to provide efficient recovery of transgenic trees that express transgenes reliably and suffer minimal genetic damage during gene transfer; 4) maintaining cooperation with forest industries via the Tree Biosafety and Genomics Research Cooperative; and 5) analyzing the extent and impacts of gene movement from transgenic plantations and their ecological and agronomic impacts. This last year we found that GA-modified, semi-dwarf poplars have several useful characteristics. They have
accelerated flowering; increased allocation of growth to roots; and altered root chemistry that may improve their resistance to decomposition. In collaboration with colleagues in Sweden, we showed the FT is a central gene for control of flowering and budset in trees. This gene could substantially speed breeding and assessment of sterility genes in research. We verified four activation-tagged genes showing that this method is an effective means for gene discovery in poplar and established a major new field study. In 2006, we were invited to make 14 presentations.
Impacts
Research on several tracks is helping to provide answers about reliability of gene expression, and risk of deploying transgenic trees, needed for regulatory and public acceptance of transgenic plantations with improved performance or yield.
Publications
- Wei, H., R. Meilan, A.M. Brunner, J.S. Skinner, C. Ma, H.T. Gandhi and S.H. Strauss. 2006. Field trail detects incomplete barstar attenuation of vegetative cytotoxicity in Populus trees containing a poplar LEAFY promoter::barnase sterility transgene. Molecular Breeding. DOI 10.1007/s1132-006-9045-Y. (In Press).
- Wei, H., R. Meilan, A.M. Brunner, J.S. Skinner, C. Ma and S.H. Strauss. 2005. Transgenic sterility in Populus: Expression properties of the poplar PTLF, Agrobacterium NOS, and two minimal 35S promoters in vegetative tissues. Tree Physiology 26:401-410.
- Arias, R., S. Filichkin and S.H. Strauss. 2006. Divide and conquer: development and cell cycle genes in plant transformation. Trends in Biotechnology 24:267-273.
- Bohlenius, H., T. Huang, L. Charbonnel-Campaa, A.M. Brunner, S. Jansson, S.H. Strauss and O. Nilsson. 2006. The conserved CO/FT regulatory module controls timing of flowering and seasonal growth cessation in trees. Science 312:1040-1043.
- Brunner, A., J. Li, S. DiFazio, O. Shevchenko, R. Mohamed, B. Montgomery, A. Elias, K. Van Wormer, S.P. DiFazio and S.H. Strauss. 2006. Genetic containment of forest plantations. Tree Genetics & Genomes, Online: DOI 10.1007/s11295-006-0067-8.
- Busov, V.B., M. Fladung, A. Groover and S.H. Strauss. 2005. Insertional mutagenesis in Populus: Relevance and feasibility. Tree Genetics & Genomes 1:135-142.
- Busov, V., R. Meilan, D.W. Pearce, S.B. Rood, C. Ma, T.J. Tschaplinski and S.H. Strauss. 2006. Transgenic modification of gai or rgl1 causes dwarfing and alters gibberellins, root growth, and metabolite profiles in Populus. Planta 24:288-299.
- Meilan, R. and C. Ma. 2006. Poplar (Populus spp.). p. 143-151 In: Methods in Molecular Biology. Vol. 344. Agrobacterium Protocols, 2nd ed. K. Wang, ed. Humana Press, Inc., Totowa, NJ.
- Filichkin, S.A., R. Meilan, V.B. Busov, C. Ma, A.M. Brunner and S.H. Strauss. 2006. Alcohol-inducible gene expression in transgenic Populus. Plant Cell Reports 25:660-667.
- Gandhi, H.T., C. Mallory-Smith, L. Morrison, R.S. Zemetra, C.J.W. Watson, M.I. Vales and O. Riera-Lizarazu. 2005. Patterns of mating between Triticum aestivum and Aegilops cylindrica under natural conditions. Weed Science. (Accepted for publication).
- Filichkin, S.A., Q. Wu, V.B. Busov, R. Meilan, C. Lanz-Garcia, C. Ma, P. Dharmawardhana, A.M. Brunner and S.H. Strauss. 2006. Enhancer trapping in woody plants: Isolation of the ET304 gene encoding a putative AT-hook motif transcription factor and characterization of the expression patterns conferred by its promoter in transgenic Populus and Arabidopsis. Plant Science 171:206-216.
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Progress 01/01/05 to 12/31/05
Outputs
We are advanced transgenic technology and risk mitigation on several tracks: 1) Flowering control. Develop a highly effective and reliable method for genetically engineering reproductive sterility to limit spread of transgenes. This year we will plant more than 1,000 transgenic events with a diversity of flowering genes. The focus is on studying the effectiveness of RNAi (RNA interference), employing double stranded DNA versions of selected floral genes from poplar, in causing sterility. We identify transgenic events with RNAi gene suppression, where target floral genes can be amplified with a wide range in level of suppression. 2) Accelerating "normal" flowering. Development of a method of flowering acceleration in all poplar genotyped to increase speed of breeding and research on effective sterility systems. A number of transgenic trees in clone 717-1B4 (P. tremula x alba) were producing unusual flowers at an unusual time in a field trial due to reduced gibberellic
acid gene signaling, or reduced expression of the poplar homology to CENTRORADIALIS. The large majority of trees (13 events) had genes that inhibit GA signaling, including GA2-oxidase driven by the strong 35S promoter and a wild type GAI gene and mutant gai gene. None of the extremely dwarfed mutants have flowered, suggesting that trees must have sufficient size or rate of growth to support floral development. In contrast to normal catkins that hang downward, all of these catkins were produced on upward growing shoots. While studying the effectiveness of RNAi (RNA interference), in causing sterility, we determined that target floral homeotic genes can be consistently amplified and can predict early flowering in one type of transgenic construct. 3) Transformation. The adaptation of methods of gene transfer from agronomic crops to provide efficient recovery of transgenic trees that express transgenes reliably and suffer minimal genetic damage during gene transfer. RNAi and reporter gene
transgenic populations with MAR elements were tested to understand level and stability of gene expression. The distribution of expression values was skewed to the right, but also included five events with abnormally low expression. 4) Industry Collaborators. We maintain cooperation with forest industries via the Tree Biosafety and Genomics Research Cooperative. We found that the degree of herbicide resistance among more than two dozen events had remained the same over time and no cases of gene silencing had been observed. We analyzed the level of herbicide-resistance gene expression through ELISA and found a correlation of protein concentration and level of herbicide resistance. The goal was to use the herbicide resistance trait to speed the assessment of stability of expression. 5) Risk Assessment. To analyze the extent and impacts of gene movement from transgenic plantations and their ecological and agronomic impacts. We are readying an invited publication on sterility technology
that will include a risk assessment evaluation of how strong sterility must be for useful gene containment. It will be presented at a meeting and submitted in March. Also, we had 5 invited presentations.
Impacts
Research on several tracks is helping to provide answers about reliability of gene expression, and risk of deploying transgenic trees, needed for regulatory and public acceptance of transgenic plantations with improved performance or yield.
Publications
- Busov, V.B., A.M. Brunner, R. Meilan, S. Filichkin, L. Ganio, S. Gandhi and S.H. Strauss. 2005. Genetic transformation: A powerful tool for dissection of adaptive traits in trees. New Phytol. 167:219-228.
- Strauss, S.H., R. Arias, Y. Bao, A. Brunner, V. Busov, P. Dharmawardhana, E. Etherington, S. Filichkin, H. Gandhi, E. Jaeger, J. Li, C. Ma and R. Mohamed. 2005. Annual Report. Tree Biosafety and Genomics Research Cooperative.
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Progress 01/01/04 to 12/31/04
Outputs
The research conducted for this project continues to focus on the improvement of trees for intensive plantation forestry through genetic engineering, utilizing poplars (genus Populus) as model tree taxa. Grant support is solicited from forest industries and competitive federal sources to support infrastructure and enable this research to take place. We receive major competitive grants from USDA, NSF, DOE & Consortium for Plant Biotechnology Research. In addition, we also received a grant of $430,000 from the USDA National Research Initiative Plant Genome Program this year. The new USDA funds will enable us to examine wood characteristics to see whether any changes in wood chemistry might have been missed during morphological assessments of trees. Flowering control continues to be our major area of emphasis, with new insights continuing from field experiments planted long-ago, to the production of a new generation of sterility genes and transgenic poplars. We continued
to monitor selected constructs for sterility and growth from our first generation sterility trial, established in 1994 and 1995. Most of these trees have been growing for 8 years and annually produce large numbers of visible catkins. We were very pleased to see that of seven independent events examined, catkins collected from six of them appeared to release no pollen. If confirmed, this high rate of sterility could make this system a very attractive means for producing male-sterile trees. To our knowledge, this is the first observation of strong engineered sterility in a field-grown tree anywhere. We were also able to demonstrated continued stability of expression of transgenic traits after seven years of coppice in field trails. Using herbicide resistance as a marker trait, we found that 72 transgenic genotypes tested maintained their levels of resistance despite repeated pruning and cycles of dormancy. This shows that transgenes can provide highly stable traits during vegetative
growth in the field. One promising kind of transgenic tree contained an APETALA1::DTA transgene which precedes floral meristem differentiation, and is required for formation of normal male and female flowers. A reduction in flowering branches was evident; AP1::DTA trees had approximately one-half as many flowering branches as control trees. This suggests that a number of the AP1::DTA transgenic events may be ablating all or most inflorescence primordia. Field studies conducted for the activation tagging research were unexpectedly effective for generating mutant phenotypes that were missed from laboratory and greenhouse examination with an additional 32 mutants identified. We took dormant cuttings from our activation-tagged trees in the field and rooted them under mist in a greenhouse to screen for tagged genes that affect rates of shoot expansion and root development. Identification of a gene whose elevated expression promotes rootability could be of substantial value in hard to root
species and genotypes.
Impacts
A key measure of impact is social demand for information. Included under publications are the invited presentations that our staff presented last year, many at national and international meetings. These demonstrate the strong social and scientific value of work in relation to tree biotechnology, biosafety, as judged by peers and science policy leaders in forestry, agriculture, and biotechnology. Support from industry for our research cooperative (http://www.fsl.orst.edu/tgerc/) shows the relevance of our work or commercial tree production.
Publications
- Andersson, A., J. Keskitalo, A. Sjodin, R. Bhalerao, F. Sterky, K. Wissel, K. Tandre, R. Moyle, Y. Ohmiya, R. Bhalerao, A. Brunner, P. Gustafsson, J. Karlsson, J. Lundeberg, O. Nilsson, G. Sandberg, S. Strauss, B. Sundberg, M. Uhlen, S. Jansson, P. Nilsson and H. Aspeborg. 2004. A transcriptional timetable of autumn senescence. Genome Biol. 5:R24, http://genomebiology.com/2004/5/4/R24
- Busov V.B., R. Meilan, C. Ma, D. Pearce, S.Rood and S.H. Strauss. 2004. Activation tagging in Populus. Plant and Animal Genome Conference XII. San Diego, CA.
- Meilan, R., D. Ellis, G. Pilate, A. Brunner and J. Skinner. 2004. Accomplishments and challenges in genetic engineering of forest trees. p. 36-51 In: The Bioengineered Forest: Challenges for Science and Society. S.H. Strauss and H.D. Bradshaw, eds. Resources for the Future, Washington, D.C.
- Slavov, G.T., G.T. Howe, I. Yakovlev, K.J. Edwards, K.V. Krutovskii, G.A. Tuskan, J.E. Carlson, S.H. Strauss and W.T. Adams. 2004. Highly variable SSR markers in Douglas-fir: Mendelian inheritance and map locations. Theoretical and Applied Genetics 108:873-880.
- Sterky, F., R.R. Bhalerao, P. Unneberg, B. Segerman, P. Nilsson, A.M. Brunner, L. Campaa, J. Johanson Lindvall, K. Tandre, S.H. Strauss, B. Sundberf, P. Gustafsson, M. Uhlen, R.P. Bhalerao, O. Nilsson, G. Sandberg, J. Karlsson, J. Lundeberg and S. Jansson. 2004. A Populus EST resource for functional genomics. Proc. Natl. Acad. Sci. USA. (In press).
- Sterky, F., R.R. Bhalerao, P. Unneberg, B. Segerman, P. Nilsson, A.M. Brunner, L. Charbonnel-Campaa, J.J. Lindvall, K. Tandre, S.H. Strauss, B. Sundberg, P. Gustafsson, M. Uhlen, R.P. Bhalerao, O. Nilsson, G. Sandberg, J. Karlsson, J. Lundeberg and S. Jansson. 2004. A Populus expressed sequence tag resource for plant functional genomics. Proc. Natl. Acad. Sci. USA. www.pnas.org_cgi_doi_10.1073_pnas.0401641101.
- Strauss, S.H. 2004. Forest biotechnology: thriving despite controversy. Review of "Molecular Genetics and Breeding of Forest Trees" by S. Kumar and M. Fladung. New Phytologist 163:9-11.
- Strauss, S.H. 2004. GE trees: The buzz is not from chain saws. TimberWest May/June:28.
- Strauss, S.H. and S.P. DiFazio. 2004. Hybrids abounding: Review of "Dangerous liaisons: When plants mate with their wild relatives" by Norman Ellstrand. Nature Biotechnology 22:29-30.
- Strauss, S.H. and F.M. Martin. 2004. Poplar genomics comes of age. New Phytologist 164:1-4.
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Progress 01/01/03 to 12/31/03
Outputs
The research conducted for this project focuses on the improvement of trees for intensive plantation forestry through genetic engineering, utilizing poplars (genus Populus) as a model tree taxa. Grant support is solicited from forest industries and competitive federal sources to support infrastructure and enable this research to take place. We received support from competitive grants from USDA, NSF, DOE and Consortium for Plant Biotechnology Research this year to study flowering control, gene expression during tree maturation, novel genes that affect height and form, nursery tree development through biotechnology, and transgene confinement strategies. We obtained an annual grant of $75,000 from USDA-ARS to develop methods for producing non-invasive nursery tree crops via genetic engineering. These funds will be able to expand our efforts to test sterility methods in trees using sweetgum as a model nursery crop and potential commercial demonstration product. The USDA
Biotechnology Risk Assessment Program awarded us $358,000 over three years to study the effectiveness of engineered sterility in field environments. This will allow us to produce trees and establish field trials from which the degree of gene containment can be directly measured. This data will be critical for use of sterility as a risk reduction tool to aid regulatory approval. We identified new kinds of dominant negative mutant genes that give high rates of sterility. This method, based on highly conserved parts of floral homeotic genes, was studied in the model plant Arabidopsis but should also be effective in poplars and many other trees. A gene from poplar that is homologous to the TFL1/CEN gene family can greatly delay the onset of flowering. This effect was studied in the model plant Arabidopsis but is now being tested in transgenic poplars. It may provide a means to greatly delay or prevent flowering in many tree species. Dwarfism transgenes can be used to selectively modify
tree height and root biomass. This can be useful for fine-tuning the development of trees for diverse purposes, and the strong root growth induced may be particularly useful for producing trees that are highly drought tolerant, suitable for growth under powerlines, or efficient at bioremediation of soils. Graduate Students = 1.
Impacts
A key measure of impact is social demand for information. Included under publications are the invited presentations that our staff presented last year, many at national and international meetings. These demonstrate the strong social and scientific value of work in relation to tree biotechnology, biosafety, as judged by peers and science policy leaders in forestry, agriculture, and biotechnology. Support from industry for our research cooperative (http://www.fsl.orst.edu/tgerc/) shows the relevance of our work or commercial tree production.
Publications
- Strauss, S.H. 2003. Invited to present lecture on "state of science" at USDA APHIS national meeting on regulation of genetically engineered trees, July, Greenbelt, MD.
- Strauss, S.H. 2003. Invited Science Facilitator at Stakeholder Meeting on USDA Biotechnology Risk Assessment Grant Program Review, June, Washington, D.C.
- Brunner, A.M., V. Busov and S.H. Strauss. 2004. The poplar genome sequence: Functional genomics in a keystone plant species. Trends Plant Sci. 9:49-56.
- Busov, V., R. Meilan, D.W. Pearce, C. Ma, S.B. Rood and S.H. Strauss. 2003. Activation tagging of a dominant gibberellin catabolism gene (GA 2-oxidase) from poplar that regulates tree stature. Plant Physiol. 132:1283-1291.
- Groover, A., J. Fontana, G. Dupper, C. Ma, R. Martienssen, S.H. Strauss and R. Meilan. 2003. Gene and enhancer trap tagging of vascular-expressed genes in poplar trees. Plant Physiol. (In Press).
- Slavov, G.T., S.P. DiFazio and S.H. Strauss. 2003. Gene flow in forest trees: Gene migration patterns and landscape modeling of transgene dispersion in hybrid poplar. Proceedings of the International Conference on Introgression from Genetically Modified Plants into Wild Relatives. (In Press).
- Skinner, J.S., R. Meilan, C. Ma and S.H. Strauss. 2003. The Populus PTD promoter imparts floral-predominant expression and enables high levels of floral-organ ablation in Populus, Nicotiana and Arabidopsis. Molec. Breed. 12:119-132.
- Strauss, S.H. 2003. Genomics, genetic engineering, and domestication of crops. Science 300:61-62.
- Strauss, S.H. and A. M. Brunner. 2003. Tree biotechnology in the 21st century: Transforming trees in the light of comparative genomics. In: The BioEngineered Forest: Challenges to Science and Society, S.H. Strauss and H.D. Bradshaw, eds. Resources for the Future, Washington, D.C. (In Press).
- Strauss, S.H. and S.P. DiFazio. 2004. Hybrids abounding: Review of "Dangerous Liaisons: When Plants Mate With Their Wild Relatives" by Norm Ellstrand. Nature Biotechnol. 22:29-30.
- Strauss, S.H. 2003. Invited speaker at Canadian Forest Service- Canadian Food Inspection Service panel on Regulatory Challenges in Forest Biotechnology, World Forestry Congress, September, Quebec City, Canada.
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Progress 01/01/02 to 12/31/02
Outputs
This project conducts research on genetic engineering of trees to improve their value for intensive plantation forestry using poplars (genus Populus) as model tree taxa. We solicit grant support from forest industries and competitive federal sources to enable research to take place. Support and infrastructure. The staff received major competitive grants from USDA, DOE, and the Consortium for Plant Biotechnology this year to support work on biotechnology of flowering control, changes in gene expression during maturation, and discovery of novel genes for control of tree height and form. We have greatly expanded field-testing areas, within which several field trials were established to study genetic engineering of sterility and to identify new genes that control tree form. In the laboratories, we have had a significant expansion of tissue culture facilities, providing new space for the growing number of transgenic studies underway. We have also installed new mechanisms
to provide laboratory security against vandalism. Research activities. With USDA IFAFS support we have produced a number of new constructs aimed at producing sterile trees via induction of RNAi (RNA interference) using double-stranded transgenes aimed at several floral homeotic genes isolated from poplar. Many of these constructs are now undergoing transformation into trees. We established a field study of more than 600 activation tagged lines of poplars, which has led to production of several mutant phenotypes. One of the genes underlying a phenotype, that of dwarfism, has already been isolated and a manuscript submitted for publication. The gene appears to be a GA2-oxidase, which controls catabolism of active gibberellins (GA)-a key plant hormone that regulates height, growth, crown form, and flowering. We have also submitted two new proposals to USDA competitive grant programs to expand work on dwarfism as a means to increase productivity, reduce hazards and costs of managing large
trees, and to provide new biosafety mechanisms. Several dozen independent lines of transgenic poplars with three kinds of dwarfing genes will be planted in a field trial this summer for a preliminary study of their stability and wood production rate. We are propagating more than one hundred independent lines of transgenic trees for a study of a method for insuring vigorous growth in trees engineered for sterility with a potent cytotoxin. Finally, we will be planting a large field study with approximately two-hundred independent lines of transgenic trees to study stability of expression of trees with diverse reporter genes under stresses associated with vegetative propagation. Graduate Students = 4.
Impacts
A key measure of impact is social demand for information. Included under publications are the invited presentations that our staff presented last year, many at national and international meetings. These demonstrate the strong social and scientific value of work in relation to tree biotechnology and biosafety, as judged by our peers and science policy leaders in forestry, agriculture, and biotechnology. Support from industry for our research cooperative (http://www.fsl.orst.edu/tgerc/) shows the relevance of our work for commercial tree production.
Publications
- Strauss, S.H., R. Meilan, A. Brunner, V. Busov and J. Carson. 2002. Tree Genetic Engineering Research Cooperative Annual Report. Forestry Research Laboratory, Oregon State University, Corvallis. 40 p.
- Slavov, G.T., S.P. DiFazio and S.H. Strauss. 2002. Gene flow in transgenic trees: From empirical estimates to transgenic risk assessment. p. 94-114 In: Proceedings of Consequences of Gene Flow, A Scientific Methods Workshop: Ecological and Agronomic Consequences of Gene Flow from Transgenic Crops to Wild Relatives, March 5-6, Ohio State University, Columbus. http://www.biosci.ohio-state.edu/~lspencer/Proceedings.pdf
- Strauss, S.H. 2002. Ecoterrorism against biotechnology research threatens knowledge and social options. The Forestry Source 7(3) March:10.
- Strauss, S.H. 2002. Trees, homologs, and poisons. Science 296:262 (letter to the editor).
- Strauss, S.H. and A.M. Brunner. 2003. Tree biotechnology in the 21st century: Transforming trees in the light of comparative genomics. Forest Biotechnology: Scientific Opportunities and Social challenges. S.H. Strauss and H.D. Bradshaw, eds. Resources for the Future, Washington, DC. (In press).
- S.H. Strauss and H.D. Bradshaw, eds. 2003. Resources for the Future, Washington, DC. (In press).
- Strauss, S.H. and H.D. Bradshaw, eds. 2001. Proceedings of the First International Symposium on Ecological and Social Aspects of Transgenic Plantations. College of Forestry, Oregon State University, Corvallis. 250 p. (http://www.fsl.orst.edu/tgerc/iufro2001/eprocd.htm)
- Strauss, S.H., M.M. Campbell, S.N. Pryor, P. Coventry and J. Burley. 2001. Plantation certification and genetic engineering research: Banning research is counterproductive. J. Forestry 99(12):4-7.
- Strauss, S.H., W. Rottmann, A. Brunner and L. Sheppard. 2002. Floral homeotic genes for manipulation of flowering in poplar and other plant species. United States Patent No. 6,395,892 B1; May 28, 2002.
- Adams, J.M., G. Piovesan, S.H. Strauss and S. Brown. 2002. Genetic engineering of forest trees against introduced pests and diseases. Conservation Biology 16:874-879.
- Brunner, A.M., B. Goldfarb, V.B. Busov and S.H. Strauss. 2002. Controlling maturation and flowering for forest tree domestication. In: Transgenic Plants: Current Innovations and Future Trends. C.N. Stewart, Jr., ed. Horizon Scientific Press, Wymondham, UK. (In press).
- Campbell, M.M., A.M. Brunner, H.M. Jones and S.H. Strauss. 2003. Forestry's Fertile Crescent: The application of biotechnology to forest trees. Plant Biotechnol. J. (In press).
- DiFazio, S.P., G.T. Slavov, J. Burczyk, S. Leonardi and S.H. Strauss. 2003. transgenic risk assessment. In: Plantation Forest Biotechnology for the 21st Century. C. Walter and M. Carson, eds. Research Signpost, Kerala, India. (In press).
- Meilan, R., A. Brunner, J. Skinner and S.H. Strauss. 2001. Modification of flowering in transgenic trees. p. 247-256 In: Molecular Breeding of Woody Plants. Progress in Biotechnology Series. A. Komamine and N. Morohoshi, eds. Elsevier Science BV, Amsterdam.
- Meilan, R., D.J. Auerbach, C. Ma, S.P. DiFazio and S.H. Strauss. 2001. Stability of herbicide resistance and GUS expression in transgenic hybrid poplars (Populus sp.) during several years of field trials and vegetative propagation. HortScience 37(2):1-4.
- Meilan, R., K.-H. Han, C. Ma, S.P. DiFazio, J.A. Eaton, E. Hoien, B.J. Stanton, R.P. Crockett, M.L. Taylor, R.R. James, J.S. Skinner, L. Jouanin, G. Pilate and S.H. Strauss. 2002. The CP4 transgene provides high levels of tolerance to Roundupr herbicide in field-grown hybrid poplars. Can. J. For. Res. 32:967-976.
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Progress 01/01/01 to 12/31/01
Outputs
Highlights 2001 TGERC staff receive a four-year grant of nearly $600,000 from the Agenda 2020 program, administered by the United States Department of Energy, to continue major studies on the engineering of reproductive sterility. These funds will allow our multi-pronged research program on sterility to continue for several years, through to establishment of field verification trials, ultimately providing key data for industry, regulators, and the public about the effectiveness of sterility as an environmental mitigation strategy. Transgenic studies with floral homeotic genes demonstrate the potential for altering gender in poplars. This finding indicates that transgene expression might be useful for producing certain kinds of hybrid crosses, and allowing selfing to occur during research and breeding programs. Transgenic trees in several of our multi-year field trials continue to demonstrate high levels of health, yield, and stability in transgene expression. These
studies inspire confidence that selecting commercially viable and stable transgenic lines with desirable traits can be readily achieved using routine gene-transfer methods. Computer simulations demonstrate a key role for fertility control, and tolerance for incomplete sterility, in reducing the extent of transgene spread. Studies modeled on a test landscape similar to those found in the Pacific Northwest, and based on TGERC studies of gene flow in wild and planted populations, show that even incomplete sterility can provide a high level of biological safety with transgenes that impart a selective advantage. TGERC staff continue to work intensively with the media while participating in public discussions on the appropriate role of biotechnology in forestry. Through numerous interviews, including regional, national, and international newspaper, radio, and television journalists, TGERC staff continue to be sought for their expertise on the benefits and safety of transgenic trees. TGERC
staff published a number of papers in international journals, and presented invited lectures at diverse venues, concerning the ecological, policy, and certification aspects of transgenic plantations. TGERC staff continue to be recognized as world leaders in making a scientifically-based, rational case for field research and socially acceptable applications of genetic engineering in forestry. TGERC staff co-organized and hosted a major international symposium on forest biotechnology, and the first international symposium on the ecological and social dimensions of transgenic plantations. The meeting received wide press coverage, was attended by over 228 scholars from 21 countries, had major support from public and private sources, and was widely praised for its scholarly quality and the diversity of views it accommodated. Graduate Students = 5.
Impacts
Our goal is to conduct research, technology transfer, and education to facilitate use of genetically engineered trees in plantations. We seek to test and develop select innovations, based on progress in molecular biology and agricultural biotechnology, that may have commercial value to tree farmers and wood-growing industries. Research is presently focused on poplars as scientific models and commercial products. The two major themes underlying our research are environmental assessment and mitigation of transgenic plantations, and testing of transgenic approaches that have direct relevance to plantation management. Our activities, and the expertise we possess, have both grown considerably in social value in recent years. The public concerns over genetically modified (GM) crops around the world have led to numerous calls for respected scientists with broad understanding of the connections among molecular biology, crop production, industry, and the environment to
participate in academic, industrial, and government-led forums.
Publications
- Mohamed, R., R. Meilan, M.E. Ostry, C.H. Michler and S.H. Strauss. 2001. Bacterio-opsin gene over-expression fails to elevate fungal disease resistance in transgenic poplar. Canadian Journal of Forest Research 31:1-8.
- Strauss, S.H., S.P. DiFazio and R. Meilan. 2000. Challenges to commercial uses of transgenic trees in forest plantations: The case of poplars. International Symposium on Biosafety of Transgenic Crops, Saskatoon, Canada, p. 191-195.
- Strauss, S.H., M.M. Campbell, S.N. Pryor, P. Coventry and J. Burley. 2001. Plantation certification and genetic engineering: Banning research is counterproductive. Journal of Forestry. (In Press).
- Strauss, S.H., P. Coventry, M.M. Campbell, S.N. Pryor and J. Burley. 2001. Certification of genetically modified forest plantations. International Forestry Review 3(2):85-102.
- Adams, J.M., G. Piovesan, S.H. Strauss and S. Brown. 2001. Genetic engineering of forest trees against introduced pests and diseases. Conservation Biology. (In Press).
- Strauss, S.H., S.P. DiFazio and R. Meilan. 2001. Genetically modified poplars in context. Forestry Chronicle 77(2):1-9.
- Meilan, R., D.J. Auerbach, C. Ma, S.P. DiFazio and S.H. Strauss. 2001. Stability of herbicide resistance and GUS expression in transgenic hybrid poplars (Populus sp.) during several years of field trials and vegetative propagation. HortScience. (In Press).
- Meilan, R., A. Brunner, J. Skinner and S. Strauss. 2001. Modification of flowering in transgenic trees. In: Molecular Breeding of Woody Plants. Progress in Biotechnology series. A. Komamine and N. Morohoshi, eds. Elsevier Science BV, Amsterdam. Book Chapter. (In Press).
- Mohamed, R., R. Meilan and S.H. Strauss. 2001. Complex behavior of a copper-inducible gene expression system in transgenic poplar. Forest Genetics 8(1):69-72.
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Progress 01/01/00 to 12/31/00
Outputs
Highlights 2000
The promoter region of the poplar PTD floral gene gave consistent floral expression, and was used to successfully disrupt the growth of floral organs, in Arabidopsis, tobacco, and poplar. This could be a highly effective tool for engineering reproductive sterility in poplar and other tree species, reducing environmental impacts and facilitating regulatory approval of transgenic plantations.
We identified more than 70 poplar genes, comprising 26 gene families, that are homologous to genes affecting time of flowering in Arabidopsis. These genes provide new probes for studying tree maturation and may provide new tools to induce early flowering to speed breeding, or to suppress flowering to increase growth.
Seven new field trials, including 4,583 trees and 111 new transgenic lines, that contain insect and/or glyphosate resistance genes, were planted in five states. These trials will help to determine the effectiveness and value of
transgenic trees under diverse field conditions.
Three scientific articles were published in major international journals that describe the DNA sequence and expression of four floral homeotic genes from poplar. These papers demonstrate the strong science conducted by our staff and lay the groundwork for our continued use of these genes to manipulate flowering.
A new competitive research grant from the U.S. Department of Agriculture for $539,000 will accelerate and expand research in control of flowering. The grant will allow us to study stability of gene expression in detail and to evaluate effectiveness of gene suppression for producing non-flowering trees.
Plans are well underway for an international meeting on molecular biology of forest trees in the Pacific Northwest, including a symposium on ecological aspects of transgenic plantations. This meeting, supported by a competitive grant from USDA, will bring together leading economists, ethicists, ecologists,
and geneticists to discuss the benefits and safety aspects of use of transgenic trees in forest plantations.
Our staff continue to play key roles in the global and national discussion on genetically modified (GM) trees in forestry. Staff were invited to give talks and write papers for a number of major forums on the rationale, methods, and safety of GM crops and trees. Graduate Students = 4
Impacts
Our goal is to conduct research, technology transfer, and education to facilitate use of genetically engineered trees in plantations. We seek to test and develop select innovations, based on progress in molecular biology and agricultural biotechnology, that may have commercial value to tree farmers and wood-growing industries. Research is presently focused on poplars as scientific models and commercial products. The two major themes underlying our research are environmental assessment and mitigation of transgenic plantations, and testing of transgenic approaches that have direct relevance to plantation management. Our activities, and the expertise we possess, have both grown considerably in social value in recent years. The public concerns over genetically modified (GM) crops around the world have led to numerous calls for respected scientists with broad understanding of the connections among molecular biology, crop production, industry, and the environment to
participate in academic, industrial, and government-led forums. For example, this year we were asked to present the case for benefits and safety of GM trees in an international context to the U.S. National Research Council and the International Symposium on the Biosafety of Genetically Modified Crops. While we are surprised and frustrated at the acrimony of activist-led concern over biotechnology, we also feel gratified that we have been conducting precisely the kinds of research that are demanded by those with reasonable concerns over use of transgenic trees in forestry.
Publications
- Thompson, P.B. and S.H. Strauss. 2000. Research ethics for molecular silviculture. p. 585-611 In: Molecular Biology of Woody Plants. S.M. Jain and S.C. Minocha, eds. Kluwer Academic Publishers, The Netherlands.
- Meilan, R., K.-H. Han, C. Ma, R.R. James, J.A. Eaton, B.J. Stanton, E. Hoien, R.P. Crockett and S.H. Strauss. 2000. Development of glyphosate-tolerant hybrid cottonwoods. TAPPI Journal 83(1):164-166.
- Meilan, R., C. Ma, S. Cheng, J.A. Eaton, L.K. Miller, R.P. Crockett, S.P. DiFazio and S.H. Strauss. 1999. High levels of Roundupr and leaf-beetle resistance in genetically engineered hybrid cottonwoods. In: Hybrid Poplars in the Pacific Northwest: Culture, Commerce and Capability. K.A. Blatner and J.J. Johnson, eds. Washington State University Cooperative Extension, Pullman, WA. (In Press).
- Rottmann, W.H., R. Meilan, L.A. Sheppard, A.M. Brunner, J.S. Skinner, C. Ma, S. Cheng, L. Jouanin, G. Pilate and S.H. Strauss. 2000. Diverse effects of overexpression of LEAFY and PTLF, a poplar (Populus) homolog of LEAFY / FLORICAULA, in transgenic poplar and Arabidopsis. The Plant Journal 22:235-246.
- Sheppard, L.A., A.M. Brunner, K.V. Krutovskii, W.H. Rottmann, J.S. Skinner, S.S. Vollmer and S.H. Strauss. 2000. A DEFICIENS homolog from the dioecious tree Populus trichocarpa is expressed in both female and male floral meristems of its two-whorled, unisexual flowers. Plant Physiology 124:627-639.
- Skinner, J.S., R. Meilan, A.M. Brunner and S.H. Strauss. 2000. Options for genetic engineering of floral sterility in forest trees. p. 135-153 In: Molecular Biology of Woody Plants. Volume 1. S.M. Jain and S.C. Minocha, eds. Kluwer Academic Pubishers, Dordrecht, The Netherlands.
- Strauss, S. and R. Meilan. 2000. Tree Genetic Engineering Research Cooperative. Western Forester 45(2):14.
- Strauss, S.H., K. Raffa and P. List. 2000. Ethics and transgenic plantations. Journal of Forestry 98(7):47-48.
- Bradshaw, H.D., Jr. and S.H. Strauss. 2000. Breeding strategies for the 21st century: Domestication of poplar. Book Chapter. (In Press).
- Brunner, A.M., W.H. Rottmann, L.A. Sheppard, K.V. Krutovskii, S.P. DiFazio, S. Leonardi and S.H. Strauss. 2000. Structure and expression of duplicate AGAMOUS orthologs in poplar. Plant Molec. Biol. 44:619-634.
- Han, K.-H., R. Meilan, C. Ma and S.H. Strauss. 2000. An Agrobacterium tumefaciens transformation protocol effective in a variety of cottonwood hybrids (genus Populus). Plant Cell Rep. 19:315-320.
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