Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: The Cp4 Transgene Provides High Levels of Tolerance to Roundup Herbicide in Field-Grown Hybrid Poplars

Authors
item Meilan, R. - OREGON ST. UNIV
item Han, K-H. - OREGON ST. UNIV
item Ma, C. - OREGON ST. UNIV
item Difazio, S. - OREGON ST. UNIV
item Eaton, J. - POTLATCH CORP
item Stanton, B. - GREEN WOOD RESOURCES
item Crockett, R. - MONSANTO COMPANY
item James, Rosalind
item Strauss, S. - OREGON ST. UNIV

Submitted to: Canadian Journal of Forest Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 4, 2002
Publication Date: May 17, 2002
Citation: MEILAN, R., HAN, K., MA, C., DIFAZIO, S.P., EATON, J.A., STANTON, B.J., CROCKETT, R.P., JAMES, R.R., STRAUSS, S.H. The CP4 transgene provides high levels of tolerance to Roundup herbicide in field-grown hybrid poplars. CANADIAN JOURNAL OF FOREST RESEARCH. 2002. 32:967-976

Interpretive Summary: Hybrid poplars are grown on plantations in the U. S. for a variety of uses, including pulp for paper production, plywood, timber, and wood fuel. Weeds can seriously affect the survival and growth of the trees, particularly in the first 2-3 years. Two genes (CP4 and GOX) which could produce resistance to the herbicide Roundup (glyphosate resistance), were inserted into the several different hybrids, producing 80 different lines. We evaluated Roundup tolerance over 2 years in field studies conducted in eastern and western Oregon. Ten percent of our transgenic lines showed no foliar damage or reduced growth after being sprayed with Roundup at concentrations above normal commercial rates. Lack of damage was associated with expression of the CP4 gene but not the GOX gene. It was suspected that GOX caused undesirable side effects, so we produced 12 lines into which only the CP4 gene was inserted. The performance of these newly regenerated lines was compared with an identical number of lines, produced in the same genotype, that had previously been engineered to containing both CP4 and GOX. Growth of the lines transformed with just CP4 was significantly better than those containing both genes and exhibited less damage in response to glyphosate treatment. This is the first report of transgenic poplars exhibiting high levels of glyphosate tolerance when grown under field conditions. With a modest transformation effort, it is possible to produce lines with commercially useful levels of glyphosate tolerance and little apparent collateral genetic damage.

Technical Abstract: We tested two genes together (CP4 and GOX) for imparting tolerance to glyphosate (the active ingredient in Roundup herbicide) in hybrid poplars. Using Agrobacterium-based transformation, 80 independent transgenic lines (i.e. products of asexual gene transfer) were produced in a variety of hybrid poplar clones (40 lines in Populus trichocarpa x P. tremuloides, 35 lines in P. tremula x P. alba, and five lines in P. tremula x P. tremuloides hybrids). We evaluated glyphosate tolerance over 2 years in field studies conducted in eastern and western Oregon. Ten percent of our transgenic lines showed no foliar damage or reduced growth after being sprayed with Roundup at concentrations above normal commercial rates. Lack of damage was associated with expression of the CP4 gene but not the GOX gene. It was suspected that GOX caused undesirable side effects, so we produced 12 lines into which only the CP4 gene was inserted. The performance of these newly regenerated lines was compared with an identical number of lines, produced in the same genotype, that had previously been engineered to containing both CP4 and GOX. Growth of the lines transformed with just CP4 was significantly better than those containing both genes and exhibited less damage in response to glyphosate treatment. This is the first report of transgenic poplars exhibiting high levels of glyphosate tolerance when grown under field conditions. With a modest transformation effort, it is possible to produce lines with commercially useful levels of glyphosate tolerance and little apparent collateral genetic damage.

Last Modified: 7/25/2014
Footer Content Back to Top of Page