A genetically modified eucalyptus (GM eucalyptus) is an eucalyptus whose genetic material has been altered through genetic engineering techniques, conferring desirable traits such as increased biomass, accelerated growth, pest resistance, and herbicide tolerance. In 2015, a GM eucalyptus variety, event H421, which provides higher wood volume and faster growth, received regulatory approval in Brazil for commercial release by the National Technical Biosafety Commission (CTNBio), becoming the first genetically modified eucalyptus approved in the world. Subsequently, other GM eucalyptus varieties have also been approved, incorporating traits for pest resistance and herbicide tolerance. While other countries conduct research on genetically modified trees, Brazil is the only one to have released them for commercial-scale cultivation.
Examples of transgenic eucalyptus
H421 eucalyptus In 2015, a genetically modified eucalyptus variety, the event H421, which provides greater wood volume and accelerated growth, received regulatory approval in Brazil for commercial release. The event, developed by FuturaGene, a biotechnology company owned by Suzano, a Brazilian pulp and paper company, was created in 2000 through the Agrobacterium tumefaciens mediated recombination technique, in which the cel1 gene, originating from the plant Arabidopsis thaliana, was inserted into the genome of a hybrid Eucalyptus grandis × E. urophylla. This gene encodes the enzyme endo-(1,4)-β-glucanase Cel1, whose function is related to cell wall remodeling during growth. Endoglucanases act by breaking bonds in regions of non-crystalline cellulose and in xyloglucans, structural components of the plant cell wall. This process reduces the cross-linking between these fibers, increasing the flexibility of the cell wall matrix and facilitating cell expansion and elongation. In A. thaliana, the Cel1 enzyme is highly expressed in rapidly growing young tissues and is essential for cell elongation. When transferred to eucalyptus, this mechanism provided greater cell wall plasticity, allowing the cells to expand further and accumulate more biomass. GM eucalyptus can increase wood productivity by 30 to 40% and reduce the harvest cycle from seven to about five and a half years, in addition to expanding the use of biomass for paper, bioenergy, biofuels, and other products.
Glyphosate-tolerant eucalyptus FuturaGene developed and obtained approval in Brazil for the commercial use of genetically modified eucalyptus tolerant to the herbicide glyphosate. These GM events received the cp4-epsps gene, which expresses a version of the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), associated with the synthesis of the essential amino acids phenylalanine, tyrosine, and tryptophan, from the CP4 strain of the bacterium Agrobacterium tumefaciens, which is not inhibited by glyphosate. The 751K032 characterized the first event of this type, approved in Brazil in 2021.
Bt eucalyptus Bt eucalyptus is a GM variety developed to resist insect attacks, particularly from defoliating lepidopterans. These pests can significantly reduce productivity, with losses of up to 40% per year, in addition to compromising wood quality and pulp production. The company FuturaGene inserted into eucalyptus three genes from the bacterium Bacillus thuringiensis (Bt). This bacterium produces insecticidal proteins called Cry, which specifically target the intestines of certain caterpillars. In the case of Bt eucalyptus, the genes Cry1Ab, Cry1Bb, and Cry2Aa were introduced, ensuring broad protection against defoliators. The Bt event 1521K059 was approved by CTNBio in 2023.
Frost tolerance eucalyptus Freeze-tolerant GM eucalyptus trees for use in southern US plantations are currently being tested in open air sites with such an objective in mind. ArborGen, a tree biotechnology company and joint venture of pulp and paper firms Rubicon (New Zealand), MeadWestvaco (US) and International Paper (US) is leading this research. Until now the cultivation of eucalyptus has only been possible on the southern tip of Florida, freeze-tolerance would substantially extend the cultivation range northwards.
Stacked traits FuturaGene developed GM varieties that combine multiple traits of interest. In 2024, CTNBio approved event H421 × 955P082 × 1521K059, obtained through conventional crossing of these respective varieties, which combines higher productivity, glyphosate herbicide tolerance, and insect resistance.
Controversy
… excerpt ends here. Continue reading the full article.
