RESUMEN
Eucalyptus covers approximately 7.5 million hectares in Brazil and serves as the primary woody species cultivated for commercial purposes. However, native insects and invasive pests pose a significant threat to eucalyptus trees, resulting in substantial economic losses and reduced forest productivity. One of the primary lepidopteran pests affecting eucalyptus is Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae), commonly referred to as the brown looper caterpillar. To address this issue, FuturaGene, the biotech division of Suzano S.A., has developed an insect-resistant (IR) eucalyptus variety, which expresses Cry pesticidal proteins (Cry1Ab, Cry1Bb, and Cry2Aa), derived from Bacillus thuringiensis (Bt). Following extensive safety assessments, including field trials across various biomes in Brazil, the Brazilian National Technical Commission of Biosafety (CTNBio) recently approved the commercialization of IR eucalyptus. The biosafety assessments involved the analysis of molecular genomics, digestibility, thermostability, non-target organism exposure, degradability in the field, and effects on soil microbial communities and arthropod communities. In addition, in silico studies were conducted to evaluate allergenicity and toxicity. Results from both laboratory and field studies indicated that Bt eucalyptus is as safe as the conventional eucalyptus clone for humans, animals, and the environment, ensuring the secure use of this insect-resistant trait in wood production.
RESUMEN
Eucalyptus comprises the largest planted area of cultivated production forest in Brazil. Genetic modification of eucalyptus can provide additional characteristics for increasing productivity, protecting plant yield, and potentially altering fiber for various industrial uses. With this objective, a transgenic eucalyptus variety, event H421, received regulatory approval for commercial release after 6 years of approved risk assessment studies by the Brazilian National Technical Biosafety Commission (CTNBio) in 2015, becoming the first approved genetically modified (GM) eucalyptus in the world. GM event H421 enables increased plant biomass accumulation through overexpression of the Arabidopsis 1,4-ß-endoglucanase Cel1, which remodels the xyloglucan-cellulose matrix of the cell wall during development to promote cell expansion and growth. As required, in that time, by the current normative from CTNBio, a post-commercial release monitoring plan for H421 was submitted, incorporating general surveillance for five consecutive years with the submission of annual reports. The monitoring plan was conducted on fields of H421 progenies, with conventional clones as comparators, cultivated in representative regions where eucalyptus is cultivated in the states of São Paulo, Bahia, and Maranhão, representing Southeast, Northeast, and Northern Brazil. Over the course of the five-year general surveillance monitoring plan for the approved GM eucalyptus H421, no adverse effect that could impact the biosafety of the commercially approved event was identified. Additionally, the GM eucalyptus exhibited behavior highly consistent with that of conventional commercial clones. Therefore, there was no need for an extra risk assessment study of a case-specific monitoring plan. The results show the importance of continuously updating the regulation norms of governmental agencies to align with scientific advances.
