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.

中文翻译：

---

基因工程桉树表达苏云金芽孢杆菌杀虫蛋白以提高抗虫性：风险评估视角

巴西桉树面积约 750 万公顷，是商业用途种植的主要木本树种。然而，本土昆虫和入侵性害虫对桉树构成重大威胁，导致巨大的经济损失和森林生产力下降。影响桉树的主要鳞翅目害虫之一是蓟马(Stoll, 1782)（鳞翅目：尺蛾科），通常称为棕色尺蠖毛虫。为了解决这个问题，Suzano SA 的生物技术部门 FuturaGene 开发了一种抗虫 (IR) 桉树品种，该品种表达 Cry 杀虫蛋白（Cry1Ab、Cry1Bb 和 Cry2Aa），源自苏云金芽孢杆菌（BT）。经过广泛的安全评估，包括在巴西各个生物群落的现场试验，巴西国家生物安全技术委员会 (CTNBio) 最近批准了速释桉树的商业化。生物安全评估涉及分子基因组学、消化率、热稳定性、非目标生物暴露、田间降解性以及对土壤微生物群落和节肢动物群落的影响的分析。此外，计算机模拟进行研究以评估过敏性和毒性。实验室和现场研究的结果表明，Bt 桉树对人类、动物和环境与传统桉树克隆一样安全，确保了这种抗虫特性在木材生产中的安全利用。