Bt Research 2025, Vol.16, No.5, 182-193 http://microbescipublisher.com/index.php/bt 190 damaging their own growth. To this end, researchers have codon optimization and fragment modification of the Cry1Ab gene sequence to make it more suitable for the transcriptional translation system of plants (Huang, 2011). This gene optimization is essentially to better utilize the metabolic pathway resources of plant cells, improve mRNA stability and translation efficiency, and avoid unnecessary energy waste. Figure 3 Insect gut immunity protects against infections and maintains gut microbiota homeostasis (Adopted from Li et al., 2020) 7.3 Metabolic optimization examples of genetically engineered Bt corn Genetically engineered insect-resistant corn (often called Bt corn) resists insect pests such as corn borer and sticky insects by expressing the Bt toxin gene in the plant body. In the process of cultivating Bt corn, researchers have optimized the Bt gene and corn's own metabolism in many aspects to achieve efficient and stable yield and anti-worm effect. One classic example is the MON810 corn incident of Mengsandu. The modified cry1Ab gene it carries is codon-optimized, removes unstable sequences, and uses strong promoter drivers to continuously express Cry1Ab toxic protein at a high level in corn leaves. This optimization fully takes into account the transcriptional translational metabolic characteristics of maize cells, so that the transferred Bt gene is integrated into the plant metabolic network without causing metabolic burden. Experiments have shown that MON810 corn has lasting resistance to European corn borers, but has no significant adverse effects on corn yield and physiology, which indicates that plant metabolism has reached a new balance on the expression of exogenous insect-resistant proteins (AL-Harbi et al., 2019). Another example is the insect-resistant corn strain cultivated in China in recent years, such as superposition of multiple Bt toxin genes (gold brick combinations such as Cry1Ac/Cry2Ab, etc.). In order to avoid the stress on plant metabolism of multiple exogenous protein expression, the researchers adopted strategies such as tissue-specific promoter and content optimization to enable different Bt toxins to be highly expressed in different parts of the plant or at different growth periods (Huang, 2011). 8 Future Outlook and Challenges 8.1 Application prospects of metabolomics and systems biology in Bt research With the development of high-throughput omics technology, we have the opportunity to deeply analyze the metabolic network of Bt and its association with pathogenicity from the overall level. Metabolomics can comprehensively capture the metabolic profile changes of Bt at different growth conditions and in different infection stages, thereby helping to identify key metabolic pathways and signaling molecules. By comparing Bt's
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