We chose this project because we wanted to address one of the most critical environmental challenges today: microplastic pollution. Microplastics are tiny plastic particles that accumulate in rivers, lakes, and oceans, harming wildlife and entering the food chain. We are motivated by creating a plant that can internally decompose microplastics, breaking them down inside its tissues. Traditional approaches, such as reducing plastic use, switching to other alternatives, or recycling, are essential, but they cannot remove plastics that already exist in the environment. PET, one of the most common plastics, persists in waterways and breaks down into microplastics. Inspired by the discovery of PETase, an enzyme capable of degrading PET, our team decided to explore a plant-based solution. Using Nicotiana benthamiana as a model system, we designed and tested a composite genetic part, IsPETase-Amy3SP, which fuses the PETase enzyme with an α-amylase signal peptide to enable extracellular secretion. By developing a living system, we hope our project will contribute to a sustainable solution, improve environmental health, and inspire future iGEM teams to pursue practical, impactful synthetic biology projects.

Our contribution to the iGEM community lies in creating these new composite parts and in the thorough creation of a new part, IsPETase-Amy3SP, designed for plant-based microplastic degradation. We codon-optimized PETase for plant expression, integrated it into two widely used vectors (pCAMBIA1302 and pGWB2), and provided detailed maps, sequences, primers, and protocols. Each plasmid component and the predicted cleavage site and secretion pathway are explained. By sharing this part and its associated methods, we provide future iGEM teams with a ready-to-use, well-characterized tool for exploring plant-based enzyme expression and secretion, saving time and reducing trial-and-error in experimental setups.

Every member of our team contributed to different aspects of the project, including part design, codon optimization, molecular modeling, cloning strategies, and documentation. Together, we created a resource that improves knowledge regarding plant-based PETase expression and provides a practical, sustainable tool for tackling microplastic pollution. Our work demonstrates the potential of plants as living biofilters and offers a foundation for future teams to innovate, improve, and scale plant-based bioremediation strategies. We hope to inspire and support future iGEM teams, provide a foundation for sustainable microplastic bioremediation, and demonstrate the potential of plants as living biofilters.

Following our localization analysis using our composite part (BBa_25OB1A28), we can establish proof of concept for plant-based PETase expression using our BBa_252Q5ZWV part. With this successful test, we hope our registry paves the way for scalable, sustainable bioremediation strategies that integrate prevention and active degradation of plastic pollution.