bacterial pathogens.
The gene-editing tool CRISPR allows scientists to make highly precise and targeted changes in plant DNA sequences. In most cases, CRISPR has been used to completely turn off specific genes to study their function or improve traits. However, our previous research found that switching off certain key defense genes can lead to serious problems - such as dwarfism, sterility, or even plant death - making it difficult to study the function of these genes or use these genes to strengthen disease resistance (Zhang et al., 2020). To overcome this, we propose fine-tuning the activity of these important genes instead of completely turning them off. We do this by editing the “switches” that control when and how strongly a gene is activated, known as promoter regions. During my PhD research, I discovered that even a single nucleotide (the basic building block of DNA) change in a promoter, can significantly alter how much of a protein is produced (Zhang et al., 2019). This finding supports a powerful new approach: instead of changing what genes do, we can fine- tune how they are expressed to achieve better plant performance. This allows us to find the right balance between disease resistance and healthy growth. In addition, because these edits are small, precise, and could naturally occur in plants, they may not fall under strict federal regulations, making it easier to apply our findings to real-world agriculture. Our project will proceed in four main steps: 1) Identify key plant defense genes that protect against disease but cause growth issues when completely turned off. Candidate genes will be identified based on my postdoc project and other published papers. 2) Pinpoint the functional parts of promoters that control how and when these genes are activated, using specialized reporter tests and targeted DNA changes. 3) Use CRISPR tools to make precise, single-nucleotide or small-sequence edits in promoter regions that increase or decrease gene activity. Generate a series of tomato mutant plants with slightly adjusted promoter sequences through tomato tissue culture and transformation. 4) Evaluate these tomato mutants for both disease resistance and growth performance by measuring disease symptoms, morphological changes, and yield. Identify lines that show strong resistance without reduced yield or vigor. Through this fine-tuning strategy, we aim to develop tomato plants that balance strong disease resistance with robust growth and productivity, paving the way for more sustainable agriculture. Specifically, two outcomes are listed below. 1) A group of tomato plants with elevated bacterial disease resistance and healthy growth. 2) Generalizable design rules for promoter engineering that can be applied to improve other crop species.
Madison Trust 2026 Project Proposal
2
Made with FlippingBook - professional solution for displaying marketing and sales documents online