Continuous Directed Evolution Platform to Reduce Crop Respiration and Boost Yield

Overview

Crop yield is ultimately limited by the balance between photosynthesis and respiration. Roughly half of the carbon a plant fixes is lost back to the atmosphere through respiration, and a large share of that loss comes from continually breaking down and resynthesizing enzymes (protein turnover). This offering applies continuous directed evolution to slow the turnover of specific high-cost enzymes, freeing carbon that can instead be captured in harvested biomass, roots, and soil organic matter. Reducing respiration at this level offers a complementary path to raising yield beyond conventional photosynthesis-focused approaches, and also enhances the carbon sequestration value of cropping systems.

Technical specifications

• Core approach: Continuous directed evolution using the OrthoRep yeast platform to evolve target enzymes toward longer catalytic lifetimes in vivo.
• Lead targets: Thiamin biosynthesis enzymes THI4 (a single-turnover suicide enzyme) and THIC (approximately four turnovers), both of which turn over far faster than typical plant enzymes (greater than 100,000 catalytic cycles).
• Enzyme prospecting: Identification of non-suicidal prokaryotic THI4 variants that catalyze multiple cycles, followed by evolution of improved aerobic activity.
• Deployment in crops: CRISPR/Cas9 knockout of native THI4 and THIC in a partner-selected crop and replacement with evolved, longer-lived variants.
• Validation pipeline: Bioenergetics and crop modeling (predicting approximately 4% biomass gains in an annual crop from just two enzyme swaps), followed by greenhouse and field assessment of growth, total biomass, harvested yield, and root biomass.
• Future targets: The platform extends to the many additional plant enzymes that mediate fewer than 10,000 catalytic cycles, broadening the addressable opportunity over time.

Technology readiness level

The platform is at an early-to-mid technology readiness stage. Bioenergetics modeling and enzyme prospecting have identified viable targets and non-suicidal THI4 candidates, and feasibility of evolving aerobic activity has been demonstrated in the OrthoRep yeast system. The next milestone is a crop proof-of-concept in a partner-selected species, combining directed evolution, molecular breeding via CRISPR/Cas9, and growth and yield assessment. Broader deployment across additional enzymes and crops represents a staged expansion path.