Gene-edited legume forages that convert soluble proanthocyanidins to insoluble forms for enhanced soil carbon sequestration
A patented gene-knockout approach that converts soluble proanthocyanidins (condensed tannins) into insoluble, cell-wall–bound forms in legume forage crops, slowing litter decomposition and increasing soil carbon storage. The technology uses CRISPR to disable the LAR gene in species such as Lotus corniculatus and Trifolium arvense, offering a plant-based route to improved soil carbon sequestration.
Overview
This solution offers a plant-genetics approach to strengthening soil carbon sequestration in agricultural systems. The core idea is to slow the decomposition of plant residues—both surface litter and root material—so that carbon fixed by living plants remains stored in the soil for longer periods. The team has discovered that the LAR gene controls the polymerization of proanthocyanidins (PAs), also known as condensed tannins. Knocking out LAR in Medicago completely converts soluble PAs into insoluble PAs that cross-link with cell wall components, making plant tissues more resistant to microbial breakdown. Applying this approach to legume forage crops that naturally accumulate PAs provides a pathway to increase the carbon sequestration capacity of soils used for livestock production and cover cropping.
Technical specifications
- Target trait: Conversion of soluble proanthocyanidins to insoluble, cell-wall–bound proanthocyanidins
- Mechanism: Disabling the LAR gene, which controls PA polymerization, shifting PA partitioning from soluble to insoluble forms
- Editing method: CRISPR-based gene knockout
- Target species: Lotus corniculatus (birdsfoot trefoil) and Trifolium arvense (rabbit-foot clover), with applicability to other PA-accumulating legume forages
- Benefit pathway: Insoluble PAs cross-link with cell wall materials, reducing litter and root decomposition rates and thereby prolonging soil carbon residence time
- Project duration: Approximately one year for initial generation and validation of edited lines
Technology readiness level
The underlying concept—converting soluble PAs to insoluble PAs via LAR knockout—has been demonstrated in Medicago, and the inventors hold an issued patent on this conversion. The proposed next stage extends the approach to additional legume forage species using CRISPR editing. The technology is at an early-to-mid stage of development: proof-of-concept has been achieved in a model legume, with planned translation to commercially relevant forage species and field-level decomposition and carbon-sequestration validation still to be completed.
About University of North Texas
The University of North Texas is a comprehensive public research university in Denton, part of the UNT System, serving a large and diverse student body with broad academic programs. A dedicated research campus brings engineering and science together with shared user facilities, advanced instrumentation, prototyping spaces, and technology transfer support that speed collaboration with industry. Its Dallas–Fort Worth location offers ready access to major corporate R&D, suppliers, and testing partners, supported by project-based engagements, internships, and sponsored capstones. Research is backed by competitive federal funding from agencies such as the National Science Foundation, Department of Defense, and Department of Energy, alongside state and industry support.
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