Sorghum microspore bank, transformation and regeneration system for gene editing
A novel 3-in-1 platform combining a cryopreserved microspore bank, a chemical and nanoparticle-based transformation method, and a plant regeneration system for sorghum. Designed to enable CRISPR/Cas9 gene editing without Agrobacterium, accelerating development of improved varieties for food, bioenergy, and bioproduct applications.
Overview
Sweet sorghum is a high-value C4 crop that accumulates significant sugar levels in its stalks while requiring low inputs, making it attractive for food, bioenergy, and bioproduct markets. However, improving sorghum varieties for sugar yield, biofuel traits, and environmental stress tolerance has been limited by the lack of efficient transformation and regeneration tools.
This proposal addresses that gap by developing an integrated 3-in-1 microspore platform: a cryopreserved bank of competent microspores, a robust transformation pipeline, and a regeneration method producing transgenic sorghum plants. By replacing Agrobacterium-based delivery with chemical and nanoparticle techniques applied to naturally protoplast-like microspores, the system streamlines gene editing and over-expression workflows for research and breeding programs.
Technical specifications
Core platform components:
- Microspore bank: Cryopreserved sorghum microspores from five varieties, starting with the Topper genotype, with demonstrated pre- and post-cryopreservation viability of 89% to 92% and cell density supporting downstream use
- Transformation platform: DNA delivery via chemical methods and electroporation, eliminating reliance on Agrobacterium and enabling work with microspores that naturally behave as protoplasts
- Gene editing capability: Compatible with over-expression vectors and CRISPR/Cas9 constructs for targeted trait improvement
- Regeneration pipeline: Androgenesis-based regeneration of transgenic plants from edited microspores
- Preliminary performance: Transformation efficiency of up to 46% in the Topper variety, indicating strong platform readiness
Target applications:
- Accelerated development of sorghum lines with improved sugar accumulation and biofuel-related traits
- Introduction of tolerance traits for environmental stresses such as drought and heat
- Support for sustainable food and energy crop improvement programs
Technology readiness level
The platform is at an early-to-mid development stage. Proof-of-concept results have been demonstrated in the Topper sorghum variety, with validated microspore viability and transformation efficiency. The next phase will expand the microspore bank to five sorghum varieties, optimize chemical and nanoparticle delivery methods alongside electroporation, and complete regeneration protocols for transgenic plants. The research team is seeking $15,000 in funding to continue these validation activities, with a two-year horizon for delivering a fully functional 3-in-1 system suitable for downstream field studies and breeding applications.
About Tennessee State University
Tennessee State University conducts applied and fundamental research across agriculture and environmental sciences, engineering and computer science, education and learning sciences, and health and behavioral studies. Its land‑grant programs include agricultural research and Cooperative Extension with long‑running USDA‑supported projects in plant science, urban agriculture, food safety, and natural resource management. Notable research units include the College of Agriculture’s research programs and extension centers, the Center of Excellence for Learning Sciences, and the Center of Excellence in Information Systems, along with specialized facilities such as the Otis L. Floyd Nursery Research Center. TSU investigators regularly secure funding from federal agencies including USDA‑NIFA, NSF, NIH, and the State of Tennessee, often in partnership with regional industry and community organizations. Technology transfer and outreach emphasize practical solutions in sustainable agriculture, biotechnology, data and information systems, and workforce development for Middle Tennessee and beyond.
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