Fusarium head blight (FHB; scab) is a devastating disease in barley and wheat caused by the same pathogen. While significant progress has been made in understanding and improving host resistance in wheat with molecular cloning of the major QTL Fhb1 and Fhb7, similar research with barley has lagged behind due mainly to the lack of highly resistant genotypes, which makes it very difficult to effectively control FHB and DON contamination. Thus, there is an urgent need for a breakthrough in gene discovery and germplasm development to achieve higher levels of FHB resistance and a greater capacity to detoxify DON in barley using transformative approaches.

The use of wheat genes to breed barley FHB resistance is the road not taken because of strong reproductive barriers. Considering that Fhb7 detoxifies DON, we hypothesize that Fhb7 can also contribute greatly to FHB resistance in barley. Taking the advantage of our ongoing work on Fhb7 and CRISPR-based genome editing, we propose to continue our effort with an overall goal to transfer Fhb7 to barley through CRISPR-mediated targeted gene insertion as a proof of concept. The proposed research includes three objectives:

1)      Generate transgenic barley expressing both CRISPR/Cas9 and Fhb7 donor.  

2)      Evaluate the Fhb7 function in transgenic barley.

3)      Screen the transgenic plants for targeted Fhb7 insertion events.

The project is transformational because it (1) uses a wheat FHB-resistance gene to improve the FHB resistance of barley, which is unprecedented, (2) utilizes CRISPR-mediated target gene insertion to develop novel FHB-resistance germplasm, and (3) aligns with the multiple priorities of several USWBSI programs, including GDER, VDHR, and BAR-CP. This project serves our long-term goal to improve the FHB resistance of barley and wheat using CRISPR-based approaches

Supported by the USWBSI-TRSC program, we are establishing a CRISPR-mediated targeted gene insertion system in barley. We have developed an all-in-one construct to express CRISPR/Cas9 and the Fhb7 donor DNA. The construct has been used to transform barley cultivars Gold Promise (GP) and Quest, plantlets are regenerating from the transformed GP calluses. Results from the proposed research will have a positive impact on barley production and the (malting, feed, and food) industry, benefiting barley growers and end-users.