Authors: Yueqiang Leng 1, Madhusudhana Janga 2, Alireza Poursafar 1, Shahed Safar 1, Wenhao Dai 3, and Shaobin Zhong 1
1. North Dakota State University, Department of Plant Pathology, Fargo, North Dakota, USA
2. Texas Tech University, Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Lubbock, Texas, USA
3. North Dakota State University, Department of Plant Sciences, Fargo, North Dakota, USA
Corresponding Author: Shaobin Zhong, shaobin.zhong@ndsu.edu
Presenting Author: Shaobin Zhong
Abstract
Fusarium head blight (FHB) caused by Fusarium graminearum is a devastating disease, which causes significant grain yield and quality losses in wheat. Use of resistance is one of the most effective approaches for management of the disease. Fhb1 originally derived from the Chinese wheat variety Sumai3 is a major QTL for FHB resistance, which has been widely used for fighting against FHB worldwide. Two genes (TaPFT and TaHRC) have been reported to be involved in the Fhb1-mediated resistance. TaPFT encodes a pore-forming toxin-like protein, while TaHRC encodes a histidine-rich calcium-binding protein. However, the role and function of these two genes in FHB resistance are still in controversy. In this study, we aimed to generate doubled haploid (DH) lines containing mutated alleles of TaPFT and TaHRC from various wheat genotypes via wide hybridization with transgenic maize expressing Cas9 and single guide RNA (sgRNA) for targeting the two genes, respectively. Five varieties (Bobwhite, Dayn, Fielder, ND VitPro and SD4539) without the Fhb1 resistance and three varieties (Wangshuibai, Sumai3 and Alsen) with the Fhb1 resistance were used in the targeted gene editing experiments. We generated 13, 9, 6, 4, and 6 DH lines with mutations in TaHRC-S (the susceptible allele of TaHRC) from Bobwhite, Dayn, Fielder, ND VitPro, and SD4539, respectively. We also obtained 3 and 19 DH lines with mutations in TaHRC-R (the resistant allele of TaHRC) from Sumai3 and Alsen, respectively. Evaluating some of the DH mutant lines along with their wildtype parents for FHB resistance in greenhouse didn’t clarify the issue regarding if the Fhb1-mediated resistance is the result of a loss-of-function mutation of TaHRC-S or a gain of function of TaHRC-R. In addition, we identified one Wangshuibai-derived DH line (DH-P3WSB) with a 4-bp deletion in TaPFT, but observed no significant difference in FHB resistance between DH-P3WSB and Wangshuibai. To solve the mystery of Fhb1-mediated resistance, we are evaluating more DH lines with mutations in TaHRC-S or TaHRC-R allele, and generating and evaluating DH lines with mutated TaPFT derived from Sumai3 and Alsen.
ACKNOWLEDGEMENT AND DISCLAIMER
This material is based upon work supported by North Dakota Wheat Commission and the U.S. Department of Agriculture under Agreement No. 59-0206-2-156. This is a cooperative project with the U.S. Wheat & Barley Scab Initiative (USWBSI). Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the view of the U.S. Department of Agriculture.