Adam Schoen, Guilherme V. Yoshikawa, Parva Kumar Sharma, Alex Mahlandt, Yi Chen, Huajin Sheng, Leon V. Kochian, Peng Gao, Daoquan Xiang, Teagen D. Quilichini, Prakash Venglat, Sheng Wang, Inderjit Singh Yadav, Robert Sablowski, Yuqi Wang, Peng Zhang, Annabel Whibley, Amy M. Hill, Yong Gu, Daniel Rodriguez-Leal, Weifeng Luo, Yiping Qi, Nathan Meier, Anmol Kajla, Matthew Willman, Gina Brown‐Guedira, Sheron Simpson, Ramey C. Youngblood, Amanda M. Hulse‐Kemp, Angus Murphy, Bikram S. Gill, Cristóbal Uauy, Raju Datla, Nidhi Rawat, Scott A. Boden, Vijay Tiwari
Innovative genetic improvements in food crops are needed to maintain global food security. Here, we report the map-based cloning of TaWUSCHEL-D1 ( WUS-D1 ) as the gene responsible for the multiovary phenotype in wheat, which produces three fertile ovaries and grains per floret. We generated a 14.5 Gbp chromosome-level assembly of multiovary wheat line “MOV” that shows unique structural variation in the Mov-1 physical region, resulting in widespread gene upregulation. High-resolution genetic mapping refined the locus to a 135 kbp region that contains two genes. We used nine independent deletion mutants, eight TILLING mutants, and genetic complementation of these genotypes to show that a WUSCHEL ortholog, WUS-D1 , is the causal gene of the Mov-1 locus. Expression studies showed that WUS-D1 is highly expressed during early inflorescence development in MOV, whereas the gene is inactive in wild-type wheat. The higher WUS-D1 expression is associated with the formation of larger meristems and floret primordia that are competent to produce multiple ovaries. These insights provide a foundation to manipulate floral organ numbers to enhance breeding capabilities of bread wheat.