Genome-Edited Triple-Recessive Mutation Alters Seed Dormancy in Wheat

• DOI: 10.1016/j.celrep.2019.06.090
• Publication Date: 2019-07-30T17:48:41Z
• Authors: Fumitaka Abe; Emdadul Haque; Hiroshi Hisano; Tsuyoshi Tanaka; Yoko Kamiya; Masafumi Mikami; Kanako Kawaura; Masaki Endo; Kazumitsu Onishi; Takeshi Hayashi; Kazuhiro Sato
• Keywords: Qsd1; Gene Editing; 2. Zero hunger; 0303 health sciences; QH301-705.5; seed dormancy; Cell Cycle Proteins; Genes, Recessive; Plant Dormancy; 630; Gene Knockout Techniques; 03 medical and health sciences; wheat; Mutation; Seeds; Biology (General); CRISPR/Cas9; multiple mutation; Triticum; Plant Proteins

Common wheat has three sets of sub-genomes, making mutations difficult to observe, especially for traits controlled by recessive genes. Here, we produced hexaploid wheat lines with loss of function of homeoalleles of Qsd1, which controls seed dormancy in barley, by Agrobacterium-mediated CRISPR/Cas9. Of the eight transformed wheat events produced, three independent events carrying multiple mutations in wheat Qsd1 homeoalleles were obtained. Notably, one line had mutations in every homeoallele. We crossed this plant with wild-type cultivar Fielder to generate a transgene-free triple-recessive mutant, as revealed by Mendelian segregation. The mutant showed a significantly longer seed dormancy period than wild-type, which may result in reduced pre-harvest sprouting of grains on spikes. PCR, southern blotting, and whole-genome shotgun sequencing revealed that this segregant lacked transgenes in its genomic sequence. This technique serves as a model for trait improvement in wheat, particularly for genetically recessive traits, based on locus information from diploid barley.