Generation of paternal haploids in wheat by genome editing of the centromeric histone CENH3.

Abstract

New breeding technologies accelerate germplasm improvement and reduce the cost of goods in seed production^1-3. Many such technologies could use in vivo paternal haploid induction (HI), which occurs when double fertilization precedes maternal (egg cell) genome loss. Engineering of the essential CENTROMERIC HISTONE (CENH3) gene induces paternal HI in Arabidopsis^4-6. Despite conservation of CENH3 function across crops, CENH3-based HI has not been successful outside of the Arabidopsis model system⁷. Here we report a commercially operable paternal HI line in wheat with a ~7% HI rate, identified by screening genome-edited TaCENH3α-heteroallelic combinations. Unlike in Arabidopsis, edited alleles exhibited reduced transmission in female gametophytes, and heterozygous genotypes triggered higher HI rates than homozygous combinations. These developments might pave the way for the deployment of CENH3 HI technology in diverse crops.