CRISPR/Cas9‐mediated knockout of Ms1 enables the rapid generation of male‐sterile hexaploid wheat lines for use in hybrid seed production

Abstract

Summary The development and adoption of hybrid seed technology have led to dramatic increases in agricultural productivity. However, it has been a challenge to develop a commercially viable platform for the production of hybrid wheat (Triticum aestivum) seed due to wheat's strong inbreeding habit. Recently, a novel platform for commercial hybrid seed production was described. This hybridization platform utilizes nuclear male sterility to force outcrossing and has been applied to maize and rice. With the recent molecular identification of the wheat male fertility gene Ms1, it is now possible to extend the use of this novel hybridization platform to wheat. In this report, we used the CRISPR/Cas9 system to generate heritable, targeted mutations in Ms1. The introduction of biallelic frameshift mutations into Ms1 resulted in complete male sterility in wheat cultivars Fielder and Gladius, and several of the selected male‐sterile lines were potentially non‐transgenic. Our study demonstrates the utility of the CRISPR/Cas9 system for the rapid generation of male sterility in commercial wheat cultivars. This represents an important step towards capturing heterosis to improve wheat yields, through the production and use of hybrid seed on an industrial scale.

Gene editing of the wheat homologs of TONNEAU1‐recruiting motif encoding gene affects grain shape and weight in wheat

“…In wheat, CRISPR‐Cas9 gene editing was successfully applied to modify such traits of agronomic value as disease resistance (Wang et al ., ), gluten content (Sánchez‐León et al ., ), protein content (Zhang et al ., ), male sterility (Okada et al ., ) and grain size and weight (Wang et al ., ; Zhang et al ., , ). These studies also demonstrated that the editing of either individual copies of duplicated genes on homoeologous chromosomes or all three homoeologous copies of genes is possible (Wang et al ., 2014, 2018a).…”

Targeted mutation of barley (1,3;1,4)-β-glucan synthases reveals complex relationships between the storage and cell wall polysaccharide content

“…Previous studies in barley reported CRISPR/Cas9-induced mutation frequencies of 10-23% (Lawrenson et al, 2015), 44% (Holme et al, 2017) and ~80% (Gasparis et al, 2018;Kapusi et al, 2017) of plants after Agrobacterium-mediated transformation. In other cereals such as wheat, mutant production efficiency was reported from 0.3-5% using biolistic bombardment of CRISPR/Cas9 components (Zhang et al, 2016;Gil-Humanes et al, 2017;Liang et al, 2017;Sánchez-León et al, 2018) and Agrobacterium-mediated transformation (Okada et al, 2019). In the T0 plants described here, all mutants were heterozygous (monoallelic) across the targeted genes, with 83% of the lines carrying short InDels 3-4 bp upstream the PAM sequence.…”

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

“…Agrobacterium-meditated transformation is a straightforward approach to plant transformation resulting in the insertion of only one or a few copies of the transgene (Kohli et al, 2003;Travella et al, 2005). Several reports describe the use of Agrobacterium-delivered CRISPR/Cas9 for wheat genome editing, despite the low transformation efficiency of this crop (Zhang et al, 2018a(Zhang et al, , 2019Howells et al, 2018;Okada et al, 2019).…”