The application of gene editing techniques such as TALENs and CRISPR-Cas9 is
hindered by the long life cycle of crop species. Moreover, desired genotypes
generally require multiple generations to achieve. Meanwhile, single-celled
microspores are haploid cells that can be developed into double haploid
plants and have been widely used as a breeding tool to generate homozygous
plants within a generation.
A researcher from the National Research Council Canada, Pankaj Bhowmik, and
his colleagues combined the CRISPR-Cas9 system with microspore technology to
develop a haploid mutagenesis system to induce genetic modifications in the
The team first investigated the optimal conditions for microspore
transfection of the CRISPR-Cas9 into microspores. Using multiple Cas9 and
sgRNA constructs, the team successfully introduced targeted mutations in the
reporter gene, DsRed, as well as two endogenous wheat genes, TaLox2 and
TaUbiL1. However, the regeneration efficiency from microspores is still low
and requires further study.
This study demonstrates the feasibility of combining microspore technology
and CRISPR-Cas9 for trait discovery and crop improvement.