Revolutionizing molecular plant breeding through genetic engineering of in vivo haploid induction genes

Haploid and doubled haploid plants serve critical functions in plant genetics and breeding studies, as they enable the production of genetically uniform lines (pure lines) and thereby accelerate the development of new cultivars. Nowadays, various key genes regulating haploid induction have been found in maize and other plant species (e.g. Arabidopsis, rice, and wheat). These genes offer insights into the mechanisms underlying in vivo haploid induction and provide targets for genetic manipulation. Recent advancements in gene editing and genetic engineering technologies, such as CRISPR/Cas9, have revolutionized our ability to understand gene functions and precisely modify genomes. By leveraging these technologies, scientists can introduce targeted genetic changes, optimize the haploid induction process, and broaden the range of species amenable to haploid production. The application of gene editing and genetic engineering in haploid production holds immense promise for various fields, including agriculture and biotechnology. This focused review aims to advance our understanding of haploid induction genes as well as the potential applications of gene editing/genetic engineering technologies in haploid production, paving the way for innovative solutions to pressing challenges in future plant breeding and agriculture.