Triticeae Genomics and Genetics, 2025, Vol.16, No.3, 120-129 http://cropscipublisher.com/index.php/tgg 122 Figure 1 Deployment strategy of resistance gene stacks (RTGS). A range of resistance genes (R-genes) are needed to diversify RTGS for durable, broad-spectrum resistance. In addition to wheat R genes, genes can be sourced from land races, wild relatives, nonhost species or novel engineered genes (synthetic R-genes). Customized RTGS for regional or seasonal disease management can be rapidly assembled and integrated into breeding programs to adapt and react to newly evolving pathogen strains. The single locus inheritance of RTGS enables single or multiple cassettes to be used in breeding programs by backcrossing or alternatively direct transformation of elite wheat cultivars (Adopted from Jost et al., 2023) 3.2 Synthetic gene constructs and multigene vectors Putting several resistance genes together is actually not a simple package. The design of synthetic constructs and multi-gene vectors should be ingenious. Each gene not only needs to have its own promoter, but also must ensure that their expressions do not "steal the show" from each other. The commonly used approach at present is to synthesize these genomes into a whole as a single transgenic event and introduce them into wheat, which not only ensures co-inheritance but also avoids expression conflicts. There is a rather typical example: After a construct containing five resistance genes was successfully introduced into wheat, the variety acquired broad-spectrum resistance to powdery mildew and rust. By designing in this way, researchers can also avoid those combinations that are prone to interfere with each other or cause chain burdens, reducing subsequent unstable factors from the source. 3.3 CRISPR/Cas and genome editing for gene integration If we talk about which tool best fits the "modern feel", CRISPR/Cas definitely deserves the nomination. In the past, hybridization and backcrossing were exhausting to superimpose several genes. Now, with gene editing, multiple resistance genes can be precisely inserted into a target site in the wheat genome, and the entire process is
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