Li, Y., Wei, Z-Z., Sela, H., Govta, L., Klymiuk, V., Roychowdhury, R., Chawla, H.S., Ens, J., Wiebe, K., Bocharova, V., Ben-David, R., Pawar, P.B., Zhang, Y., Jaiwar, S., Molnár, I., Doležel, J., Coaker, G., Pozniak, C.J., Fahima, T.
PLANT COMMUNICATIONS 5: 100646, 2024

Keywords:
Abstract: Gene cloning in repeat-rich polyploid genomes remains challenging. Here, we describe a strategy for overcoming major bottlenecks in cloning of the powdery mildew resistance gene (R-gene) Pm69 derived from tetraploid wild emmer wheat. A conventional positional cloning approach was not effective owing to suppressed recombination. Chromosome sorting was compromised by insufficient purity. A Pm69 physical map, constructed by assembling Oxford Nanopore Technology (ONT) long-read genome sequences, revealed a rapidly evolving nucleotide-binding leucine-rich repeat (NLR) R-gene cluster with structural variations. A single candidate NLR was identified by anchoring RNA sequencing reads from susceptible mutants to ONT contigs and was validated by virus-induced gene silencing. Pm69 is likely a newly evolved NLR and was discovered in only one location across the wild emmer wheat distribution range in Israel. Pm69 was successfully introgressed into cultivated wheat, and a diagnostic molecular marker was used to accelerate its deployment and pyramiding with other R-genes.
DOI: 10.1016/j.xplc.2023.100646
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IEB authors: Jaroslav Doležel, Istvan Molnar