Pooled effector library screening in protoplasts rapidly identifies novelAvrgenes

Abstract

AbstractCrop breeding for durable disease resistance is challenging due to the rapid evolution of pathogen virulence. While progress in resistance (R) gene cloning and stacking has accelerated in recent years1-3, the identification of corresponding avirulence (Avr) genes in many pathogens is hampered by the lack of high-throughput screening options. To address this technology gap, we developed a platform for pooled library screening in plant protoplasts for rapid identification of interactingR/Avrpairs. We validated this platform by isolating known and novelAvrgenes from wheat stem rust (Puccinia graminisf. sp.tritici) by screening a designed library of putative effectors against individualRgenes. RapidAvrgene identification provides molecular tools to understand and track pathogen virulence evolution by genotype surveillance and optimiseRgene deployment and stacking strategies. This screening platform is broadly applicable to many crop pathogens, whilst also adaptable for screening genes involved in other protoplast-selectable traits.