FUNCTIONAL CHARACTERIZATION OF NOVEL RESISTANCE GENE CANDIDATES TO THE EMERGING SOYBEAN CYST NEMATODE HG TYPE 1.2.5.7

Soybean is among the major agricultural crops in the United States with 33.3 million hectares harvested in 2020. While many efforts have been made to optimize and improve soybean yield, significant yield losses caused by soybean cyst nematode (SCN) are frequently observed in almost all soybean growing regions. Since the first report in the US in 1955, SCN has spread to nearly every soybean producing county cussing substitutional yield losses.Considering the the narrow genetic base of SCN resistance in commercial soybean cultivars cultivated in the United States together with the high genetic diversity of field populations, SCN populations have evolved to break resistance in these cultivars. Unsurprisingly, recent reports revealed that SCN populations are able to reproduce on and cause yield losses to resistant cultivars to a similar extent as in SCN-susceptible cultivars. With the emergence of SCN Hg Type 1.2.5.7 (race 2) as one of the most common Hg Type in several Eastern and Southern States, and limited resistance to this Hg Type in commercially cultivated soybean cultivars, it is imperative to identify major resistance gene(s) for this Hg Type in order to generate durable resistance that spans several Hg Types from different resistant accessions.The goal of this research proposal is to identify and functionally characterize major soybean genes conferring resistance against SCN Hg Type 1.2.5.7 (race 2), one of the most widely distributed SCN Hg Types in the US.Objective #1: Determine the levels of SCN resistance or susceptibility in soybean conferred by two novel candidate genesObjective #2: Elucidate the mode of action of the candidate resistance and host susceptibly genesThe proposed research experiments are expected to confirm the function of two genes in mediating soybean resistance against the widely distributed SCN Hg Type 1.2.5.7. Protein interaction networks and downstream targets of these two proteins will be also established. These data will be translated to resistant soybean germplasm and intellectual property that could be potentially used by the public and private seed companies via traditional breeding, genome editing or transgenic approaches to generate improved soybean cultivars with broad-spectrum and durable resistance against multiple SCN Hg-types.