The greatest emerging pathogenic threat to the US soybean crop is soybean rust, a disease caused by the fungus Phakopsora pachyrhizi. Soybean rust is so threatening that it was once preliminarily listed alongside small pox and Ebola virus as Select Agents with potential to upset national security. That was until soybean rust naturally entered the continental US after hurricane Ivan hit Louisiana in 2004 (Schneider et al., 2005). The fungus now colonizes kudzu during the winter months and spreads by wind to major regions of soybean cultivation during the summer. Unfortunately, the US soybean crop remains very vulnerable. There are only five known dominant resistance genes in soybean (Rpp1-5) (Hartwig and Bromfield, 1983; Anderson et al., 2006; Hyten et al., 2007; van de Mortel et al., 2007; Garcia et al., 2008; Meyer et al., 2009), a new resistance allele Rpp1b and two recessive resistance genes (Calvo et al., 2008; Chakraborty et al., 2009), but none is in production cultivars. Nevertheless, it may matter little if any of the genes were deployed since some US rust strains remain virulent on plants with these alleles (Pham et al., 2009). Now, soybean growers in at least 19 states where the fungus has spread rely on cultural practices and profit-eroding fungicide applications to control disease. A cost-effective soybean variety with durable resistance is desperately needed.
The objective of the Cooper lab is to discover and characterize soybean and soybean rust genes and the molecular signals important for resistance or pathogenicity. The Cooper lab emphasizes a systems biology approach to attain a better understanding of soybean and soybean rust, and employs DNA and RNA sequencing and mass spectrometry-based proteomics techniques.