José Sanchez, the newest postdoc in the Khokhani lab, is here to examine how some strains of Ralstonia solanacearum (race 3 biovar 2, R3bv2) bacteria hold up to the harshest Minnesota winters inside native hosts. As José explains, the ultimate goal of this research is to understand the threat of this pathogen to our food supply, particularly our ability to grow potatoes in the Midwest: “The particular [Ralstonia] strains that I'm going to be working with in the lab are strains that could threaten food production, especially here in the potato producing areas of the country.”
His research will focus on the relationship between R3bv2 Ralstonia solanacearum strains and nightshades native and non-native to Minnesota. A pattern has been observed in Europe where bittersweet nightshade serves as a highly effective reservoir host for these Ralstonia solanacearum species that cannot survive in the soil during the colder months. Once the pathogen colonizes the plant and survives the winter in the nightshade and temperatures begin to warm, the bacteria go back into the soil and water bodies, finding their way into new host plants through irrigation during the warm months.
At present, José explains, there are native nightshade species in Minnesota, and there is presence of some Ralstonia solanacearum strains in warmer states like Florida, but little is known about whether the accidental introduction of a R3bv2 strain could lead to major damage to the American potato in a region where nightshades could be used for overwintering by the pathogen and then cause major damage to potato growers. He describes his research project as a valuable way to provide context and information around this potential threat:
“We are going to be trying three different species of nightshades, here, native from the region of Minnesota. And we're going to be infecting them with these Ralstonia strains to see if they can survive freeze and thaw cycles. All of these R3bv2 strains are not yet present in the U.S., and they're highly regulated, but this will give us information about if they were to get here, is that a potential risk factor? Because normally Ralstonia would not survive in soil alone, below freezing point, but maybe they’re good if they’re inside these plants.”
José worked with both Ralstonia and potatoes while getting his PhD at UW-Madison, but never at the same time. First he worked on a different side of plant-microbe interactions, researching the introduction of beneficial microbes to enhance production of mini-tubers. Then, he studied the pathogen Ralstonia solanacearum.
Like many members of our department community, José found plant pathology by coincidence while studying a different branch of science. During his undergraduate studies in his home country of Colombia, José was initially a pharmaceutical chemistry major, but found himself more compelled by his biology coursework. He changed his major to biology and started working in a lab focused on plant-microbe interactions, graduating with a biology degree in 2018. Eager to learn more biology, he took an internship at Purdue University studying plant abiotic stress, and from there, followed his interests (and the advice of his mentor at Purdue) to a PhD at UW-Madison. José hopes to eventually teach at an undergraduate-focused institution, introducing students to a love of lab work.