Soybean cyst nematodes resistance
Andrew Bent, Professor
Department of Plant Pathology
UW-Madison College of Agricultural and Life Sciences
Total Time – 2:56
0:15 – What’s a nematode
0:26 – Why are they a problem?
0:50 – How nematodes work
1:05 – How widespread they are
1:31 – New findings
2:05 – RHG1 functions
2:33 – When RHG1 is expressed
2:44 – Lead out
Sevie Kenyon: Fighting the soybean cyst nematode. We’re visiting today with Andrew Bent, Department of Plant Pathology, University of Wisconsin-Madison in the College of Agricultural and Life Sciences and I’m Sevie Kenyon. Andrew, start out by telling us what’s nematode?
Andrew Bent: Well, they’re little worms and there are millions of them in the soil and they are one of the most plentiful organisms on the planet Earth.
Sevie Kenyon: Why are they such a problem with soybeans?
Andrew Bent: They actually are a problem for two reasons. One is that they are the most economically damaging disease of soybean. They make the plant produce less soybeans, but the sneaky problem is that they don’t cause lesions, or yellow splotches, or leaves falling off or anything, so farmers often don’t know they have a problem.
Sevie Kenyon: Can you describe how the nematode works?
Andrew Bent: The nematode infects the plant and then it climbs into the roots and it sets up a feeding site. It reprograms a set of plant cells to basically become food factories for the nematode.
Sevie Kenyon: Andrew, how widely dispersed are these soybean cyst nematodes?
Andrew Bent: They’ve been spreading throughout the United States over the last 20-30 years, and so now they’re in basically every soybean growing county in Wisconsin, throughout Minnesota, North Dakota, they’re moving in. They’re basically expanding northward and they are a big problem and, as I said before, often an undetected problem.
Sevie Kenyon: Andrew, you’ve found something about nematode and nematode resistance, can you describe that for us?
Andrew Bent: Well, a few years ago we cloned the genes for a disease resistance locus, they call it, called RHG1 for resistance to Heterodera glycines, which is the soybean cyst nematode, and this is a gene that is used throughout farming, throughout the United States, throughout the world. It’s one of the most important genes for disease resistance in soybean and what we’ve done most recently is learn the mechanism for how RHG1 operates.
Sevie Kenyon: Can you describe that process? How the RHG1 functions?
Andrew Bent: RHG1 encodes a protein that is a core housekeeping protein, we call it, just takes care of normal life processes and RHG1 is a dysfunctional version of that protein and normally it would be completely poisonous to the plant, but the plant has other versions of the same protein and the plant expresses this RHG1 version of the protein where the nematode infects.
Sevie Kenyon: What happens then when this expression takes place?
Andrew Bent: When the RHG1 protein becomes abundant at those sites the plant cells stops functioning well and the nematode basically declines and fails to complete its lifecycle.
Sevie Kenyon: We’ve been visiting with Andrew Bent, Department of Plant Pathology, University of Wisconsin-Madison in the College of Agricultural and Life Sciences and I’m Sevie Kenyon.