Rooting Out Nematodes

Nematodes are pretty sneaky. The parasitic worms destroy about $100 billion in crops worldwide every year, but many of them do their damage only after somehow conning their way into plant root systems. So a multidisciplinary group of NC State researchers is using various approaches to outsmart nematodes, learning how they find their way inside plants and, more importantly, how to slam the door on them for good.

To get a better idea of how to attack nematodes, plant pathology professors David Bird and Charles Opperman, co-directors of the Center for the Biology of Nematode Parasitism in the College of Agriculture and Life Sciences, have been sequencing its genome for several years. But it was a bit of serendipity that unlocked the secret of the nematode’s trickery. Plant biology professor Nina Allen’s research team was working on another project when they noticed plant root hairs behaving the same way around nematodes as they do with Nodulation factor, signal molecules produced by beneficial bacteria that help plants take in nutrients. Roots and bacteria swap chemical signals through the soil so they can find each other, so Allen and Bird surmised that nematodes must have the ability to not only sense the signal from the roots, but also secrete their own chemical signal to fake out the plants and gain access to the roots.

Knowing the chemical composition of Nod factor, Bird enlisted the help of Dr. Nigel Deighton, director of NC State’s Metabolomics and Proteomics Lab, to use a mass spectometer to isolate a similar molecule in nematodes. “Instead of having me look for a needle in a haystack, they’ve given me a pin and said to find something that looks like it,” Deighton says. Likewise, Dr. Michael B. Goshe, an assistant professor of biochemistry, is using mass spectrometry to examine the protein changes within a nematode when it reacts to plants. “They really wake up when they sense plants are near,” Goshe says. “It’s like they’ve had a cup of coffee.”

“There are so many interactions going on between the plant and the nematode. It’s a true systems ecology within which we’re trying to work.”

Attacking the nematode problem on a molecular, genetic, and proteomic level is producing reams of data, so Dr. Dahlia Nielsen of the Bioinformatics Research Center is crunching those numbers. In addition to helping the team find ways to shut the nematodes down, she hopes to find metabolic pathways that could be used to make plants resistant to the parasites. “There are so many interactions going on between the plant and the nematode,” Allen says. “It’s a true systems ecology within which we’re trying to work.”

 

Drs. Nigel Deighton, Michael 
Goshe, and David Bird (l.to r.) are
studying nematodes on genetic,
molecular, and proteomic levels
to find the best way to control
the parasitic worms.

Drs. Nigel Deighton, Michael Goshe, and David Bird (l.to r.) are studying nematodes on genetic, molecular, and proteomic levels to find the best way to control the parasitic worms.

Imaging by Dr. Nina Allenís 
research team unlocked a clue
to the success of a nematode
at infiltrating
plant roots.

Imaging by Dr. Nina Allenís research team unlocked a clue to the success of a nematode at infiltrating plant roots.