A new finding may help scientists develop crops with enhanced resistance to nematode pests, according to the University of Missouri.
MU researchers, with the help of researchers at the University of Bonn in Germany, have found the first genetic evidence that nematodes use a specialized hormone to help them feed from ag crops.
The hormone, cytokinin, promotes cell division in plants and might play a key role in feeding site formation for nematodes.
"Cell cycle regulation is a key aspect of plant development and one of the first events altered during the formation of the feeding sites nematodes use to acquire nutrients from host plants," said Melissa Goellner Mitchum, an MU researcher.
Carola De La Torre, a doctoral student, and Demosthenis Chronis, a postdoctoral fellow at MU, worked with Mitchum to determine if nematode infection alters the cytokinin signaling pathways plants use to regulate growth and development and how the process changes due to nematode infection.
The researchers looked at the activation of different components of the cytokinin pathway in response to nematode infection. They also evaluated numerous plants that lacked the presence of these components, finding that they were generally less susceptible to nematode infection.
"These results suggested to us that these little worms are not only utilizing parts of a plant hormonal pathway that is important for plant growth and development, but they also are doing it in a way that allows them to cause disease," De La Torre said.
Mitchum's team partnered with Florian Grundler's group in Germany, which further analyzed the connection between cytokinin and nematodes.
Using advanced genetic tools, they discovered that nematodes create their own form of plant cytokinin and that, by secreting the hormone into the plant, they actively control the cell cycle.
Controlling the cycle leads to the production of ideal feeding sites to support their development. These findings show the ability of an animal to create and secrete a functional plant hormone to become a long-term parasite.
Understanding the relationship is the first step in finding technologies to develop new crops that are resistance to these pests, Mitchum said.
The study “A Plant-Parasitic Nematode Releases Cytokinins that Control Cell Division and Orchestrate Feeding-Site Formation in Host Plants” recently was published by the Proceedings of the National Academy of Sciences and was supported in part by the National Science Foundation.