Parasitic nematode worms are a hidden enemy of potato growers worldwide, causing billions of dollars’ worth of crop damage every year.
Now an international research collaboration led by the University of Dundee (Scotland) and the James Hutton Institute has detailed the genome sequence and inner workings of the yellow potato cyst nematode, giving scientists new insights into how it can be stopped.
“This is an exciting discovery that reveals the potato cyst nematode’s ‘parasitism toolkit,’” says Sebastian Eves-van den Akker, of the University of Dundee’s Division of Plant Sciences, based at the James Hutton Institute in Scotland. “Once we had sequenced the genome of the nematode, we uncovered a hidden genetic code, or signpost, that points toward the molecular tools the nematode uses against plants. We believe this genetic code is actually how the nematode categorizes which genes it needs when infecting plants. So, in a way, we can use their own signpost against them. Using this information, we will now be able to much better target how we can prevent nematode infection.”
The results of the research are published in the journal Genome Biology and are freely available for anyone to read.
Potato cyst nematodes are devastating to crops and are exceptionally hardy: once established in a field, the pests are effectively impossible to eradicate in the short term, and because they persist as long-lived cysts in soils, growing potatoes may not be economically viable for up to two decades.
The USDA has classified the yellow potato cyst nematode as potentially more dangerous than any insect or disease affecting the potato industry. Substantial effort is already invested into keeping land free of nematodes; both species are present on USDA and European Plant Protection Organization quarantine organism lists.
All major crops are thought to be prone to infection of at least one species of plant-parasitic nematode. These nematodes cause damage estimated at over $80 billion each year.
“Nematodes are the hidden enemy to crops,” says Eves-van den Akker. “Thousands of these microscopic worms can infect a single plant, and there can be several million in an infected field. Given that they live hidden in the soil and attack the root, they have a devastating impact on the rest of the plant that is hard to recognize.”
Now that researchers have found the toolkit for potato cyst nematodes, the aim is to carry out similar analyses in other nematodes. There are currently very few pesticides available that can deal with a nematode infestation, as most of them have been withdrawn for various reasons. There is therefore a pressing need to find new ways to prevent crop infection, particularly given the increasing importance of the potato as a major food staple around the world, including in China.
The vast majority of plant-parasitic nematodes feed on plant roots, meanwhile “injecting” the plant with a variety of destructive proteins and plant hormones.
“If we can target these areas of the nematodes’ activity, we will be better able to stop it,” says Eves-van den Akker.
The international collaboration has been led by award-winning researchers at the University of Dundee and James Hutton Institute and involved scientists from the Universities of Edinburgh, Leeds, Hull and St. Andrews and the Wellcome Trust Sanger Institute in the UK; Wageningen University in the Netherlands; Aix-Marseille University, the Institute for Genetics, Environment and Plant Protection, and Institut National de la Research in France; King Abdulaziz University in Saudi Arabia; Agriculture and Agri-food Canada, the Canadian Food Inspection Agency; and the USDA-ARS Horticultural Crops Research Laboratory.
This article appears in the November 2016 issue of Potato Grower.