Microscopic manipulators: the worms tricking plants into a free lunch
BBSRC catches up with Dr Sebastian Eves-van den Akker, a David Phillips fellow who is fighting a hidden but devastating menace in our soils.
Hi Sebastian! Who are you and what do you do?
I am a plant scientist who, technically, works on animals. To be specific, I work on plant-pathogens/parasites. I have studied plant-parasitic nematodes my entire academic life, and BBSRC has supported me at every single stage: a PhD to build the basics, an Anniversary Future Leader Fellowship to carve a niche, and now a David Phillips Fellowship to establish my own group. With all of the different schemes, BBSRC really are, more broadly speaking, creating a “fellowship” that I feel so incredibly lucky to be a part of.
Copyright: Dr Eves-van den Akker
What are plant-parasitic nematodes, and why are they a problem?
Plant-parasitic nematodes are microscopic worms that eat living plant tissue. They are quite apart from the relatively large worms we are familiar with in soil that help recycle decaying matter: plant parasitic nematodes eat living tissue and cause harm to plants around the world.
Plant-parasitic nematodes alone cost world agriculture over 100 billion USD per year (that’s more than the GDP of most individual countries). Plant-parasitic nematode problems are often neglected because they are the “hidden enemy” - soil dwelling, microscopic, and no symptoms that are unique - so the problems they cause are often confounded with other issues. These problems aren’t going away and they aren’t getting better by themselves (quite the opposite).
One of the reasons why losses to world agriculture are so high is that there is at least one plant-parasitic nematode species for every significant food crop. In the UK, the major parasitic species, perhaps predictably, eat potatoes - the potato cyst nematodes then, are our biggest concern.
What drew you to this area of study?
Ignoring the gravity of the problem for a moment, I find the interactions between plants and their diseases fascinating. There is an intimate inter-kingdom communication that takes place. Parasitic nematodes are able to supress/avoid the plant immune system, and can re-programme plant cells into a new type of highly metabolically active tissue, termed a "feeding site". Everything the nematode ever eats during its life cycle comes from this feeding site. In the last few years we have made good progress and are starting to uncover the “words” of the dialogue between the nematode and its host. Nevertheless, there is a lot to do and we certainly don’t know all the right answers yet - we probably don’t even know all the right questions yet.
How is your research tackling the problem?
With the support of BBSRC, we are building a team at the University of Cambridge to tackle the threat that plant-parasitic nematodes pose to global agriculture, by going after the “regulators of parasitism”. The idea behind this approach is that there are probably a small number of “regulator” genes that control the concerted action of a large number of the “effector” genes responsible for manipulating the host plant. If we can disrupt the few regulators, we can simultaneously disrupt hundreds of effectors. The analogy I like is that without the conductor, the orchestra struggles to get going.
What do you hope to do next?
As it stands now, we think we have identified one of the “regulators”, and we think we have a way to find others. The next steps are to prove these really are regulators, and to find out what happens when we disrupt their function. The ultimate goal of this project is to demonstrate the efficacy of targeting the regulators to develop disease resistance. Beyond this project, we hope to be able to apply this principle to other plant-parasitic nematode species, or even other plant pathogens/pests.