Seaweed diseases: understanding seaweed host-pathogen interactions to improve commercial seaweed production

Seaweeds are the new superfoods, being a rich source of
minerals, vitamins, proteins and fibre. Seaweed aquaculture
is receiving increasing attention and is rapidly expanding in
Europe, including in the South West of the UK. However, like
land plants, seaweeds are susceptible to infectious diseases,
resulting in major losses to multi-billion-dollar crops such as
nori. Finding solutions to prevent or treat such outbreaks is
thus crucial. To do so, it is vital to understand the ecological
drivers of seaweed diseases and the interactions between
the pathogen, its host, and the beneficial microbes
associated with the host. Seaweeds together with their
surface associated beneficial bacteria can produce suite of
antimicrobials to defend against pathogens and pro-
microbials to attract beneficial bacteria.

Our research has shown that this defence capacity of seaweed holobionts is dynamic and can be altered by changing
abiotic factors during culture conditions, increasing growth of the seaweed and decreasing infection by pathogens.
Using sugar kelp (one of the most cultivated kelps in the EU) and dulse (the most sought-after culinary seaweed with
an increasing market demand), you will (a) test different abiotic regimes to enhance defence capacity and thus
minimize infection in sugar kelp and dulse (O1 and 2), (b) identify the antimicrobials (from both seaweeds and the
beneficial associated microbes) contributing to defence capacity (O3 and 6), (c) map metabolic information and
identify upregulated and/ downregulated metabolites between healthy and diseased individuals (O4) and, (d) use
high-throughput sequencing to characterize the microbiota of healthy and diseased individuals (O5).

This project will test seaweed-pathogen interactions using two economically important edible species using an
interdisciplinary approach combining chemical ecology, microbiology, analytical chemistry and statistical tools. This
knowledge will contribute to improving aquaculture practices and maximize farming yield in the south west of UK and
beyond.