Abstract
Recent evidence suggests that seaweed extracts can protect plants against microbial disease by upregulating the host’s immune system. However, if this upregulation comes at a cost to host vegetative and reproductive growth it will make the use of seaweed extracts in crop disease protection less attractive. In a series of experiments, using Arabidopsis thaliana infected by white rust (Albugo sp.) and treated with crude extracts of Ulva lactuca and Saccharina latissima, we test the hypothesis that a growth-immunity trade-off exists. We include temporal samples of the two seaweed species because the composition of bioactive molecules in them is known to vary over the year. Our results confirm that extracts of both species have the potential to protect against disease, but that both the timing of seaweed sampling and extraction procedures can introduce considerable variation to this effect. Importantly, these seaweed treatments were also associated with reduced host vegetative mass, though treatment with S. latissima could compensate for this as it also stimulated increased seed mass. We conclude that the effects of crude seaweed extracts from U. lactuca and S. latissima on plant fitness are not immediately predictable, and benefits in terms of disease protection may come with costs.
| Original language | English |
|---|---|
| Journal | Journal of Applied Phycology |
| Volume | 34 |
| Issue | 4 |
| Pages (from-to) | 2201–2209 |
| Number of pages | 9 |
| ISSN | 0921-8971 |
| DOIs | |
| Publication status | Published - Aug 2022 |
Keywords
- Biostimulant
- Immunity
- Pathogen
- Saccharina
- Seaweed
- Ulva