Tomas Lang1, Alexandra Campbell2, Nicholas Paul1, Scott Cummins1
1School of Science, Technology and Engineering, University of the Sunshine Coast, Maroochydore DC, Queensland 4558, Australia, 2School of Health and Behavioural Sciences, University of the Sunshine Coast, Maroochydore DC, Queensland 4558, Australia
The red seaweed Asparagopsis taxiformis is considered as a prospective feed additive due to its capacity to biosynthesise bromoform, a halogenated compound that interferes with the production of the greenhouse gas methane in livestock rumen. Therefore, there are currently efforts to grow this seaweed on a commercial scale, however, successful establishment of Asparagopsis aquaculture requires data elucidating the molecular basis of the response of this species to co-occurring organisms. To inform the development of this study, we conducted a systematic review assessing the current literature examining the molecular basis of seaweeds’ response to co-occurring organisms with respect to types of interactions investigated, and the molecular methodologies that were applied. Of the 87 unique experiments conducted across 81 screened articles, majority assessed the response of seaweeds to herbivores (52%), pathogens (25%), and fouling organisms (11%); however, only 5% assessed chemically mediated response (allelopathy). Regarding the molecular methodologies, majority of the screened studies utilised metabolomics (75%) whereas transcriptomics and proteomics were merely utilised in 9% and 4% of the conducted experiments, respectively. We then screened the draft A. taxiformis genome (in preparation) for interaction-associated molecules using a combined in-silico omics approach and identified 345 putatively secreted (allelopathy consistent feature) biomolecules and 606 defense-related molecules inclusive of, but not limited to pathogen recognition receptors, ROS scavenging species, and potential defense effectors. In addition, a combined proteomics approach was employed to identify the presence biomolecules in A. taxiformis-conditioned seawater resulting in a peak-rich RP-HPLC profile and further characterisation of 3 novel proteins.