Highlights
- Increase of carbon dioxide emission to the atmosphere acidifies the ocean.
- Ocean acidification drives the growth of a small green phytoplankter (picochlorophyte).
- Picochlorophytes exhibit distinct metabolism compared to other polar phytoplankton.
- Genes related to ribosomal proteins, amino acid synthesis, RNA post-transcriptional modification, nitrogen assimilation, molecular chaperones, light harvesting complexes, pigment synthesis, were found to be differentially expressed under future predicted CO2 levels.
Abstract
Human emissions of carbon dioxide are causing irreversible changes in our oceans and impacting marine phytoplankton, including a group of small green algae known as picochlorophytes. Picochlorophytes grown in natural phytoplankton communities under future predicted levels of carbon dioxide have been demonstrated to thrive, along with redistribution of the cellular metabolome that enhances growth rate and photosynthesis. Here, using next-generation sequencing technology, we measured levels of transcripts in a picochlorophyte Chlorella, isolated from the sub-Antarctic and acclimated under high and current ambient CO2 levels, to better understand the molecular mechanisms involved with its ability to acclimate to elevated CO2. Compared to other phytoplankton taxa that induce broad transcriptomic responses involving multiple parts of their cellular metabolism, the changes observed in Chlorella focused on activating gene regulation involved in different sets of pathways such as light harvesting complex binding proteins, amino acid synthesis and RNA modification, while carbon metabolism was largely unaffected. Triggering a specific set of genes could be a unique strategy of small green phytoplankton under high CO2 in polar oceans.
Yong-Hao T., Sze-Wan P., Cing-Han Y., Phaik-Eem L., Beardall J., Tun-Wen P. & Siew-Moi P., 2022. Transcriptomic analysis reveals distinct mechanisms of adaptation of a polar picophytoplankter under ocean acidification conditions. Marine Environmental Research 182: 105782. doi: 10.1016/j.marenvres.2022.105782. Article.
