When you imagine about algae, you may imagine vivid green threads swaying in a riverbed or blue-green masses invading lakes. However, the vast majority of these complex aquatic creatures that absorb sunshine for sustenance are brown in hue, such as the vast forests of seaweeds seen in arctic areas or along California’s coast.
Brown algae are brown in colour (and hence less attractive) since they have evolved a unique collection of colours that absorb more light needed for photosynthesis than green algal and plant species. As a result, brown algae are critical to life on Earth, generating 20% of the oxygen humans breath. Scientists have yet to unravel the molecular pathways that enable these brown algae to turn sunlight into energy.
Colorado State University scientists, in collaboration with researchers from Germany and China, have revealed ground-breaking fresh perspectives into the developmental pathways these algae underwent to produce their unusual brown pigments known as fucoxanthin.
The study was co-led by Graham Peers, an associate professor at CSU’s Faculty of Biology, Xiaobo Li at Westlake University in Hangzhou, China, Martin Lohr at Johannes Gutenberg-Universität in Germany. These scientists employed the genetic inquiry approach known as CRISPR/CAS9 to abolish the role of the genes that contribute for the algae’s brown colour, making its mutant types green in the procedure, according to a paper published in Proceedings of the National Academy of Sciences. Yu Bai, a postdoctoral researcher at CSU, was the manuscript’s first author.
The Peers group, which researches photosynthetic productivity and algal ecophysiology, discovered the gene targets and carried out the tests that allowed the researchers to examine what occurred when these brown pigment-related pathways were turned off.
Fucoxanthin is used in nutraceuticals and pharmaceuticals.
Fucoxanthin has gained popularity in nutraceutical and medicinal uses over the past decade. The molecular makeup of fucoxanthin was discovered in the 1960s after it was first reported in scholarly literature 150 years ago. What was unknown was how the algae produced this natural substance.
This biochemical manufacturing route proved to be complicated; the researchers demonstrated in PNAS that the brown pigment fucoxanthin developed through the multiplication of old genes that produce photoprotective pigments. Some of these gene copies evolved increasingly sophisticated roles along the route, allowing the manufacture of additional pigments that became particularly well-suited for photosynthesis.
Peer stated, “These algae are somehow able to mix and match, then reprogram their cellular machinery for capturing light in a way that land plants have not done.”
The new finding provides a rich framework for future research that might allow the brown pigment’s extraordinary light-harvesting performance to be transferred to other creatures or purposes.
For example, understanding how brown algae originated might help scientists better understand the fucoxanthin ingredient as a nutraceutical for a variety of health purposes. In biofuels research, learning how to change the quantity of this pigment in a cell might lead to greater photosynthetic efficiency, allowing for the production of bigger amounts of biofuels using the same quantity of light, land, and labour as traditional fuels.
