Login

GPC Members Login
If you have any problems or have forgotten your login please contact [email protected]


Genome of Sea Lettuce that Spawns Massive "Green Tides" Decoded

Sea lettuce, a fast-growing seaweed that spawns massive “green tides,” is a prolific thief, according to research that for the first time sequenced the genome of a green seaweed.

An international team including Rutgers scientists found 13 cases where the sea lettuce Ulva mutabilis stole genes from bacteria. Remarkably, this ubiquitous seaweed expanded more than half of the pilfered genes – creating so-called “gene families” – and used some of them to adapt to stresses such as excessive light, high salinity and dehydration to become a dominant intertidal seaweed, according to study co-author Debashish Bhattacharya, distinguished professor at Rutgers University–New Brunswick. Ulva also lives with bacteria and relies on them to gain its multicellular form. Both stolen genes and intact bacteria that live in symbiosis with Ulva play key roles in the seaweed’s success.

Ulva’s rapid growth is not all negative. Indeed, it can be exploited to produce biofuels, generate protein for animal feed, remove excessive nutrients in aquaculture and serve as a seaweed crop, according to a study published online in Current Biology.

“Ulva provides insights into how evolution acts on genomes to modify the biology of organisms,” said Bhattacharya, who works in the Department of Biochemistry and Microbiology in the School of Environmental and Biological Sciences. “Learning these rules will be crucial to understanding what traits define winners and losers under climate change, allowing us to better predict future trends among seaweed, algae and other life at the base of the food chain.”

Fatima Foflonker, a post-doctoral researcher, and Bhattacharya were part of an international team that analyzed Ulva’s recently determined genome sequence. They studied the sea lettuce to gain insights into the growth and reproduction of multicellular green algae. Seaweeds evolved independently from land plants, and the research found that the mechanisms underlying their growth and development are distinct.

Ulva species are widely found along tropical and temperate coasts, and several species penetrate freshwater streams and lakes. In high-nutrient conditions, spectacular blooms of Ulva (green tides) often cover several hundred kilometers of coastal waters. Beached algae may reach one million tons and smother entire coastlines. Although not toxic, green tides have killed people when blooms die and generate hydrogen sulfide.

The Ulva genome offers new opportunities to understand coastal and marine ecosystems and the evolution of green seaweeds. Comparison of Ulva species that bloom and don’t bloom may boost understanding of the molecular mechanisms underpinning growth and reproduction in response to environmental conditions, the study says.

Read the paper: Current Biology

Article source: Rutgers

Image credit: Helena Abreu/AlgaPlus

News

Scientists engineer shortcut for photosynthetic glitch, boost crop growth 40%

Plants convert sunlight into energy through photosynthesis; however, most crops on the planet are plagued by a photosynthetic glitch, and to deal with it, evolved an energy-expensive process called photorespiration that drastically suppresses their yield potential. Researchers from the University of Illinois and U.S. Department of Agriculture Agricultural Research Service report in the journal Science that crops engineered with a photorespiratory shortcut are 40 percent more productive in real-world agronomic conditions.


Should researchers engineer a spicy tomato?

The chili pepper, from an evolutionary perspective, is the tomato's long-lost spitfire cousin. They split off from a common ancestor 19 million years ago but still share some of the same DNA. While the tomato plant went on to have a fleshy, nutrient-rich fruit yielding bountiful harvests, the more agriculturally difficult chili plant went defensive, developing capsaicinoids, the molecules that give peppers their spiciness, to ward off predators.


European wheat lacks climate resilience

The climate is not only warming, it is also becoming more variable and extreme. Such unpredictable weather can weaken global food security if major crops such as wheat are not sufficiently resilient – and if we are not properly prepared.