What makes this invasive, non-native reed grass thrive in the wetlands?

Native and invasive Phragmites australis. Credit: Dassanayake Lab

The Mississippi River Delta is home to the world’s largest contiguous swath of Phragmites australis, or more commonly known as the common reed. But the plant that can grow to nearly 20 feet tall and has been a critical component in stabilizing the state’s coast against erosion is not actually native to Louisiana—well, not entirely.

There are multiple P. australis genotypes. P. australis , or ssp., americanus is the native subspecies in the U.S. and Canada. However, Phragmites australis ssp. australis originated in central Europe and was subsequently introduced to the U.S. where it is now considered to be one of the most problematic invasive species in North America.

What has perplexed environmental researchers is the invasive ssp. australis has displayed capabilities beyond that of the native ssp. americanus in its ability to thrive in the wetlands, especially around the Great Lakes, often growing up to be much taller and denser, and in turn, disturbing the native ecosystem.

In a newly published study in Molecular Ecology, and recently featured in an edition of The Scientist, LSU researchers collaborated with Tulane University and the U.S. Geological Survey to study the genomic bases of P. australis and to investigate what exactly makes the invasive reed grass subspecies thrive in wetlands, in comparison to its native counterpart. Samples were used from sites located around the Great Lakes region for this pioneering genomic study, though the plant can be found growing throughout North America.

“We are trying to understand the genomic basis for invasiveness in plants,” said Dong-Ha Oh, research assistant professor in the Dassanayake Lab in LSU’s Department of Biological Sciences and lead author of the paper.

This project resulted in the first genome reference for this globally recognized invasive plant that can be used by plant scientists studying evolution of invasive traits as well as scientists designing genetic-based strategies to manage in conservation biology.

The study also included a comparison of gene expression data, or comparative transcriptomics. When used with the newly assembled genome, it suggested that genes associated with pathogen and defense responses were highly expressed in the invasive subspecies continuously, while similar genes in the native subspecies were found at much lower expression levels and were only induced when there was a pathogen.

“We are seeing a built-in defense response in the invasive plants that is much higher than in the native plant,” said Maheshi Dassanayake, associate professor in the LSU Department of Biological Sciences and a corresponding author of the paper. “For example, if we give both of these plants a pathogen and then test what happens, we see the native one acting drastically to respond to the attack, while the invasive one just doesn’t care because it always has its shields up.”

Chathura Wijesinghege, a graduate student in the Dassanayake Lab contributed to this work by tracing the evolutionary history of Phragmites and closely related grasses. Dassanayake was invited to collaborate on an existing project between Tulane’s Keith Clay and USGS’s Kurt Kowalski that funded a genome project with a goal to design genetic control measures that can differentiate native subspecies from the invasive sub-species without causing unintentional damage to native fauna and flora.

“The USGS recognized the management need and initiated analysis of the genetic makeup of Phragmites as part of the new study,” said Kowalski. “This cutting-edge research provides a roadmap for further development of species-specific treatments to control invasive Phragmites and offers insights into how it compares to other grasses.”

The Dassanayake Lab analyzed the invasive plant’s genome using LSU’s High Performance Computing services and revealed a unique history of genome-wide duplication events that likely provided novel genetic material for the divergence of the invasive and native subspecies. After identifying reference genes in the genome, the group looked at their expression in the native subspecies in comparison to the invasive.

“[This invasive reed subspecies] is destroying ecosystems that have been adapted to the native reeds, and [the USGS] wants to find out some biological solution that avoids the use of generic herbicides or labor intensive-mechanical removal,” Oh said. “If we just leave it, perhaps in hundreds of years the ecosystem may eventually adapt to this invasive species, but we may likely lose much of the local biodiversity in the meantime. So, plant biologists and conservation biologists can work together to find effective and sustainable solutions to control this problem before irreversible damage is observed to our native communities.”



More information:
Dong‐Ha Oh et al, Novel genome characteristics contribute to the invasiveness of Phragmites australis (common reed), Molecular Ecology (2021). DOI: 10.1111/mec.16293

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Hexbyte Glen Cove Grace makes landfall in Mexico as major hurricane thumbnail

Hexbyte Glen Cove Grace makes landfall in Mexico as major hurricane

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A lifeguard watches waves crash on the shore in Boca del Rio in Mexico’s eastern state of Veracruz as Hurricane Grace nears.

Hurricane Grace slammed into Mexico for a second time early Saturday as a major Category Three storm, threatening to bring significant flooding and mudslides, US forecasters said.

The made landfall near Tecolutla in Veracruz state, clocking maximum sustained winds of 125 miles (200 kilometers) per hour, according to the US National Hurricane Center (NHC).

Category Three is the third highest of five levels on the Saffir-Simpson scale.

A hurricane warning was in effect for coastline stretching from Puerto Veracruz to Cabo Rojo.

“Rapid weakening is expected as Grace moves inland over the mountains of central Mexico later today,” the NHC said.

Nearly 8,000 civil defense members, soldiers and electricity board workers were ready to tackle the aftermath of the storm, Mexican President Andres Manuel Lopez Obrador wrote on Twitter.

He urged residents living in places considered to be at risk to “seek refuge in high places with relatives and in shelters.”

Highways closed

Authorities in the state of Veracruz said they had prepared 200 storm shelters and planned to open another 2,000 if necessary.

Veracruz Governor Cuitlahuac Garcia warned of the risk of flooding and mudslides as the storm dumped heavy rain on the mountainous region.

Workers board up windows of a supermarket in Mexico’s eastern state of Veracruz to prevent damage from approaching Hurricane Grace.

Members of the Mexican armed forces were ready to deploy if needed to protect residents, said civil protection national coordinator Laura Velazquez.

Authorities closed most highways in Veracruz, which is crossed by numerous rivers.

In preparation for the storm, workers along the coast boarded up windows to protect stores, fishermen brought their boats ashore and residents secured their homes after stocking up on canned food and water.

“We will spend many days without fishing—almost a week,” said Isabel Pastrana Vazquez, head of Veracruz’s federation of fisheries cooperatives.

“About 35,000 fishermen will be affected because we can’t go out. We’re going to have a swell and rain,” he said.

‘Dangerous storm surge’

The NHC warned that heavy rainfall in Mexico through the weekend “will result in significant flash and urban flooding as well as mudslides.”

A “dangerous storm surge” would be accompanied by “large and destructive waves” near the coast, it said.

The hurricane had already lashed Mexico’s Yucatan Peninsula, where more than 6,000 tourists and residents were evacuated to storm shelters earlier in the week across the southeastern state of Quintana Roo.

The storm first struck near the town of Tulum, famed for its Mayan temples, drenching a string of Caribbean beach resorts.

The hurricane passed the Riviera Maya coastline without any loss of life, according to Quintana Roo Governor Carlos Joaquin. He said electricity had been almost completely restored across the state.

It then churned across the Gulf of Mexico, gathering strength as it headed for the mainland.

Authorities in Mexico City warned that the storm could also bring to the capital over the weekend.



© 2021 AFP

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Grace makes landfall in Mexico as major hurricane (2021, August 21)
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Hexbyte Glen Cove Mars helicopter makes 4th flight, gets extra month of flying thumbnail

Hexbyte Glen Cove Mars helicopter makes 4th flight, gets extra month of flying

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NASA’s Ingenuity Mars Helicopter (above center to the right) is viewed by one of the hazard cameras aboard the Perseverance rover during the helicopter’s fourth flight on April 30, 2021. Credit: NASA/JPL-Caltech

After proving powered, controlled flight is possible on the Red Planet, NASA’s Mars Ingenuity helicopter has new orders: scout ahead of the Perseverance rover to assist in its search for past signs of microbial life.

The next phase extends the rotocraft’s mission beyond the original month-long technology demonstration. Now, the goal is to assess how well flyers can help future exploration of Mars and other worlds.

“We’re going to gather information on the operational support capability of the helicopter while Perseverance focuses on its ,” Lori Glaze, director of NASA’s Planetary Science Division, told reporters Friday.

The type of reconnaissance that Ingenuity performs could one day also prove useful to human missions, by scoping out the best paths for explorers to traverse, and reaching locations that aren’t otherwise possible.

The four pound (1.8 kilogram) mini chopper successfully performed the fourth of its five originally planned flights on Friday, “going farther & faster than ever before,” NASA tweeted.

The fifth is planned in the coming days, then its mission will be extended, initially by one Martian month.

Whether it continues beyond that will depend on if it’s still in good shape and if it’s helping, rather than hindering, the rover’s goals of collecting soil and rock samples for future lab analysis on Earth.

NASA’s Mars Perseverance rover acquired this image of the Ingenuity Mars Helicopter (upper right) using its left Mastcam-Z camera. Mastcam-Z is a pair of cameras located high on the rovers mast. This is one still frame from a sequence captured by the camera while taking video. This image was acquired on Apr. 30, 2021 (Sol 69) at the Local Mean Solar Time of 12:33:27. Credit: NASA/JPL-Caltech/ASU/MSSS

Chief engineer Bob Balaram predicted a limiting factor will be its ability to withstand the frigid Mars nights, where temperatures plunge to -130 degrees Fahrenheit (-90 degrees Celsius).

Ingenuity keeps warm with a solar-powered heater, but it was only designed to last for a month and engineers aren’t sure “how many freeze and thaw cycles (it) can go through before something breaks,” he said.

NASA initially thought Perseverance would be driving away from the site where it landed at the Jezero Crater on February 18, just north of the planet’s equator.

That would have meant the rover leaving Ingenuity behind and moving beyond communications range.

Now though, the agency wants to keep Perseverance in the area for some time after finding a rocky outcrop that they believe contains some of the oldest material on the crater floor.







Credit: NASA

They hope to collect their first sample in July.

Ingenuity’s exploits have captured the public’s imagination since it made its first flight on April 19, but NASA said this wasn’t a factor in its decision to allow the two robots to keep exploring Mars together.

“We really wish to spend a considerable amount of time where we are and so it’s sort of a fortuitous alignment,” said Perseverance project scientist Ken Farley.



© 2021 AFP

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Mars helicopter makes 4th flight, gets extra month of flying (2021, April 30)
retrieved 2 May 2021
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Hexbyte Glen Cove Accelerator makes cross-country trek to enable laser upgrade thumbnail

Hexbyte Glen Cove Accelerator makes cross-country trek to enable laser upgrade

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Thomas Jefferson National Accelerator Facility has shipped the final new section of accelerator that it has built for an upgrade of the Linac Coherent Light Source (LCLS). The section of accelerator, called a cryomodule, has begun a cross-country road trip to DOE’s SLAC National Accelerator Laboratory, where it will be installed in LCLS-II, the world’s brightest X-ray laser. Credit: DOE’s Jefferson Lab

Today, the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility has shipped the final new section of accelerator that it has built for an upgrade of the Linac Coherent Light Source (LCLS). The section of accelerator, called a cryomodule, has begun a cross-country road trip to DOE’s SLAC National Accelerator Laboratory, where it will be installed in LCLS-II, the world’s brightest X-ray laser.

“This is the culmination of seven years of work,” said Naeem Huque, the cost account manager who led the cryomodule efforts at Jefferson Lab. “A lot of the staff in Jefferson Lab’s Superconducting Radiofrequency Institute came in right from the start of the project, and they’re still here seeing it off. We are happy to see this project conclude successfully.”

LCLS-II is a project to upgrade the existing Linac Coherent Light Source (LCLS), the world’s first X-ray free-electron laser. The X-ray pulses generated by the machine act like a powerful microscope, allowing researchers to watch chemical reactions in real time, probe materials and more. Once complete, LCLS-II will begin its reign as the biggest and brightest X-ray free-electron laser in the world.

LCLS-II will provide even better resolution than the original LCLS, which accelerated electrons at room temperature and generated 120 X-ray laser pulses per second. The upgraded machine will accelerate electrons at superconducting temperatures to generate 1 million X-ray laser pulses per second. Jefferson Lab is a key contributor to the upgrade project, providing a total of 21 cryomodules for the new superconducting portion of LCLS-II since work began in 2013.

The superconducting that will power the upgraded machine is made up of cryomodules. Electrons zip through the cryomodules, where they are loaded up with extra energy. Then, magnets make the electrons zigzag to give off their energy as X-rays. The upgraded LCLS will boast 37 cryomodules in total. Of those,18 are from Jefferson Lab (plus three spares), and the rest will come from Fermilab, another key contributor.

“The LCLS-II cryomodules are the highest-performing cryomodules that anybody has ever built,” said Joe Preble, senior team leader for the LCLS-II project at Jefferson Lab. “We pushed out the performance frontier on this sort of technology and turned it into a regular, turnkey process.”

Jefferson Lab is a world leader in superconducting radiofrequency accelerator technologies and is home to the first large-scale SRF accelerator. As the team at Jefferson Lab contributed to the design of, built, tested and shipped these record-breaking cryomodules for LCLS-II, they encountered unprecedented challenges to push the cryomodule technology’s performance.

“These very high-performing cryomodules are sensitive to things that we never had to worry about before, like our assembly procedures, the way we treat materials, the way we build things,” Preble said.

Jefferson Lab modified its facilities to accommodate the cryomodules, which were a different shape and size than those that came before. Jefferson Lab staff members even figured out a new way to ship the finished cryomodules, after some broke during shipment.

“We explored a lot of different options, everything from hiring a NASA aircraft to take it over there, to trying to send it by train or ship,” Huque explained.

In the end, they managed to improve safety without pulling the cryomodules off the road. Sitting in a bed of springs to prevent damage from jostling, Jefferson Lab’s newly shipped cryomodule will travel almost 3,000 miles to its home in the LCLS-II linear accelerator in Menlo Park, California, over the course of 72 hours.

However, Jefferson Lab’s work on improving the LCLS is likely not yet done. Another upgrade to this accelerator may be on the horizon: LCLS-II HE (High Energy). If that project is greenlighted, Jefferson Lab will build between 10 and 13 more cryomodules with a newer procedure. It’s expected that those cryomodules will have even better performance than the 21 they just finished.

“I think that’s one of the biggest signs that we’ve done really well, is that something that was already ambitious is now getting pushed even further,” Huque said. The HE upgrade, which is the culmination of work by staff at both Jefferson lab and Fermilab, will dramatically increase the performance capabilities of LCLS-II.”

For now, this momentous final delivery closes the book on Jefferson Lab’s part in delivering new cryomodules for LCLS-II while the R&D and prototyping for HE is already ongoing. Its conclusion comes thanks to the help of many.

“From the procurement people to the engineers, the scientists, the technicians, and the administrators, it’s taken everybody working together across laboratories to get this done,” Preble said. “It’s a great success and demonstration of the way the DOE needs to continue to work in building these new big projects.”



Citation:
Accelerator makes cross-country trek to enable laser upgrade (2020, November 21)
retrieved 22 November 2020