stems

Mining with plants

February 21, 2025 By EarthWise Leave a Comment

Plants absorb nutrients and minerals from the soil as they grow and incorporate them into their leaves and stems. Such plants can be used to remove toxic elements from soil. Cleaning soil in this way is called phytoremediation.

Researchers at the University of Massachusetts Amherst are trying to go beyond phytoremediation and do phytomining, in which hyperaccumulated minerals from the soil can be harvested from plants for use in industrial or manufacturing applications.

One mineral that is critically needed for modern technology is nickel. There are trace amounts of nickel in nearly one million acres of topsoil in the US, making the soil inhospitable for most crops, but the economics and environmental impact of extracting it make doing it impractical.

A common plant, Alyssum murale, is a nickel hyperaccumulator; in fact, up to 3% of the plant’s biomass can be made up of nickel. But the plant is slow-growing and difficult to manage and is also considered an invasive species

Another common plant, Camelina sativa, does not have the downsides associated with Alyssum and is also a rich source of valuable biofuel. The Amherst researchers are working to determine which genes and proteins are responsible for Alyssum’s nickel hyperaccumulation and hope to genetically engineer Camelina sativa to have the same ability.

The researchers believe there is enough nickel in barren soil in the US to supply 50 years of phytomining. It wouldn’t supply all the nickel the economy needs, but it could account for 20 to 30 percent of the projected demand.

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Scientists at UMass Amherst Engineer Plant-based Method of ‘Precious’ Mineral Mining

Photo, posted July 10, 2017, courtesy of Matt Lavin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A dangerous invasive species

August 28, 2024 By EarthWise Leave a Comment

Weeds are the bane of every gardener’s existence. They pop up, uncontrolled and unwelcome, and must be tediously managed time and time again. But in some cases, weeds are more than just a nuisance. Some are a public health hazard.

Meet giant hogweed. Native to Europe’s Caucasus Mountains, giant hogweed belongs to the carrot family. The plant resembles Queen Anne’s Lace – on steroids. Giant hogweed can grow up to 15 feet tall with three inch stems, five-foot-wide leaves, and an umbrella-like canopy of white flowers.

Botanists brought giant hogweed to England as an ornamental plant in the 1890s. It made its way to the U.S. via horticultural channels. In fact, one of the first specimens was planted in a Victorian garden near Rochester, NY.

As with most invasive plants, it quietly escaped cultivation. In the U.S., giant hogweed can be found in New England, the Mid-Atlantic Region, and the Northwest, with plants preferring moist habitat near roadside ditches and stream banks.

While a seemingly innocent flowering plant, giant hogweed is actually one of the most hazardous plants in the U.S. Brushing against or breaking the plant releases sap that, when combined with sunlight and moisture, can cause severe burn-like lesions, blistering sores, and purplish or blackened scars. Getting sap in your eyes can result in temporary or even permanent blindness.

With each plant dropping up to 120,000 seeds, it’s no surprise that giant hogweed is proving difficult to eradicate.

If you suspect giant hogweed is growing near you, photograph the plant from a safe distance and report the sighting to local environmental authorities.

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Plant Pest Risk Assessment for Giant Hogweed

Giant Hogweed

Photo, posted March 22, 2021, courtesy of Scottish Invasive Species Initiative via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Detecting dangerous chemicals with plants

December 11, 2023 By EarthWise Leave a Comment

Researchers at University of California Riverside have been studying how to enable plants to sense and react to a chemical in the environment without damaging their ability to function in all other respects. Why do this? The idea is to be able to use plants as environmental sensors that can detect the presence of harmful substances.

The impetus for the work is presence of a protein in plants that senses a plant hormone called abscisic acid (or ABA) that helps plants acclimate to environmental changes. During drought, plants produce ABA causing the plant to produce ABA receptor proteins that close pores in its leaves and stems, keeping in moisture.

The UCR researchers demonstrated that these ABA receptor proteins can be trained to bind to chemicals other than ABA. This ability enabled them to create sensors for many chemicals, including banned pesticides.

In their recent publication, they demonstrated a green plant that turns bright red in the presence of azinphos-ethyl, a banned pesticide. The goal is to easily detect chemicals in the environment from a distance. A field of these plants would provide an obvious visual indicator of the use of a banned pesticide. The researchers also demonstrated the ability to turn a variety of yeast into a sensor that could respond to two different chemicals at the same time.

Ultimately, it would be extremely valuable to design plants that sense dozens of chemicals to they could be used as living sensors that persist for years and provide environmental information. The sensor plants are not being grown commercially at this time. That will require regulatory approvals that are likely to take years. But the discovery opens up real possibilities.

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Plants transformed into detectors of dangerous chemicals

Photo, posted August 29, 2013, courtesy of the United Soybean Board via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fighting Disease in Cavendish Bananas | Earth Wise

January 31, 2022 By EarthWise Leave a Comment

Cavendish bananas account for about half of global banana production and the vast majority of bananas entering international trade. The plant is unable to reproduce sexually and instead is propagated via identical clones. So, the genetic diversity of the Cavendish banana is exceedingly low.

In 2008, Cavendish cultivars in Sumatra and Malaysia started to be attacked by Panama disease, a wilting disease caused by a fungus. In 2019, Panama disease was discovered on banana farms in the coastal Caribbean region, its first occurrence in the Americas. In the 1950s, Panama disease wiped out the Gros Michel banana, the commercial predecessor of the Cavendish.

Scientists at the University of Cambridge have found a novel way to combine two species of grass-like plants – which include bananas, rice, and wheat – using embryonic tissue from their seeds. The technique allows beneficial characteristics, such as disease resistance, to be added to the plants.

Joining the shoot of one plant to the root of another to grow as one plant is known as grafting. It was thought to be impossible to do with grass-like plants – called monocotyledonous grasses – because they lack a certain tissue type in their stems. But the new research, published in the journal Nature, showed it can be done with the plants in their earliest embryonic stages.

Cavendish bananas are sterile, so disease resistance can’t be bred into future generations. But the grafting technique may provide a way to produce Cavendish banana plants that are resistant to Panama disease. It may be possible to save an important food crop before it is too late.

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New grafting technique could combat the disease threatening Cavendish bananas

Photo, posted July 1, 2015, courtesy of Augustus Binu via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Restoring Seagrass In Virginia | Earth Wise

December 10, 2020 By EarthWise Leave a Comment

Seagrass is found in shallow waters in many parts of the world. They are plants with roots, stems, and leaves, and produce flowers and seeds. They can form dense underwater meadows that constitute some of the most productive ecosystems in the world. Seagrasses provide shelter and food to a diverse community of animals including tiny invertebrates, fish, crabs, turtles, marine mammals and birds.

In the late 1920s, a pathogen began killing seagrasses off the coast of Virginia. In 1933, a hurricane finished them off completely. For nearly 70 years thereafter, the bay bottoms of the Virginia coast were muddy and barren, essentially devoid of fish, shellfish, mollusks and other creatures that inhabit seagrass meadows. The local scallop industry was no more.

The largest seagrass restoration project ever attempted has changed all that. During the past 21 years, scientists and volunteers have spread more than 70 million eelgrass seeds within four previously barren seaside lagoons. This has spurred a natural propagation of meadows that have so for grown to almost 9,000 acres, the largest eelgrass habitat between North Carolina and Long Island Sound.

The long-term research conducted by the team from the University of Virginia shows that the success of the seagrass restoration project is improving water quality, substantially increasing the abundance of fish and shellfish in the bays, and capturing carbon from the water and atmosphere and storing it in the extensive root systems of the grasses and in the sediment below.

The study shows that marine restorations are possible on scales that contribute directly to human well-being.

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Some Good News: Seagrass Restored to Eastern Shore Bays is Flourishing

Photo, posted May 17, 2019, courtesy of Virginia Sea Grant via Flickr. Photo credit: Aileen Devlin | Virginia Sea Grant.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving Beaches With Seagrass

February 22, 2019 By EarthWise Leave a Comment

Almost a quarter of the Gross Domestic Product of places around the Caribbean Sea is earned from tourism. Preserving the beaches in the region is an economic imperative. With increasing coastal development, the natural flow of water and sand is disrupted, natural ecosystems are damaged, and many tropical beaches simply disappear into the sea.

With such high stakes, expensive coastal engineering efforts such as repeated replenishing of sand and the construction of concrete protective walls are common strategies. Rising sea levels and increasingly powerful storms only increase the threat to tropical beaches.

Researchers from The Netherlands and Mexico recently published a study in the journal BioScience on the effectiveness of seagrass in holding onto sand and sediment along shorelines.

Seagrasses are so-named because most species have long green, grass-like leaves. They are often confused with seaweeds but are actually more closely related to flowering plants seen on land. Seagrasses have roots, stems and leaves, and produce flowers and seeds. Seagrasses can form dense underwater meadows and are one of the most productive ecosystems in the world. Seagrasses provide shelter and food to an incredibly diverse community of animals, from tiny invertebrates to large fish, crabs, turtles, marine mammals and birds.

The researchers performed measurements of the ability of seagrass along Mexico’s Yucatan Peninsula coastline to keep sand in place and prevent erosion. They found that the amount of erosion was strongly linked to the amount of vegetation. Quite often, seagrass beds have been regarded as a nuisance, rather than a valuable asset for preserving valuable coastlines. The study opens opportunities for developing new tropical beach protection schemes in which ecology is integrated into engineering solutions.

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