Asplenium submarginatum

As the world races to slow the pace of climate change, it is clear that <a href="https://www.earth.com/news/big-trees-are-crucial-in-stabilizing-climate-new-model-predicts/">trees</a> will play a pivotal role. Trees remove carbon dioxide from the atmosphere every day, and store it in their leaves, branches and trunks. They also release oxygen, contribute to the water cycle through transpiration, attract animals, prevent soil erosion and provide cooling shade. In the Amazon, the world’s most biodiverse tropical rainforest, trees have been under threat for decades, as human activities change the forest landscapes.&nbsp;



In a major new study conducted by researchers from Brazil and the U.K., the ecological impacts of different types of land use in the Amazon have been investigated in two regions of the Brazilian State of Pará – Santarém and Paragominas.&nbsp; In addition, the rate of transformation between these different forms of land use has been quantified, in order to identify the most serious environmental threats to the forest ecosystems, as the Amazon moves closer to a ‘tipping point’ from which it is potentially unable to recover.



“While the focus to date has been on deforestation, we know tropical forest landscapes are being altered by a much broader range of human activities,” said lead researcher Dr Cássio Alencar Nunes from Universidade Federal de Lavras in Brazil and <a href="https://www.lancaster.ac.uk/">Lancaster University</a> in the United Kingdom.



“These modifications include deforestation and degradation of primary forest, for example through selective logging and fires, but even deforested landscapes are changing as agricultural abandonment leads to secondary forest regrowth. As a result, many tropical landscapes are now a mosaic of non-forest land uses, regenerating secondary forests, and degraded primary forests."



The researchers collected data from 310 plots that were in primary forest, degraded primary forest, secondary forest, pasture land or lands on which mechanized farming of crops currently occurs. They assessed the biodiversity in these plots, recording more than 2,000 species of trees, lianas, birds and insects in total. The experts also measured soil carbon, along with analyzing other soil properties at each of the plots. Data on the rate of change of land-use practices in the region came from published information for the years between 2006 and 2019.



The results, published today in the <a href="https://www.pnas.org/">Proceedings of the National Academy of Sciences</a>, show that where primary or secondary forests are converted to pasture or mechanized agriculture, the biodiversity decreases by between 18 and 100 percent. Transitions from forest to mechanized crop farming did the most severe ecological damage, but were not very frequent. However, changes from primary and secondary forests to pasture, through the process of deforestation, were much more common, and accounted for a forest loss of around 24,000 km² a year.&nbsp;



“Deforestation of primary forests to create pasture is the most damaging land-use change in the Brazilian Amazon,” said Dr. Nunes. “Our results show that transitions from primary forests to pasture were always classed as ‘high impact, high rate’ for biodiversity, carbon storage and soil properties. This underlines the critical and urgent importance of combating deforestation, which has been increasing in the past few years.”



Apart from identifying the severe ecological impacts from human activities that are affecting Amazonian forests, the researchers also identified some opportunities for positive action. They found that protecting secondary forests and allowing them to mature improved biodiversity and increased the carbon storage capacity of the vegetation. In particular, they found that the diversity of large trees doubled and small tree diversity increased by 55 percent when young secondary forests became older than 20 years.



Other results revealed less obvious forms of degradation that are affecting the Amazon’s ecology. The researchers found that changing between types of farming, from cattle pasture to more intensive mechanized agriculture, also diminishes biodiversity, with the diversity of ants and birds decreasing by 30 percent and 59 percent respectively. The effects of deforestation are devastating, but the use of mechanized farming practices clearly also has catastrophic effects on the ecology of the Amazonian forests.



“These are important findings as they show that there are a multitude of actions that can be taken to protect and improve the ecology of the Amazon," said Dr. Nunes. "When farmers switch land from pasture to growing crops using mechanized agricultural methods, that is also impacting on biodiversity, but it is a process that is largely hidden when compared to deforestation.”



“By reducing the amount of land that is converted to mechanical farming, and by allowing secondary forests to regrow, we can deliver significant ecological restoration gains in the Amazon,” he added.



The researchers feel that the study’s findings have allowed a richer understanding of how human activities impact the Amazon and its ecosystems. They also provide a critical base of evidence that can be used to inform urgently needed conservation and regeneration strategies. In addition, the analysis has identified some encouraging opportunities to foster ecologically sustainable practices in the Amazon in the future.&nbsp;&nbsp;



Study co-author Jos Barlow, a professor of Conservation Science at the Lancaster Environment Centre, highlighted noted that the research has further implications for conservation and policy.



“Our results emphasize yet again the importance of tackling deforestation, as well as the additional benefits of avoiding degradation and enhancing the permanence of secondary forests. However, achieving this will require transforming the way the Amazon is currently being managed, including a much better integration of science, policy and local practices," said Professor Barlow.



“We also highlight the need to focus on biodiversity as well as carbon in tropical forests – of the three ecosystem components that we analyzed, biodiversity was the most affected by all the land-use changes. We hope that biodiversity can be included in climate change mitigation actions, and that this will be emphasized in the upcoming COP15 on Biodiversity."



Image Credit: Erika Berenguer



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Land-use changes expose the Amazon to environmental threats

As the world races to slow the pace of climate...

Niger is one of the driest countries in sub-Saharan Africa, being plagued by frequent <a href="https://www.earth.com/news/europe-will-face-more-frequent-and-extreme-droughts/">droughts</a> that are considerably hindering its farming business, leading to dying crops and widespread famine. In an attempt to find cheap and sustainable solutions for reviving this country’s agriculture, a team of researchers from Niger, the United Kingdom, and Germany has assessed the benefits of using a mineral-rich, low-cost, and easily accessible fertilizer: sanitized human urine, which they renamed “Oga” (meaning “the boss” in the Igbo language) in order to avoid the negative connotations of the term “urine.”



For thousands of years, humans have known that urine is an excellent fertilizer for crops, since it contains many of the ingredients found in commercial fertilizers, such as phosphorous, nitrogen, and potassium. However, due to the squeamishness associated with utilizing urine to grow crops, its use has always been limited.&nbsp;



To test its effectiveness on large-scale farming, the researchers conducted a total of 159, 288, and 234 on-farm trials between 2014 and 2016. The farmers were divided into two groups - the first continued to use their traditional farming methods to grow their pearl millet grains (a common type of crops in the region), while the second group applied Oga (with or without animal manure) to their experimental plots, after being trained on how to safely use it. The results revealed that, over a period of three years, those who used Oga experienced an average 30 percent increase in their crop yields.&nbsp;



“Oga is a low risk, low financial input fertilizer option ready for dissemination on sandy Sahelian sites with low pearl millet yield level,” the study author wrote. Two years after these experiments, the scientists found that this method has significantly increased in popularity, with over one thousand farmers regularly using it to fertilize their crops.&nbsp;



Further research is needed to assess the benefits of using urine as a fertilizer in industrialized countries too. According to several scientists, switching from commercial fertilizers to urine could not only increase crop yields and reduce fossil fuel intensive resources needed to grow them, but also make our sanitation systems more sustainable.



“Millions and millions of dollars a year are spent trying to treat our waste before it goes into receiving waters for acceptable nitrogen and phosphorus criteria,” said Cara Beal, a researcher in Environmental Health at <a href="https://www.griffith.edu.au/">Griffith University</a> in Australia. “But if we can close that nutrient loop it’d be very sensible in terms of sustainability, the circular economy, and looking after our planet a little bit better,” she concluded.



The study is published in the journal <a href="https://link.springer.com/article/10.1007/s13593-021-00675-2#Abs1">Agronomy for Sustainable Development</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Human urine can effectively fertilize crops

Niger is one of the driest countries in sub-Saharan Africa,...

In a new study from <a href="https://en.wikipedia.org/wiki/Ural_Federal_University">Ural Federal University</a>, experts have demonstrated that flowers and tobacco can thrive on polluted land. These plants can adapt to copper in the soil by limiting the accumulation of the metal to the stem and leaves.&nbsp;



“Plants of the Asteraceae and Nightshade families, namely zinnia and tobacco, are copper-exclusive, their root system performs the function of copper accumulation,” explained study co-author Anastasia Tugbaeva. "Biotechnologies for maintaining and restoring components of natural and transformed biosystems", UrFU.&nbsp;



“Using zinnia as an example, we have shown for the first time that it can grow in copper-contaminated soils and even flower faster than in pure soils. That is, it can be used for landscaping areas, it will grow well. Tobacco, an important agricultural crop and useful fertilizer, also adapted to long-term exposure to copper in our experiments and grew comparable to control plants, despite the high content of copper in the substrate.”



For the investigation, the scientists recreated realistic levels of humidity and temperature0. They tested the effect of various concentrations of copper sulfate on growth, and analyzed various physiological characteristics of the plants.



“We conducted experiments for 20, 40, 60 days and used substrates in which the content of copper could even exceed its content in urban soils,” said Tugbaeva. “Under the influence of copper in the root and stem of plants, the expression of five genes responsible for the synthesis of phenolic compounds and lignin is enhanced. Lignin is one of the components of the plant cell wall, which makes it stronger. It is lignin that is the mechanism of plant adaptation, which limits the transfer of metals from the cell wall and the effects of metals on the intracellular structure of the plant.”



The study is published in the journal <a href="https://www.mdpi.com/journal/horticulturae">Horticulturae</a>.



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Tobacco and zinnia can thrive in polluted land

In a new study from Ural Federal University, experts have...

Trees are crucial components of ecosystems as they support biodiversity, help ecosystems function and provide important services, such as supplying food, sequestering <a href="https://www.earth.com/news/marshes-may-soon-flip-from-carbon-sinks-to-carbon-sources/">carbon</a> and contributing to the water cycle. Conserving tree diversity is thus a conservation priority for the functioning of natural ecosystems, for mitigating the effects of climate change, and for use by human societies across the world. Despite these important roles, many tree species are not adequately protected, have become rare and may even be at risk of disappearing altogether.



In a recent large-scale study, an international team of researchers headed by scientists from <a href="https://international.au.dk/">Aarhus University</a> in Denmark, has determined the worldwide distribution of more than 46,000 different species of trees, and estimated the extent to which this distribution falls within protected areas. In addition, they have assessed the intensity of human activity in the areas where the trees are found.&nbsp;



In order to do this, the researchers integrated five large databases, each containing millions of records of tree occurrence. They used these data to calculate the distribution of each tree species and then combined the distributions with a global map of the intensity of human activities. Lastly, they used the world database on protected areas (which includes information of more than 200,000 such areas) to map out the levels of protection for each tree species. Their results are published in the <a href="https://www.pnas.org/">Proceedings of the National Academy of Sciences</a>.



The findings highlight the fact that tree species are poorly protected in general, and some have no protection whatsoever. For the 46,752 tree species included in the study, an average of 50 percent of every tree species’ range falls in landscapes that have no protected areas. For 13.6 percent of the species, there is no protection at all, and most of these species have a limited distribution anyway, making them even more vulnerable.



Furthermore, the authors found that only 17 percent of the species considered are not under pressure from human activities. On average, 14.8 percent of the species are exposed to high or very high human pressure, while 68.5 percent are under moderate pressure.&nbsp;



“By compiling millions of registrations collected by researchers and citizens across the world and shared in open databases, we can calculate where it’s most important to preserve and restore natural areas in order to effectively protect biodiversity,” said Josep M. Serra-Diaz, who was previously affiliated with Aarhus University, and who is now an associate professor at AgroParisTech in France.



The researchers not only quantified the threat to tree species on a global scale, but they also suggested how this situation can be improved by means of the ambitious and smart designation of new protected natural areas.



“We did this by calculating the most suitable locations of potential protection areas if we are to safeguard tree species diversity, not only with regard to the coverage of species, but also with regard to their evolutionary and functional differences,” explained lead author Dr. Wen-Yong Guo, who started the work at the Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), but is now affiliated with East China Normal University in Shanghai.



The researchers have based their work on two existing plans for protecting the world's biodiversity:



<ul><li>According to the UN Strategic Plan for Biodiversity 2011-2020, adopted in 2010, at least 17 per cent of land areas, lakes and watercourses were to be protected by 2020.</li><li>Now, the 2050 Vision of Biodiversity is on the drawing board, and many interest groups are calling for the vision to be brought in line with the Half-Earth Project proposed by Harvard biologist, E.O. Wilson. The Half-Earth Project advocates protecting half the earth’s surface by no later than 2050.</li></ul>



The researchers calculate that, following the above two conservation scenarios, protection of the top 17 percent or the top 50 percent of tree priority areas would make a considerable difference in protecting global tree diversity. They find that protecting 17 percent and 50 percent of the high-priority areas for trees would increase the average protected proportion of each tree species’ range to 65.5 percent and 82.6 percent respectively. This would also leave far fewer species (2,151 and 2,010) completely unprotected.&nbsp;



“But taking a broad-brush approach or just designating the most convenient areas, for example uninhabited tundra and desert areas, will not have the desired effect. Based on our calculations in this study, we’ve identified the areas in which nature conservation makes most sense to safeguard global tree diversity. If we’re smart, protecting 17 per cent of land areas would mean that, on average, a tree species will have protected areas in 66 per cent of the landscapes in which it is found, as opposed to the current 50 per cent. With the Half-Earth vision, the proportion would be 83 per cent. Two-thirds of the tree species that are currently unprotected will have protected areas in the landscapes in which they’re found if we reach the 17 per cent target,” explained Jens-Christian Svenning, professor of Biology at Aarhus University and director of BIOCHANGE.



“But in order to achieve this, we have to look at the distribution of all species across the world, and establish protected areas so that they cover the species and their biological functions and evolutionary differences in the best possible way."



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Human activity and poor protection threaten tree diversity worldwide

Trees are crucial components of ecosystems as they support biodiversity,...

Photosynthesis, the conversion of <a href="https://www.earth.com/news/sunlight-helps-green-sea-turtles-with-tumors-recover/">sunlight</a> into plant material, is responsible for supporting all life on Earth outside of deep sea thermal environments and other such rarified examples. Now, scientists have found a way to create artificial photosynthesis, according to new research published in the journal <a href="https://www.nature.com/natfood/">Nature Food</a>.



Photosynthesis is a process that evolved billions of years ago. It created a habitable atmosphere, oxygenated the ocean and freshwater, and is the basis of our food chain. The scientists point out, however, traditional photosynthesis converts only one percent of the energy from sunlight into food. The new approach of artificial photosynthesis promises to be more efficient, if not quite as momentous.&nbsp;&nbsp;&nbsp;&nbsp;



“With our approach we sought to identify a new way of producing food that could break through the limits normally imposed by biological photosynthesis,” said study co-author Robert Jinkerson, a chemical and environmental engineer of <a href="https://www.ucr.edu/">University of California Riverside</a>.



The research outlines a way to create acetate, the main component of vinegar from water, carbon dioxide and electricity. Plants can then be fed the acetate while growing and producing food in the dark.&nbsp;



“Using a state-of-the-art two-step tandem CO2 electrolysis setup developed in our laboratory, we were able to achieve a high selectivity towards acetate that cannot be accessed through conventional CO2 electrolysis routes,” said Feng Jiao of the <a href="https://www.udel.edu/">University of Delaware</a>.



The researchers grew a wide array of different food organisms using this method, not only plants but also yeast, a fungi that often grows in the dark but in this case 18 times more efficiently. This means alcohol could be created with less input as from corn sugars or other traditional methods.&nbsp;



“We were able to grow food-producing organisms without any contributions from biological photosynthesis," said study co-author and doctoral candidate Elizabeth Hann. "Typically, these organisms are cultivated on sugars derived from plants or inputs derived from petroleum - which is a product of biological photosynthesis that took place millions of years ago. This technology is a more efficient method of turning solar energy into food, as compared to food production that relies on biological photosynthesis,”



The researchers hope their study allows us to grow food more efficiently, using less land or feeding an increasingly growing population using the same amount of land. They also imagine the possibility of using this method to cultivate crops on space ships or Mars in total darkness.&nbsp;&nbsp;



“Using artificial photosynthesis approaches to produce food could be a paradigm shift for how we feed people. By increasing the efficiency of food production, less land is needed, lessening the impact agriculture has on the environment. And for agriculture in non-traditional environments, like outer space, the increased energy efficiency could help feed more crew members with less inputs,” said Jinkerson.



The study is published in the journal <a href="https://www.nature.com/natfood/">Nature Food</a>.



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By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Artificial photosynthesis could help grow food more efficiently

Photosynthesis, the conversion of sunlight into plant material, is responsible...

Trees absorb carbon from the atmosphere, in the form of <a href="https://www.earth.com/news/new-carbon-sinks-may-be-appearing-in-the-arctic/">carbon</a> dioxide. This is then used during the process of photosynthesis to form organic carbon compounds, such as carbohydrates, in the leaves, branches, trunks and roots. A living tree is thus an important storage site for carbon that might otherwise be adding to the levels of carbon dioxide in the atmosphere. And a big, living tree is even more important.&nbsp;



However, when scientists attempt to understand the importance of the carbon storage currently provided by woody vegetation, and the effects of anthropogenic impacts on the carbon cycle, they are faced with the fact that there are no direct measurements of carbon cycling from the pre-industrial period. Furthermore, scientists do not really know how woody biomass has changed on Earth over recent millennia.



Without empirical data on changes in woody biomass spanning more than a few decades, scientists have to estimate and make assumptions when trying to model the effects of climate change. This can lead to uncertainties in predictions about the role of vegetation as a long-term carbon sink, and to inaccuracies when projecting future changes in the carbon and climate systems.&nbsp;



A new study, published today in the journal&nbsp;<a href="https://www.science.org/">Science</a>, seeks to fill this knowledge gap using the assemblages of fossil pollen in the soil as an indication of woody vegetation biomass in the past. Led by Ann Raiho of the <a href="https://www.umd.edu/">University of Maryland</a>’s Earth System Science Interdisciplinary Center (ESSIC), an international team of scientists used fossil pollen data as a proxy to reconstruct the natural pace and pattern of carbon storage in the forests of the Midwestern U.S. over the past 10,000 years. Their findings cast a new light on how landscapes can be managed to maximize carbon storage while also meeting conservation goals.&nbsp;



“We found that the forests in the Midwestern U.S. were expanding and getting bigger over the last 10,000 years,” said Raiho, a postdoctoral associate at ESSIC. “This tells us that the prehistoric baseline for understanding forests was wrong and that it’s important from a carbon sequestration perspective to preserve trees that grow larger and live longer.”



The research team, which also included researchers from the University of Notre Dame, University of California, Berkeley, University of Calgary and the U.S. Geological Survey, developed a Bayesian model that they named ReFAB (Reconstructing Forest Aboveground Biomass). This model estimates aboveground woody biomass based on a time-series of fossil pollen assemblages in sediments. The experts used ReFAB to reconstruct changes in woody biomass across a 600,000-plus kilometer area in the Upper Midwest of the U.S. over the last 10,000 years.&nbsp;



Their work painted a vivid picture of how forests have changed over this time. The researchers found that, after an initial postglacial decline, woody biomass nearly doubled during the last 8,000 years. This result differs substantially from prior reconstructions of forest biomass in eastern Canada, a finding they suggest may be due to differences in the forest species in the two regions.&nbsp;&nbsp;



Previous studies used simpler models that indicated little or no change in woody biomass over the last 6,000 years. ReFAB corrects this situation by accounting for temporal autocorrelation, uncertainty in sediment-dating, and uncertainty in the relationship between aboveground woody biomass and multivariate pollen data. Removing these uncertainties has allowed the researchers to understand past changes in vegetation at a finer scale, thereby uncovering trends that were previously not visible.&nbsp;



“We found that the ecology of forests matters for understanding the carbon cycle,” Raiho said. “The steady accumulation of carbon was driven by two separate ecological responses to regionally changing climate: the spread of forested biomes and the population expansion of high-biomass tree species within forests.”



The data from fossil pollen assemblages showed, sadly, that the woody biomass accumulated in the Midwestern forests over millennia took under two centuries to destroy. Industrial-era logging and agricultural clearance severely depleted this carbon accumulation. The researchers found that the decline in woody biomass in the studied region occurred at more than 10 times the rate of aboveground woody biomass change in any century over the last 10,000 years.



The researchers found that storage of carbon in woody biomass in the study area was driven by population expansions of high-biomass tree species, such as eastern hemlock and American beech. After these species became established, high-biomass forests were sustained in the study region for millennia. This discovery emphasizes the importance of preserving large trees when managing forests to mitigate the effects of climate change – large trees sequester considerable amounts of carbon.&nbsp;



“Forest management should emphasize sustaining populations of large trees,” Raiho said. “This has the potential to emulate the natural carbon sequestration processes and ultimately extend the timescales and magnitude at which terrestrial ecosystems will continue to buffer climate change by acting as a carbon sink.”



The research team will work in future with NASA’s Global Ecosystem Dynamics Investigation (GEDI), which will enable the protection of large trees by providing high resolution maps of the 3D structure of forests around the world. GEDI will expand existing knowledge about biomass magnitude, structure, and density. With this wealth of information, researchers will be able to predict the future of forests better.



“This work would not be possible without all of the people who collected and counted the fossil pollen data,” noted Raiho. “There were probably a hundred people over the last several decades who did all the field work. We used over 232 fossil pollen cores in this research. Thousands of hours went into the data collection. We used the Neotoma database to access this valuable data.”&nbsp;



Raiho and her team plan to use their pollen-based method of forest reconstruction to improve the simulation models used by the Intergovernmental Panel on Climate Change. This will enable scientists to understand better how climate change will impact Earth and its ecosystems in future.&nbsp;



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Big trees are crucial in stabilizing climate, new model predicts

Trees absorb carbon from the atmosphere, in the form of...

Researchers have found a way to alter <a href="https://www.earth.com/news/when-was-land-first-colonized-by-plants/">plant</a> proteins and create a fast test for dangerous chemicals, according to a new study published in the journal <a href="https://www.nature.com/nbt/">Nature Biotechnology</a>.



During droughts, plants produce a chemical called ABA which allows them to hold onto more water. Plants also create receptors that detect ABA. With a few small changes, the scientists showed that these ABA receptors can detect up to 20 chemicals. The tests could be used to look for illegal pesticides and dangerous synthetic cannabinoids.&nbsp;



“It would be transformative if we could develop rapid dipstick tests to know if a dangerous chemical, like a synthetic cannabinoid, is present. This new paper gives others a roadmap to doing that," said study co-author Sean Cutler, a plant cell biologist at <a href="https://www.ucr.edu/">UC Riverside</a>.



Synthetic cannabinoids, in particular, are created faster than regulations can keep up. These drugs are often dangerous, and even deadly. Fast tests could help regulators keep up with new products containing dangerous synthetic cannabinoids.&nbsp;&nbsp;



“Our system could be configured to detect lab-made cannabinoid variations as quickly as they appear on the market,” Cutler said.



The tests are also able to detect organophosphates, some of which (but not all) are illegal and dangerous pesticides. Being able to quickly identify the illegal pesticides would make testing water quality quicker.&nbsp;



To create these tests, the scientists used the nature of ABA to turn on receptors. When ABA interacts with receptors it can create many different reactions, such as glowing. Redesigning the receptors allows them to signal the presence of different chemicals. The scientists hope to expand this method to other types of chemicals as well.&nbsp;&nbsp;&nbsp;



“We take an enzyme that can glow in the right context and split it into two pieces. One piece on the switch, and the other on the protein it binds to,” Cutler said. “This trick of bringing two things together in the presence of a third chemical isn’t new. Our advance is showing we can reprogram the process to work with lots of different third chemicals.”



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By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

A plant-based test can detect dangerous chemicals

Researchers have found a way to alter plant proteins and...

Asplenium submarginatum

Taxonomic tree: