Two small changes, that may transform agriculture

Researchers from Aarhus University are one step closer to understanding how some plants survive without nitrogen. A breakthrough that could eventually reduce the need for artificial fertilizer in crops such as wheat, maize, or rice

Aarhus University

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Barley is one of the crops that seems to respond positively to a genetic fix that enables it to fixate nitrogen from the air through symbiosis with bacteria.

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Credit: Cliff from Arlington, Virginia, USA (Wikimedia Commons)

"We are one step closer to a greener and climate-friendlier food production."

That is the assessment from Kasper Røjkjær Andersen and Simona Radutoiu, both professors of molecular biology at Aarhus University.

The two researchers led a new study where they discovered an important key to understanding how we can reduce agriculture’s need for artificial fertilizer.

Plants need nitrogen to grow, a nutrient that most crops solely get from fertilizer. Only a few plants, such as peas, clover, and beans, can manage without it. They live in symbiosis with special bacteria that convert nitrogen from the air into a form that the plant can use.

Today, researchers around the world are striving to understand the genetic and molecular mechanisms behind this special ability, so that it one day may be transferred to crops such as wheat, barley, and maize.

This would make the plants self-sufficient in nitrogen and thus reduce the need for artificial fertilizer, which currently accounts for about two percent of the world's total energy consumption and emits large amounts of CO2.

The researchers from Aarhus University have identified the small changes in the plants’ receptors that cause them to switch-off the immune system and allow a symbiosis with nitrogen-fixing bacteria.

Friend or foe?
Plants use receptors on the surface of their cells to pick up signals from microorganisms in the soil.    

Some bacteria emit a chemicals which signal that they are "enemies" and that the plants need to defend themselve. Others are "friends" that help provide nutrition.

Legumes, such as peas, beans, and clover, invite special bacteria into their roots. Here, the bacteria convert nitrogen from the air and pass it on to the plant. This cooperation is called symbiosis, and it is the reason why legumes can grow without artificial fertilizer.

The researchers from the Aarhus University discovered that this ability is largely controlled by two amino acids – two small "building blocks" of a protein in the plants’ roots.

“This is a remarkable and important finding," Simona Radutoiu points out.
The protein in the roots functions as a "receptor" that receives signals from the bacteria. It decides whether the plant should sound the alarm (immune system) or welcome the bacteria (symbiosis).

The researchers found a small area in the protein, which they have called Symbiosis Determinant 1. The area acts as a kind of switch that determines which message is sent inside the plant cell.

By changing just two amino acids in this switch, the researchers could get a receptor that normally triggers an immune response to instead start symbiosis with nitrogen-fixing bacteria.

"We have shown that two small changes can cause plants to alter their behavior on a crucial point – from rejecting bacteria to cooperating with them," Simona Radutoiu explains.

Possible in wheat, barley, and maize?
In the laboratory the researchers successfully modified the plant Lotus japonicus. But the same principle proved to apply in barley.

"It is quite remarkable that we are now able to take a receptor from barley, make small changes in it, and then nitrogen fixation works again," says Kasper Røjkjær Andersen.

And the perspectives are big. If the modification can be transferred to other crops, eventually it may be possible to breed cereal plants such as wheat, maize, or rice with the ability to fix nitrogen themselves – just as legumes do today.

"But we have to find the other, essential keys first," says Simona Radutoiu, adding:

"Only very few crops can perform symbiosis today. If we can extend that to widely used crops, it can really make a big difference on how much nitrogen needs to be used."

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Journal

Nature

DOI

10.1038/s41586-025-09696-3 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Two residues reprogram immunity receptors for nitrogen-fixing symbiosis

Article Publication Date

5-Nov-2025

 

Concealed deals drive up 401(k) fees

When mutual funds share revenue with plan administrators, employees get higher costs and lower performance

University of Texas at Austin

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In 401(k) plans, one of the attractions has always been that employees choose where to invest their retirement funds. The average plan offers 28 options, according to the Investment Company Institute.

Employees might assume those options are picked to serve their best interests. But new research from Clemens Sialm, professor of finance at Texas McCombs, suggests they’re also serving someone else’s interests. Many funds are paying plan administrators to include them in a plan’s menu, a practice called revenue-sharing.

The result: Without knowing it, employees may be offered funds with higher fees and lower performance.

“It is a significant problem if employees do not understand the costs of their investment options in 401(k) plans,” Sialm says.

In the study, Sialm investigated the prevalence of revenue sharing and how it might influence recordkeepers: companies that administer retirement plans.

With Veronika Pool of Vanderbilt University and Irina Stefanescu of the Federal Reserve, he looked at the 1,000 largest 401(k) plans reporting to the U.S. Department of Labor between 2009 and 2013.

The researchers found that recordkeepers are more likely to include funds that pay them.

• More than half of plans — 54% — included at least one fund that shared revenue with recordkeepers.
• Revenue-sharing funds were 60% more likely to be added to plans than non-revenue-sharing funds were. They were less likely to be deleted.

Higher Fees, Lower Returns

But revenue-sharing funds don’t necessarily pay off for workers who invest in them. They charge higher administrative fees than non-revenue-sharing funds — partly because they’re rebating an average 18% of those fees to recordkeepers.

“Plan sponsors and providers are willing to include these investment options on the plan because they are willing to cover a larger fraction of administrative costs,” Sialm says.

Besides higher fees, he found revenue-sharing funds delivered worse financial performance over time than funds that didn’t share revenue.

So, what should employees do? Sialm’s primary answer is that they should demand transparency from their employers about hidden fees in their plan’s menu. A 1% higher fee over 30 years could cost them tens of thousands in lost returns.

He suggests that employers lay out fees in a clear and concise format. “Disclosing this information in hidden footnotes in lengthy documents is not very helpful,” he says.

The most effective way to limit revenue sharing, Sialm adds, might be for employers to pay recordkeepers directly for administering their plans. That way, recordkeepers wouldn’t need to rely on hidden fees for part of their compensation.

“Administering 401(k) plans is expensive, and recordkeepers need to be compensated for their services,” he says. “It would be more fair if the sponsor companies would cover their administrative costs.”

“Mutual Fund Revenue Sharing in 401(k) Plans” is published in Management Science.

 

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Journal

Management Science

DOI

10.1287/mnsc.2023.01560 

Article Title

Mutual Fund Revenue Sharing in 401(k) Plans

STEM IS D.E.I.

U.S. topped goal of ‘one million more’ STEM graduates over the past decade

But study also warns that current threats to agencies that track such data risks future progress and global competitiveness

University of California - Santa Cruz

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Between 2012 and 2022, a national target of 4 million STEM degrees earned in the United States was surpassed by 16%, cumulatively totaling 4.65 STEM degrees (red line) over that decade. This exceeded a projected need (blue dashed line) of 4 million, which was one million more than the baseline projection (green dotted line).

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Credit: Journal of Microbiology & Biology Education

SANTA CRUZ, Calif. – With this Saturday marking the national and international day of observance for STEM and STEAM, a fair question to ask is if the United States is producing enough college graduates with degrees in science, technology, engineering, and mathematics to maintain its leadership position in an increasingly competitive global arena?

An analysis by a National Science Foundation fellow at the University of California, Santa Cruz, concluded that we were on the right track. The study of national higher-education data, published in the Journal of Microbiology & Biology Education, found that the United States exceeded the goal of producing one million more graduates in STEM fields over the course of a decade.

That goal, set in a 2012 report by then-President Barack Obama’s Council of Advisors on Science and Technology (PCAST), was one of several national objectives created to maintain America’s scientific leadership position amid increasingly global competition.

But the good news delivered by the study came with an equally loud warning: that maintaining this momentum is threatened by the current assault on national-data infrastructure and the federal agencies that house them. These records help keep academic institutions accountable and show proof of return on investments that funded expansion of STEM education programs over the past decade.

Indeed, author Haider Ali Bhatti frames his study in the present-day context of the headwinds U.S. universities face: public skepticism of their value, claims of ideological indoctrination, and the ongoing dismantling of diversity, equity, and inclusion initiatives.

“Overall, these results reveal patterns that challenge public narratives about the diminishing state of higher education—particularly in undergraduate STEM education,” Bhatti said. “These findings provide an evidence-based foundation for both evaluating past investments and guiding future strategies to strengthen America’s talent development in the evolving global STEM ecosystem.”

For his analysis, Bhatti relied largely on data from the National Center for Education Statistics (NCES), noting it as a division of the U.S. Department of Education, which has been critically defunded and affected by mass layoffs due to federal restructuring.

The study's main takeaways and a full summary can be found in on the UC Santa Cruz Newscenter.

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Journal

Journal of Microbiology and Biology Education

DOI

10.1128/jmbe.00155-25 

Method of Research

Data/statistical analysis

Subject of Research

Not applicable

Article Title

One million more: assessing a decade of progress in undergraduate STEM education

Island reptiles face extinction before they are even studied, warns global review

University of Oxford

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Ricardo Rocha with a Príncipe Green Snake (Hapsidophrys principis), endemic from Principe Island. Photo by Patricia Guedes

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Credit: Patricia Guedes

More images available via the link in the notes section

A new study led by the University of Oxford has revealed that reptiles confined to islands are facing a double jeopardy. Despite being more likely to go extinct than mainland species, they remain largely ignored by researchers compared to their mainland counterparts.

Although islands make up less than 7% of the Earth’s surface, they harbour a disproportionate share of the planet’s biodiversity. Out of the roughly 12,000 known reptile species, around one-third are confined to islands - including iconic species such as the Galapagos tortoise and Komodo Dragon. These isolated ecosystems act as natural laboratories of evolution, where species adapt and diversify in unique environments.

Yet the very isolation that fosters this uniqueness also makes island reptiles more vulnerable. A new global assessment, published today (6 Nov) in Conservation Science and Practice, found that 30% of island dwelling reptiles are threatened with extinction (compared with 12.1% of reptiles overall). Despite this, only 6.7% of reptile-focused research publications since 1960 have studied them.

Ricardo Rocha, Associate Professor in Conservation Science (Department of Biology, University of Oxford) and senior author of the study, said: “Reptiles are keystone species for island ecosystems. For example, on Madeira Island - my birthplace - wall lizards are everywhere, chasing insects, pollinating plants and eating fruits. If island reptiles are allowed disappear, this would have huge impacts on many other species.”

Globally, reptiles are one of the most vulnerable vertebrate groups to human disturbance, with populations threatened by agricultural expansion, logging, pollution and invasive species.

“Many island reptiles evolved in the absence of mammalian predators, so they haven’t developed strong defensive behaviours,” added Professor Rocha. “This makes them easy targets for predators such as free-ranging cats, which are a leading cause of extinctions on islands. On Madeira Island, our research found that a single cat can eat more than 90 lizards in just one year - a striking example of how introduced predators can upset fragile island ecosystems.”

The researchers compared the volume of research published 1960-2021 between island and mainland reptiles and examined how factors such as species size, distribution, geography and socioeconomic context influence research focus. They found that larger and more widespread species receive most attention, while smaller, recently described and high-altitude island species remain largely unstudied.

“Many of the world’s most distinctive reptiles - those that evolved in isolation on islands - are the least known,” said PhD candidate Sara Nunes from the University of Porto. “This knowledge gap is especially concerning because these species often have small ranges and face intense human pressures.”

According to the study’s authors, reasons for the disparity may include the remoteness and inaccessibility of many islands, a global bias towards charismatic or medically significant reptiles, and a mismatch in research funding priorities. In wealthier island nations, investment may focus more on tourism infrastructure than biodiversity science.

To address this imbalance, the researchers propose a series of actions:

• Prioritise targeted research on island-dwelling reptiles - especially those at high risk of extinction and with little or no existing data;
• Foster equitable collaborations between national institutions and island communities to build local capacity;
• Incorporate knowledge from beyond academic literature to include reports from NGOs, government agencies and local institutions;
• Translate and integrate non-English language studies to capture a fuller picture of global reptile research.

Examples of the ecological and evolutionary importance of island reptiles abound - from the spectacular radiation of Anolis lizards in the Caribbean to the diversity of giant tortoises in the Galápagos. Madagascar alone, covering less than 0.4% of Earth’s land area, is home to over 450 reptile species - 3.8% of all known reptiles - and a quarter of all IUCN-listed threatened reptile species.

The Indo-Malayan region emerged as a critical hotspot of island reptile diversity, yet it remains one of the most poorly studied. The researchers identified several high-priority species, many of them endemic to a single island, for which no research has yet been conducted.

“As the biodiversity crisis deepens, understanding and protecting island reptiles has never been more urgent,” added Professor Rocha. “Focusing scientific and conservation efforts where they are most needed - e.g., on islands and their unique reptile species - is essential to prevent irreversible losses. Imagine visiting Komodo Island and not seeing its dragons. It just wouldn’t be the same, would it?”

The study also involved researchers from the University of Porto; Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) Berlin; Global Change and Sustainability Institute, Lisbon; Universidade de Lisboa; University of Helsinki.

Notes to editors

For media requests and interviews, contact Ricardo Rocha: ricardo.rocha@biology.ox.ac.uk

The study ‘Island-restricted reptiles are more threatened but less studied than their mainland counterparts’ will be published in Conservation Science and Practice at 00:01 GMT on Thursday 6 November 2025 at https://conbio.onlinelibrary.wiley.com/toc/25784854/0/0. To view a copy of the study before this under embargo, contact Ricardo Rocha: ricardo.rocha@biology.ox.ac.uk

Images related to this study that can be used to illustrate articles can be found here: https://drive.google.com/drive/folders/1RANAD5rL6dRqIGguMuwU1C9ErQMKPoH5?usp=sharing These are for editorial purposes relating to this press release ONLY and MUST be credited to Ricardo Rocha. They MUST NOT be sold on to third parties.

About the University of Oxford

Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the tenth year running, and ​number 3 in the QS World Rankings 2024. At the heart of this success are the twin-pillars of our ground-breaking research and innovation and our distinctive educational offer.

Oxford is world-famous for research and teaching excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research alongside our personalised approach to teaching sparks imaginative and inventive insights and solutions.

Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 300 new companies since 1988. Over a third of these companies have been created in the past five years. The university is a catalyst for prosperity in Oxfordshire and the United Kingdom, contributing around £16.9 billion to the UK economy in 2021/22, and supports more than 90,400 full time jobs.

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Journal

Conservation Science and Practice

DOI

10.1111/csp2.70184 

Article Title

Island-restricted reptiles are more threatened but less studied than their mainland counterparts

Sanzinia m. madagascariensis - restricted to Madagascar. 

Calumma oshaughnessyi - restricted to Madagascar. 



Tarentola boettgeri - restricted to the Selvagens and Canary Islands.


Uroplatus phantasticus, restricted to Madagascar.

 Photo by Ricardo Rocha.