Plants use a blend of external influences to evolve defense mechanisms

Findings reveal how plants use a blend of genes, geography, demography and environmental conditions to evolve defense chemicals over time

ELIFE

Research News

 

IMAGE: AN IMAGE OF ARABIDOPSIS THALIANA (A. THALIANA) -- A TYPE OF CRESS. view more 

CREDIT: PUBLIC DOMAIN

Plants evolve specialised defence chemicals through the combined effects of genes, geography, demography and environmental conditions, a study published today in eLife reports.

The findings reveal a pattern in the types of defence chemicals plants produce across Europe, and describe some of the evolutionary processes that create them.

As plants are immobile organisms, they rely on producing defence chemicals called specialised metabolites for survival. Specialised metabolites have extensive variation in their structure, such as the number of carbon molecules and the other chemical groups that attach to those carbon molecules. Each plant under each environment has a unique profile of specialised metabolites as a result of genetic variation that has developed over years by different evolutionary processes and events.

"We already know that environmental pressures such as the type of herbivores that prey on plants influences the specialised metabolites plants produce," explains first author Ella Katz, Postdoctoral Researcher at the Department of Plant Sciences, University of California, Davis, US. "We wanted to understand how the intersection of environmental pressure, demography and genomic complexity gives rise to the pattern of metabolic variation across a plant species."

To do this, the team measured the variation in specialised metabolites across a population of almost 800 seed samples of the plant species Arabidopsis thaliana (A. thaliana) - a type of cress - taken from across Europe.

They looked at three locations in the plant genome known to influence A. thaliana's survival fitness as well as across the entire genome to find genes linked to metabolite production. They then grouped each gene into classes representing types of specialised metabolite, called chemotypes. This allowed them to see which chemotypes were most prevalent in different regions of Europe and reveal specific geographic patterns. For example, in central Europe and parts of Northern Europe, such as Germany and Poland, there was large variability in the chemotypes. But in southern Europe, including the Iberian Peninsula, Italy and the Balkan, there were two predominant chemotypes that were clearly geographically separated.

Next, they looked at whether these geographical differences in chemotypes were linked to weather and landscape conditions. They assigned each gene an environmental value based on its location - such as distance to the coast, rainfall in the wettest and driest months, and temperature of the warmest and coldest months. They also assigned the genes to Northern or Southern locations, based on their position relative to the Pyrenees, Alps or Carpathian mountain ranges. Using the most commonly found chemotypes, they showed that the environmental conditions had different relationships to the chemotypes that shift by geographical area. This suggests that the relationship between environmental conditions and specialised metabolites varies across different regions in Europe - so, even if wetter weather was linked to a certain chemotype in Southern Europe, this was not the same in Northern Europe.

Finally, they looked at how these genes evolved over time. Gene traits can evolve either independently within a species, called convergent evolution, or by parallel evolution, where species respond to similar external challenges in a similar way. They found that gene evolution at the three most common genome locations was shaped by a blend of events reminiscent of either parallel or convergent evolution. Moreover, the presence of variation at each of the three locations also plays a role in further shaping the evolution of the other genes. This is most likely because the effects of different specialised metabolites may work with or against each other to help the plant survive.

"Our work provides a new perspective on the complexity of the forces and mechanisms that shape the generation and distribution of specialised metabolites and affect the plant's ability to survive in a changing environment," concludes senior author Daniel Kliebenstein, Professor at the Department of Plant Sciences, University of California, Davis, and the DynaMo Center of Excellence, University of Copenhagen, Denmark. "Using a larger plant population from other locations around the world will enable us to deepen our understanding of the evolutionary mechanisms that determine the variation in a population."

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About eLife

eLife is a non-profit organisation created by funders and led by researchers. Our mission is to accelerate discovery by operating a platform for research communication that encourages and recognises the most responsible behaviours. We aim to publish work of the highest standards and importance in all areas of biology and medicine, including Ecology and Plant Biology, while exploring creative new ways to improve how research is assessed and published. eLife receives financial support and strategic guidance from the Howard Hughes Medical Institute, the Knut and Alice Wallenberg Foundation, the Max Planck Society and Wellcome. Learn more at https://elifesciences.org/about.

To read the latest Ecology research published in eLife, visit https://elifesciences.org/subjects/ecology.

And for the latest in Plant Biology, see https://elifesciences.org/subjects/plant-biology.

 

How to improve energy efficiency of historically significant buildings

UNIVERSITY OF GOTHENBURG

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IMAGE: PHOTO OF VISBY, SWEDEN. view more 

CREDIT: PETRA ERIKSSON

How can historic buildings become more energy efficient while conserving their heritage values? A doctoral thesis provides the answer by presenting a new method for combining climate goals and heritage values in historic buildings stocks.

Renovate to improve energy efficiency of historic buildings - and at the same time preserve them for the future. It is not easy to balance careful administration of historic buildings with the need to make them more energy smart. A new thesis at the University of Gothenburg has taken up the challenge and shows the way towards improving energy efficiencies that does not damage the historic and cultural values. The goal is to make it easier to develop strategies for energy efficiency in large building stocks.

"Historic buildings are a significant part of our total building stocks," says Petra Eriksson, who has conducted her research in a collaboration between the University of Gothenburg and Uppsala University. "There are excellent opportunities for improved energy efficiency here. At the same time, we need to take into account the buildings' importance as part of our cultural heritage. If we are to achieve our climate and energy goals, we need a broad-based approach that addresses not only individual historic buildings, but entire building stocks."

The thesis presents a method that takes a holistic approach to the assessment of both potential energy savings and management of the buildings' specific conditions. The method includes categorised buildings representing a building stock and takes into account restrictions that limits which methods can be implemented if heritage values are to be preserved.

"By working according to this method, it becomes possible to visualise differences both within and between different parts of a building stock, which depends on the buildings' age, materials, construction and heritage values," says Eriksson.

She regards the method as an important decision support tool for decision makers, administrators and major property owners, enabling them to make more informed decisions about how to strike a balance between energy saving and conserving cultural values.

"I hope that future research will continue to support development in the area that leads to more standardised planning and decision support processes for stocks of buildings with cultural values," she says.

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About the research:
Title: "Balancing Building Conservation with Energy Conservation - Towards differentiated energy renovation strategies in historic building stocks"
Link: https://gupea.ub.gu.se/handle/2077/68356

The study objects in the thesis have been building stocks in Visby, Stockholm and Halland, Sweden.

The thesis will be presented on 16 June 2021 at the University of Gothenburg.

 WE ARE COLLECTIVISTS

Greater than the sum of our parts: The evolution of collective intelligence

UNIVERSITY OF CAMBRIDGE

Research News

 

The period preceding the emergence of behaviourally modern humans was characterised by dramatic climatic and environmental variability - it is these pressures, occurring over hundreds of thousands of years that shaped human evolution.

New research published today in the Cambridge Archaeological Journal proposes a new theory of human cognitive evolution entitled 'Complementary Cognition' which suggests that in adapting to dramatic environmental and climactic variabilities our ancestors evolved to specialise in different, but complementary, ways of thinking.

Lead author Dr Helen Taylor, Research Associate at the University of Strathclyde and Affiliated Scholar at the McDonald Institute for Archaeological Research, University of Cambridge, explained: "This system of complementary cognition functions in a way that is similar to evolution at the genetic level but instead of underlying physical adaptation, may underlay our species' immense ability to create behavioural, cultural and technological adaptations. It provides insights into the evolution of uniquely human adaptations like language suggesting that this evolved in concert with specialisation in human cognition."

The theory of complementary cognition proposes that our species cooperatively adapt and evolve culturally through a system of collective cognitive search alongside genetic search which enables phenotypic adaptation (Darwin's theory of evolution through natural selection can be interpreted as a 'search' process) and cognitive search which enables behavioural adaptation.

Dr Taylor continued, "Each of these search systems is essentially a way of adapting using a mixture of building on and exploiting past solutions and exploring to update them; as a consequence, we see evolution in those solutions over time. This is the first study to explore the notion that individual members of our species are neurocognitively specialised in complementary cognitive search strategies."

Complementary cognition could lie at the core of explaining the exceptional level of cultural adaptation in our species and provides an explanatory framework for the emergence of language. Language can be viewed as evolving both as a means of facilitating cooperative search and as an inheritance mechanism for sharing the more complex results of complementary cognitive search. Language is viewed as an integral part of the system of complementary cognition.

The theory of complementary cognition brings together observations from disparate disciplines, showing that they can be viewed as various faces of the same underlying phenomenon.

Dr Taylor continued: "For example, a form of cognition currently viewed as a disorder, dyslexia, is shown to be a neurocognitive specialisation whose nature in turn predicts that our species evolved in a highly variable environment. This concurs with the conclusions of many other disciplines including palaeoarchaeological evidence confirming that the crucible of our species' evolution was highly variable."

Nick Posford, CEO, British Dyslexia Association said, "As the leading charity for dyslexia, we welcome Dr Helen Taylor's ground-breaking research on the evolution of complementary cognition. Whilst our current education and work environments are often not designed to make the most of dyslexia-associated thinking, we hope this research provides a starting point for further exploration of the economic, cultural and social benefits the whole of society can gain from the unique abilities of people with dyslexia."

At the same time, this may also provide insights into understanding the kind of cumulative cultural evolution seen in our species. Specialisation in complementary search strategies and cooperatively adapting would have vastly increased the ability of human groups to produce adaptive knowledge, enabling us to continually adapt to highly variable conditions. But in periods of greater stability and abundance when adaptive knowledge did not become obsolete at such a rate, it would have instead accumulated, and as such Complementary Cognition may also be a key factor in explaining cumulative cultural evolution.

Complementary cognition has enabled us to adapt to different environments, and may be at the heart of our species' success, enabling us to adapt much faster and more effectively than any other highly complex organism. However, this may also be our species' greatest vulnerability.

Dr Taylor concluded: "The impact of human activity on the environment is the most pressing and stark example of this. The challenge of collaborating and cooperatively adapting at scale creates many difficulties and we may have unwittingly put in place a number of cultural systems and practices, particularly in education, which are undermining our ability to adapt. These self-imposed limitations disrupt our complementary cognitive search capability and may restrict our capacity to find and act upon innovative and creative solutions."

"Complementary cognition should be seen as a starting point in exploring a rich area of human evolution and as a valuable tool in helping to create an adaptive and sustainable society. Our species may owe our spectacular technological and cultural achievements to neurocognitive specialisation and cooperative cognitive search, but our adaptive success so far may belie the importance of attaining an equilibrium of approaches. If this system becomes maladjusted, it can quickly lead to equally spectacular failures to adapt - and to survive, it is critical that this system be explored and understood further."

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Inkjet printing show promise as new strategy for making e-textiles, study finds

NORTH CAROLINA STATE UNIVERSITY

Research News

 

In a new study, North Carolina State University researchers demonstrated they could print layers of electrically conductive ink on polyester fabric to make an e-textile that could be used in the design of future wearable devices.

Since the printing method can be completed at room temperature and in normal atmospheric conditions, researchers believe inkjet printing could offer a simpler and more effective method of manufacturing electronic textiles, also known as e-textiles. In addition, researchers said the findings suggest they could extend techniques common in the flexible electronic industry to textile manufacturing. They reported their findings in the journal ACS Applied Materials & Interfaces.

"Inkjet printing is a rapidly advancing new technology that's used in flexible electronics to make films used in cellphone displays and other devices," said the study's corresponding author Jesse S. Jur, professor of textile engineering, chemistry and science at NC State. "We think this printing method, which uses materials and processes that are common in both the electronics and textiles industries, also shows promise for making e-textiles for wearable devices."

In the study, researchers described how they used a FUJIFILM Dimatix inkjet printer to create a durable and flexible e-textile material, what they did to reliably create the e-textile, and its properties. Part of their challenge was to find the right composition of materials so the liquid ink would not seep through the porous surface of the textile materials and lose its ability to conduct electricity.

"Printing e-textiles has been a very big challenge for the e-textile industry," said the study's first author Inhwan Kim, a former graduate student at NC State. "We wanted to build a structure layer by layer, which has not been done on a textile layer with inkjet printing. It was a big struggle for us to find the right material composition."

They created the e-textile by printing layers of electrically conductive silver ink like a sandwich around layers of two liquid materials, which acted as insulators. They printed those sandwich layers on top of a woven polyester fabric. After they printed the layers of silver ink and insulating materials - made of urethane-acrylate, and poly(4-vinylphenol) - they monitored the surface of the material using a microscope. They found that the chemical properties of the insulating materials, as well as of the textile yarns, were important to maintaining the ability of the liquid silver ink to conduct electricity, and prevent it from penetrating through the porous fabric.

"We wanted a robust insulation layer in the middle, but we wanted to keep it as thin as possible to have the entire structure thin, and have the electric performance as high as possible," Kim said. "Also, if they are too bulky, people will not want to wear them."

The researchers evaluated the electrical performance of the e-textile after they bent the material multiple times. They tested more than 100 cycles of bending, finding the e-textile didn't lose its electrical performance. In future work, they want to improve the materials' electrical performance compared to e-textiles created using methods that require special facilities and atmospheric conditions, as well as increase the material's breathability.

Eventually, they want to use the printing method to create an e-textile that could be used in wearable electronics such as biomedical devices that could track heart rate, or used as a battery to store power for electronic devices.

"We were able to coat the ink on the fabric in a multi-layer material that's both durable and flexible," Kim said. "The beauty of this is, we did everything with an inkjet printer - we didn't use any lamination or other methodologies."

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The study, "Microstructures in All-Inkjet Printed Textile Capacitors with Bilayer Interfaces of Polymer Dielectrics and Metal-Organic Decomposition Silver Electrodes" was published online in ACS Applied Materials & Interfaces. In addition to Jur and Kim, the other authors were Beomjun Ju, Ying Zhou and Braden Li. It was funded by VF Corporation. The authors also acknowledge Liquid X Printed Metals for the preparation of the reactive silver inks used in this study. The authors acknowledge the U.S. Department of Defense and the Air Force Research Laboratory for provision of the Science Mathematics and Research for Transformation (SMART) scholarship to Li. This work was supported by the National Science Foundation through Nanosystems Engineering Research Center for Advanced Self Powered Systems for Integrated Sensors and Technologies under Grant EEC 1160483.

Note to editors: The abstract follows.

"Microstructures in All-Inkjet Printed Textile Capacitors with Bilayer Interfaces of Polymer Dielectrics and Metal-Organic Decomposition Silver Electrodes"

Authors: Inhwan Kim, Beomjun Ju, Ying Zhou, Braden M. Li and Jesse S. Jur

Published online May 14, 2021, in ACS Applies Materials & Interfaces.

DOI: 10.1021/acsami.1c01827.

Abstract: Soft printed electronics exhibit unique structures and flexibilities suited for a plethora of wearable applications. However, forming scalable, reliable multi-layer electronic devices with heterogeneous materials interfaces on soft substrates, especially on porous and anisotropic structures, is highly challenging. In this study, we demonstrate an all-inkjet printed textile capacitor using a multi-layer structure of bilayer polymer dielectrics and particle-free metalorganic decomposition (MOD) silver electrodes. Understanding the inherent porous/anisotropic microstructure of textiles and their surface energy relationship was an important process step for successful planarization. The MOD silver ink formed a foundational conductive layer through uniform encapsulation of individual fibers without blocking fiber interstices. Urethane-acrylate and poly(4-vinylphenol)-based bilayer were able to form a planarized dielectric layer on polyethylene terephthalate (PET) textiles. A unique chemical interaction at the interfaces of bilayer dielectrics performed a significant role in insulating porous textile substrates resulting in high chemical and mechanical durability. In this work, we demonstrate how textiles' unique microstructures and bilayer dielectric layer designs benefit reliability and scalability in the inkjet process as well as the use in wearable electronics with electromechanical performance.

USA

How political bias impacts believing sexual assault victims

SYRACUSE UNIVERSITY

Research News

 

New research from Syracuse University Newhouse School of Public Communications reveals a relationship between political biases and attitudes about sexual assault.

Authored by assistant professor Rebecca Ortiz and PhD student Andrea Smith, the article "A social identity threat perspective on why partisans may engage in greater victim blaming and sexual assault myth acceptance in the #MeToo era," was published in the peer-reviewed journal Violence Against Women.

Ortiz and Smith found that the stronger the partisan identity of Republicans and Democrats, the more likely they were to engage in victim blaming attitudes, which was then related to a lesser likelihood to perceive the #MeToo movement as having a positive impact in the United States, possibly as a way of defending their political identities in a time when many political leaders have been accused of sexual assault.

In this cross-sectional study, the researchers sent a survey to Democrats, Republicans and independents and asked them a series of questions related to how strongly they identify with their political party affiliation.

The next series of questions looked at their attitudes about sexual assault and violence against women. These questions explored how likely they were to agree with myths about sexual assault, such as believing that female victims are at least somewhat responsible. The researchers then broke down responses by political identity and gender.

"What we found is that the more Republicans and Democrats strongly identified with their party, the more likely they were to agree, or at least not strongly disagree, with these sexual assault myths and then the less likely they were to perceive the #MeToo movement as having a positive impact," said Ortiz. "As predicted, these sexual assault myth attitudes were significantly higher among Republicans than Democrats and among men than women. We also found that our participants aligned more closely by party than gender, such that Republican women more closely aligned with Republican men and Democratic men with Democratic women."

However, while the Democratic Party has championed the #MeToo movement and women's rights, the researchers' findings indicate that even strongly partisan Democrats may still be willing to, at least somewhat, question a victim's story or believe in sexual assault myths, perhaps especially when a Democratic politician is accused of harassment or assault.

This narrative has played out on both sides of the political spectrum. In 2016, former President Donald Trump was accused by several women of sexual misconduct and harassment. During the campaign, an infamous tape resurfaced of Trump making lewd remarks about women and bragging about sexually harassing women. He still won the election and enjoyed popular support from Republicans. Likewise, while many Democrats called out former President Trump for the numerous sexual assault allegations against him, some Democrats were far less willing to criticize President Biden when a similar accusation was made by a former staffer during the 2020 elections.

"It appears that both Democrats and Republicans have the potential to engage in victim blaming and acceptance of these harmful cultural myths about sexual assault survivors as a means of preserving and defending their political identities, perhaps especially when powerful members and leaders of their political group are accused of these crimes," said Ortiz.

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Ortiz currently has another manuscript under peer review where she experimentally tested how partisanship can lead Democrats and Republicans to perceive sexual assault allegations and the news sources reporting on these allegations in politically biased ways.

Ortiz conducts research at Syracuse University's Newhouse School with a focus in health communication, social marketing and entertainment and news media effects. She has managed and consulted on several health communication campaigns and research projects focused primarily on sexual health issues, such as sexual violence prevention.

The link to the abstract is here: https://journals.sagepub.com/doi/10.1177/10778012211014554

Hollywood stereotypes of female journalists feed a 'vicious cycle' of sexism

A researcher asks, who believes that female reporters have sex with their sources?

UNIVERSITY OF FLORIDA

Research News

 

When a fictional female journalist appears on screen, chances are she's about to sleep with one of her sources. It's a trope that infuriates actual women in news media -- and it can have real-life consequences, says University of Florida researcher Frank Waddell, Ph.D.

In shows like "House of Cards" and movies like "Thank You for Smoking," female reporters are quick to trade sex for information. Even when sex with sources has nothing to do with ambition -- such as the hookups in "Sharp Objects," "Top Five," "Trainwreck," and the "Gilmore Girls" reboot, to name a few -- it still portrays unethical behavior.

"In the past 20 to 30 years, Hollywood has really latched on to this. It's incredibly consistent," Waddell said.

At the same time, threats to female journalists have increased. A UNESCO study of 901 journalists from 125 countries shows that 73% experienced online harassment. And in a 2019 survey of women and gender non-conforming journalists in the United States and Canada, 70% experienced threats and 85% felt they had become less safe in past five years.

Waddell, an assistant professor in UF's College of Journalism and Communications, wanted to know who believes these sexist portrayals, as research shows we're most affected by media we perceive as realistic. In a study published in Journalism Studies, he was surprised to uncover no difference between men and women or liberals and conservatives, who tend to indicate lower levels of trust in mainstream media. Less surprising: People who already held sexist beliefs about women journalists found the portrayals believable. With repetition, Waddell explains, those views become more entrenched, creating a vicious cycle.

Understanding who falls for skewed portrayals of female journalists is the first step in finding solutions, he says.

"This is a very specific slice of the pie, but it's in the context of a larger conversation about declining trust in media overall," said Waddell, who is part of UF's multidisciplinary Consortium on Trust in Media and Technology.

In his original concept for the experiment, Waddell wanted to contrast reactions to sexist portrayals of women journalists in popular shows and movies with positive ones. He couldn't find any.

"I was actually struggling so badly to find positive examples that I couldn't do that part of the study," he said. ("Spotlight," the chronicle of the Boston Globe's reporting on child sex abuse in the Catholic church, is a rare exception, but Waddell was concerned that the subject matter could have skewed the data.)

Because most people have few, if any, first-hand encounters with reporters, Hollywood can have an outsized influence. Ways to counter that could include increased contact between regular folks and journalists, whether it's through town hall events, expanded social media interaction, or creative approaches to demystifying what goes on inside a newsroom, Waddell said.

"I'm also hoping that Hollywood can do a better job finding ways to dramatize the practice of journalism," he said. "People are treating women in the newsroom differently because they fail to recognize what they're seeing has nothing to do with real life."

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That song is stuck in your head, but it's helping you to remember

UC Davis research suggests 'earworms' help to preserve memory for music, life events

UNIVERSITY OF CALIFORNIA - DAVIS

Research News

 

"So, no one told you life was going to be this way.
Your job's a joke, you're broke, you're love life's DOA.
It's like you're always stuck in second gear,
When it hasn't been your day, your week, your month, or even your year..."

If you have watched TV since the 1990s, the sitcom theme song, "I'll Be There for You," has likely been stuck in your head at one point or another. New research from UC Davis suggests these experiences are more than a passing nuisance -- they play an important role in helping memories form, not only for the song, but also related life events like hanging out with friends -- or watching other people hang with their friends on the '90s television show, Friends.

"Scientists have known for some time that music evokes autobiographical memories, and that those are among the emotional experiences with music that people cherish most," said Petr Janata, UC Davis professor of psychology and co-author on a new study.

"What hasn't been understood to date is how those memories form in the first place and how they become so durable, such that just hearing a bit of a song can trigger vivid remembering," said Janata.

The paper, "Spontaneous Mental Replay of Music Improves Memory for Incidentally Associated Event Knowledge," was published online in the Journal of Experimental Psychology: General. Co-authors are Janata and Benjamin Kubit, a postdoctoral researcher in cognitive neuroscience, both of the UC Davis Department of Psychology, and Center for Mind and Brain.

This new research offers an initial glimpse into these mechanisms and, somewhat surprisingly, finds that the songs that get stuck in your head help that process of strengthening memories as they first form, the authors said. Thus, this is the first research to link two of the most common phenomena people experience with music -- earworms (having a song stuck in your head) and music-evoked remembering.

For their latest study, the researchers worked with 25 to 31 different people in each of three experiments, over three different days, spaced weeks apart. Subjects first listened to unfamiliar music, and then, a week later, listened to the music again, this time paired with likewise unfamiliar movie clips. In one instance, movies were played without music. The research subjects, all UC Davis undergraduate and graduate students, were subsequently asked to remember as many details as they could from each movie as the music played. They were also quizzed about their recollection of the associated tunes and how often they experienced each of the tunes as an earworm. None of them had formal music training.

The more the tune played, the more accurate the memory

The results: the more often a tune played in a person's head, the more accurate the memory for the tune became and, critically, the more details the person remembered from the specific section of the movie with which the tune was paired.

With only one week between when they saw the movie, and when they were asked to remember as many details from the movie as they could while listening to the movie soundtrack, the effect of repeatedly experiencing a tune from the soundtrack as an earworm resulted in near-perfect retention of the movie details. These people's memories, in fact, were as good as when they had first seen the movie. Additionally, most subjects were able to report what they were typically doing when their earworms occurred, and none of them mentioned the associated movies coming to mind at those times.

"Our paper shows that even if you are playing that song in your mind and not pulling up details of memories explicitly, that is still going to help solidify those memories," Janata said.

"We typically think of earworms as random nuisance beyond our control, but our results show that earworms are a naturally occurring memory process that helps preserve recent experiences in long-term memory," Kubit said.

Future help for memory loss?

The authors said they hope the research, which is ongoing, could eventually lead to the development of nonpharmaceutical, music-based interventions to help people suffering from dementia and other neurological disorders to better remember events, people and daily tasks.

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Air pollution exposure during pregnancy may boost babies' obesity risk

UNIVERSITY OF COLORADO AT BOULDER

Research News

 

Women exposed to higher levels of air pollution during pregnancy have babies who grow unusually fast in the first months after birth, putting on excess fat that puts them at risk of obesity and related diseases later in life, new CU Boulder research shows.

The study of Hispanic mother-child pairs, published this week in the journal Environmental Health, is the latest to suggest that poor air quality may contribute at least in part to the nation's obesity epidemic, particularly among minority populations who tend to live in places with more exposure to toxic pollutants.

About one in four Hispanic youth in the United States are obese, compared to about 14% of white youth and 11% of Asian youth.

"Higher rates of obesity among certain groups in our society are not simply a byproduct of personal choices like exercise and calories in, calories out. It's more complicated than that," said senior author Tanya Alderete, an assistant professor in the Department of Integrative Physiology. "This study and others suggest it can also relate to how much of an environmental burden one carries."

Previous research has shown pregnant women who smoke or are chronically exposed to air pollution tend to have smaller birthweight babies. In the first year of life, those babies tend to race to catch up, gaining weight unusually fast. Accelerated weight gain in early life has been linked to diabetes, heart disease and weight problems in childhood and adolescence.

"This period, either during pregnancy or shortly after birth, is a critical window of development and adverse exposures can program the infant to have a host of problems later in life," said lead author William Patterson, a doctoral student.

To more closely examine how specific pollutants impact a baby's growth trajectory, the researchers followed 123 mother-infant pairs from the Mother's Milk Study, an ongoing trial in the Los Angeles region. About one-third were of normal weight pre-pregnancy, one-third overweight and one-third obese.

The researchers used data from the U.S. Environmental Protection Agency's Air Quality System, which records hourly air quality data from ambient monitoring stations, to quantify their prenatal exposure to four classes of pollutants: PM2.5 and PM10 (inhalable particles from factories, cars and construction sites), nitrogen dioxide (an odorless gas emitted from cars and power plants) and ozone (the main ingredient in smog).

Then they followed the babies, periodically measuring not only their weight and height, but also how much fat they carried and where.

"We found that greater exposure to prenatal ambient air pollution was associated with greater changes in weight and adiposity, or body fatness, in the first six months of life," said Patterson.

In some cases, pollutants seemed to impact males and females differently.

For instance, exposure to a combination of ozone and nitrogen dioxide in utero was associated with faster growth around the waist in females, while in males it was associated with slower growth in length and greater fat accumulation around the midsection.

In adults, excess fat around the midsection has been linked to heart disease and diabetes.

"It's not just how much fat you carry but where--that matters," said Patterson.

How can inhaling pollutants impact growth patterns of a mother's unborn child?

Researchers believe those pollutants can inflame the lungs and, in turn, cause systemic inflammation of organs, impacting metabolic processes, such as insulin sensitivity, that can influence fetal development. Pollutants have also been shown to impact gene expression in infants, potentially having life-long impacts that could transcend generations.

The authors note that the study includes a relatively small sample size. And because the study included only Hispanic mothers, a larger trial is necessary to confirm results apply to other populations.

But Alderete said that in an increasingly diverse country, where racial minorities have been shown repeatedly to shoulder a higher burden of pollutions, it's important to study how those toxins are influencing them.

In 2018, the EPA's National Center for Environmental Assessment published a study showing that poor people and people of color are exposed to as much as 1.5 times more airborne pollutants than their white counterparts.

"Generally speaking, there have not been very many studies that really represent the diversity we have in the United States," she said. "We want to fill that gap."

Meantime, the researchers recommend pregnant women take extra precautions to minimize their exposure to air pollution by closing windows on high ozone days, not exercising outdoors at times of high air pollution and steering clear of activities alongside busy roadways.

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Fungal spores from 250-year-old collections given new lease of life

UNIVERSITY OF COPENHAGEN - FACULTY OF SCIENCE

Research News

 

Echoing through history by reviving fungal specimens originally preserved and described a flabbergasting quarter of a millenium ago by the "Father of Modern Taxonomy" Carl Linnaeus, this study highlights the untapped potential of museum collections in modern research programmes. The results have just been published in the renowned Cell Press journal iScience.

The "desert coprinus" fungus Podaxis has fascinated scientists and explorers for centuries, still the genus has been subjected to relatively little research. These large mushrooms thrive in hostile and mostly species-free environments and while they occur seasonally and unpredictably in deserts and on termite mounds, researchers are faced with a problem common to many biologists: Where do we find it? The researchers from the Department of Biology turned to an unconventional sampling location: Museum collections. By requesting fungal spores from various collections, including the Linnaean Society of London and the Natural History Museum of Denmark, they were able to collect more than 200 specimens from every continent aside from Antarctica. The specimens varied in age from 2 to 250 years old.

Specimen from the South African National Collection of Fungi in Pretoria. Photo: Benjamin Schantz-Conlon

Given the finding that fungal spores can grow after 2-5 years in a museum, the limit for their revival was tested. Eventually the researchers succeeded in germinating and growing two Podaxis specimens collected in the 1770s and classified by Linnaeus in Uppsala. These results reveal an extraordinary capacity for Podaxis spores to remain viable through extended periods of drought and suggests that they can remain dormant in the environment for centuries before germinating once conditions allow.

- "It was really incredible to have these fungi growing in our lab, which we knew had been handled by a scientist as important as Linnaeus, who founded the system of naming species. It allowed us to perform experiments and produce genomes of a quality that would have been impossible with dried specimens," explains postdoc and first author Benjamin Schantz-Conlon of the Department of Biology, University of Copenhagen. Benjamin Schantz-Conlon continues: "It was very interesting to examine the adaptations allowing Podaxis to survive under extreme conditions, hereunder also in herbarium collections where the samples traditionally has been treated with mercury as a pesticide".

The researchers used the specimens to ask whether free-living Podaxis species growing in deserts were genomically and physiologically different from species growing on termite mounds. The results indicated that the association with termites gave rise to smaller genome sizes and a reduced tolerance to stressful conditions.

- "These findings suggest that Podaxis living in association with termites are experiencing a relaxed selection pressure and a potential protection from competition and exposure to stressors in the environment", says corresponding author Michael Poulsen, professor at the Department of Biology.

Podaxis growing on a termite mound. Photo: Z. Wilhelm de Beer Previous research has shown there is an overlap between tolerance to extreme conditions such as deserts and pathogenicity. By comparing the transition from a free-living state in a desert to a symbiotic state within a termite mound, the researchers hoped to learn more about the evolution of fungi that shift to associate with hosts, including pathogens.

- "While Podaxis living in an obligate association with termites exhibited relaxed selection, we also found some Podaxis which could survive both on termite mounds and free-living in deserts. In this case, we saw little genomic or physiological difference between them and the fully free-living Podaxis, suggesting the adaptations for life in the desert may facilitate the initial colonization of termite mounds; something which is also seen in opportunistic pathogens."

An immense resource of knowledge is stored in museum collections and we should work to ensure that these specimens can be used to answer important questions in science in the future.

Untapped rice varieties could sustain crop supplies in face of climate change

EARLHAM INSTITUTE

 NEWS RELEASE 15-JUN-2021

Research News

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IMAGE: WORKING ALONGSIDE INTERNATIONAL COLLABORATORS, THE EARLHAM INSTITUTE'S RICE GENOMICS PROJECT IN VIETNAM IDENTIFIES NEW VARIETIES TO HELP BREED CLIMATE-RESILIENT RICE CROPS. view more 

CREDIT: MEKONG DELTA, VIETNAM, MARCH 2014. CREDIT: GEORGINA SMITH, CIAT

Local rice varieties in Vietnam could be used to help breed improved crops with higher resilience to climate change, according to a new study published in Rice.

Earlham Institute researchers are part of an international collaboration with genebanks and rice breeders in Vietnam - championed by the International Rice Research Institute (IRRI) to help abolish world poverty and hunger - are aiming to identify varieties that can survive an increasingly unpredictable climate.

The new genomic data they have generated will significantly support efforts to breed resilient rice crops for optimum global production.

The unparalleled geography and history of Vietnam, together with its diverse range of ecosystems and latitudinal range, means it has been blessed with a vast diversity of rice landraces.

Rice production in Vietnam is of enormous value, both as an export commodity and a daily food staple for the more than 96 million people who live there. An important part of diets worldwide, rice is a healthy, versatile and cheap carbohydrate.

However, climate change is threatening its wide availability, with the country's unique geography and environments putting Vietnam at particular risk.

Critically, it is the world's poorest that are most dependent on this crop, who are also under the most threat from climate change - amplified by the COVID-19 pandemic disrupting food and nutrition security for billions of people.

Green super rice

To fully understand the uniqueness and potential of this native crop diversity, the research team analysed 672 Vietnamese rice genomes; 616 were newly sequenced, which encompass the range of rice varieties grown in the diverse ecosystems found throughout Vietnam.

The team of scientists discovered a previously overlooked 'I5 Indica' large rice subpopulation in some regions of Vietnam, which had not been used before to produce the more common elite rice varieties resulting from previous rice improvement studies.

These locally adapted rice varieties provide a potential source of novel genes that carry important agronomic traits, which can potentially be leveraged by future rice breeding programmes.

This will help with a new generation of 'Green Super Rice', designed to lower production input while enhancing nutritional content and suitability for growing on marginal lands - resulting in a sustainable and resilient rice to better withstand extreme weather conditions.

First author Dr Janet Higgins at the Earlham Institute, said: "Vietnam has a rich history in rice breeding, especially at the local level. The adaptation to multiple environmental conditions and regional preferences has created a wide range of varieties.

"Studies like this suggest that this diversity constitutes a largely untapped and highly valuable genetic resource for local and international breeding programmes."

To understand how rice diversity within Vietnam relates to worldwide varieties, the team analysed nine landrace subpopulations that were likely adapted to the demands in the different regions of origin.

They then compared this new data to the previous global study on rice diversity in Asia, consisting of fifteen worldwide Asian subpopulations (from 89 countries) in the publicly available '3000 Rice Genomes Project'. From this, the Earlham Institute researchers discovered how the new rice varieties native to Vietnam were related to the global Asian data set - leading to the I5 Indica subpopulation finding.

Sustainable rice breeding

This genetic diversity is a highly valuable resource when the highest rice production areas in the low-lying Mekong and Red River Deltas are enduring increasing threats from climate changes - unpredictable weather patterns, increasing sea levels causing overflow of saltwater, and consequential drought in the upland areas.

Dr Higgins, explains: "Improved varieties, which are high yielding but can also be grown sustainably, are needed to ensure we can continue to meet the worldwide demand for rice. Salt and drought tolerance are related critical traits which need to be addressed in order to secure future rice production.

"This requires agronomic, smart crop management practices and genomic solutions to stop the vicious cycle of rice contributing to global warming due to greenhouse gas emissions from crop fields, and areas of production being threatened by climate change.

"We are now analysing the Indica I5 subpopulation in further detail. We hope to try and detect regions of the genome which have been selected in the Indica I5 subpopulation and relate these to traits of interest for sustainable rice crops.

"It would be fantastic if the IRRI were in a position to incorporate some of the Indica I5 varieties from Vietnam we describe in our study in their future breeding programmes. We believe this new data will massively help optimise sustainable rice production for global demand while protecting our planet."

The paper 'Resequencing of 672 Native Rice Accessions to Explore Genetic Diversity and Trait Associations in Vietnam' is published in the journal Rice.

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