Study shows how plant roots access deeper soils in search of water

Scientists have discovered how plants adapt their root systems in drought conditions to grow steeper into the soil to access deeper water reserves.

Plant scientists from the University of Nottingham, in collaboration with Shanghai Jiao Tong University, have identified how abscisic acid (ABA), a plant hormone known for its role in drought response, influences root growth angles in cereal crops such as rice and maize. The results have been published in Current Biology.

The study highlights how ABA and auxin, another key hormone, work together to shape root growth angle, providing a potential strategy to develop drought-resistant crops with improved root system architecture.

Drought poses a major threat to global food security, and enhancing the ability of crops to withstand water shortages is crucial. Drought, a major abiotic stressor, has caused substantial crop production losses of approximately $30 billion over the past decade. With a projected population of 10 billion by 2050 and serious freshwater depletion, developing drought-resistant crops is of paramount importance

Plants rely on their root systems, the primary organs for interacting with soil, to actively seek water. In drought conditions, water often depletes in the topsoil and remains accessible only in the deeper subsoil layers. Abscisic acid (ABA) plays an important role in helping plants adapt to these challenging conditions. This new study gives new insights into how ABA changes root growth angles to enable plants to reach out deeper subsoils in search of water.

The researchers discovered a new mechanism where ABA promotes the production of auxin, which enhances root gravitropism to grow them at steeper angles in response to drought. Experiments showed that plants with genetic mutations that block ABA production had shallower root angles and weaker root bending response to gravity compared to normal plants. These defects were linked to lower auxin levels in their roots. By adding auxin externally, the researchers restored normal root growth in these mutants, showing that auxin is key to this process.

The findings were consistent across both rice and maize, suggesting that this mechanism could apply to other cereal crops as well.

Dr Rahul Bhosal, Assistant Professor from the School of Bioscience is one of the lead authors on the study, he said: “Finding ways to tackle food insecurity is vital and the more we understand the mechanisms that control plant growth, the closer we are to designing systems to help plants to do this and improve crop yields during droughts.”

Share Button

Dementia with Lewy bodies has been difficult to diagnose early, but comprehensive cognitive testing could change that

Cognitive profiles for early diagnosis of Dementia with Lewy bodies (DLB) have been outlined in a new study, out today in Alzheimer’s & Dementia. Although DLB is the second most common neurodegenerative dementia following Alzheimer’s Disease, it is usually misdiagnosed, preventing affected people from accessing care better tailored to their prognosis.

“Criteria for better identifying DLB exists in research settings, but we wanted to pull research studies together to establish something applicable for clinical settings,” says Ece Bayram, MD, PhD, assistant professor of neurology at the University of Colorado Anschutz Medical Campus and study lead author. “By pooling information from available publications, we were able to establish a cognitive profile that can differentiate DLB from Alzheimer’s before the dementia stage hits, which could better help inform the direction of care for people with these diseases.”

Researchers were able to identify consistencies in cognitive symptoms among people with DLB compared to people with Alzheimer’s in a meta-analysis of pre-dementia stage diagnoses. At the pre-dementia stage, people with DLB demonstrated more diminished attention, processing speed and executive function as well as better immediate recall and memory compared to people with Alzheimer’s.

“Identifying cognitive profiles gave us the outcome necessary to suggest guidelines that practitioners could easily be trained in to better tailor plans of care,” says Bayram. “Furthermore, providing framework for clinical assessment versus biomarker testing means more accessibility for practitioners. It is easier and cheaper to train in providing cognitive assessments than administering imaging or invasive biomarker tests,” says Bayram.

Researchers say identifying the form of dementia early can guide future planning for both the person with dementia and their care partners, and ease disease by providing proper symptomatic treatment. People with DLB, for instance, are reactive to certain types of commonly prescribed medications for psychosis, such as haloperidol, that tend to worsen their condition. Dr. Bayram says, overall, this study provides a promising step in advancing dementia prevention and care.

“We are seeing more and more treatment trials that are focused on disease modification for both Alzheimer’s and Lewy body diseases. Having validated clinical criteria to diagnose DLB before dementia hits means we can prevent it from happening instead of reacting to it after significant loss in the brain has occurred. These types of clinical assessments provide opportunities for everyone to receive care even without access to a specialty center.”

Share Button

A battle of rafts: How molecular dynamics in CAR T cells explain their cancer-killing behavior

A study published in Science Advances shares new insights into how two of the most common types of chimeric antigen receptor (CAR) T cells kill cancer. Investigators from Baylor College of Medicine, Texas Children’s Cancer Center and the Center for Cell and Gene Therapy at Baylor, Houston Methodist Hospital and Texas Children’s Hospital examined how molecular dynamics at the immune synapse — where CAR T cells bind to cancer cells — affect anticancer activity.

In this study, researchers aimed to understand how CAR T cells with different signaling domains work at the molecular and cellular levels to lay the foundation for designing CAR molecules that maximize antitumor activity beyond B cell malignancies.

“We looked at two different types of CAR T cells. The first, CD28.ζ-CART cells, are like sprinters. They kill cancer cells quickly and efficiently, but their activity is short-lived. The second, 4-1BB.ζ-CART cells, are like marathon runners. They kill cancer cells consistently over a long period,” said senior author Dr. Nabil Ahmed, professor of pediatrics — hematology and oncology at Baylor and Texas Children’s. “We need to understand what’s happening at the molecular level so we can engineer CAR T cells to adapt their killing behavior to target hard-to-treat malignancies, such as solid tumors.” Ahmed also is a member of the Center for Cell and Gene Therapy and the Dan L Duncan Comprehensive Cancer Center.

Led by first author Dr. Ahmed Gad, postdoctoral associate in Ahmed’s lab, the research team examined molecular dynamics at the immune synapse. The team biopsied the CAR T cell immunological synapse by isolating the membrane lipid rafts — cholesterol-rich molecules on the cell surface where most molecular interactions between cells take place.

They found that CD28.ζ-CAR molecules shuttle through the immune synapse quickly, working within minutes to kill cancer cells. This enabled fast CAR T cell recovery and a mastery of “serial killing” of cancer cells. In contrast, researchers found that 4-1BB.ζ-CAR molecules linger in the lipid rafts and immune synapse. The 4-1BB.ζ-CAR T cells multiply and work together, resulting in sustained “collaborative” killing of tumor cells.

“Observing the distinct pattern of dynamics between single molecules helps us understand the big picture of how these products work,” Gad said. “Next, we are studying how to dynamically adapt these CAR T cells at the synapse level to make them more effective.”

“Tumors are very sophisticated. We need to adapt our tools to the biology of the disease. This may involve using multiple tools that work in different ways at different stages,” Ahmed added.

Other authors who contributed to this work include Jessica S. Morris, Lea Godret-Miertschin, Melisa J. Montalvo, Sybrina S. Kerr, Harrison Berger, Jessica C.H. Lee, Amr M. Saadeldin, Mohammad Abu-Arja, Shuo Xu, Spyridoula Vasileiou, Rebecca M. Brock, Kristen Fousek, Mohamed F. Sheha, Madhuwanti Srinivasan, Yongshuai Li, Arash Saeedi, Kandice Levental, Ann M. Leen, Maksim Mamonkin, Alexandre Carisey, Navin Varadarajan, Meenakshi Hegde, Sujith K. Joseph, Ilya Levental and Malini Mukherjee. They are affiliated with one or more of the following institutions: Baylor College of Medicine, Texas Children’s Hospital, Center for Cell and Gene Therapy, the Dan L Duncan Comprehensive Cancer Center, the University of Houston, and the University of Virginia.

This work was supported by the National Institutes of Health U54 Moonshot Grant, the National Cancer Institute, the Cancer Prevention and Research Institute of Texas, the Be Brooks Brave Fund St. Baldrick’s Foundation Fellowship, Stand Up To Cancer, the St. Baldrick’s Pediatric Cancer Dream Team Translational Research Grant, Triumph Over Kids Cancer Foundation, the Alex Moll Family Fund, and The Faris Foundation.

Share Button

‘What is that?’ Scientists explain white patch that appears near northern lights

A whitish, grey patch that sometimes appears in the night sky alongside the northern lights has been explained for the first time by researchers at the University of Calgary.

The article, which was published on Dec. 30 in the journal Nature Communications, explores a “structured continuum emission” that’s associated with aurora borealis.

“You’d see this dynamic green aurora, you’d see some of the red aurora in the background and, all of a sudden, you’d see this structured — almost like a patch — grey-toned or white toned-emission connected to the aurora,” says Dr. Emma Spanswick, PhD, lead author on the paper and an associate professor with the Department of Physics and Astronomy in the Faculty of Science.

“So, the first response of any scientist is, ‘Well, what is that?'”

Spanswick says the white patch has been referenced in scientific papers before, but it has never been explained.

Her team’s paper concludes it’s “most certainly a heat source” and says it suggests that the aurora borealis are more complex than previously thought.

Spanswick says the discovery was made possible because an advancement in camera technology allows both amateur photographers and scientists to see true colour images of the night sky.

“Everyone has noticed the advancement in digital photography. Your cellphone can now take pictures of the aurora,” she says. “That has flowed to the commercial sensor market now.

“Those types of sensors can now be found in more commercial, more robust sensors that we would use in science.”

The team’s research came after there was a renewed interest in continuum emission with the discovery and observations of the long, glowing ribbon of purple light known as STEVE — or Strong Thermal Emission Velocity Enhancement.

“There are similarities between what we’re seeing now and STEVE,” explains Spanswick. “STEVE manifests itself as this mauve or grey-toned structure.

“To be honest, the elevation of the spectrum between the two is very similar but this, because of its association with dynamic aurora, it’s almost embedded in the aurora. It’s harder to pick out if you were to look at it, whereas STEVE is separate from the aurora — a big band crossing the sky.”

The latest research is also significant because it includes three UCalgary students, including undergraduate Josh Houghton who was initially hired as an intern on the project.

“I was still learning things at the time,” he says. “I had just started my internship, and I very quickly got involved. It’s just very, very cool.”

Spanswick says Houghton did a lot of the analysis on the research, which led to his participation in the Nature paper as an undergraduate student.

“He’s had one heck of an internship experience,” she says.

Houghton will continue the research as part of his undergrad honours thesis, before taking on his master’s degree at UCalgary next year.

The research was made possible by the Transition Region Explorer (TREx), which is a UCalgary project jointly funded by the Canadian Foundation for Innovation, the Government of Alberta and the Canadian Space Agency.

The TREx RGB and Spectograph instruments are operated and maintained by Space Environment Canada with the support of the Canadian Space Agency through its Geospace Observatory (GO) Canada initiative.

Share Button

New insights into acoustic bubbles give boost to future applications

Active bubbles hold potential in fields ranging from water purification to medicine. Researchers can generate microbubbles by exposing liquids to high-intensity ultrasonic waves, a process known as sonication, and these energy waves heat up and pressurize the bubbles. For example, when bubbles in water are adiabatically collapsed by ultrasonic waves, the temperature inside the bubbles reaches more than several thousand degrees and the pressure several hundred atmospheres.

These bubbles are called active bubbles or acoustic bubbles. Osaka Metropolitan University researchers have now found key indicators to assess the chemical activity and temperature of these microbubbles.

The group led by Professor Kenji Okitsu of the Graduate School of Sustainable System Sciences showed that, when water is undergoing sonication, the amount of hydrogen is a more important indicator of the chemical activity of acoustic bubbles than hydrogen peroxide during thermal decomposition of the water.

The team also conducted experiments using an aqueous t-butanol (tertiary alcohol) solution to investigate the temperature and number of active bubbles generated when exposed to ultrasonic waves. As the temperature of the solution and the concentration of inorganic salts increased, the temperature of the active bubbles became lower and the number of active bubbles produced decreased.

“Our research provides new insights into the relationship between bubble temperature and chemical activity,” Professor Okitsu exclaimed. “As the characteristics of active bubbles become clearer, more precise control of chemical reactions will become possible. We expect further applications and progress in water purification technology and nanotechnology, such as the decomposition of persistent organic pollutants and the synthesis of highly functional, high value-added nanomaterials.”

The findings were published in Ultrasonics Sonochemistry.

Share Button

I woke from a coma to find my baby had been born

Atlanta McIntyre hopes to raise awareness of hyperemesis gravidarum, a condition that affects 1 in 100 pregnant women.

Share Button

‘I paid fake doctor thousands for fillers – now I look like a gargoyle’

Cosmetics clinic says it has “totally reviewed all procedures” since treating Andrea.

Share Button

Inside the UK’s first legal drug consumption room

The Thistle will open its doors next week after nearly a decade of deadlock over drug laws.

Share Button

Researchers find betrayal doesn’t necessarily make someone less trustworthy if we benefit

Imagine this scenario: Two people cheat on their partners with each other and then leave their partners to be together. Should they trust each other, or “once a cheater, always a cheater”?

Intuition and past research suggest that whether people deem someone trustworthy depends on that person’s past behavior and reputation for betrayal. But now, new work from psychologists at UCLA and Oklahoma State University is helping to explain why people might nevertheless trust certain cheaters and other betrayers.

When we benefit from someone’s betrayal, we tend to still regard that person as inherently trustworthy, the psychologists reported in a study published in Evolution and Human Behavior. Their experiments found that, although subjects tended to regard people who betrayed others as generally less trustworthy, when a person’s betrayal benefited the subject, that person was still thought to be worthy of trust.

At question is the role concepts like “trustworthiness” play in our relationships. According to the research team, inferences about someone’s trustworthiness are used for making adaptive choices — that is, choices that benefit us. So, while people might be attuned to whether someone has betrayed others in the past, the researchers predicted that people would also be attuned to certain relationship-based factors that impact how that person is viewed/trusted.

“Making decisions about whom to trust based only on whether that person has betrayed someone else might not be the best way to determine whether or not I can trust someone,” said study co-author and UCLA professor of psychology Jaimie Krems.

“Sure, if someone betrays other people, that could be a valuable cue that they might betray me — but not always. For example, think about that friend who always tells you other friends’ secrets but doesn’t share yours. This friend is betraying other people but enriching you with information,” Krems added.

This was the researchers’ main contention: The mind should be attuned to whether someone has a reputation for betrayal, yes, but also to how someone’s betrayal affects you.

The researchers designed experiments to test whether people deemed targets more trustworthy when the targets avoided betrayal — but also when the betrayal had different impacts on the subject.

In one series of experiments, participants were randomly assigned to read one of three vignettes describing their interaction with a target. The first experiment involved sharing secrets among friends, while the second involved romantic infidelity. The third described an interaction in the context of international relations, with participants acting as CIA agents attempting to cultivate a French official as a source.

The targets exhibited one of three behaviors: they did not betray anyone when they had the opportunity; they betrayed another person to the participant or betrayed the participant to someone else. For example, some targets did not share a secret, others shared a secret about someone else with the participant, and still others shared the participant’s secret with a third party. After reading the vignettes, participants rated the target’s trustworthiness on a 7-point scale with questions such as, “I would trust the target to keep my secrets.”

As intuition would predict, across all types of relationships, participants regarded targets as more trustworthy if they did not betray anyone and less trustworthy if they did. But people who betrayed were not all deemed equally untrustworthy. When betrayal benefited the participants, they still considered the target trustworthy. This pattern was largely consistent across friendships, romantic relationships and professional relationships.

The findings upheld the researchers’ hypothesis that judgments of trustworthiness are partly a reflection of the person’s disposition and idiosyncratic factors specific to the participant and the person at hand.

The findings show that while people might start with lofty ideals when it comes to trusting people, what they do in practice is often based more on self-interest.

The research was funded by the National Science Foundation.

Key takeaways

  • Both intuition and past research suggest that whether people deem someone trustworthy depends on that person’s past behavior and reputation for betrayal.
  • In a series of experiments, psychologists found that subjects regarded those who previously exhibited that behavior as less trustworthy. However, when the betrayal benefited them or had no effect on them, participants regarded the betrayer as trustworthy.
  • This pattern was largely consistent across the types of relationships studied: friendships, romantic relationships and professional relationships.
Share Button

Rapid return of water from ground to atmosphere through plants

A new study led by scientists in the Schmid College of Science and Technology at Chapman University provides the first comprehensive global estimates of the amount of water stored in Earth’s plants and the amount of time it takes for that water to flow through them. The information is a missing piece of the puzzle in understanding the global water cycle and how that cycle is being altered by changes in land use and climate.

The study, published today, January 9, in the journal Nature Water, finds that Earth’s vegetation stores about 786 km3 of water, only about 0.002% of the total amount of freshwater stored on Earth. The study also finds that the time it takes for water to flow through plants (referred to as transit or turnover time) and return to the atmosphere is among the fastest in the global water cycle, ranging from just five days in croplands to 18 days in evergreen needleleaf forests. The transit of water through plants is particularly fast in croplands, grasslands and savannas. The results underscore vegetation’s dynamic role in the water cycle. In comparison to the global annual median of 8.1 days for water to transit through plants from entry to exit, the water in lakes is estimated to take 17 years, and the water in glaciers is estimated to take 1600 years.

“We have known for a long time that most of the water that returns from the ground to the atmosphere does so through plants, but until now, we did not really know how long it took for that water to transit through plants. Our results show that the transit of water through plants occurs on the order of days, rather than months, years, or centuries, as it does in other parts of the water cycle,” said the study’s lead author Dr. Andrew Felton, who carried out the work as part of a U.S. Department of Agriculture Fellowship while at Chapman University and is now a professor at Montana State University.

The research team notes that by combining estimates of the transit of water through plants with the transit of water through the atmosphere (about 8-10 days) and the transit time of water through soil before being taken up by plants (about 60 to 90 days), they can begin to estimate the complete amount of time it takes for a drop of water to move through the terrestrial water cycle.

“Plants are the forgotten part of the global water cycle,” said Felton. “In many cases, plants are not even represented on water cycle diagrams, which is ironic because we already know they play this critical role in returning water from the ground to the atmosphere.”

To generate the estimates, the research team first calculated the amount of water stored in plants using data from NASA’s Soil Moisture Active Passive Mission (SMAP) satellite mission, which provided high-resolution estimates of the water in soils. The SMAP mission originally saw plants as interfering with the soil moisture measurements, and was correcting for their presence. The Chapman researchers found those corrections actually held valuable information for understanding the water cycle. The team combined estimates of plant water storage with cutting-edge estimates of the rates at which water is leaving plants to determine the transit time of water through vegetation. The result was five years of monthly water storage and transit time estimates at a spatial resolution of 9 km2.

The research team also found that the transit time of water through vegetation varied considerably across different land cover types, climate and seasons. The transit time of water through croplands was significantly and consistently the fastest, with water transiting through plants in less than a day during the peak of the growing season.

“One important observation is that croplands around the world tend to have very similar and very fast transit times,” said Dr. Gregory Goldsmith, senior author and an associate professor of Biological Sciences at Chapman University. “This indicates that land use change may be homogenizing the global water cycle and contributing to its intensification by more rapidly recycling water back to the atmosphere where it can turn into heavy rain events.”

“The results suggest that the transit time of water through plants is likely to be very sensitive to events such as deforestation, drought and wildfire, which will fundamentally change the time it takes for water to flow through the water cycle,” Felton said.

Share Button