Monday, March 10, 2025

Scientists identify key gene enhancing citrus survival in cold climates

Nanjing Agricultural University The Academy of Science

image:
A simplified model illustrating the regulation of PtrPAT1 mediated under cold stress in trifoliate orange. Exposure to cold induces PtrPAT1, which transactivates *PtrBADH-l* by directly binding to its promoter, thus enhancing GB accumulation. Moreover, the cold-induced PtrPAT1 could regulate the expression of *PtrPOD* and *PtrSOD* either directly or indirectly, thus facilitating ROS removal. This, along with the two independent pathways, ultimately enhances the cold tolerance of *P. trifoliata*. The solid lines indicate a direct role, and dashed lines indicate an indirect role. Whether PtrPAT1 regulates the transcription of *PtrPOD* and *PtrSOD* in other ways needs further investigation.
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Credit: Horticulture Research

A pioneering study has uncovered the role of a key gene, PtrPAT1, in boosting cold tolerance in citrus plants by regulating the accumulation of glycine betaine (GB). This breakthrough not only deepens our understanding of how plants cope with cold stress but also opens the door to developing cold-resistant citrus varieties, which could be a game changer for global citrus production in the face of climate change.

Citrus plants, traditionally cultivated in tropical and subtropical climates, are highly vulnerable to cold stress, which can drastically affect both yield and fruit quality. With climate change triggering more frequent and intense cold spells, the demand for citrus varieties that can withstand these conditions has never been more pressing. Although previous studies have pointed to the protective role of glycine betaine (GB) in plants under cold stress, the molecular pathways governing GB accumulation have remained unclear—until now. This research addresses that gap, offering new genetic insights to enhance citrus cold tolerance.

In a recent study (DOI: 10.1093/hr/uhae296) published on October 23, 2024, in Horticulture Research, an international team of scientists from Guangxi University of Chinese Medicine and Huazhong Agricultural University identified the PtrPAT1 gene in Poncirus trifoliata, a hardy citrus relative known for its cold resistance. Their findings reveal that PtrPAT1 plays a crucial role in cold tolerance by stimulating the biosynthesis of GB, providing a potential genetic tool to improve cold resistance in commercial citrus crops.

The research focused on the PtrPAT1 gene, which belongs to the GRAS transcription factor family and is highly responsive to cold stress. The team discovered that PtrPAT1 is localized in both the nucleus and plasma membrane, where it activates the PtrBADH-1 gene, a key player in GB production. Through genetic modification, researchers showed that overexpressing PtrPAT1 in transgenic tobacco plants increased GB accumulation, boosted antioxidant enzyme activity, and enhanced cold tolerance. In contrast, silencing PtrPAT1 resulted in lower GB levels and a marked increase in cold sensitivity. Notably, the team pinpointed a specific DNA motif, TTTCATGT, in the PtrBADH-1 promoter, which binds with PtrPAT1 to activate gene expression, confirming its role as a transcriptional activator. These findings position PtrPAT1 as a critical regulator of cold stress, paving the way for potential genetic engineering in citrus crops.

Dr. Ji-Hong Liu, co-corresponding author of the study, emphasized the significance of these findings: "This research marks a major breakthrough in understanding how citrus plants manage cold stress. Identifying PtrPAT1 and its role in regulating GB biosynthesis opens new avenues for developing cold-resistant citrus varieties, which are vital as climate change continues to impact agricultural productivity."

The implications of this discovery extend far beyond citrus cultivation. The ability to harness PtrPAT1 could lead to the creation of genetically modified citrus varieties with enhanced resilience to cold stress, reducing crop losses and stabilizing yields in vulnerable regions. Moreover, this research could inspire similar genetic strategies in other crops, providing a roadmap for improving stress resistance across agriculture. As climate change continues to challenge global food security, innovations like these will be crucial in ensuring the sustainability and resilience of crop production.

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References

DOI

10.1093/hr/uhae296

Original Source URL

https://doi.org/10.1093/hr/uhae296

Funding information

This work was funded by National Key Research and Development Program of China (2022YFD1200503), National Natural Science Foundation of China (32102327), and Guangxi University of Chinese Medicine Scientific Research Fund (2021QN004).

About Horticulture Research

Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.

Journal

Horticulture Research

DOI

10.1093/hr/uhae296

Subject of Research

Not applicable

Article Title

The GRAS transcription factor PtrPAT1 of Poncirus trifoliata functions in cold tolerance and modulates glycine betaine content by regulating the BADH-like gene

From lab to lunchbox: violet LED light stops apple browning in its tracks

Nanjing Agricultural University The Academy of Science

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Violet LED light increased the antioxidant capacity and decreased oxidative enzyme activities of fresh-cut apple fruit. (a) ‘Fuji’ apple fruit were harvested in 2020 at 180 DAFB. Apple slices were treated with violet LED light at 700 lx at 10°C for 4 days, and samples were collected every 2 days. The samples were stored in the dark at 10°C as a control. Bars: 1 cm. BI (b), total phenolics content (c), DPPH radical scavenging rate (d), PPO activity (e), and POD activity (f) were investigated in the control and violet LED light-treated samples. The samples placed in the dark were used as a control. Data represents the means ± SE. Asterisks indicate significant differences (*P < 0.05; **P < 0.01, Student’s t-test).
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Credit: Horticulture Research

A recent study has revealed that violet Light-Emitting-Diode (LED) light can significantly reduce browning in fresh-cut apples by enhancing phenolic compounds and suppressing oxidative enzymes. This discovery not only boosts the visual appeal and shelf life of fresh-cut fruits but also offers a sustainable, chemical-free alternative to a long-standing problem in the food industry. The study sheds light on the molecular mechanisms behind light-induced fruit preservation, particularly the role of specific transcription factors, MdHY5 and MdHYH, in regulating the browning process.

Fresh-cut fruits have become a staple in modern diets, valued for their convenience and nutritional benefits. However, enzymatic browning, caused by the oxidation of phenolic compounds, remains a persistent challenge. This browning leads to unsightly discoloration and shorter shelf life, compromising both the aesthetic appeal and marketability of the produce. Traditionally, chemical treatments have been used to tackle this issue, but they come with drawbacks, including high costs and potential health concerns. Light-based solutions have emerged as a promising alternative, yet the precise molecular mechanisms at play have remained unclear. This study addresses these gaps, focusing on how violet Light-Emitting-Diode (LED) light can help preserve the quality of fresh-cut fruits.

On September 28, 2024, Horticulture Research published the findings (DOI: 10.1093/hr/uhae276) of a study led by researchers from Shenyang Agricultural University and Liaoning Agricultural Vocational and Technical College. The team demonstrated that violet LED light effectively inhibits browning in fresh-cut apples, enhancing their appeal and shelf life. Crucially, the research pinpointed two key transcription factors—MdHY5 and MdHYH—that regulate the expression of genes involved in phenolic metabolism and oxidative enzyme activity, providing a molecular foundation for using light as a natural, non-invasive preservation method.

The study uncovered that violet LED light treatment reduced browning in fresh-cut apples by boosting the accumulation of antioxidant-rich phenolic compounds and inhibiting the activity of oxidative enzymes like polyphenol oxidase (PPO) and peroxidase (POD). Through transcriptomic analysis, the researchers found that the expression of genes responsible for phenolic degradation (MdPPO and MdPOD) was suppressed, while the expression of a key phenolic synthesis gene (MdPAL) was enhanced. The transcription factors MdHY5 and MdHYH were identified as crucial regulators of this process, forming a positive feedback loop that binds to the promoters of MdPPO, MdPOD, and MdPAL to control their expression. When these transcription factors were silenced, the browning inhibition effect of violet LED light was lost, highlighting their essential role in the process.

"This research opens up exciting possibilities for the food industry," says Dr. Aide Wang, the corresponding author of the study. "By understanding how violet LED light and specific transcription factors work together to prevent browning, we can develop more effective, eco-friendly methods to extend the shelf life of fresh-cut fruits without relying on chemicals." Dr. Wang’s insights underline the potential of this innovative technique to revolutionize fruit preservation.

The findings of this study have far-reaching implications for the fresh-cut fruit industry. The use of violet LED light provides a cost-effective, chemical-free method to prevent browning, improving both the visual appeal and nutritional quality of fresh-cut apples. This technology could easily be incorporated into existing postharvest processing systems, reducing food waste and improving consumer satisfaction. Additionally, the identification of MdHY5 and MdHYH as key regulators opens the door for future research into genetic engineering or breeding programs aimed at developing browning-resistant fruit varieties. This research sets the stage for a more sustainable and efficient approach to fruit preservation, paving the way for greener food industry practices.

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References

DOI

10.1093/hr/uhae276

Original Source URL

https://doi.org/10.1093/hr/uhae276

Funding information

This work was supported by the National Key Research and Development Program of China (2022YFD2100105) and the National Natural Science Foundation of China (32125034).

About Horticulture Research

Journal

Horticulture Research

DOI

10.1093/hr/uhae276

Subject of Research

Not applicable

Article Title

Violet LED light-activated MdHY5 positively regulates phenolic accumulation to inhibit fresh-cut apple fruit browning

Quaise Energy reports new insights into designing superhot geothermal plants

Work informs “roadmap” for a superhot future

Science Communications

image:
Daniel Dichter of Quaise Energy has written two recent papers giving insights into the design of superhot geothermal plants. Here he presents one of them at the latest Geothermal Rising Conference.
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Credit: Quinlan Byrne, Quaise Energy

HOUSTON, Texas--Clean, renewable geothermal energy has the potential to become a major player in the energy transition, according to recent reports from organizations including the International Energy Agency. According to the Clean Air Task Force and others, the size of the prize could increase by an order of magnitude if we can tap into superhot rock over 375 degrees Celsius (about 700oF).

But the geothermal plants of today work at considerably lower temperatures, most ranging from about 100 to 250oC, and relatively little is known about designing plants for much higher temperatures.

Now, Daniel W. Dichter of Quaise Energy reports insights to that end in two papers. One was published online recently by Geothermal Rising (the work was presented at the 2024 Geothermal Rising Conference); the other was presented at the 50th Stanford Geothermal Workshop last month and is now also available online.

“We have a good understanding of how to design geothermal power plants in the conventional temperature domain, but we don’t have much experience with geothermal source temperatures any higher than that. These papers apply conventional geothermal design principles to a higher-temperature range beginning at 300oC,” says Dichter, a senior mechanical engineer at Quaise.

Dichter hopes the work will inform a roadmap toward a superhot future.

In geothermal plants, water exposed to hot rock picks up that heat and is then pumped to the surface where the carried energy is converted into electrical power. Among Dichter’s conclusions: for systems tapping into superhot rock, it may not be necessary to maintain water at temperatures above 375oC all the way to the surface. He also found that plants working with geothermal fluids at temperatures higher than 300oC at the surface can use common turbines to turn the resulting steam into electricity. Most geothermal plants operating today at lower, conventional geothermal temperatures must employ a more expensive turbine system that is not as commercially available.

Toward the Superhot

Water pumped into rock at temperatures above 375oC will become supercritical, a steam-like phase that most people aren’t familiar with. (Familiar phases are liquid water, ice, and the vapor that makes clouds.) Supercritical water, in turn, can carry some 5-10 times more energy than hot water at conventional geothermal temperatures, making it a power-dense energy source if it could be pumped above ground to turbines that could convert it into electricity.

Today, however, rock at those temperatures can only be accessed at a few locations around the globe, such as Iceland, where they are relatively close to the surface. The number one problem: we can’t drill down far enough.

The mother lode of superhot geothermal energy is some two to 12 miles beneath the surface. Drills used by the oil and gas industries can’t withstand the formidable temperatures and pressures that are found that far down. As a result, drilling becomes exponentially more expensive with depth. Quaise aims to solve the problem with a completely new way to drill using millimeter wave energy (cousins to the microwaves we cook with) that can literally melt and vaporize rock.

Artist’s conception of a future Quaise Energy geothermal plant capable of tapping into the superhot rock deep beneath our feet.

Credit

Hector Vargas, Quaise Energy

New Insights

Among other conclusions, Dichter found that if we can tap into superhot rock miles down, we don’t have to maintain the water at supercritical temperatures (above 375oC) all the way to the surface. In other words, “supercriticality is not necessary for maximum performance at the surface,” he says. And that could make superhot systems more economical.

It turns out that there are diminishing returns in keeping the water that hot all the way to the surface. That’s due to the physics involved in transporting it over long distances through the slender pipes associated with geothermal, which are only a little over eight inches in diameter.

“While the heat content of supercritical water is higher, the mass flow rate through the pipes decreases, and they basically cancel each other out,” Dichter says. Nevertheless, Dichter found that water at a production, or surface, temperature as low as 350oC can still lead to power outputs “up to an order of magnitude higher than those of conventional geothermal systems.” He emphasized, however, that “you may still need supercritical conditions in the reservoir [the superhot rock deep below] to achieve sub-critical production because of losses between the surface and the reservoir.”

Another of Dichter’s conclusions involves the turbine system used to convert superhot water into power. Many of the geothermal plants in operation today involve a binary cycle with two working fluids. That’s because heat cannot be converted to electricity efficiently by only using water at lower temperatures, and the geothermal water pumped to the surface contains impurities that can damage the above-ground equipment associated with power generation.

The solution is to transfer heat from the geothermal water to a second fluid flowing in separate but adjoining pipes. Hydrocarbons like isobutane are the preferred secondary fluid in most binary cycles, but Dichter found that they could be replaced with water (a clean source separate from that pumped to the surface). He specifically found that at higher temperatures, water works better than most hydrocarbons as the secondary fluid.

Replacing hydrocarbons with water has several advantages. Water is less expensive, and steam turbines using it are quite common, as opposed to those based on hydrocarbons (organic Rankine cycles, or ORCs). “Steam turbines have a much more mature supply chain than ORC turbines,” says Dichter, who presented more about water-based geothermal binary cycles and how they compare to ORCs at the 50th Stanford Geothermal Workshop in February.

Dichter is excited about our geothermal future. “The applications are diverse, from power plants to regional heating to domestic ground-source heat pumps, and there are a lot of fresh new eyes on the field,” he says. “There’s a renaissance happening in geothermal right now.”

Dissociation is a coping mechanism impeding effective climate action

Cambridge University Press

Collective dissociation is preventing people from taking effective action to tackle the overwhelming climate emergency, research published in Cambridge Prisms: Global Mental Health has found.

The overwhelming scale and complexity of the climate emergency often leave individuals feeling powerless, leading to a sense of futility in their ability to effect meaningful change. Collective dissociation is a form of trauma processing, and it threatens the cooperation needed to address the climate emergency. Instead, it reinforces isolation and prevents objective assessment of a destructive reality.

Climate-related disasters consequently have profound and lasting effects on mental health, leading to trauma responses and dissociation as subconscious coping mechanisms. It is therefore essential to understand these coping mechanisms, to drive impactful climate action.

The need for empathetic climate activism

Recognising how the climate emergency impacts people emotionally and psychologically can help policymakers and individuals to develop more effective climate responses.

Empathetic climate activism and a focus on safeguarding planetary and population health helps in combatting inaction and denial. This new research highlights the need to shift towards proactive climate activism with lasting implications for health systems and policies.

Vulnerable communities are also disproportionately affected by the climate emergency, especially in terms of food security. Extreme weather events, exacerbated by global warming, can trigger a wide range of psychopathological responses, including mood disturbances, anxiety, and physical symptoms – and those impacted most by climate change, such as people displaced by environmental factors, are at increased risk. These events also contribute to lasting mental health issues such as depression, post-traumatic stress disorder (PTSD), increased suicide rates, and substance abuse.

Don-Eliseo Lucero-Prisno, of the London School of Hygiene & Tropical Medicine Department of Global Health and Development, the University of the Philippines Open University Faculty of Management and Development Studies, and the Mahidol University Faculty of Public Health, said:

“Local moral support is vital for fostering sustainable adaptation strategies and community resilience to climate change, such as by organising vulnerability assessments and developing tailored action plans. These plans should include measures for improving infrastructure, enhancing social cohesion, and providing mental health support, reducing vulnerability to climate-related stresses.

“Emphasising community engagement reduces despair, providing essential solidarity for coping with climate trauma. Local leadership should support community-based climate action by providing resources and frameworks, facilitating engagement, and ensuring mental health support is accessible.”

Lead researcher Deborah Shomuyiwa, of the University of Lagos Faculty of Pharmacy and Global Health Focus Africa, said: “To make meaningful progress, we need to move beyond rhetorical calls for citizen action and directly confront the systemic forces that perpetuate the climate emergency.

“Corporate resistance, government paralysis, and prioritising profits over environmental sustainability all drive community inaction. The financial sector's continued investment in coal and oil, alongside unchecked consumerism, greenwashing, and the war economy, accelerate the climate emergency. Citizens see these decisions by those in power and are alienated by these, which can foster feelings of helplessness and dissociation from the emergency.”

She and her co-author Don-Eliseo Lucero-Prisno argue that policy development must therefore prioritise accountability for corporations and governments, recognising that citizen-driven sustainability initiatives alone will not suffice in the face of larger organisations’ destructive practices.

How to combat dissociation

In response to these findings, researchers have developed four key recommendations for how to combat dissociation.

1. Policymakers must strive for greater transparency and accountability in political funding to align actions with public support for effective climate measures.
2. Policymakers should prioritise sustainable practices, accountability, monitoring progress rigorously, and remaining adaptable to research and technological advancements.
3. Policies should emphasise education and public awareness campaigns about the mental health consequences of climate change. By fostering a deeper understanding of climate trauma, these campaigns can mobilise public support for climate action and promote collective resilience.
4. Policies should prioritise the needs of vulnerable populations and aim to build inclusive, resilient communities.

Conclusion

Beyond its tangible environmental effects, this research shows that climate change poses significant mental health challenges both in the immediate and longer term. Taking steps to combat human dissociation from the climate emergency – on both large and small scales – is therefore essential to preventing human nature from remaining entrenched in harmful environmental practices, undermining planetary health even when climate action is vital.

Journal

Cambridge Prisms Global Mental Health

DOI

10.1017/gmh.2024.119

Method of Research

Observational study

Subject of Research

People

Article Title

Climate change trauma and collective dissociation: Unraveling the impact on mental health and advocating for collective action

AI-based math: individualized support for schoolchildren

Now in use at first school in North Rhine-Westphalia in Germany

Technical University of Munich (TUM)

Researchers at the Technical University of Munich (TUM) and the University of Cologne have developed an AI-based learning system that recognizes strengths and weaknesses in mathematics by tracking eye movements with a webcam to generate problem-solving hints. This enables teachers to provide significantly more children with individualized support.

An up-to-date PC, a good graphics card and a standard webcam: according to research by Prof. Achim Lilienthal, that's all you need to identify pupils' strengths and weaknesses in mathematics. The principle: a webcam tracks the eye movements. Depending on the task, specific patterns emerge that can be displayed digitally on a heatmap, with red indicating areas where the children look frequently and green the areas where they glance only briefly. This helps the researchers analyze the data. “The AI system classifies the patterns,” says the TUM robotics professor. On this basis, the software selects learning videos and exercises for the pupil.

Identify learning strategies via heat maps

“Tracking eye movements in a single system using a webcam, recognizing learning strategies via patterns and offering individual support, and finally creating automated support reports for teachers is completely new,” says Maike Schindler. The Professor of Mathematics in Inclusive and Special Education Contexts at the University of Cologne has worked with TUM Professor Lilienthal for ten years. She also heads the recently completed KI-ALF research project, which was funded by the German Federal Ministry of Education and Research (BMBF) and in which the webcam-based eye-tracking system was developed. Her research focuses on pupils “who have great difficulties in learning mathematics.” Prof. Lilienthal believes that “individually customized lessons” for high-achieving children are also possible in the future.

Prof. Schindler – who holds a teaching degree – and her team have defined hundreds of tasks in which children add, subtract, multiply and divide numbers, or have to recognize or represent them. “Tasks involving visually presented, digital learning materials are particularly suitable for this approach,” says Schindler. For example, the children are asked to count the dots in a ten-row table with a few dots missing only in the bottom row.

The pupils who catch on quickly jump to the bottom row and only count backwards. Those who count the rows and dots individually are among the ones who need support. The digital system uses a heat map to show where the children look and the AI translates the patterns into individual practice programs.

Simplified, high-precision eye tracking

To develop the simplified eye tracking system, which now registers eye movements, TUM Professor Lilienthal benefits from the fact that he also works with corresponding systems in robotics research. In that work, he currently uses eye trackers with the small humanoid robot Nao. This enables it to communicate better with humans. However, these very precise systems cost many thousands of euros.

To find a more cost-effective solution for schools, the researchers cleverly combined technical expertise with knowledge from mathematical didactics. While advanced systems work with a maximum deviation of one degree, webcams have a lower accuracy of three to four degrees. The solution: “With the AI-ALF math tasks, we know that the students are ultimately looking at the on-screen display of the problems,” says Lilienthal. “We use this to automatically readjust the eye tracking with the webcam.” The system has gradually learned to deal with inaccuracy. “Today it makes no difference to our application whether we work with our webcams or high-end eye trackers,” says the professor. This makes the AI system developed with Prof Maike Schindler affordable and, therefore, increasingly important for school use.

Wulfen Comprehensive School: first school in Germany to use the system

This is one reason why the first school to use the AI-based learning system is the Wulfen Comprehensive School in Dorsten, North Rhine-Westphalia. Here, a standardized math test revealed that one-third of 180 children at the start of Year 5 had “arithmetic difficulties.” “We are delighted that we can now support significantly more children in their basic math skills with the help of the AI-based learning system. This means we can help more learners improve their math performance than in the past due to a lack of teachers.”

In the comprehensive school, five pupils can work with the KI-ALF system simultaneously in individual remedial lessons and are supported and accompanied by a math teacher. Normally teachers can give individual support to only one child at a time. “Especially in times of scarce resources and teacher shortages, our system for promoting basic math skills is simply an excellent support for schools,” says Schindler.

Additional material for media outlets:

Foto zum Download: https://mediatum.ub.tum.de/1773230

Youtube video: https://youtu.be/7fzWbT1O4Zs

Homepage of the research project: www.ki-alf.de

Publication:

Introduction to eye tracking in mathematics education: interpretation, potential, and challenges; Maike Schindler, Anna Shvarts & Achim J. Lilienthal; Educational Studies in Mathematics (ESM); 3-2025; https://link.springer.com/article/10.1007/s10649-025-10393-1

Structure Sense in Students’ Quantity Comparison and Repeating Pattern Extension Tasks: An Eye-Tracking Study with First Graders
Demetra Pitta-Pantazi, Eleni Demosthenous, Maike Schindler, Achim J. Lilienthal, and Constantinos Christou; Educational Studies in Mathematics (ESM), 2024, pp. 1 – 19; https://link.springer.com/article/10.1007/s10649-023-10290-5

Journal

Educational Studies in Mathematics

DOI

10.1007/s10649-025-10393-1

Method of Research

Observational study

Subject of Research

People

Article Title

Introduction to eye tracking in mathematics education: interpretation, potential, and challenges

Article Publication Date

10-Mar-2025

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Monday, March 10, 2025

Scientists identify key gene enhancing citrus survival in cold climates

Journal

DOI

Subject of Research

Article Title

From lab to lunchbox: violet LED light stops apple browning in its tracks

Journal

DOI

Subject of Research

Article Title

Quaise Energy reports new insights into designing superhot geothermal plants

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Dissociation is a coping mechanism impeding effective climate action

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DOI

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Subject of Research

Article Title

AI-based math: individualized support for schoolchildren

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DOI

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