It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Wednesday, October 04, 2023
Gain-of-function allele of HPY1 coordinates source and sink to increase grain yield in rice
IMAGE: HPY1 MUTATION ENHANCES THE TRANSCRIPTIONAL LEVEL OF ITSELF THROUGH FEEDBACK REGULATION. THEN, THE HPY1 TARGETS RBCS2, RBCS3, AND RBCS4 TO INCREASE THEIR EXPRESSION AND RUBISCO ACTIVITY, WHICH IMPROVES PHOTOSYNTHETIC EFFICIENCY AND BIOMASS ACCUMULATION IN RICE. MEANWHILE, THE HPY1 TARGETS TO CCP1 AND FLO2, KEY GENES FOR GLUME DEVELOPMENT, TO ENHANCE THEIR EXPRESSION TO INCREASE GRAIN SIZE. FINALLY, THE IMPROVED PHOTOSYNTHETIC RATE, BIOMASS ACCUMULATION AND HIGH EXPRESSION OF CCP1 AND FLO2 WORKING TOGETHER LEAD TO A HIGH GRAIN YIELD OF RICE.view more
This study is led by Prof. Shaoqing Li (State Key Laboratory of Hybrid Rice, Wuhan University).
Rice is a primary staple crop for over half of the global population, and the continual enhancement of its yield holds significant significance in ensuring world food security. Therefore, achieving sustained increases in rice production has remained a major scientific challenge in the field of rice science research. Physiologically, rice yield is jointly determined by photosynthetic capacity (source) and grain size/number (sink). However, current research predominantly focuses on either source or sink, with relatively limited studies addressing the synergy between the two.
The team led by Prof. Shaoqing Li obtained a large-grain, tall stature mutant through radiation mutagenesis. Subsequently, using positional cloning, they cloned a gene that concurrently regulates photosynthetic efficiency, grain size, biomass, and yield, naming it HPY1 (high photosynthetic rate and yield 1). HPY1 is a transcription factor derived from a transposon, highly conserved without any mutations across rice germplasm resources. A SNP variation in the coding region of this gene leads to an alteration in an amino acid of the HTH (helix-turn-helix) domain's C-terminus, causing a change in protein structure and thereby increasing its DNA binding capacity. This ultimately triggers an increase in downstream gene expression, resulting in a phenotype of high photosynthetic efficiency, large grains, high biomass, and high yield.
Further analysis revealed that HPY1 enhances rice yield by synergistically improving both source and sink. HPY1 mutation enhances the transcriptional level of itself through feedback regulation. Then, HPY1 directly binds to source-related genes (RbcS2, RbcS3, and RbcS4, encoding Rubisco small subunits) to enhance their transcription, consequently increasing Rubisco content and activity, thereby raising photosynthetic rates and biomass. Simultaneously, it directly binds to sink-related genes (CCP1 and FLO2, genes regulating grain size) and upregulates their transcription, leading to larger grain size. Ultimately, relying on the simultaneous enhancement of source and sink, rice yield is increased.
In summary, this study identified a high-yielding gene, HPY1, that coordinates source and sink to enhance rice yield. This discovery not only contributes to a deeper molecular understanding of source-sink coordination in rice but also offers an effective strategy for rice high-yield improvement.
IMAGE: A FILAMENT OF THE PLASMONIC PLASTIC. DUE TO ITS FLEXIBILITY, THE MATERIAL CAN BE FORMED INTO ALMOST ANY SHAPE. IN THIS PARTICULAR EXAMPLE, THE FILAMENT IS INTENDED FOR USE IN 3D PRINTERS.view more
CREDIT: CHALMERS/MALIN ARNESSON
In a multi-year project, researchers at Chalmers University of Technology in Sweden have developed plasmonic plastic – a type of composite material with unique optical properties that can be 3D-printed. This research has now resulted in 3D-printed optical hydrogen sensors that could play an important role in the transition to green energy and industry.
Interest in plasmonic metal nanoparticles and their many different applications has grown rapidly, developing across a broad spectrum over the past two decades. What makes these particles so special is their ability to interact strongly with light. This makes them useful for a wide range of applications: as optical components for medical sensors and treatments, in photocatalysis to control chemical processes, and in various types of gas sensors.
Plasmonic plastic
For six years, Chalmers researchers Christoph Langhammer, Christian Müller, Kasper Moth-Poulsen, Paul Erhart and Anders Hellman and their research teams collaborated in a research project on plasmonic plastic. At the time the project began, plasmonic metal nanoparticles were being used primarily on flat surfaces and required production in advanced cleanroom laboratories. The researchers’ starting point was to ask: what if we could produce large volumes of plasmonic metal nanoparticles in a sustainable way that would make it possible to manufacture three-dimensional plasmonic objects? This is where the plastic came into the picture. The properties of plastic materials mean that they can be shaped into almost any form, are cost-effective, have upscaling potential, and can be 3D-printed.
And it worked. The project resulted in the development of new materials consisting of a mix (or composite) of a polymer and colloidal, plasmonically active, metal nanoparticles. With these materials, you can 3D-print objects of anything from a fraction of a gram up to several kilograms in weight. Some of the most important research results from the entire project have now been summarised in an article in the scientific journal Accounts of Chemical Research.
3D-printed hydrogen sensors
Plasmonic sensors that can detect hydrogen are the target application for this type of plastic composite material that the researchers chose to focus on in their project. In doing so, they have pioneered an entirely new approach in the field of optical sensors based on plasmons, namely being able to 3D-print these sensors.
“Different types of sensors are needed to speed up development in medicine, or the use of hydrogen as an alternative carbon-free fuel. The interplay between the polymer and nanoparticles is the key factor when these sensors are fabricated from plasmonic plastic. In sensor applications, this type of plastic not only enables additive manufacturing (3D printing), as well as scalability in the material manufacturing process, but has the additional important function of filtering out all molecules except the smallest ones – in our application, these are the hydrogen molecules we want to detect. This prevents the sensor from deactivating over time,” says Christoph Langhammer, professor at the Department of Physics, who led the project.
“The sensor is designed so that the metal nanoparticles change colour when they come in contact with hydrogen, because they absorb the gas like a sponge. The colour shift in turn alerts you immediately if the levels get too high, which is essential when you are dealing with hydrogen gas. At too high levels, it becomes flammable when mixed with air,” says Christoph Langhammer.
Many applications possible
While a reduction in the use of plastics is desirable in general, there are numerous advanced engineering applications that are only possible thanks to the unique properties of plastics. Plasmonic plastics may now make it possible to exploit the versatile toolbox of polymer technology for designing novel gas sensors, or applications in health and wearable technologies as other examples. It may even inspire artists and fashion designers due to its appealing and tuneable colours.
“We have shown that the production of the material can be scaled up, that it is based on environment-friendly and resource-efficient synthesis methods for creating the nanoparticles, and is easy to implement. Within the project, we chose to apply the plasmonic plastic to hydrogen sensors, but in reality only our imagination is the limit for what it can be used for,” says Christoph Langhammer.
How plasmonic plastic works
Plasmonic plastic consists of a polymer, such as amorphous Teflon or PMMA (plexiglass), and colloidal nanoparticles of a metal that are homogenously distributed inside the polymer. At the nanoscale, the metal particles acquire useful properties such as the ability to interact strongly with light. The effect of this is called plasmons. The nanoparticles can then change colour if there is a change in their surroundings, or if they change themselves, for example through a chemical reaction, or by absorbing hydrogen.
By dispersing the nanoparticles in the polymer, they are protected from the surroundings because larger molecules are not as capable of moving through the polymer as hydrogen molecules, which are extremely small. The polymer acts as molecular filter. This means that a plasmonic plastic hydrogen sensor can be used in more demanding environments, and will age less. The polymer also makes it possible to easily create three-dimensional objects of vastly different sizes that have these interesting plasmonic properties.
This unique interaction between the polymer, nanoparticles and light can be used to achieve customized effects, potentially in a wide range of products. Different types of polymers and metals contribute different properties to the composite material, which can be tailored to the particular application.
More about the research
The research project “Plastic Plasmonics” received SEK 28.9 million in funding from the Swedish Foundation for Strategic Research and was concluded in the summer of 2022.
The article’s authors are Iwan Darmadi, Ida Östergren, Sarah Lerch, Anja Lund, Kasper Moth-Poulsen, Christian Müller and Christoph Langhammer. The authors are active at the Department of Physics and the Department of Chemistry and Chemical Engineering at Chalmers University of Technology in Sweden. Researchers Anders Hellman and Paul Erhart, both of the Department of Physics, and their research teams, also contributed to the project.
In addition to his work at Chalmers, Kasper Moth-Poulsen is also active at the Institute of Materials Science of Barcelona, the Catalan Institution for Research and Advanced Studies (ICREA) and the Department of Chemical Engineering at the Universitat Politècnica de Catalunya.
A 3D-printed sensing element made from plasmonic plastic for use in an optical hydrogen sensor. This particular element contains nanoparticles of the metal palladium, which gives it its grey colour.
CREDIT
Chalmers/Malin Arnesson
A 3D-printed model of West-Sweden’s landmark, Vinga Lighthouse. The colour of the material is determined by the metal used for the nanoparticles in the plasmonic plastic, as well as their shape and size.
Bulk-Processed Plasmonic Plastic Nanocomposite Materials for Optical Hydrogen Detection
COI STATEMENT
The authors declare the following competing financial interest(s): C.L. is co-founder and scientific advisor at Insplorion AB that markets plasmonic hydrogen sensors. K.M-P. is co-founder and S.L. is R&D scientist at Nanoscientifica Scandinavia AB that markets colloidal nanoparticles
Tuesday, October 03, 2023
Accounting for oxygen in modeling coastal ecosystems
Driven by climate change and pollution, the decline of oxygen levels in oceans is altering biogeochemical cycles, threatening marine plants, animals and ecosystems. But how accurately are we projecting the fate of marine life? If models of marine ecosystems are to truly inform management — especially of coastal areas — they must account for the variation in oxygen levels across time and space, KAUST researchers say.
“Our study provides a perspective on the monitoring of oxygen decline in the ocean from a different angle,” says principal investigator Daniele Daffonchio. “Oceanic systems have a natural mechanism for regulating oxygen dissolution by balancing oxygen-consuming (respiration) and oxygen-producing (photosynthesis) processes.”[1]
Current models fail to project oxygen dynamics of coastal ecosystems that have an abundance of organisms that photosynthesize, says marine scientist Marco Fusi, who led the study with Folco Giomi from the University of Padova, Italy. Examples include seagrass meadows, mangrove forests and coral reefs. “It’s a very different dynamic from what’s seen in unproductive parts of the ocean in some cases called the ‘blue desert,’” he says.
In an initial observation of crabs in a mangrove forest, Fusi found they could survive in waters reaching over 40 degrees, well above their known thermal threshold. The waters were “oxygen-supersaturated,” a state in which more oxygen was dissolved in the water than would be through equilibrium with the atmosphere. This extra oxygen production due to warmer temperatures was helping the crustaceans cope.
The researchers also discuss fluctuations in the Venice Lagoon, once considered one of the most oxygen-depleted “dead zones” in the Adriatic Sea. The lagoon hosts a complex mosaic of ecosystems that include seagrasses and salt marshes colonized by microalgae and cyanobacteria. While dissolved oxygen was low at night, the lagoon reached nearly 300 percent saturation during the day.
Data from coral reefs in the Red Sea — formerly regarded a low oxygen zone due to high temperatures — shows a similar pattern. “The marine species in these areas are accustomed to living in a rollercoaster of oxygen levels,” says Fusi.
The team advises that conservation management should be based not on linear models focusing on average values of dissolved oxygen, but on a more complex mathematical model that incorporates the variation.
“Predictions of biodiversity loss in the Red Sea from two decades ago indicated that 90 percent of biodiversity would have been lost by now. That hasn’t happened yet. This could mean two things: that the modeling had been too simplistic and that species living in productive marine ecosystems have high capacity for adaptation,” says Fusi. “Our hope is that our study boosts the discussion on how we could better incorporate fluctuations into models and of new methods to study the resilience of marine species.”
LEIBNIZ-INSTITUT FÜR LEBENSMITTEL-SYSTEMBIOLOGIE AN DER TU MÜNCHEN
IMAGE: PHOTO OF COMMON HOP (HUMULUS LUPULUS) ON WHITE BAKGROUND.view more
CREDIT: GISELA OLIAS / LEIBNIZ-LSB@TUM
Hop-derived constituents not only increase shelf-life and bitterness of beer, but can also significantly influence aroma. An important hop odorant is linalool, which has a floral and citrus-like scent. Under the leadership of the Leibniz Institute for Food Systems Biology at the Technical University of Munich, a team of scientists has now disproved a roughly 20-year-old assumption about this odorant. The new study contributes to a better understanding of changes in beer bouquet during the brewing process and beer aging.
Two molecular variants of the odorant linalool are found in hops and beer: the enantiomers (R)- and (S)-linalool. Both molecules consist of the same number and type of atoms, and show the same connectivity. Nevertheless, they have a different spatial structure and differ like an image from its mirror image. This "small" but nevertheless crucial difference is also reflected in different odor intensities of the molecules.
In addition, it has long been known that beer aroma changes during the brewing process and storage because, among other things, part of the (R)-linalool predominant in hops is converted to (S)-linalool. Previously, based on a 1999 paper, researchers assumed that the odor threshold concentration of (R)-linalool is about a factor of 80 lower than that of (S)-linalool. Put simply, they assumed that (R)-linalool has a much stronger influence on beer aroma than its mirror-image counterpart. However, reliable data on the odor thresholds of both substances were lacking.
Preparative method optimized
To close this knowledge gap and enable more precise predictions of changes in beer aroma, the team led by brewing and beverage technologist Klaas Reglitz and food chemist Martin Steinhaus from the Leibniz Institute first optimized a preparative method. In close cooperation with the Research Center Weihenstephan for Brewing and Food Quality, the researchers thus succeeded for the first time in isolating enantiomerically pure (S)-linalool.
Having the pure substance available in sufficient quantities was an indispensable prerequisite for determining the specific odor threshold concentrations of the two odorant variants in water and unhopped beer using a trained sensory panel. This was essential because only (R)-linalool is commercially available as a pure substance.
As the team showed, the thresholds of (R)- and (S)-linalool in water were 0.82 and 8.3 micrograms per kilogram, respectively. In unhopped beer, the team determined thresholds of 6.5 micrograms per kilogram for (R)-linalool and 53 micrograms per kilogram for (S)-linalool.
Influence of (R)-linalool overestimated
"Our results thus confirm the previously postulated higher odor potency of (R)-linalool. However, they also refute the previous assumption that the odor threshold concentrations of the two enantiomers differ extremely. Instead, the study shows that the difference is only about eight to tenfold," says Martin Steinhaus, head of Section I and the Food Metabolome Chemistry Research Group at the Leibniz Institute.
First author Klaas Reglitz adds, "The conversion of (R)- to (S)-linalool thus does not have as great an influence on beer aroma as has long been assumed. Thanks to our study, we now better understand how and why the aroma changes during storage."
Linalool Linalool is an important constituent in many essential oils, often as a major component. It is found in various spice plants such as coriander, star anise, hops, nutmeg, ginger, basil and many others. Linalool is used both as a component of essential oils and as a pure compound for flavoring purposes.
Hops The common hop (Humulus lupulus) is mainly used for beer production. For brewing, the cones of the female hop plants are used. In 2022, the hop acreage in Germany was approximately 20,600 hectares, which is roughly one-third of the world's acreage. Germany is thus one of the leading hop producers and plays a significant role in global exports. With an export volume of 26,648 tons, Germany tops the list of hop exporting countries. At the same time, Germany is also one of the most important destination countries for the international hop trade. Source:https://de.statista.com/
LEIBNIZ-INSTITUT FÜR LEBENSMITTEL-SYSTEMBIOLOGIE AN DER TU MÜNCHEN
The photo shows a full glass of beer with a brown beer bottle next to it.
CREDIT
Gisela Olias / Leibniz-LSB@TUM
Information about the Institute:
The Leibniz Institute for Food Systems Biology at the Technical University of Munich (Leibniz-LSB@TUM) comprises a new, unique research profile at the interface of Food Chemistry & Biology, Chemosensors & Technology, and Bioinformatics & Machine Learning. As this profile has grown far beyond the previous core discipline of classical food chemistry, the institute spearheads the development of food systems biology. It aims to develop new approaches for the sustainable production of sufficient quantities of food whose biologically active effector molecule profiles are geared to health and nutritional needs, but also to the sensory preferences of consumers. To do so, the institute explores the complex networks of sensorically relevant effector molecules along the entire food production chain with a focus on making their effects systemically understandable and predictable in the long term.
The Leibniz-LSB@TUM is a member of the Leibniz Association (https://www.leibniz-gemeinschaft.de/en/), which connects 97 independent research institutions. Their orientation ranges from the natural sciences, engineering, and environmental sciences through economics, spatial and social sciences to the humanities. Leibniz Institutes devote themselves to social, economic, and ecological issues. They conduct knowledge-oriented and application-oriented research, also in the overlapping Leibniz research networks, are or maintain scientific infrastructures and offer research-based services. The Leibniz Association focuses on knowledge transfer, especially with the Leibniz Research Museums. It advises and informs politics, science, business, and the public. Leibniz institutions maintain close cooperation with universities - among others, in the form of the Leibniz Science Campuses, industry, and other partners in Germany and abroad. They are subject to a transparent and independent review process. Due to their national significance, the federal government and the federal states jointly fund the institutes of the Leibniz Association. The Leibniz Institutes employ around 21,000 people, including almost 12,000 scientists. The entire budget of all the institutes is more than two billion euros.
+++ Stay up to date via our Twitter channel twitter.com/LeibnizLSB +++
IMAGE: CAPE BARREN GOOSE (PHOTO COURTESY D COLOMBELLI-NEGREL, FLINDERS UNIVERSITY)view more
CREDIT: S KLEINDORFER (KONRAD LORENZ RESEARCH CENTRE FOR BEHAVIOUR AND COGNITION, UNIVERSITY OF VIENNA)
Facial recognition software used to study the social behaviour of individual Greylag Geese in Europe will soon be used to monitor one of the rarest geese in the world, the Cape Barren Goose in South Australia.
The technology was used to assess how each bird responds to images of themselves, other flock mates or partners and researchers from the University of Vienna and Flinders University say it could be used by other scientists or in citizen science apps around the world to monitor and record endangered wildlife or even to promote the welfare of animals in captivity.
Flinders BirdLab leaders Professor Sonia Kleindorfer and Dr Diane Colombelli-Négrel, worked on the software with support from the University of Vienna, University of Veterinary Medicine in Austria and the Konrad Lorenz Research Centre for Behaviour and Cognition.
The program tested each goose face with lifesize 2D images of members of the Greylag Goose flock, originally started by the founding father of animal behaviour, Austrian scientist Konrad Lorenz in the 1950s.
With 97% accuracy, each goose face could be correctly assigned within a photo library containing 6000 possible matches, researchers say in a new article in Journal of Ornithology.
“Next the team placed life-sized photos in a grassy field to see whether geese behave differently to each image – which they do,” says Professor Kleindorfer, who founded Flinders University’s BirdLab 20 years ago and now directs the Konrad Lorenz Research Centre, a core facility at the University of Vienna in Austria.
“The geese approached the photo of their partner more quickly, gave friendly contactcalls and fed for longer. In contrast, when they saw a picture of themselves – a goose they had never seen before – they hissed and took longer to approach food, if they fed at all.”
The latest findings into visual cues of individuality not only gives insights into the birds’ social structure but illustrate how the software to monitor individual faces or body patterns can be monitored using photographs collected in the field – for animal numbers and movements – in conservation efforts.
“Animal welfare could also be enhanced through the use of photographs in captivity,” says Flinders University’s Dr Colombelli-Négrel, from the College of Science and Engineering.
"For example, a photo might reduce the sense of isolation in a social species held in captivity, or serve as a ‘soft introduction’ before a new animal is introduced into an enclosure, although care should be given to avoid photos of a deceased relative, ally or dominant animal in the group.
“Perhaps captive individuals in group-living species express reduced anxiety when exposed to a photograph of an unknown and smaller non-specific,” she adds.
Zoologist Konrad Lorenz, who was awarded the Nobel Prize in Physiology or Medicine with Nikolas Tinbergen and Karl von Frisch in 1973, used the behaviour of the Greylag Goose to found the discipline of animal behaviour.
Playing Tetris for fifteen minutes can prevent psychological trauma in mothers after a difficult birth. These are the conclusions of a large-scale study conducted at CHUV and HUG and published in Molecular Psychiatry. The study's findings pave the way for a routine intervention to prevent the development of post-traumatic stress symptoms linked to childbirth.
An international team at Lausanne University (UNIL) and Lausanne University Hospital (CHUV) shows that a therapeutic activity comprising fifteen minutes of playing the video game Tetris can prevent the development of symptoms of posttraumatic stress linked to childbirth - or "CB-PTSD". The large-scale study led by the team of Antje Horsch, associate professor at UNIL’s Faculty of Biology and Medicine and research consultant at the Department Mother-Infant-Child of CHUV, involved 146 women. Of these women, half played Tetris and half carried out a placebo activity in the first six hours following their emergency caesarean section. The results show that the Tetris group had significantly fewer symptoms of PTSD, and this for up to six months after childbirth.
By engaging the 'visuospatial' region of the brain, the area that deals with vision and orientation in space, Tetris can interfere with the memory consolidation of traumatic images. Such images play a critical role in the development of PTSD. As memory consolidation takes place within few hours, playing Tetris shortly after a difficult event may thereby prevent the development of PTSD. The team around Antje Horsch is the first to prove the preventive effectiveness of such an intervention for traumatic childbirth.
With one in five women negatively impacted after an emergency caesarean section, PTSD linked to childbirth is a common mental health disorder. It manifests itself in the form of flashbacks and nightmares, irritability, difficulty sleeping, and hypervigilance about the baby. These symptoms can seriously disrupt daily life and have repercussions for the whole family. At present, prevention of childbirth-related PTSD is challenging due to the lack of scientifically validated treatments.
The results of Antje Horsch's team may have a significant impact not only on the prevention of PTSD after traumatic childbirth, but also after other types of trauma. "We are very enthusiastic because the activity was carried out under the supervision of the midwives and nurses in the maternity units, showing that it can be integrated into routine care. What's more, it's short, inexpensive, and accessible to anyone, regardless of their native language. It therefore has real clinical potential", explain Drs. Camille Deforges and Vania Sandoz, the study's first authors.
Funded by the Swiss National Science Foundation, the study was conducted in a rigorous manner using a randomised, controlled, double-blind protocol, reinforcing the reliability and robustness of the results. It thereby represents a major advance in mental health care after difficult childbirth and, more generally, after any traumatic event.
Publication
Deforges, C.*, Sandoz, V.*, Noël, Y., Avignon, V., Desseauve, D., Bourdin, J.,Vial, Y., Ayers, S., Holmes, E.A., Epiney, M. & Horsch, A. (2023). Single-session visuospatial task procedure to prevent childbirth-related posttraumatic stress disorder: a multicentre double-blind randomised controlled trial. Molecular Psychiatry. DOI: 10.1038/s41380-023-02275-w
