Purdue University researchers found that a subset of epidermal cells in plant leaves serves as early responders to chemical cues from bacterial pathogens and communicate this information to neighbors through a local traveling wave of calcium ions. The properties of this local wave differ from those generated when epidermal cells are wounded, suggesting that distinct mechanisms are used by plants to communicate specific types of pathogen attack, the team reported Dec. 2 in Science Signaling.
The new work from Purdue’s Emergent Mechanisms in Biology of Robustness Integration and Organization (EMBRIO) Institute highlights the importance of calcium ion signatures or patterns in the cytoplasm of cells. Plants and animals use calcium ions to transmit biologically critical sensory information within single cells, across tissues and even between organs.
“When a bacterium infects plant material, or when a fungus tries to invade plant tissue, cells and tissues recognize the presence of an attacker,” said Christopher Staiger, a professor in the Department of Botany and Plant Pathology and Distinguished Professor of Biological Sciences. “They recognize both chemical and mechanical cues. This study is largely about how the chemical cues are sensed.”
One of the hallmarks of cancer cells is their ability to evade apoptosis, or programmed cell death, through changes in protein expression. Inducing apoptosis in cancer cells has become a major focus of novel cancer therapies, as these approaches may be less toxic to healthy tissue than conventional chemotherapy or radiation. Many chemical agents are currently being tested for their ability to trigger apoptosis, and researchers are increasingly exploring light-activated molecules that can be precisely targeted to tumor sites using lasers, sparing surrounding healthy tissue.
Cancer cells have mitochondria that supply energy for rapid growth and division, but an overly alkaline environment is thought to disrupt mitochondrial function, leading to apoptosis.
A microbial protein called Archaerhodopsin-3 (AR3) may hold the key to alkalinity-induced apoptosis. When exposed to green light, AR3 pumps hydrogen ions out of the cell, increasing alkalinity, disrupting cellular functions, and eventually inducing apoptosis.
Cornell scientists have discovered a potentially transformative approach to manufacturing one of the world’s most widely used chemicals—hydrogen peroxide—using nothing more than sunlight, water and air. The research is published in the journal Nature Communications.
“Currently, hydrogen peroxide is made through the anthraquinone process, which relies on fossil fuels, produces chemical waste and requires transport of concentrated peroxide—all of which have safety and environmental concerns,” said Alireza Abbaspourrad, associate professor of Food Chemistry and Ingredient Technology in the Department of Food Science in the College of Agriculture and Life Sciences, and corresponding author of the research.
Hydrogen peroxide is ubiquitous in both industrial and consumer settings: It bleaches paper, treats wastewater, disinfects wounds and household surfaces, and plays a key role in electronics manufacturing. Global production runs into the millions of tons each year. Yet today’s process depends almost entirely on a complex method involving hazardous intermediates and large-scale central chemical plants.
Addressing the staggering power and energy demands of artificial intelligence, engineers at the University of Houston have developed a revolutionary new thin-film material that promises to make AI devices significantly faster while dramatically cutting energy consumption.
The breakthrough, detailed in the journal ACS Nano, introduces a specialized two-dimensional (2D) thin film dielectric —or an electric insulator—designed to replace traditional, heat generating components in integrated circuit chips. This new thin film material, which does not store electricity, will help reduce the significant energy cost and heat produced by the high-performance computing necessary for AI.
“AI has made our energy needs explode,” said Alamgir Karim, Dow Chair and Welch Foundation Professor at the William A. Brookshire Department of Chemical and Biomolecular Engineering at UH.
A chromosome pulled from the flowers of Arabidopsis thaliana (green and white) unspools to reveal DNA (blue) coiled around packaging-proteins called histones (purple). The direction of epigenetic changes by genetic features begins as the RIM transcription factor (pink) docks on a corresponding DNA sequence (pink). Once docked, the RIM transcription factor directs methylation machinery to tack methyl groups (orange) onto specific nearby cytosines (orange). Click here for a high-resolution image. Credit: Salk Institute.
All the cells in an organism have the exact same genetic sequence. What differs across cell types is their epigenetics—meticulously placed chemical tags that influence which genes are expressed in each cell. Mistakes or failures in epigenetic regulation can lead to severe developmental defects in plants and animals alike. This creates a puzzling question: If epigenetic changes regulate our genetics, what is regulating them?
Scientists at the Salk Institute have now used plant cells to discover that a type of epigenetic tag, called DNA methylation, can be regulated by genetic mechanisms. This new mode of plant DNA methylation targeting uses specific DNA sequences to tell the methylation machinery where to dock. Prior to this study, scientists had understood only how DNA methylation was regulated by other epigenetic features, so the discovery that genetic features can also guide DNA methylation patterns is a major paradigm shift.
Scientists at EPFL have created a scalable 3D organoid model that captures key features of early limb development, revealing how a specialized signaling center shapes both cell identity and tissue organization.
During early development, the embryo builds the body’s organs by exchanging chemical signals between different cell types. When developing limbs, a thin band of skin cells at the limb’s surface, called the “apical ectodermal ridge” (AER), sends signals that guide the underlying population as it grows and forms bone, cartilage, and connective tissue.
The AER is hard to study because it forms only briefly in the embryo and secretes several types of signaling molecules at once. Studying these interactions in embryos is difficult, so scientists often turn to organoids, tiny lab-grown organs that offer researchers a controlled way to study how cells behave and interact as tissues form.
A Johns Hopkins Medicine study involving a dozen people with the inflammatory skin disease hidradenitis suppurativa (HS), which mostly affects skin folds, is believed to be the first to provide evidence that hormone-disrupting chemicals commonly found in ultra-processed food and single-use water bottles may contribute to the development of or worsen the condition in some people.
The new findings about the disorder build on previous reports about the role of endocrine-disrupting chemicals, a common environmental contaminant known to mimic, block or alter the body’s hormones, in human health. Researchers believe their findings suggest that reducing exposure could ease HS symptom severity and provide a new avenue of relief for a disease with limited FDA-approved treatment options that include biologic therapy and surgery.
The full report on the study was published in Nature Communications on Nov. 28 and includes insights into the molecular mechanisms that are involved in the disease.
By analyzing the data from the SuperCOSMOS Hα Survey (SHS) and from the Gaia satellite, astronomers have inspected a bipolar planetary nebula designated PHR J1724-3859. Results of the study, published Nov. 19 on the arXiv pre-print server, deliver crucial insights into the properties of this nebula.
Planetary nebulae (PNe) are the final stages of evolution of low-to-intermediate mass stars. They are expanding shells of gas and dust that have been ejected from a star during the process of its evolution from a main sequence star into a red giant or white dwarf. PNe are relatively rare, but important for astronomers studying the chemical evolution of stars and galaxies.
