Georgia’s saltwater marshes — living where the land meets the ocean — stretch along the state’s entire 100-mile coastline. These rich ecosystems are largely dominated by just one plant: grass.
Known as cordgrass, the plant is an ecosystem engineer, providing habitats for wildlife, naturally cleaning water as it moves from inland to the sea, and holding the shoreline together so it doesn’t collapse. Cordgrass even protects human communities from tidal surges.
Understanding how these plants stay healthy is of crucial ecological importance. For example, one known plant stressor prevalent in marsh soils is the dissolved sulfur compound, sulfide, which is produced and consumed by bacteria. But while the Georgia coastline boasts a rich tradition of ecological research, understanding the nuanced ways bacteria interact with plants in these ecosystems has been elusive. Thanks to recent advances in genomic technology, Georgia Tech biologists have begun to reveal never-before-seen ecological processes.
The team’s work was published in Nature Communications.
Joel Kostka, the Tom and Marie Patton Distinguished Professor and associate chair for Research in the School of Biological Sciences, and Jose Luis Rolando, a postdoctoral fellow, set out to investigate the relationship between the cordgrass Spartina alterniflora and the microbial communities that inhabit their roots, identifying the bacteria and their roles.
“Just like humans have gut microbes that keep us healthy, plants depend on microbes in their tissues for health, immunity, metabolism, and nutrient uptake,” Kostka said. “While we’ve known about the reactions that drive nutrient and carbon cycling in the marsh for a long time, there’s not as much data on the role of microbes in ecosystem functioning.”
Out in the Marsh
A major way that plants get their nutrients is through nitrogen fixation, a process in which bacteria convert nitrogen into a form that plants can use. In marshes, this role has mostly been attributed to heterotrophs, or bacteria that grow and get their energy from organic carbon. Bacteria that consume the plant toxin sulfide are chemoautotrophs, using energy from sulfide oxidation to fuel the uptake of carbon dioxide to make their own organic carbon for growth.
“Through previous work, we knew that Spartina alterniflora has sulfur bacteria in its roots and that there are two types: sulfur-oxidizing bacteria, which use sulfide as an energy source, and sulfate reducers, which respire sulfate and produce sulfide, a known toxin for plants,” Rolando said. “We wanted to know more about the role these different sulfur bacteria play in the nitrogen cycle.”
Kostka and Rolando headed to Sapelo Island, Georgia, where they have regularly conducted fieldwork in the salt marshes. Wading into the marsh, shovels and buckets in hand, the researchers and their students collected cordgrass along with the muddy sediment samples that cling to their roots. Back at the field lab, the team gathered around a basin filled with creek water and carefully washed the grass, gently separating the plant roots.
Next, they used a special technique involving heavier versions of chemical elements that occur in nature as tracers to track the microbial processes. They also analyzed the DNA and RNA of the microbes living in different compartments of the plants.
Using a sequencing technology known as shotgun metagenomics, they were able to retrieve the DNA from the whole microbial community and reconstruct genomes from newly discovered organisms. Similarly, untargeted RNA sequencing of the microbial community allowed them to assess which microbial species and specific functions were active in close association with plant roots.
Using this combination of techniques, they found that chemoautotrophic sulfur-oxidizing bacteria were also involved in nitrogen fixation. Not only did these bacteria help plants by detoxifying the root zone, but they also played a crucial role in providing nitrogen to the plants. This dual role of the bacteria in sulfur cycling and nitrogen fixation highlights their importance in coastal ecosystems and their contribution to plant health and growth.
"Plants growing in areas with high levels of sulfide accumulation tend to be smaller and less healthy," said Rolando. "However, we found that the microbial communities within Spartina roots help to detoxify the sulfide, enhancing plant health and resilience."
Local to Global Significance
Cordgrasses aren’t just the main player in Georgia marshes; they also dominate marsh landscapes across the entire Southeast, including the Carolinas and the Gulf Coast. Moreover, the researchers found that the same bacteria are associated with cordgrass, mangrove, and seagrass roots in coastal ecosystems across the planet.
"Much of the shoreline in tropical and temperate climates is covered by coastal wetlands,” Rolando said. “These areas likely harbor similar microbial symbioses, which means that these interactions impact ecosystem functioning on a global scale."
Looking ahead, the researchers plan to further explore the details of how marsh plants and microbes exchange nitrogen and carbon, using state-of-the-art microscopy techniques coupled with ultra-high-resolution mass spectrometry to confirm their findings at the single-cell level.
"Science follows technology, and we were excited to use the latest genomic methods to see which types of bacteria were there and active,” Kostka said. “There's still much to learn about the intricate relationships between plants and microbes in coastal ecosystems, and we are beginning to uncover the extent of the microbial complexity that keeps marshes healthy.”
Citation: Rolando, J.L., Kolton, M., Song, T. et al. Sulfur oxidation and reduction are coupled to nitrogen fixation in the roots of the salt marsh foundation plant Spartina alterniflora. Nat Commun 15, 3607 (2024).
DOI: https://doi.org/10.1038/s41467-024-47646-1
Funding: This work was supported in part by an institutional grant (NA18OAR4170084) to the Georgia Sea Grant College Program from the National Sea Grant Office, National Oceanic and Atmospheric Administration, US Department of Commerce, and by a grant from the National Science Foundation (DEB 1754756).
Faculty from the George W. Woodruff School of Mechanical Engineering, including Associate Professors Gregory Sawicki and Aaron Young, have been awarded a five-year, $2.6 million Research Project Grant (R01) from the National Institutes of Health (NIH).
“We are grateful to our NIH sponsor for this award to improve treatment of post-stroke individuals using advanced robotic solutions,” said Young, who is also affiliated with Georgia Tech's Neuro Next Initiative.
The R01 will support a project focused on using optimization and artificial intelligence to personalize exoskeleton assistance for individuals with symptoms resulting from stroke. Sawicki and Young will collaborate with researchers from the Emory Rehabilitation Hospital including Associate Professor Trisha Kesar.
“As a stroke researcher, I am eagerly looking forward to making progress on this project, and paving the way for leading-edge technologies and technology-driven treatment strategies that maximize functional independence and quality of life of people with neuro-pathologies," said Kesar.
The intervention for study participants will include a training therapy program that will use biofeedback to increase the efficiency of exosuits for wearers.
Kinsey Herrin, senior research scientist in the Woodruff School and Neuro Next Initiative affiliate, explained the extended benefits of the study, including being able to increase safety for stroke patients who are moving outdoors. “One aspect of this project is testing our technologies on stroke survivors as they're walking outside. Being outside is a small thing that many of us take for granted, but a devastating loss for many following a stroke.”
Sawicki, who is also an associate professor in the School of Biological Sciences and core faculty in Georgia Tech's Institute for Robotics and Intelligent Machines, is also looking forward to the project. "This new project is truly a tour de force that leverages a highly talented interdisciplinary team of engineers, clinical scientists, and prosthetics/orthotics experts who all bring key elements needed to build assistive technology that can work in real-world scenarios."
Download photos from this year’s Sciences Celebration on the College of Sciences’ Flickr.
Members of the College of Sciences community gathered at Harrison Square on May 8 to recognize outstanding faculty and staff as part of the 2023-2024 academic year Spring Sciences Celebration.
“It is always a pleasure to honor faculty who excel in teaching and research,” says Susan Lozier, dean of the College of Sciences, Betsy Middleton and John Clark Sutherland Chair, and professor in the School of Earth and Atmospheric Sciences, “and to celebrate staff members across our College who are exceptionally committed to service and excellence.”
During the annual event, Lozier also recognized faculty and staff members who recently retired.
This year’s honorees include:
FACULTY DEVELOPMENT AWARDS
The Cullen-Peck Fellowship Awards were established by Frank Cullen (‘73 Math, MS ‘76 ISyE, PhD ‘84 ISyE) and Elizabeth Peck (‘75 Math, MS ‘76 ISyE) to encourage the development of especially promising mid-career faculty:
- Wenjing Liao, Mathematics
- Jenny McGuire, Biological Sciences
- Elisabetta Matsumoto, Physics
The Gretzinger Moving Forward Award, endowed by Ralph Gretzinger (‘70 Math) and named to honor his late wife Jewel, recognizes the leadership of a school chair or senior faculty member who has played a pivotal role in diversifying the composition of tenure-track faculty, creating a family-friendly work environment, and providing a supportive environment for early-career faculty:
- Michael Lacey, Mathematics
The Eric R. Immel Memorial Award for Excellence in Teaching, endowed by Charles Crawford (‘71 Math), honors exemplary instruction of lower division foundational courses. It honors the late School of Mathematics professor Eric R. Immel, who greatly influenced Crawford’s undergraduate experience at the Institute:
- Samantha Wilson, Earth and Atmospheric Sciences
The Leddy Family Dean’s Faculty Excellence Award, established by Jeff Leddy (’78 Physics) and Pam Leddy, supports a faculty member at the associate professor level with proven accomplishments in research and teaching:
Simon Sponberg, Physics
The Faculty Mentor Award, established jointly by the College of Sciences and its ADVANCE Professor, awards the efforts and achievements of our faculty members who mentor fellow faculty:
Shana Kerr, Biological Sciences
RESEARCH FACULTY AWARDS
The Outstanding Junior Research Faculty Award and Outstanding Senior Research Faculty Award honor postdoctoral and non-tenure track research faculty who have made exceptional research contributions with significant impact on their field of study:
Outstanding Junior Research Faculty: Yinghao Wen, Earth and Atmospheric Sciences
Outstanding Senior Research Faculty: Anna Österholm, Chemistry and Biochemistry
The Research Faculty Community Trailblazer Award recognizes postdoctoral and non-tenure track research faculty who have demonstrated and sustained leadership that strengthens the sense of community among research faculty within the College of Sciences:
- Jessica Bowman, Chemistry and Biochemistry
STAFF AWARDS
The College of Sciences Staff Awards are made possible by funding from the Betsy Middleton and John Clark Sutherland Dean’s Chair endowment. They include:
The Exceptional Staff Member Award and Staff Excellence Awards honor College of Sciences staff who exemplify outstanding performance above and beyond the call of duty — positively impacting the strategic goals of their department and the College, consistently providing excellent service within their school or the overall College, and demonstrating exemplary teamwork.
Exceptional Staff Member Award
- Verene Lancaster, Biological Sciences
Staff Excellence Awards
- Lea Marzo, Center for Promoting Inclusion and Equity in the Sciences
Faith Taylor, Dean’s Office
The Leadership in Action Staff Award and Excellence in Leadership Staff Awards recognize College of Sciences staff who have made exceptional contributions to the College through innovative and strategic leadership, change management, business process improvement, special project leadership, and similar accomplishments.
Leadership in Action Staff Award
Erin Nagle, Dean’s Office
Excellence in Leadership Staff Awards
Monica Branch, Chemistry and Biochemistry
Troy Hilley, Academic and Research Computing Services
From her home more than 800 miles away, Georgia Tech online master's student Jasmine Tata is monitoring fish in aquariums at Georgia Tech.
Tata is a New York-based QA analyst and project manager. She started the Online Master of Science in Computer Science (OMSCS) program in Fall 2022 and joined FishStalkers last year.
The student-led research program is part of the School of Biological Sciences' McGrath Lab. Its researchers use machine learning, computer vision, and other technologies to better understand the evolution of animal behaviors.
One of the lab's research projects studies Lake Malawi cichlids to explore connections between observed behavior and brain function.
The FishStalkers are vital to the project. They collect video, depth, and other data from individual fish using Raspberry Pi single-board computers. This information, coupled with open-source code they developed, allows the group to track, monitor, and classify the behaviors of a fish as it builds and maintains its bower, which is a sand structure these cichlids use to attract mates.
Kaixiang Cao, Ph.D
Assistant Professor
Department of Biochemistry
Department of Genetics and Genome Sciences
Case Comprehensive Cancer Center
School of Medicine, Case Western Reserve University
Histone modifications are thought to instruct gene transcription via specific reader proteins; however, recent results suggest that multiple types of histone modifications are not essential for regulating gene expression and cell identity. How histone modifications and histone modifiers function in regulating gene expression and cell fate remains enigmatic. Focusing on the mono-methylation of the lysine 4 residue on histone H3 (H3K4me1), a major enhancer mark deposited by methyltransferases MLL3/MLL4 and removed by the lysine-specific histone demethylase 1A (LSD1/KDM1A), we have previously demonstrated that LSD1 antagonizes MLL4 at enhancers to regulate gene expression and cellular differentiation, suggesting that resetting the perturbed epigenetic balance at enhancers is an effective strategy to treat diseases driven by enhancer malfunction. However, how LSD1 and H3K4me1 regulate such epigenetic balance at enhancers is largely unknown. We now utilize state-of-the-art precise genome engineering, small molecule targeting, transcriptomics, epigenomics, and stem cell biology techniques to dissect the role of LSD1 and the crosstalk of multiple epigenetic pathways in regulating transcription and cell fate. Our results suggest novel molecular mechanisms by which gene expression and cell identity are regulated and provide insight into understanding diseases driven by mis-regulation of epigenetic programs.
Hosted By: Yuhung Fan
Event Details
Mutations in genes encoding histones, which package DNA into chromatin, have been identified as cancer drivers, yielding oncohistones. Most of the validated oncohistones support single amino acid mutations that occur at lysines that support histone posttranslational modification (PTM), which perturbs the histone PTM landscape. Here, we examine the oncogenicity of a series of globular domain histone H3 mutations in which any residue is mutated to a lysine, “H3 X to K,” which were identified as recurrent H3 missense mutations in human cancers. H3 X to K mutation promotes oncogenic growth in immortalized but untransformed human cells. Some H3 X to K mutations alter PTMs at proximal H3 residues. Bulk RNA sequencing comparing H3 X to K mutant expression with wildtype H3 expressing cells identifies alterations in expression of genes implicated in unique cancer-related pathways. To complement studies in human cells, we created a budding yeast model where we express H3 X to K mutants as the sole cellular copy of histone H3 or in the presence of wildtype H3, which simulates the dominant phenotype observed in human cancers. Expression of some H3 X to K mutations in yeast confer growth sensitivity to DNA damage and general cellular stress in a dominant fashion. Together, these studies suggest that H3 X to K mutation within the H3 globular domain creates bona-fide oncohistones that disrupt normal growth through altering histone PTMs, the transcriptome, and/or DNA damage repair.
Event Details
The University System of Georgia Board of Regents has approved a new Neuroscience and Neurotechnology Ph.D. Program at Georgia Tech.
The interdisciplinary degree is a joint effort across the Colleges of Sciences, Computing, and Engineering. The program expects to enroll its first graduate students in Fall 2025, pending approval by the Southern Association of Colleges and Schools Commission on Colleges.
The Institute Curriculum Committee has also approved a new Minor in Neuroscience, set to become available in the Georgia Tech 2024-2025 Catalog.
B.S. in Neuroscience
The Ph.D. and Minor offerings build on the recently launched Neuro Next Initiative in Research, and the established Undergraduate Program in Neuroscience, respectively.
Approved by the Board of Regents in 2017, the interdisciplinary B.S. in Neuroscience degree in the College of Sciences enrolled more than 400 undergraduate students in 2022, and has been the fastest growing undergraduate major at Georgia Tech.
The B.S. in Neuroscience is also key to a strong ecosystem of undergraduate neuroscience education across the state, which includes peer programs at Mercer University, Augusta University, Georgia State University, Agnes Scott College, and Emory University.
Ph.D. in Neuroscience and Neurotechnology
The new doctoral degree will provide a path for the rapidly growing pipeline of in-state neuroscience undergraduate students and young alumni — while also welcoming a wider slate of graduate researchers to campus.
The Ph.D. Program’s mission is focused on educating students to advance the field of neuroscience through an interdisciplinary approach, with scientists and engineers of different backgrounds — ultimately integrating neuroscience research and technological development to study all levels of nervous system function.
Biological Sciences Professor Lewis A. Wheaton, who chaired the Ph.D. Program Planning Committee, shares that a cohort model will fuse “experimental and quantitative skill development, creating opportunities for students to work in science and engineering labs to promote collaborations, while also fostering a program and community that’s unique to the state and against national peer offerings.”
Expanding innovation — and impact
Wheaton explains that the new Ph.D. aims to equip graduates for a wide range of employment opportunities and growing specializations, including computational neuroscience, neurorehabilitation, cultural and social neuroscience, neuroimaging, cognitive and behavioral neuroscience, developmental neuroscience, and neurolinguistics.
The new degree will also help meet the country’s growing demand for a neuro-centric workforce. According to the U.S. Bureau of Labor Statistics, job growth for medical scientists (including neuroscientists) tracked around 13% between 2012 and 2022, faster than the average for all tracked occupations.
Wheaton adds that the program will equip neuroscientists to conduct research that can significantly improve lives.
Seeking students
The Planning Committee anticipates a tentative February 1, 2025 application deadline for Fall 2025 enrollments — and encourages students with the following interests to learn more and apply in the coming school year:
- Developing deeper quantitative, computing and/or engineering skills to make scientific discoveries that support innovations in neuroscience
- A clear, comprehensive understanding of the nervous system at all scales from molecular to systems
- Understanding how to use and innovate new tools and approaches to investigate the nervous system at all levels
- Becoming uniquely qualified to translate knowledge across neuroscience and related disciplines to create new knowledge in their professional pursuits
Director search
The participating Colleges will soon conduct a search for a program director, engaging a tenured member of the Georgia Tech faculty to serve as the new program’s administrator. A graduate program committee composed of five faculty members and mentors across the Colleges of Sciences, Computing, and Engineering, will also be created.
During their April 2024 meeting, Regents also announced budget approvals and tuition changes for Georgia's 26 member institutions.
The Ph.D. Program Planning Committee included the following faculty:
- Lewis Wheaton (Committee Chair, Biological Sciences)
- Constantine Dovrolis (Computer Science)
- Christopher Rozell (Electrical and Computer Engineering)
- Eric Schumacher (Psychology)
- Garrett Stanley (Biomedical Engineering)
- David Collard (College of Sciences Office of the Dean)
Robots that can run, jump, and even talk have shifted from the stuff of science fiction to reality in the past few decades. Yet even in robots specialized for specific movements like running, animals are still able to outmaneuver the most advanced robotic developments.
Georgia Tech’s Simon Sponberg recently collaborated with researchers at the University of Washington, Simon Fraser University, University of Colorado Boulder, and Stanford Research Institute to answer one deceptively complex question: Why can’t robots outrun animals?
“This work is about trying to understand how, despite have some really amazing robots, there still seems to be a gulf between the capabilities of animal movement and what we can engineer,” says Sponberg, who is Dunn Family Associate Professor in the School of Physics and School of Biological Sciences.
Recently published in Science Robotics, their study systematically examines a suite of biological and robotic runners to figure out how to further advance our best robotic designs.
“In robotics design we are often very component focused — we are used to having to establish specifications for the parts that we need and then finding the best component solution,” said Sponberg, who also serves on the executive committee for Georgia Tech's Neuro Next Initiative. “This is of course not how evolution works. We wondered if we systematically analyzed the performance of animals in the same component way that we design robots, if we might see an obvious gap.”
The gap turns out not to be in the function of individual robotic components, but rather the ability of those components to work together in the seamless way biological components do, highlighting a field of opportunity for new research in robotic development.
“This means that the frontier is not necessarily figuring out how to design better motors or sensors or controllers,” says Sponberg, “but rather how to integrate them together — this is where biology really excels.”
Read more about man versus machine and the future of bioinspired robotics here.
April is Earth Month, and according to the National Oceanic and Atmospheric Administration, 2023 was the warmest year on record for our planet. As the global conversation around the climate and humans’ effect on it continues, Georgia Tech researchers are taking a leading role in quantifying the issues posed by climate change and crafting solutions for the road ahead.
The latest episode of Generating Buzz follows the College of Sciences’ Frontiers in Science event, giving listeners an opportunity to hear from experts, including dean and renowned oceanographer Susan Lozier, Associate Professor Alex Robel, Professor Valerie Thomas, and Associate Vice President of Sustainability Jennifer Chirico as they explore the intersection of science, policy, and human nature.
April 12 is a significant date in the history of exploration, as it marks the first space flight of a human, Yuri Gagarin, in 1961. This year on April 12, the Georgia Tech Space Research Initiative (Space RI) hosted an event highlighting the Institute’s interdisciplinary space research. The Yuri’s Day Symposium was Space RI’s first public event.
A multidisciplinary initiative, the Space RI brings together faculty, researchers, and students from across campus who share a passion for space exploration. Their combined research explores a broad array of space-related topics, all considered from a human perspective.
“Launching Georgia Tech’s Space Research Initiative reinforces our commitment to advancing our understanding of space and our universe,” said Executive Vice President for Research Chaouki Abdallah. “It is also a testament to Georgia Tech's unwavering dedication to pushing the limits of what is possible and to fostering innovations that benefit humankind.”
The symposium was organized by Glenn Lightsey, interim executive director of the Space RI, and the Space RI steering committee, which consists of representatives from the Georgia Tech Research Institute (GTRI) and the Colleges of Engineering, Computing, and Sciences, the Ivan Allen College of Liberal Arts, and the Scheller College of Business. The day began with remarks from Research leadership and an overview of the Space RI and its mission. “This is an exciting time for space exploration at Georgia Tech and across the world,” Lightsey said. “Space research is a critical part of solving our world’s most challenging problems and improving life for everyone on Earth.”
Space research and exploration yield many societal benefits that improve life on Earth and even foster economic growth. These advances include rapidly evolving technologies, improvements in medicine, and the development of enhanced materials — such as self-healing materials and those designed for extreme environments. Additionally, space research provides essential tools, data, and insights for climate scientists.
Sessions and panels throughout the day covered space science, space media, NASA’s Moon to Mars program, GTRI’s space research program, commercial space initiatives, and space in popular culture. A.C. Charania, NASA’s chief technologist and a Georgia Tech alumnus, delivered the keynote address. He shared insights into his work at NASA and Moon to Mars.
Following the symposium, the Space RI hosted a “star party” at the Georgia Tech Observatory. People of all ages gathered at the event, where they could use the observatory’s telescope to observe the moon, Jupiter, and the Orion Nebula, an immense cloud of dust and gas from which new stars are born.
“It was a clear night, and we were able to view the lunar terminator — the boundary where the sun is setting on the moon — which accentuates craters and mountains,” said Lightsey. “It was exciting to officially launch our initiative on a day when the world celebrated space exploration and the star party was a fantastic way to end our event.”
In July 2025, the Space RI will transition into one of Georgia Tech’s Interdisciplinary Research Institutes. Learn more about the initiative at space.gatech.edu.
Sign up to receive space news and event updates from the Space RI.
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