{"674734":{"#nid":"674734","#data":{"type":"news","title":"From Roots to Resilience: Investigating the Vital Role of Microbes in Coastal Plant Health","body":[{"value":"\u003Cp\u003EGeorgia\u2019s saltwater marshes \u2014 living where the land meets the ocean \u2014 stretch along the state\u2019s entire 100-mile coastline. These rich ecosystems are largely dominated by just one plant: grass.\u003C\/p\u003E\u003Cp\u003EKnown 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\u2019t collapse. Cordgrass even protects human communities from tidal surges.\u003C\/p\u003E\u003Cp\u003EUnderstanding 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.\u003C\/p\u003E\u003Cp\u003EThe team\u2019s work was \u003Ca href=\u0022https:\/\/www.nature.com\/articles\/s41467-024-47646-1\u0022\u003Epublished\u003C\/a\u003E in \u003Cem\u003ENature Communications\u003C\/em\u003E.\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022https:\/\/biosciences.gatech.edu\/people\/joel-kostka\u0022\u003EJoel Kostka\u003C\/a\u003E, the Tom and Marie Patton\u0026nbsp;Distinguished Professor and associate chair for Research in the \u003Ca href=\u0022https:\/\/biosciences.gatech.edu\/\u0022\u003ESchool of Biological Sciences\u003C\/a\u003E, and \u003Ca href=\u0022https:\/\/www.linkedin.com\/in\/jose-luis-rolando-17074b17\u0022\u003EJose Luis Rolando\u003C\/a\u003E, a postdoctoral fellow, set out to investigate the relationship between the cordgrass\u003Cem\u003E Spartina alterniflora \u003C\/em\u003Eand the microbial communities that inhabit their roots, identifying the bacteria and their roles.\u003C\/p\u003E\u003Cp\u003E\u201cJust like humans have gut microbes that keep us healthy, plants depend on microbes in their tissues for health, immunity, metabolism, and nutrient uptake,\u201d Kostka said. \u201cWhile we\u2019ve known about the reactions that drive nutrient and carbon cycling in the marsh for a long time, there\u2019s not as much data on the role of microbes in ecosystem functioning.\u201d\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EOut in the Marsh\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EA 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.\u003C\/p\u003E\u003Cp\u003E\u201cThrough previous work, we knew that \u003Cem\u003ESpartina alterniflora\u003C\/em\u003E\u0026nbsp;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,\u201d Rolando said. \u201cWe wanted to know more about the role these different sulfur bacteria play in the nitrogen cycle.\u201d\u003C\/p\u003E\u003Cp\u003EKostka 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.\u003C\/p\u003E\u003Cp\u003ENext, 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.\u003C\/p\u003E\u003Cp\u003EUsing 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.\u003C\/p\u003E\u003Cp\u003EUsing 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.\u003C\/p\u003E\u003Cp\u003E\u0022Plants growing in areas with high levels of sulfide accumulation tend to be smaller and less healthy,\u0022 said Rolando. \u0022However, we found that the microbial communities within Spartina roots help to detoxify the sulfide, enhancing plant health and resilience.\u0022\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ELocal to Global Significance\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003ECordgrasses aren\u2019t 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.\u003C\/p\u003E\u003Cp\u003E\u0022Much of the shoreline in tropical and temperate climates is covered by coastal wetlands,\u201d Rolando said. \u201cThese areas likely harbor similar microbial symbioses, which means that these interactions impact ecosystem functioning on a global scale.\u0022 \u0026nbsp;\u003C\/p\u003E\u003Cp\u003ELooking 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.\u003C\/p\u003E\u003Cp\u003E\u0022Science follows technology, and we were excited to use the latest genomic methods to see which types of bacteria were there and active,\u201d Kostka said. \u201cThere\u0027s 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.\u201d\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003ECitation: Rolando, J.L., Kolton, M., Song, T.\u0026nbsp;\u003Cem\u003Eet al.\u003C\/em\u003E\u0026nbsp;Sulfur oxidation and reduction are coupled to nitrogen fixation in the roots of the salt marsh foundation plant\u0026nbsp;\u003Cem\u003ESpartina alterniflora\u003C\/em\u003E.\u0026nbsp;\u003Cem\u003ENat Commun\u003C\/em\u003E\u0026nbsp;\u003Cstrong\u003E15\u003C\/strong\u003E, 3607 (2024).\u003C\/p\u003E\u003Cp\u003EDOI: https:\/\/doi.org\/10.1038\/s41467-024-47646-1\u003C\/p\u003E\u003Cp\u003EFunding: 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).\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EUnderstanding how salt marsh grass stays healthy is of crucial ecological importance, and studying the ways bacteria interact with these plants is key. Thanks to recent advances in genomic technology, Georgia Tech biologists have begun to reveal never-before-seen ecological processes.\u003C\/p\u003E\r\n","format":"limited_html"}],"field_summary_sentence":[{"value":"Understanding how salt marsh grass stays healthy is of crucial ecological importance, and studying the ways bacteria interact with these plants is key."}],"uid":"36123","created_gmt":"2024-05-15 18:52:12","changed_gmt":"2024-08-30 16:54:34","author":"Catherine Barzler","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2024-05-15T00:00:00-04:00","iso_date":"2024-05-15T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"674019":{"id":"674019","type":"image","title":"Screenshot 2024-05-15 at 1.26.57\u202fPM.jpg","body":"\u003Cp\u003E\u0026nbsp;Georgia Tech researchers surveying field sites in the salt marshes of Sapelo Island, Georgia.\u003C\/p\u003E\r\n","created":"1715800209","gmt_created":"2024-05-15 19:10:09","changed":"1715800209","gmt_changed":"2024-05-15 19:10:09","alt":"Four people walking across a salt marsh","file":{"fid":"257482","name":"Screenshot 2024-05-15 at 1.26.57\u202fPM.jpg","image_path":"\/sites\/default\/files\/2024\/05\/15\/Screenshot%202024-05-15%20at%201.26.57%E2%80%AFPM.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2024\/05\/15\/Screenshot%202024-05-15%20at%201.26.57%E2%80%AFPM.jpg","mime":"image\/jpeg","size":688116,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2024\/05\/15\/Screenshot%202024-05-15%20at%201.26.57%E2%80%AFPM.jpg?itok=plpMUK7i"}},"674020":{"id":"674020","type":"image","title":"IMG_0277.jpeg","body":"\u003Cp\u003EJoel Kostka, the Tom and Marie Patton\u0026nbsp;Distinguished Professor and associate chair for Research in the School of Biological Sciences.\u003C\/p\u003E\r\n","created":"1715800875","gmt_created":"2024-05-15 19:21:15","changed":"1715800875","gmt_changed":"2024-05-15 19:21:15","alt":"A man in a blue shirt holds a shovel in a salt marsh. ","file":{"fid":"257483","name":"IMG_0277.jpeg","image_path":"\/sites\/default\/files\/2024\/05\/15\/IMG_0277.jpeg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2024\/05\/15\/IMG_0277.jpeg","mime":"image\/jpeg","size":5785839,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2024\/05\/15\/IMG_0277.jpeg?itok=HqcNyLb2"}},"674022":{"id":"674022","type":"image","title":"PastedGraphic-3[60].jpg","body":"\u003Cp\u003EGeorgia Tech postdoctoral fellow Jose Rolando (right) and graduate student Gabrielle Krueger\u0026nbsp;prepare samples for chemical analysis in the field at Sapelo Island, Georgia.\u003C\/p\u003E","created":"1715801461","gmt_created":"2024-05-15 19:31:01","changed":"1715802529","gmt_changed":"2024-05-15 19:48:49","alt":"Two people sitting on a ground with a cooler and scientific equipment (including sample vials) between them. ","file":{"fid":"257485","name":"PastedGraphic-3[60].jpg","image_path":"\/sites\/default\/files\/2024\/05\/15\/PastedGraphic-3%5B60%5D.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2024\/05\/15\/PastedGraphic-3%5B60%5D.jpg","mime":"image\/jpeg","size":403670,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2024\/05\/15\/PastedGraphic-3%5B60%5D.jpg?itok=pyvxYt3e"}},"674021":{"id":"674021","type":"image","title":"PastedGraphic-6[93].jpg","body":"\u003Cp\u003EResearchers washing cordgrass roots for microbial analysis.\u003C\/p\u003E\r\n","created":"1715801172","gmt_created":"2024-05-15 19:26:12","changed":"1715801172","gmt_changed":"2024-05-15 19:26:12","alt":"Several people stand around a large basin washing grass. ","file":{"fid":"257484","name":"PastedGraphic-6[93].jpg","image_path":"\/sites\/default\/files\/2024\/05\/15\/PastedGraphic-6%5B93%5D.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2024\/05\/15\/PastedGraphic-6%5B93%5D.jpg","mime":"image\/jpeg","size":248349,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2024\/05\/15\/PastedGraphic-6%5B93%5D.jpg?itok=vhzIGkfk"}},"674023":{"id":"674023","type":"image","title":"PastedGraphic-4.jpg","body":"\u003Cp\u003EGeorgia Tech graduate student Tianze Song collects porewater samples for chemical analysis in the marsh on Sapelo Island, Georgia.\u003C\/p\u003E","created":"1715802407","gmt_created":"2024-05-15 19:46:47","changed":"1715802407","gmt_changed":"2024-05-15 19:46:47","alt":"A person does scientific sampling in the midst of a marsh.","file":{"fid":"257486","name":"PastedGraphic-4.jpg","image_path":"\/sites\/default\/files\/2024\/05\/15\/PastedGraphic-4.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2024\/05\/15\/PastedGraphic-4.jpg","mime":"image\/jpeg","size":509222,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2024\/05\/15\/PastedGraphic-4.jpg?itok=omnEkxhT"}}},"media_ids":["674019","674020","674022","674021","674023"],"groups":[{"id":"1278","name":"College of Sciences"},{"id":"1188","name":"Research Horizons"},{"id":"1275","name":"School of Biological Sciences"}],"categories":[{"id":"130","name":"Alumni"}],"keywords":[{"id":"187915","name":"go-researchnews"},{"id":"193266","name":"cos-research"},{"id":"192254","name":"cos-climate"}],"core_research_areas":[],"news_room_topics":[{"id":"71911","name":"Earth and Environment"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}