{"id":{"repo_id":"buffalo","oai_identifier":"oai:ubir.buffalo.edu:10477/86661"},"canonical_url":"https://search.dev.ndltd.org/etd/buffalo/oai:ubir.buffalo.edu:10477/86661","repository":{"repo_id":"buffalo","name":"Buffalo","base_url":"https://ubir.buffalo.edu/oai/request"},"display":{"title":"Investigation of Salt Tolerance in Two Species of Chara","abstract":"Ph.D.","abstract_html":"Ph.D.","abstract_has_math":false,"creators":["Phipps, Shaunna; 0000-0001-6967-9451"],"institution":"State University of New York at Buffalo","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Bisson, Mary","Evolution, Ecology and Behavior"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-02-21T21:36:12Z","date_published":"2025-02-21T21:36:12Z","updated_at":"2026-07-27T19:05:34Z","subjects":["plant sciences","physiology","molecular biology"],"languages":["eng"],"rights":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10477/86661","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Bisson, Mary","Evolution, Ecology and Behavior"]},{"key":"dc:creator","label":"Author","values":["Phipps, Shaunna; 0000-0001-6967-9451"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-02-21T21:36:12Z","2020"]},{"key":"dc:publisher","label":"Institution","values":["State University of New York at Buffalo"]},{"key":"dc:type","label":"Dc Type","values":["Text","Dissertation"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["plant sciences","physiology","molecular biology"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/10477/86661"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Ph.D.","Species within the genus Chara have a wide range of salinity tolerances. We examine two species, salt tolerant Chara longifolia and salt sensitive Chara australis, for mechanisms of salt tolerance and their potential role in adaptation to salt for both species. Although Chara is a green alga, it is more closely related to embryophytes than to other green algae (chlorophytes). The close evolutionary relationship between two phyla resulted in them sharing many morphological and molecular similarities. We hypothesize that genes similar to those in embryophytes are likely to be the mechanisms behind salt tolerance in Chara; these include a non-specific cation transporter (HKT), a Na+/H+ antiport (NHX), a H+-ATPase (AHA), and a Na+-ATPase (ENA). Time-course Illumina transcriptomes for each species were created using RNA from multiple time points (0hr, 6hr, 12hr, 24hr & 48hr) after freshwater cultures were exposed to salt stress. These transcriptomes were used to identify transcripts representing genes of interest for both species but also to determine differentially expressed genes at each time point to identify any significant transcriptome-wide responses to salt stress. This data provided the validation of the presence of all candidate genes of interest in both species of Chara, except the Na+-ATPase, which is present only in salt tolerant C. longifolia. The expression of these transcripts identified as genes of interest was further validated through use of qPCR, in a similar experimental set-up used for the RNAseq data described above. The qPCR data shows significant up-regulation of ENA in C. longifolia, as well as NHX and AHA in C. australis. Differential gene analysis suggests down-regulation of genes corresponding to energetically costly biological processes such as photosynthesis, metabolism and tetrapyrrole production for the salt sensitive species. C. australis also showed down-regulation in genes associated with transport, a molecular function significantly up-regulated in the salt tolerant C. longifolia. This research explores salt tolerant and salt sensitive species of Chara and their response to salt stress. The mechanisms homologous to those in land plants are present in both species (with the exception of ENA, which occurs only in C. longifolia). Response to salt stress varies across both species with C. longifolia relying heavily on the export of sodium through ENA, and C. australis exporting sodium through NHX and AHA.","**To request an accessible version of the file(s) associated with this item, contact library@buffalo.edu. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.**"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Investigation of Salt Tolerance in Two Species of Chara"]}]}],"canonical_facts":{"dc:contributor":["Bisson, Mary","Evolution, Ecology and Behavior"],"dc:creator":["Phipps, Shaunna; 0000-0001-6967-9451"],"dc:date":["2025-02-21T21:36:12Z","2020"],"dc:description":["Ph.D.","Species within the genus Chara have a wide range of salinity tolerances. We examine two species, salt tolerant Chara longifolia and salt sensitive Chara australis, for mechanisms of salt tolerance and their potential role in adaptation to salt for both species. Although Chara is a green alga, it is more closely related to embryophytes than to other green algae (chlorophytes). The close evolutionary relationship between two phyla resulted in them sharing many morphological and molecular similarities. We hypothesize that genes similar to those in embryophytes are likely to be the mechanisms behind salt tolerance in Chara; these include a non-specific cation transporter (HKT), a Na+/H+ antiport (NHX), a H+-ATPase (AHA), and a Na+-ATPase (ENA). Time-course Illumina transcriptomes for each species were created using RNA from multiple time points (0hr, 6hr, 12hr, 24hr & 48hr) after freshwater cultures were exposed to salt stress. These transcriptomes were used to identify transcripts representing genes of interest for both species but also to determine differentially expressed genes at each time point to identify any significant transcriptome-wide responses to salt stress. This data provided the validation of the presence of all candidate genes of interest in both species of Chara, except the Na+-ATPase, which is present only in salt tolerant C. longifolia. The expression of these transcripts identified as genes of interest was further validated through use of qPCR, in a similar experimental set-up used for the RNAseq data described above. The qPCR data shows significant up-regulation of ENA in C. longifolia, as well as NHX and AHA in C. australis. Differential gene analysis suggests down-regulation of genes corresponding to energetically costly biological processes such as photosynthesis, metabolism and tetrapyrrole production for the salt sensitive species. C. australis also showed down-regulation in genes associated with transport, a molecular function significantly up-regulated in the salt tolerant C. longifolia. This research explores salt tolerant and salt sensitive species of Chara and their response to salt stress. The mechanisms homologous to those in land plants are present in both species (with the exception of ENA, which occurs only in C. longifolia). Response to salt stress varies across both species with C. longifolia relying heavily on the export of sodium through ENA, and C. australis exporting sodium through NHX and AHA.","**To request an accessible version of the file(s) associated with this item, contact library@buffalo.edu. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.**"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/10477/86661"],"dc:language":["eng"],"dc:publisher":["State University of New York at Buffalo"],"dc:rights":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."],"dc:subject":["plant sciences","physiology","molecular biology"],"dc:title":["Investigation of Salt Tolerance in Two Species of Chara"],"dc:type":["Text","Dissertation"]},"updated_at":"2026-07-27T19:05:34Z"}