Characterization of the responses to saline stress in the symbiotic green microalga Trebouxia sp. TR9

Authors
Hinojosa Vidal, Ernesto; Marco, Francisco; Martínez Alberola, Fernando; Escaray, Francisco José; García Breijo, Francisco J.; Reig Armiñana, José; Carrasco, Pedro; Barreno, Eva
Publication Year
2018
Language
English
Format
article
Status
Published version
Description
Main conclusion: For the first time we provide a study on the physiological, ultrastructural and molecular effects of salt stress on a terrestrial symbiotic green microalga, Trebouxia sp. TR9. Although tolerance to saline conditions has been thoroughly studied in plants and, to an extent, free-living microalgae, scientific data regarding salt stress on symbiotic lichen microalgae is scarce to non-existent. Since lichen phycobionts are capable of enduring harsh, restrictive and rapidly changing environments, it is interesting to study the metabolic machinery operating under these extreme conditions. We aim to determine the effects of prolonged exposure to high salt concentrations on the symbiotic phycobiont Trebouxia sp. TR9, isolated from the lichen Ramalina farinacea. Our results suggest that, when this alga is confronted with extreme saline conditions, the cellular structures are affected to an extent, with limited chlorophyll content loss and photosynthetic activity remaining after 72 h of exposure to 5 M NaCl. Furthermore, this organism displays a rather different molecular response compared to land plants and free-living halophile microalgae, with no noticeable increase in ABA levels and ABA-related gene expression until the external NaCl concentration is raised to 3 M NaCl. Despite this, the ABA transduction pathway seems functional, since the ABA-related genes tested are responsive to exogenous ABA. These observations could suggest that this symbiotic green alga may have developed alternative molecular pathways to cope with highly saline environments.
Fil: Hinojosa Vidal, Ernesto. Universidad de Valencia; España
Fil: Marco, Francisco. Universidad de Valencia; España
Fil: Martínez Alberola, Fernando. Universidad de Valencia; España
Fil: Escaray, Francisco José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina
Fil: García Breijo, Francisco J.. Universidad Politécnica de Valencia; España
Fil: Reig Armiñana, José. Universidad Politécnica de Valencia; España
Fil: Carrasco, Pedro. Universidad de Valencia; España
Fil: Barreno, Eva. Universidad de Valencia; España
Subject
ABA
LICHEN
RAMALINA
SALINE STRESS
TERRESTRIAL MICROALGAE
TREBOUXIOPHYCEAE
Bioquímica y Biología Molecular
Ciencias Biológicas
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/81690