{"title":"Physiological response of the endemic Mediterranean seagrass, Posidonia oceanica to multiple stresses","authors":"Judit Garcia , Tania Mesa , Sabina Villadangos , Gaspar Fuster , Sergi Munné-Bosch","doi":"10.1016/j.envexpbot.2025.106131","DOIUrl":null,"url":null,"abstract":"<div><div>The endemic Mediterranean marine angiosperm, <em>Posidonia oceanica</em>, stands out for being a biostructuring seagrass species with a great importance in trophic relations and coastal erosion protection. This study aimed to understand the physiological response of this emblematic seagrass to multiple stresses, with an emphasis on evaluating the acclimatory capacity of juvenile leaves to low temperatures during winter in three sites with a contrasting exposure to heavy metals of anthropogenic origin in the Mediterranean coast near Cadaqués (NE Spain). Heavy metal concentrations together with multiple physiological stress markers, including the capacity of photo- and antioxidant protection and the extent of lipid peroxidation, were evaluated. Shoots from the three studied sites accumulated foliar concentrations of heavy metals that were higher than reference threshold values, especially for Cu, which showed a decreasing concentration gradient from the coast to the open sea. The maximum photochemical efficiency of Photosystem II (PSII) (<em>F</em><sub>v</sub>/<em>F</em><sub>m</sub> ratio) of juvenile leaves was sensitive to low temperatures, despite values attained did not indicate damage to PSII, which was confirmed with studies of recovery of the <em>F</em><sub>v</sub>/<em>F</em><sub>m</sub> ratio and the absence of symptoms of photo-oxidative stress. However, the presence of heavy metals seemed to negatively influence PSII photochemistry, as sites with the highest Cu concentrations also showed the lowest <em>F</em><sub>v</sub>/<em>F</em><sub>m</sub> ratios during spring, even though water temperature had already warmed. <em>F</em><sub>v</sub>/<em>F</em><sub>m</sub> values attained were not recoverable after an extended dark acclimation period, thus indicating damage to PSII. Heavy metals did not seem to exert a negative synergistic effect with low temperatures but rather affected the physiological performance of newly produced juvenile leaves during spring. Despite the great capacity of this species to adapt to multiple stresses, results underscore the need to urgently reduce the current human footprint on seagrass meadows in the Mediterranean basin.</div></div>","PeriodicalId":11758,"journal":{"name":"Environmental and Experimental Botany","volume":"233 ","pages":"Article 106131"},"PeriodicalIF":4.5000,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental and Experimental Botany","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0098847225000486","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
The endemic Mediterranean marine angiosperm, Posidonia oceanica, stands out for being a biostructuring seagrass species with a great importance in trophic relations and coastal erosion protection. This study aimed to understand the physiological response of this emblematic seagrass to multiple stresses, with an emphasis on evaluating the acclimatory capacity of juvenile leaves to low temperatures during winter in three sites with a contrasting exposure to heavy metals of anthropogenic origin in the Mediterranean coast near Cadaqués (NE Spain). Heavy metal concentrations together with multiple physiological stress markers, including the capacity of photo- and antioxidant protection and the extent of lipid peroxidation, were evaluated. Shoots from the three studied sites accumulated foliar concentrations of heavy metals that were higher than reference threshold values, especially for Cu, which showed a decreasing concentration gradient from the coast to the open sea. The maximum photochemical efficiency of Photosystem II (PSII) (Fv/Fm ratio) of juvenile leaves was sensitive to low temperatures, despite values attained did not indicate damage to PSII, which was confirmed with studies of recovery of the Fv/Fm ratio and the absence of symptoms of photo-oxidative stress. However, the presence of heavy metals seemed to negatively influence PSII photochemistry, as sites with the highest Cu concentrations also showed the lowest Fv/Fm ratios during spring, even though water temperature had already warmed. Fv/Fm values attained were not recoverable after an extended dark acclimation period, thus indicating damage to PSII. Heavy metals did not seem to exert a negative synergistic effect with low temperatures but rather affected the physiological performance of newly produced juvenile leaves during spring. Despite the great capacity of this species to adapt to multiple stresses, results underscore the need to urgently reduce the current human footprint on seagrass meadows in the Mediterranean basin.
期刊介绍:
Environmental and Experimental Botany (EEB) publishes research papers on the physical, chemical, biological, molecular mechanisms and processes involved in the responses of plants to their environment.
In addition to research papers, the journal includes review articles. Submission is in agreement with the Editors-in-Chief.
The Journal also publishes special issues which are built by invited guest editors and are related to the main themes of EEB.
The areas covered by the Journal include:
(1) Responses of plants to heavy metals and pollutants
(2) Plant/water interactions (salinity, drought, flooding)
(3) Responses of plants to radiations ranging from UV-B to infrared
(4) Plant/atmosphere relations (ozone, CO2 , temperature)
(5) Global change impacts on plant ecophysiology
(6) Biotic interactions involving environmental factors.