It is important to investigate the molecular causes of the variation in ecologically important traits to fully understand phenotypic responses to climate change. In the Mississippi River Delta, two distinct, sympatric invasive lineages of common reed (Phragmites australis) are known to differ in several ecophysiological characteristics and are expected to become more salt resistant due to increasing atmospheric CO2 and temperature. We investigated whether different patterns of gene expression can explain their ecophysiological differences and increased vigor under future climatic conditions. We compared the transcript abundance of photosynthetic genes of the Calvin cycle (Rubisco small subunit, RbcS; Phosphoglycerate kinase, PGK; Phosphoribulokinase, PRK), genes related with salt transport (Na<sup>+</sup>/H<sup>+</sup> antiporter, PhaNHA) and oxidative stress response genes (Manganese Superoxide dismutase, MnSOD; Glutathione peroxidase, GPX), and the total aboveground biomass production between two genotypes representing the two lineages. The two genotypes (Delta-type, Mediterranean lineage, and EU-type, Eurasian lineage) were grown under an ambient and a future climate scenario with simultaneously elevated CO2 and temperature, and under two different soil salinities (0‰ or 20‰). We found neither differences in the aboveground biomass production nor the transcript abundances of the two genotypes, but soil salinity significantly affected all the investigated parameters, often interacting with the climatic conditions. At 20‰ salinity, most genes were higher expressed in the future than in the ambient climatic conditions. Higher transcription of the genes suggests higher abundance of the protein they code for, and consequently increased photosynthate production, improved stress responses, and salt exclusion. Therefore, the higher expression of these genes most likely contributed to the significantly ameliorated salinity impact on the aboveground biomass production of both P. australis genotypes under elevated temperature and CO2. Although transcript abundances did not explain differences between the lineages, they correlated with the increased vigor of both lineages under anticipated future climatic conditions. Two sympatric, highly invasive lineages of Phragmites australis from North America differ in their ecophysiological responses to salinity and climate, and differences in gene expression may cause these different phenotypic traits. Under a future climatic scenario and high soil salinity, the expression of photosynthetic and salt-stress related genes was increased in both lineages, relative to the ambient climate, but the phenotypic differences between the lineages were not explained by the gene expression. Similar changes in gene expression may therefore facilitate salt resistance and an increased invasive vigour of both reed lineages under the changing climate.

Eller, F., Lambertini, C., Nielsen, M.W., Radutoiu, S., Brix, H. (2014). Expression of major photosynthetic and salt-resistance genes in invasive reed lineages grown under elevated CO2 and temperature. ECOLOGY AND EVOLUTION, 4(21), 4161-4172 [10.1002/ece3.1282].

Expression of major photosynthetic and salt-resistance genes in invasive reed lineages grown under elevated CO2 and temperature

LAMBERTINI, CARLA;
2014

Abstract

It is important to investigate the molecular causes of the variation in ecologically important traits to fully understand phenotypic responses to climate change. In the Mississippi River Delta, two distinct, sympatric invasive lineages of common reed (Phragmites australis) are known to differ in several ecophysiological characteristics and are expected to become more salt resistant due to increasing atmospheric CO2 and temperature. We investigated whether different patterns of gene expression can explain their ecophysiological differences and increased vigor under future climatic conditions. We compared the transcript abundance of photosynthetic genes of the Calvin cycle (Rubisco small subunit, RbcS; Phosphoglycerate kinase, PGK; Phosphoribulokinase, PRK), genes related with salt transport (Na+/H+ antiporter, PhaNHA) and oxidative stress response genes (Manganese Superoxide dismutase, MnSOD; Glutathione peroxidase, GPX), and the total aboveground biomass production between two genotypes representing the two lineages. The two genotypes (Delta-type, Mediterranean lineage, and EU-type, Eurasian lineage) were grown under an ambient and a future climate scenario with simultaneously elevated CO2 and temperature, and under two different soil salinities (0‰ or 20‰). We found neither differences in the aboveground biomass production nor the transcript abundances of the two genotypes, but soil salinity significantly affected all the investigated parameters, often interacting with the climatic conditions. At 20‰ salinity, most genes were higher expressed in the future than in the ambient climatic conditions. Higher transcription of the genes suggests higher abundance of the protein they code for, and consequently increased photosynthate production, improved stress responses, and salt exclusion. Therefore, the higher expression of these genes most likely contributed to the significantly ameliorated salinity impact on the aboveground biomass production of both P. australis genotypes under elevated temperature and CO2. Although transcript abundances did not explain differences between the lineages, they correlated with the increased vigor of both lineages under anticipated future climatic conditions. Two sympatric, highly invasive lineages of Phragmites australis from North America differ in their ecophysiological responses to salinity and climate, and differences in gene expression may cause these different phenotypic traits. Under a future climatic scenario and high soil salinity, the expression of photosynthetic and salt-stress related genes was increased in both lineages, relative to the ambient climate, but the phenotypic differences between the lineages were not explained by the gene expression. Similar changes in gene expression may therefore facilitate salt resistance and an increased invasive vigour of both reed lineages under the changing climate.
2014
Eller, F., Lambertini, C., Nielsen, M.W., Radutoiu, S., Brix, H. (2014). Expression of major photosynthetic and salt-resistance genes in invasive reed lineages grown under elevated CO2 and temperature. ECOLOGY AND EVOLUTION, 4(21), 4161-4172 [10.1002/ece3.1282].
Eller, Franziska; Lambertini, Carla; Nielsen, Mette W.; Radutoiu, Simona; Brix, Hans
File in questo prodotto:
File Dimensione Formato  
Eller_et_al-2014-Ecology_and_Evolution.pdf

accesso aperto

Tipo: Versione (PDF) editoriale
Licenza: Licenza per Accesso Aperto. Creative Commons Attribuzione (CCBY)
Dimensione 747.25 kB
Formato Adobe PDF
747.25 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/566318
Citazioni
  • ???jsp.display-item.citation.pmc??? 6
  • Scopus 11
  • ???jsp.display-item.citation.isi??? 10
social impact