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Linking gene expression to productivity to unravel long- and short-term responses of seagrasses exposed to CO 2 in volcanic vents

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ABSTRACT

Ocean acidification is a major threat for marine life but seagrasses are expected to benefit from high CO2. In situ (long-term) and transplanted (short-term) plant incubations of the seagrass Cymodocea nodosa were performed near and away the influence of volcanic CO2 vents at Vulcano Island to test the hypothesis of beneficial effects of CO2 on plant productivity. We relate, for the first time, the expression of photosynthetic, antioxidant and metal detoxification-related genes to net plant productivity (NPP). Results revealed a consistent pattern between gene expression and productivity indicating water origin as the main source of variability. However, the hypothesised beneficial effect of high CO2 around vents was not supported. We observed a consistent long- and short-term pattern of gene down-regulation and 2.5-fold NPP decrease in plants incubated in water from the vents and a generalized up-regulation and NPP increase in plants from the vent site incubated with water from the Reference site. Contrastingly, NPP of specimens experimentally exposed to a CO2 range significantly correlated with CO2 availability. The down-regulation of metal-related genes in C. nodosa leaves exposed to water from the venting site suggests that other factors than heavy metals, may be at play at Vulcano confounding the CO2 effects.

No MeSH data available.


PCA (a) and Cluster analysis (b) conducted considering the combined contribution of all GOIs analysed and NPP on in situ and transplanted incubations of Cymodocea nodosa plants.REFp REFw: in situ incubations of Reference plants in Reference water; REFp CO2w: transplant incubations of Reference plants in CO2 water; CO2p CO2w: in situ incubations of CO2 plants in CO2 water; CO2p REFw: transplant incubations of CO2 plants in Reference water.
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f3: PCA (a) and Cluster analysis (b) conducted considering the combined contribution of all GOIs analysed and NPP on in situ and transplanted incubations of Cymodocea nodosa plants.REFp REFw: in situ incubations of Reference plants in Reference water; REFp CO2w: transplant incubations of Reference plants in CO2 water; CO2p CO2w: in situ incubations of CO2 plants in CO2 water; CO2p REFw: transplant incubations of CO2 plants in Reference water.

Mentions: A PCA and cluster analysis and a correlation analysis were performed to link gene expression and productivity results. The PCA and Cluster analysis, conducted considering the combined contribution of all GOIs analysed and NPP, clearly highlighted two groups (PCA component 1 explaining 66.5% of the total variance) defined by the origin of the water where plants were incubated (i.e. water from Reference vs. CO2 site) (Fig. 3). These two groups matched the patterns described in Figs 1 and 2. A general up-regulation of photosynthetic, antioxidant and metal detoxification-related genes and higher NPP was found in plants long-term growing in the Reference site (in situ incubations) and plants from CO2 site incubated in water from the Reference site (transplant incubations). Reversely, plants long-term growing in the CO2 site (in situ incubations) and plants from the Reference site incubated in water from the CO2 site (transplant incubations) showed a generalized gene down-regulation and lower NPP. The biplot in the PCA identify GR, MT, PEPC, SOD, GSH-S, LHCA1 and psbA as the genes most contributing to this separation (for detailed information on the contribution of all GOIs and NPP see Supplementary Table S8).


Linking gene expression to productivity to unravel long- and short-term responses of seagrasses exposed to CO 2 in volcanic vents
PCA (a) and Cluster analysis (b) conducted considering the combined contribution of all GOIs analysed and NPP on in situ and transplanted incubations of Cymodocea nodosa plants.REFp REFw: in situ incubations of Reference plants in Reference water; REFp CO2w: transplant incubations of Reference plants in CO2 water; CO2p CO2w: in situ incubations of CO2 plants in CO2 water; CO2p REFw: transplant incubations of CO2 plants in Reference water.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5304229&req=5

f3: PCA (a) and Cluster analysis (b) conducted considering the combined contribution of all GOIs analysed and NPP on in situ and transplanted incubations of Cymodocea nodosa plants.REFp REFw: in situ incubations of Reference plants in Reference water; REFp CO2w: transplant incubations of Reference plants in CO2 water; CO2p CO2w: in situ incubations of CO2 plants in CO2 water; CO2p REFw: transplant incubations of CO2 plants in Reference water.
Mentions: A PCA and cluster analysis and a correlation analysis were performed to link gene expression and productivity results. The PCA and Cluster analysis, conducted considering the combined contribution of all GOIs analysed and NPP, clearly highlighted two groups (PCA component 1 explaining 66.5% of the total variance) defined by the origin of the water where plants were incubated (i.e. water from Reference vs. CO2 site) (Fig. 3). These two groups matched the patterns described in Figs 1 and 2. A general up-regulation of photosynthetic, antioxidant and metal detoxification-related genes and higher NPP was found in plants long-term growing in the Reference site (in situ incubations) and plants from CO2 site incubated in water from the Reference site (transplant incubations). Reversely, plants long-term growing in the CO2 site (in situ incubations) and plants from the Reference site incubated in water from the CO2 site (transplant incubations) showed a generalized gene down-regulation and lower NPP. The biplot in the PCA identify GR, MT, PEPC, SOD, GSH-S, LHCA1 and psbA as the genes most contributing to this separation (for detailed information on the contribution of all GOIs and NPP see Supplementary Table S8).

View Article: PubMed Central - PubMed

ABSTRACT

Ocean acidification is a major threat for marine life but seagrasses are expected to benefit from high CO2. In situ (long-term) and transplanted (short-term) plant incubations of the seagrass Cymodocea nodosa were performed near and away the influence of volcanic CO2 vents at Vulcano Island to test the hypothesis of beneficial effects of CO2 on plant productivity. We relate, for the first time, the expression of photosynthetic, antioxidant and metal detoxification-related genes to net plant productivity (NPP). Results revealed a consistent pattern between gene expression and productivity indicating water origin as the main source of variability. However, the hypothesised beneficial effect of high CO2 around vents was not supported. We observed a consistent long- and short-term pattern of gene down-regulation and 2.5-fold NPP decrease in plants incubated in water from the vents and a generalized up-regulation and NPP increase in plants from the vent site incubated with water from the Reference site. Contrastingly, NPP of specimens experimentally exposed to a CO2 range significantly correlated with CO2 availability. The down-regulation of metal-related genes in C. nodosa leaves exposed to water from the venting site suggests that other factors than heavy metals, may be at play at Vulcano confounding the CO2 effects.

No MeSH data available.