Posidonia oceanica, a top producer of dimethylsulfoniopropionate and dimethylsulfoxide

(1)

Posidonia oceanica

_{, a top producer of}

Posidonia oceanica

_{, a top producer of}

dimethylsulfoniopropionate and dimethylsulfoxide

J. Richir

1,2,

*, W. Champenois

1 , G. Engels

1 , A. Abadie

2 , S. Gobert

2,3

, G. Lepoint

2 _,

J. Silva

4 , R. Santos

4 & A.V. Borges

1 (* jonathan.richir@uliege.be)

J. Silva

4 , R. Santos

4 & A.V. Borges

1 (* jonathan.richir@uliege.be)

1

Unit of Chemical Oceanography, Uliege, Liège, Belgium.

2

_{Laboratory of Oceanology, ULiege, Liège, Belgium.}

I - Introduc on

Unit of Chemical Oceanography, Uliege, Liège, Belgium. Laboratory of Oceanology, ULiege, Liège, Belgium.

3

STARESO SAS, Calvi, France.

4

_{Center of Marine Sciences of Algavare, University of Algarve, Faro, Portugal.}

• Dimethylsulfoniopropionate (DMSP) and related sulfonium compounds dimethyl sulfide

II - Material and methods

I - Introduc on

• Dimethylsulfoniopropionate (DMSP) and related sulfonium compounds dimethyl sulfide

(DMS) and dimethylsulfoxide (DMSO) constitute an integral part of the marine sulfur cycle

1

_.

• DMSP (and DMSO) has many ‘potential’ functions in marine autotrophs

2

_.

II - Material and methods

• DMSP (and DMSO) has many ‘potential’ functions in marine autotrophs

2

_.

• _{The study of DMSP and DMSO in seagrasses is at its very beginning.}

2

1

• _{The study of DMSP and DMSO in seagrasses is at its very beginning.}

=> The main

objective

of this study was

to gain basic knowledge on the

dynamics of DMSP and DMSO in

the seagrass

Posidonia oceanica

_{by the monitoring during}

dynamics of DMSP and DMSO in

the seagrass

Posidonia oceanica

_{by the monitoring during}

15 months, at 10m depth in a pristine meadow, of the leaf content of these molecules.

Coral

Macroalgae

_Coral

(e.g., Acropora millepora

4

)

Macroalgae

(e.g., Ulva intes nalis

3

)

adults intermediates juveniles

3

4 Phytoplankton

-

Phytoplankton

(e.g., Phaeocys s

globosa

7

)

Salt marsh plant

Seagrass

globosa

7

)

Salt marsh plant

(e.g., Spar na alterniﬂora

5

)

Seagrass

(Posidonia oceanica

6

)

III - Results and discussion

A

III - Results and discussion

• Posidonia oceanica

_{is a top producer of DMSP and DMSO among marine autotrophs.}

• The similar dynamic of the two molecule concentrations indicates that DMSO may result

from the oxidation of DMS(P)

5,8

_.

• There is a close relationship between the seagrass leaf size, i.e., age and DMSP and

DMSO concentrations, potentially indicative of :

- ecophysiological roles, e.g., predator deterrent and antioxidant

2,8

;

- biochemical processes of nutrient regulation

9,10

.

- biochemical processes of nutrient regulation

.

• The constant DMSP:DMSO molecule ratio could be useful as early generic indicator of

stress in seagrasses, like suggested for Spartina alterniflora

8,11

_.

B

stress in seagrasses, like suggested for Spartina alterniflora

8,11

_.

Right:

A) DMSP and B) DMSO concentrations

D

A) DMSP and B) DMSO concentrations (mean ± sd, n = 3) measured in P. oceanica leaves.

C) P. oceanica shoot (black circles) and C) P. oceanica shoot (black circles) and in-termediate leaf (grey circles) foliar surfaces (mean ± sd, n = 6).

(mean ± sd, n = 6). Left:

D) Scatterplot of DMSP and DMSO D) Scatterplot of DMSP and DMSO concen-trations in P. oceanica and S. alterniflora 5,8,11 leaves, and in phytoplankton 12_.

E) DMSP:DMSO ratio (mean ± sd, n = 3) in

C

E) DMSP:DMSO ratio (mean ± sd, n = 3) in

P. oceanica leaves, bounded to October. The

color gradient represents the expected de-crease of the DMSP:DMSO ratio in seagrass crease of the DMSP:DMSO ratio in seagrass leaves when exposed to stressors.

E

_Ref.:1

Stefels et al. 2007, Bio-geochemistry. 2 Van Alstyne 2008, in: Algal Chemical 2008, in: Algal Chemical Eco-logy. 3 Van Alstyne 2008, J Mar Biol Assoc UK. 4 Raina et

5

al. 2003, Nature. 5 Husband & Kiene 2007, Wetlands. 6 Borges & Champenois 2015,

90

th

perc.

Acknowledgements

Borges & Champenois 2015, Aquat Bot. 7 Speeckaert et al. 2018, Sci Total Environ. 8 Hus-band et al. 2012, Environ Exp

mean

10

th

perc.

_{This work was funded by the Fonds National de la Recherche Scientifique (FNRS)}

(Fellowship-Grant 1237018F and contract 2.4.637.10), the University of Liège (C-10/78 Fonds Spéciaux) and the Territorial Collectivity of Corsica and the Rhone-band et al. 2012, Environ Exp

Bot. 9 Giordano & Raven 2014, Aquat Bot. 10 Lepoint et

11

10

th

perc.

Fonds Spéciaux) and the Territorial Collectivity of Corsica and the Rhone-Mediterranean and Corsica Water Agency (STARECAPMED − Station of reference and research on change of local and global anthropogenic pressures on Mediterranean al. 2002, J Sea Res. 11 Mc

Farlin & Alber 2013, Mar Ecol Prog Ser. 12 _{Simó & Vila-Costa}

ecosystem drifts). Prog Ser. _{Simó & Vila-Costa}