40
2 Coral Reef Ecosystem
Production and Fate of DMSP in Scleractinian Corals and Its Implications
in Climate Change
Corals (Van Alstyne et al.2008), polyps (Raina et al. 2013), phytoplankton species
confined to the classes Dinophyceae (dinoflagellates) and Prymnesiophyceae (Stefels
2000) and heterotrophic bacteria (Curson et al. 2017) are capable of producing
Dimethylsulponiopropionate (DMSP); which is a ubiquitous compound in the marine
sulphur cycle. Its production is attributed entirely to the activities of their algal
endosymbiont, Symbiodinium spp (Raina 2013) and is present in coral tissue,
symbiotic microalgae and coral mucus (Broadbent and Jones 2004).
The expulsion of coral symbionts and coral mucous to reef waters raises dimethylsulphide (DMS) and DMSP concentrations (Broadbent and Jones 2004) and this
makes coral reefs potential “hotspots” of atmospheric DMS production (Broadbent
et al. 2002; Broadbent and Jones 2004; Swan et al. 2012). Zhang et al. (2019) highlighted that the “hotspots” due to high DMS and DMSP coincide with high primary
productivity ocean areas. Stefels (2000) reported that algal biosynthesis of DMSP
occurs via assimilatory sulphate reduction, which is energy utilizing metabolic
process.
Marine phytoplankton provide their own antioxidant defense by utilizing the
sulphur substances DMSP, DMS, dimethylsulphoxide (DMSO), acrylic acid (AA)
and methanesulphinic acid (MSNA); which may function individually or simultaneously as an efficient antioxidant system to scavenge the harmful oxygen freeradicals produced during elevated stress (Sunda et al. 2002). Jones and King (2015)
further highlighted that DMSP, DMS and acrylate also scavenge hydroxyl radicals
(OH) and produce DMSO. DMSO further reacts with hydroxyl radicals to produce
MSNA, which also scavenges hydroxyl radicals and other ROS (reactive oxygen
species) (Sunda et al.2002). The antioxidants (chemical defence compounds) protect
coral tissues from environmental stress, including that caused by high solar radiation
(Raina et al. 2013).
DMSP have many biological roles such as (a) osmoregulation in various species of
phytoplankton (Vairavamurthy et al. 1985; Stefels 2000); (b) an antioxidant response
in phytoplankton and coral (Sunda et al. 2002; Jones et al. 2007;Deschaseaux et al.
2014); (c) anti-predation (Otte and Morris 1994; Wolfe et al. 1997; Van Alstyne
et al. 2001; Van Alstyne and Houser 2003); (d) anti-bacterial activity (Sieburth 1960,
1961); (e) methyl donor in the synthesis of nitrogen based metabolites (Chillemi
et al. 1990); (f) chemo-attractant for a whole range of marine species (DeBose et al.
2008; Seymour et al. 2010; Knight 2012; Savoca and Nevitt 2014;); (g) chemical cue
for bacteria (Seymour et al. 2010; Garren et al. 2013); (h) cyroprotection in polar
waters (Kirst et al. 1991; Nishiguchi and Somero 1992); (i) it is a metabolite of
many marine phytoplanktons as well as an overflow mechanism that allows cells to
maintain energy balance under sub-optimal conditions (Stefels 2000).
DMSP is the precursor of DMS, a strong smelling, volatile gas that is released
into the atmosphere and has a very short atmospheric lifetime of approximately
1–2 days. DMSP can be enzymatically cleaved by DMSP lyase to produce DMS,
acrylate and acrylic acid (Jones et al. 2014). DMS provides an estimated 28.1 Tg of
2 Coral Reef Ecosystem
Production and Fate of DMSP in Scleractinian Corals and Its Implications
in Climate Change
Corals (Van Alstyne et al.2008), polyps (Raina et al. 2013), phytoplankton species
confined to the classes Dinophyceae (dinoflagellates) and Prymnesiophyceae (Stefels
2000) and heterotrophic bacteria (Curson et al. 2017) are capable of producing
Dimethylsulponiopropionate (DMSP); which is a ubiquitous compound in the marine
sulphur cycle. Its production is attributed entirely to the activities of their algal
endosymbiont, Symbiodinium spp (Raina 2013) and is present in coral tissue,
symbiotic microalgae and coral mucus (Broadbent and Jones 2004).
The expulsion of coral symbionts and coral mucous to reef waters raises dimethylsulphide (DMS) and DMSP concentrations (Broadbent and Jones 2004) and this
makes coral reefs potential “hotspots” of atmospheric DMS production (Broadbent
et al. 2002; Broadbent and Jones 2004; Swan et al. 2012). Zhang et al. (2019) highlighted that the “hotspots” due to high DMS and DMSP coincide with high primary
productivity ocean areas. Stefels (2000) reported that algal biosynthesis of DMSP
occurs via assimilatory sulphate reduction, which is energy utilizing metabolic
process.
Marine phytoplankton provide their own antioxidant defense by utilizing the
sulphur substances DMSP, DMS, dimethylsulphoxide (DMSO), acrylic acid (AA)
and methanesulphinic acid (MSNA); which may function individually or simultaneously as an efficient antioxidant system to scavenge the harmful oxygen freeradicals produced during elevated stress (Sunda et al. 2002). Jones and King (2015)
further highlighted that DMSP, DMS and acrylate also scavenge hydroxyl radicals
(OH) and produce DMSO. DMSO further reacts with hydroxyl radicals to produce
MSNA, which also scavenges hydroxyl radicals and other ROS (reactive oxygen
species) (Sunda et al.2002). The antioxidants (chemical defence compounds) protect
coral tissues from environmental stress, including that caused by high solar radiation
(Raina et al. 2013).
DMSP have many biological roles such as (a) osmoregulation in various species of
phytoplankton (Vairavamurthy et al. 1985; Stefels 2000); (b) an antioxidant response
in phytoplankton and coral (Sunda et al. 2002; Jones et al. 2007;Deschaseaux et al.
2014); (c) anti-predation (Otte and Morris 1994; Wolfe et al. 1997; Van Alstyne
et al. 2001; Van Alstyne and Houser 2003); (d) anti-bacterial activity (Sieburth 1960,
1961); (e) methyl donor in the synthesis of nitrogen based metabolites (Chillemi
et al. 1990); (f) chemo-attractant for a whole range of marine species (DeBose et al.
2008; Seymour et al. 2010; Knight 2012; Savoca and Nevitt 2014;); (g) chemical cue
for bacteria (Seymour et al. 2010; Garren et al. 2013); (h) cyroprotection in polar
waters (Kirst et al. 1991; Nishiguchi and Somero 1992); (i) it is a metabolite of
many marine phytoplanktons as well as an overflow mechanism that allows cells to
maintain energy balance under sub-optimal conditions (Stefels 2000).
DMSP is the precursor of DMS, a strong smelling, volatile gas that is released
into the atmosphere and has a very short atmospheric lifetime of approximately
1–2 days. DMSP can be enzymatically cleaved by DMSP lyase to produce DMS,
acrylate and acrylic acid (Jones et al. 2014). DMS provides an estimated 28.1 Tg of