105
gens, through H 2 O 2 as substrate, would correspond with the alteration of cell
strength, favouring the substrate adhesion of algal spores and propagules (Bitton
et al. 2006, 2007). Specifically, brown seaweeds show a high oxidised bromine
compound content, which results in compounds involved in adhesion of Laminariales
(Salgado et al. 2009).
Other volatiles, such as ethylene, derived from the oxidation of 1- aminocyclopr
opane- 1-carboxylic acid (ACC) from SAM (Vanden Driessche et al. 1997), have
also been determined. Ethylene affected the cap formation and development rates in
the unicellular alga Acetabularia in a manner that depended on the timing of ethylene application (Vanden Driessche et al. 1998). Ethylene production was also noted
through the decomposition of ethephon, a compound that spontaneously decomposes to generate ethylene. In the green seaweed Enteromorpha intestinalis, the
addition of ethephon reduces chlorophyll levels compared to thalli without ethephon (Plettner et al. 2005).
Some authors have suggested an alternative to the conventional ethylene biosynthesis
pathway through ACC for ethylene in marine organisms. Dimethylsulphoniopropionate
(DMSP) lyase (EC 4.4.1.3) would act on DMSP to produce volatile DMS and acrylate,
and acrylate would be converted to ethylene by decarboxylation (Plettner et al. 2005;
Niki et al. 2000; Yoch et al. 1997). At a physiological level, DMS could scavenge reactive oxygen intermediates from cells, while DMSP would maintain salinity acclimatisation of algae (Sunda et al. 2002).
Furthermore, the time course of ethylene and DMS production in vitro in the red
seaweed G. arbuscula suggests that ethylene is mainly produced through the ACC
synthase and the ACC oxidase pathway (Garcia-Jimenez et al. 2013; Garcia-Jimenez
and Robaina 2012). As these authors reported, two considerations can be highlighted. Initially, the time course of ethylene and DMS production revealed that
DMS levels remained unaltered, while ethylene release increased. Therefore, it is
understood that ethylene is not a result of the final transformation of DMSP. Secondly,
the determination of enzyme activities involved in both pathways showed that ACC
synthase and ACC oxidase-specific activities are predominant compared to DMSP
lyase in this red alga (Fig. 5.1).
Moreover, the jasmonic acid and its relative compounds have been determined in
the unicellular green algae Euglena and Chlorella (Ueda et al. 1991a, b) and in the
red alga Gelidium (Krupina and Dathe 1991). The content of methyl jasmonate varies during the cell cycle of the Chlorophyta Scenedesmus acutus (Christov et al.
1996), in response to temperature stress in Scenedesmus incrassulatus (Christov
et al. 2001) and for anti-herbivory activity in the brown alga Fucus vesiculosus
(Arnold et al. 2001). In Laminaria digitata, production of methyl jasmonate seems
to be involved in protection and against its brown endophyte (Küpper et al. 2009).
In the red seaweed Chondrus crispus, methyl jasmonate activates the oxidative
metabolism of polyunsaturated fatty acids, leading to the production of hydroperoxides and oxygenated fatty acids (Gaquerel 2005; Bouarab et al. 2004), inducing
resistance activities involved in defence reactions (Gaquerel et al. 2009).
5 Volatiles in the Aquatic Marine Ecosystem: Ethylene and Related Plant Hormones…
gens, through H 2 O 2 as substrate, would correspond with the alteration of cell
strength, favouring the substrate adhesion of algal spores and propagules (Bitton
et al. 2006, 2007). Specifically, brown seaweeds show a high oxidised bromine
compound content, which results in compounds involved in adhesion of Laminariales
(Salgado et al. 2009).
Other volatiles, such as ethylene, derived from the oxidation of 1- aminocyclopr
opane- 1-carboxylic acid (ACC) from SAM (Vanden Driessche et al. 1997), have
also been determined. Ethylene affected the cap formation and development rates in
the unicellular alga Acetabularia in a manner that depended on the timing of ethylene application (Vanden Driessche et al. 1998). Ethylene production was also noted
through the decomposition of ethephon, a compound that spontaneously decomposes to generate ethylene. In the green seaweed Enteromorpha intestinalis, the
addition of ethephon reduces chlorophyll levels compared to thalli without ethephon (Plettner et al. 2005).
Some authors have suggested an alternative to the conventional ethylene biosynthesis
pathway through ACC for ethylene in marine organisms. Dimethylsulphoniopropionate
(DMSP) lyase (EC 4.4.1.3) would act on DMSP to produce volatile DMS and acrylate,
and acrylate would be converted to ethylene by decarboxylation (Plettner et al. 2005;
Niki et al. 2000; Yoch et al. 1997). At a physiological level, DMS could scavenge reactive oxygen intermediates from cells, while DMSP would maintain salinity acclimatisation of algae (Sunda et al. 2002).
Furthermore, the time course of ethylene and DMS production in vitro in the red
seaweed G. arbuscula suggests that ethylene is mainly produced through the ACC
synthase and the ACC oxidase pathway (Garcia-Jimenez et al. 2013; Garcia-Jimenez
and Robaina 2012). As these authors reported, two considerations can be highlighted. Initially, the time course of ethylene and DMS production revealed that
DMS levels remained unaltered, while ethylene release increased. Therefore, it is
understood that ethylene is not a result of the final transformation of DMSP. Secondly,
the determination of enzyme activities involved in both pathways showed that ACC
synthase and ACC oxidase-specific activities are predominant compared to DMSP
lyase in this red alga (Fig. 5.1).
Moreover, the jasmonic acid and its relative compounds have been determined in
the unicellular green algae Euglena and Chlorella (Ueda et al. 1991a, b) and in the
red alga Gelidium (Krupina and Dathe 1991). The content of methyl jasmonate varies during the cell cycle of the Chlorophyta Scenedesmus acutus (Christov et al.
1996), in response to temperature stress in Scenedesmus incrassulatus (Christov
et al. 2001) and for anti-herbivory activity in the brown alga Fucus vesiculosus
(Arnold et al. 2001). In Laminaria digitata, production of methyl jasmonate seems
to be involved in protection and against its brown endophyte (Küpper et al. 2009).
In the red seaweed Chondrus crispus, methyl jasmonate activates the oxidative
metabolism of polyunsaturated fatty acids, leading to the production of hydroperoxides and oxygenated fatty acids (Gaquerel 2005; Bouarab et al. 2004), inducing
resistance activities involved in defence reactions (Gaquerel et al. 2009).
5 Volatiles in the Aquatic Marine Ecosystem: Ethylene and Related Plant Hormones…