The Phycotoxin Domoic Acid as a Potential Factor for Oxidative Alterations Enhanced by Climate Change

GONZÁLEZ, PAULA MARIELA; PUNTARULO, SUSANA; CABRERA, JOAQUIN

Frontiers in Plant Science

Frontiers Media S.A.

Lugar: Le Mans; Año: 2020 vol. 11 p. 1 - 7

Continued acidification of the ocean inhibits the growth of phytoplankton species that have shellsof calcium carbonate, which dissolve in acidic conditions, and the growth of organisms withoutcalcium carbonate shells is favored (Moore et al., 2008). During harmful algal blooms (HABs),bloom-forming diatom species tend to be more flexible in the use of different carbon sources, andthese abilities may provide a competitive advantage, especially under changing conditions as theyoccur during a bloom. The ocean acidification during blooms favored organisms that fix CO2 such as some diatoms (Hansen, 2002). It has been reported that Pseudo-nitszchia australis (Wingert, 2017), P. pseudodelicatissima (Sugie and Yoshimura, 2013), and Pseudo-nitszchia subcurvata increase their growth rate under these conditions. Even more, Pseudo-nitzschia multiseries increase the production of the biotoxin domoic acid (DA) (Trimborn et al., 2008).DA is an excitatory amino acid containing the structure of glutamic acid and resembles kainic acid (Todd, 1989). DA binds at the same receptor site in the central nervous system than kainic and glutamic acid (Mok et al., 2009), and its coexisting natural chemical analogs act as a potent excitatory neurotransmitter. The biosynthesis pathway of the DA is not fully elucidated,but it is known that large amounts of ATP are required for its production (Pan et al., 1998; Thessen, 2007). Recently, Brunson et al. (2018) established a biosynthesis model by finding a clusterof genes related to recombinant DA biosynthetic enzymes and linked their mechanisms to the construction of a pyrrolidine skeleton. Moreover, Sobrinho et al. (2017) determined that DAconcentrations of P. multiseries significantly increased under high Fe concentration, suggesting that Fe is required for the toxin synthesis. Extracellular DA in water undergoes photodegradationor biodegradation and does not accumulate in the water column (Bejarano et al., 2008; Zabaglo et al., 2016). However, the adsorption of AD in the sediment can have a long-term impacton the trophic web due to its transfer through benthic organisms (Burns and Ferry, 2007; Zabaglo et al., 2016).