Rapid phlorotannin induction and relaxation in five Washington kelps

Abstract

ABSTRACT-Wounding of both terrestrial and marine plants is known to induce chemical responses in the plants; the induced compounds may defend against herbivory or act in wound-healing processes. We demonstrate here, for the first time, induction of phlorotannins in kelps (Phaeophyta, Laminariales). an important and widespread group of marine benthic algae. The rapid response of kelps to mechanical wounding contrasts with previously published work on other marine algae, where response has been slower. In 4 of the 5 species tested, induction (increases of approximately 30 to 9036 of original levels) occurred very rapidly, within 1 to 3 d of wounding, although the magnitude and duration of the induction varied among species and tissue types. Many induced responses persisted for 5 to 7 d and then relaxed. Relaxation times are a critical component in the hypothesized cost-effectiveness of induced versus constitutive defenses, and this is one of the first attempts to measure relaxation times of chemlcal defenses in marine algae. The temporal persistence of the response suggests an antiherb~vory rather than a wound-healing function for induction of phlorotannins, although this needs further testing KEY MiORDS Kelp phlorotannins . Induction Relaxat~on Chemlcal defense . Wound heal~ng Herb~vory

Chemical mediation of interactions among marine organisms

“…The investigators suggested that the compounds responsible for this induced resistance were probably not phlorotannins because phlorotannin concentrations are very low in S. filipendula and levels of phlorotannins do not relate to feeding by this herbivore. 106 ' 155 Induced defenses in macroalgae usually occur over a period of days 145 to weeks 144 > 155 following damage. The production of activated defenses (wound-induced biotransformation) 156 is an alternative way that herbivores can influence the potency of chemical defenses in algae.…”

Invited Review - Fight on Plankton! or, Phytoplankton Shape and Size as Adaptive Tools to Get Ahead in the Struggle for Life

“…Thus, the timing of defence induction and relaxation are essential elements in the balance of costs and benefits of defences (e.g. Karban & Myers 1989;Adler & Harvell 1990;Hammerstrom et al 1998;Underwood 1998;Young & Okello 1998;Raimondi et al 2000;Zangerl 2003).…”

Variability in grazer-mediated defensive responses of green and red macroalgae on the south coast of South Africa

“…In addition the pilot study showed that grazed pieces of C. platylobium were more preferred than non-grazed pieces (t = À2.97, df = 4, P = 0.04), suggesting an inducible response and we assumed that this alga-grazer combination would be suitable for testing the indirect induction mediated by waterborne cues, as attack by a macrograzer would have a higher impact on the algae and could trigger the release of waterborne cues. Duration of the treatment phase for the screening and multi-treatment experiments was in the range of induction times found in the literature (Hammerstrom et al 1998;Toth and Pavia 2000).…”

“…Six days later, 0.1 g of each algal piece was submerged in 4 ml of 80% methanol for 48 h in total darkness in order to extract polyphenols. To determine the concentration of polyphenols per gram, we used the Folin-Ciocalteu (Sigma) assay (Waterman and Mole 1994;Van Alstyne 1995;Hammerstrom et al 1998) and compared this with a phloroglucinol standard, which was used to calculate the calibration slope (Waterman and Mole 1994). We added 5 ml of the reagent Folin-Ciocalteu to 0.18 ml of the polyphenol extract.…”

“…Grazing effects can be further classified as (a) direct grazing upon the alga (Cronin and Hay 1996;Pavia and Toth 2000;Sotka et al 2002); (b) grazing upon a neighbouring alga that causes the release of an alerting cue into the water ; and (c) the simulation of grazing by artificial damage or clipping (Van Alstyne 1988;Pavia et al 1997;Hammerstrom et al 1998;Pavia and Toth 2000). In the ''talking-trees'' debate of terrestrial systems, it is suggested that a chemical cue from a damaged plant passes through the atmosphere to an undamaged plant.…”