Wound-activated algal compounds : toxic, apoptogenic and behavioural effects in marine invertebrates

• Main Author: Maibam, Chingoileima
• Published: Open University 2012
• Subjects: 579
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.590802

Marine micro- and macro-algae produce wound-activated compounds (WACs) as a means to reduce the grazing pressure. However, the primary ecological role of WACs may have been modified by detoxification processes and/or co-evolutionary relationships to play physiologic and behavioural effects on consumers. This study aimed at investigating the possible roles of WACs produced by micro- and macro-algae, i.e., their toxic, physiologic and behavioural effects. Choice experiments revealed the effects as infochemicals of selected microalgae W ACs on invertebrates living in the same community. In parallel, the toxicity of benthic micro- and macro-algae was investigated by means of a standard test on sea urchin embryos. Finally, the physiologic role of diatoms was investigated, testing the effect of Cocconeis scutellum parva on the sex reversal of Hippolyte inermis. The comprehension of these three effects allowed us to draw the main plant-animal relationships ruling various ecological systems and demonstrate that algal WACs play mainly the role of infochemicals for invertebrates living in their typical environment, while they function mainly as allelochemicals for invertebrates living in other environments. The specific toxicity of WACs was shown to be inversely correlated to the perception ability of selected invertebrates, depending on their life strategy: when a recognition of plant-produced volatile compounds is evolved by a given invertebrate, their original power as toxicants and grazing deterrents may be altered, so they become infochemicals or physiologic regulators. The influence of seawater acidification (as forecasted for the end of this century) on the ability of marine invertebrates to perceive WACs' was also investigated and we found influences of pH on invertebrates' odour perception ability. A simulation model was built based on these data and it might find useful application in conservation policies, while the important advancements reached in the identification of the apoptogenic power of diatom's WACs could prime interesting biotechnological applications