Allelochemicals from Alexandrium minutum induce rapid inhibition of metabolism and modify the membranes from Chaetoceros muelleri

摘要: Abstract Allelochemical interactions are likely to be a contributing factor explaining the success of large blooms harmful marine dinoflagellate Alexandrium, however, physiological mechanisms allelochemical remain poorly described. Here we investigated sub-lethal effects (on an hourly scale) filtrate containing allelochemicals from Alexandrium minutum on physiology common diatom Chaetoceros muelleri. The induced deleterious within only 30 min exposure. Esterase activity and photosynthesis were drastically inhibited, with up 34% population being metabolically inactive 30% reduction in photosystem II quantum yield when exposed filtrate. In addition, intracellular reactive oxygen species increased by 26% response C. muelleri pigment lipid analyses indicated that was photoinhibition-like responses (activation xanthophyll cycles, changes associated lipids) upregulated mitigate toxic allelochemicals. Changes proportions membrane classes fatty acids saturation 9% may attempt maintain integrity enzyme activity, or could result membranes. An 8% decrease cellular storage lipids (triglycerides) revealed mobilization energy suggesting energetic cost for counteract effects. We hypothesize rapid alteration functions such as some enzymatic activities direct damage external Overall this study describes provides useful biomarkers understand role ecological processes structuring plankton communities.