Allelochemicals of Alexandrium minutum: Kinetics of membrane disruption and photosynthesis inhibition in a co-occurring diatom

摘要: Abstract Allelopathy is an efficient strategy by which some microalgae can outcompete other species. Allelochemicals from the toxic dinoflagellate Alexandrium minutum have deleterious effects on diatoms, inhibiting metabolism and photosynthesis therefore give a competitive advantage to dinoflagellate. The precise mechanisms of allelochemical interactions molecular target allelochemicals remain however unknown. To understand mechanisms, short-term A. physiology diatom Chaetoceros muelleri were investigated. culture filtrate measured cytoplasmic membrane integrity (polarity permeability) using flow-cytometry photosynthetic performance fluorescence absorption spectroscopy. Within 10 min, unknown induced depolarization membranes impairment through inhibition plastoquinone-mediated electron transfer between photosystem II cytochrome b6f. At longer time exposure, permeable photosystems I, b6f was compromised. Our demonstration essential role in this interaction provides new insights for elucidation nature allelochemicals. relationship remains unclear warrants further investigation.