Опубликована: Май 20, 2023

<p><b>With a rapidly changing environment, understanding the endosymbiotic relationship between cnidarians and dinoflagellates is crucial to elucidate ways in which corals may respond future conditions. At basis of this symbiosis exchange metabolites signalling molecules partners, all contribute establishment, maintenance, ultimately dissociation important relationship. A subset metabolites, biogenic volatile organic compounds (BVOCs) are low molecular weight, weakly lipophilic that diffuse quickly through water air, making them potential candidates for inter-species interactions. This thesis sought characterise patterns BVOC generation cnidarian-dinoflagellate across symbiotic states thermal dysfunction model cnidarian Aiptasia (Exaiptasia diaphana). </b></p> <p>In Chapter 2, I characterised suite BVOCs (collectively, ‘volatilome’) emitted by system symbiosis, each partner isolation. Relative anemones, volatilome cultured symbionts (Breviolum minutum) was more distinct than it aposymbiotic (symbiont-free) suggesting alters physiological state dinoflagellate dramatically Aiptasia. For example, B. minutum produced dimethyl sulphide (DMS) highest abundance, while anemones halogenated methanes like bromochloromethane, bromodichloromethane, tribromomethane trichloromethane, regardless state. Alternatively, relative lack alteration host, state, suggest high degree metabolic integration partners. </p> 3, examined role symbiont identity on microbiome Microbiome analysis revealed populations bacteria with family Vibrionaceae being most abundant anemones. As prominent members bacterial pathogens, higher proportion could indicate disease susceptibility volatilomes those native minutum, non-native Durusdinium trenchii indistinct from either aposymbiosis or minutum. suggests presence known form sub-optimal potentially stressful impacts metabolome. Indeed, isoprene containing abundance aldehydes octanal, nonanal dodecanal, these as biomarkers.</p> 4, investigated impact stress its Aposymbiotic were exposed control (25 °C), sub-bleaching (30 °C) bleaching (33.5 temperatures. In both observed restructuring 25 °C 33.5 °C, at 30 exhibiting an intermediate consistent previous experiments showing microbiota can shift response environmental Anemones number significantly different BVOCs, including acetone naphthalene. contrast, temperature lower treatments, largely driven quantities sulphide, eucalyptol 1-iodododecane. Overall, exhibited decline richness progressively temperatures, perhaps revealing onset collapse; decrease not temperature, stabilising effect endosymbionts. 5, describe method assess chemotactic responses Symbiodiniaceae, defined tryptone positive Cladocopium spp., D. trenchii. assessed spp. pervasive marine metabolite dimethylsulphoniopropionate (DMSP), volatiles bromodichloromethane (BrCl2CH) diiodomethane (I2CH2). Despite their production neither BrCl2CH nor I2CH2 elicited sp. The precursor (DMS), multifunctional widespread DMSP has functions osmoregulation, antioxidant defence acts chemoattractant multiple organisms. found that, repelled DMSP, did chemotactically molecule. These differing species Symbiodiniaceae reflect chemical cues used locate establish new hosts, adds literature describing functional diversity <p>Collectively, my elucidates synthesis release stress. foundational study provides platform explore roles identified associates. Additionally, non-invasive technology volatilomics applied here serve identify biomarkers ecosystem health natural habitats. Ultimately, work contributes our altered time when coral reefs threatened extinction.</p>

Язык: Английский