Abonyi András, Pilecky Matthias, Rasconi Serena, Ptacnik Robert, Kainz Martin J
WasserCluster Lunz - Biologische Station GmbH, Dr. Carl Kupelwieser Promenade 5, A-3293 Lunz am See, Austria.
Institute of Aquatic Ecology, Centre for Ecological Research, Karolina út 29, H-1113 Budapest, Hungary.
J Plankton Res. 2023 Apr 21;45(3):454-466. doi: 10.1093/plankt/fbad012. eCollection 2023 May-Jun.
Chytrid fungal parasites increase herbivory and dietary access to essential molecules, such as polyunsaturated fatty acids (PUFA), at the phytoplankton-zooplankton interface. Warming enhances cyanobacteria blooms and decreases algae-derived PUFA for zooplankton. Whether chytrids could support zooplankton with PUFA under global warming scenarios remains unknown. We tested the combined effect of water temperature (ambient: 18°C, heat: +6°C) and the presence of chytrids with as the consumer, and as the main diet. We hypothesized that chytrids would support fitness with PUFA, irrespective of water temperature. Heating was detrimental to the fitness of when feeding solely on the diet. Chytrid-infected diet alleviated the negative impact of heat and could support survival, somatic growth and reproduction. Carbon stable isotopes of fatty acids highlighted a ~3x more efficient n-3 than n-6 PUFA conversion by feeding on the chytrid-infected diet, irrespective of temperature. The chytrid diet significantly increased eicosapentaenoic acid (EPA; 20:5n-3) and arachidonic acid (ARA; 20:4n-6) retention in . The EPA retention remained unaffected, while ARA retention increased in response to heat. We conclude that chytrids support pelagic ecosystem functioning under cyanobacteria blooms and global warming via chytrids-conveyed PUFA toward higher trophic levels.
壶菌真菌寄生虫在浮游植物 - 浮游动物界面增加了食草作用以及对必需分子（如多不饱和脂肪酸，PUFA）的饮食获取。气候变暖会加剧蓝藻水华，并减少浮游动物可获取的藻类来源的PUFA。在全球变暖情景下壶菌是否能为浮游动物提供PUFA仍不清楚。我们测试了水温（环境温度：18°C，高温：+6°C）以及壶菌的存在对以[某种浮游动物]为消费者、以[某种食物]为主要食物的综合影响。我们假设，无论水温如何，壶菌都能通过PUFA来维持[某种浮游动物]的健康状况。当仅以[某种食物]为食时，加热对[某种浮游动物]的健康状况不利。感染壶菌的[某种食物]减轻了高温的负面影响，并能维持[某种浮游动物]的生存、体细胞生长和繁殖。脂肪酸的碳稳定同位素表明，无论温度如何，[某种浮游动物]摄食感染壶菌的食物时，n - 3多不饱和脂肪酸的转化效率比n - 6多不饱和脂肪酸高约3倍。壶菌食物显著提高了[某种浮游动物]中二十碳五烯酸（EPA；20:5n - 3）和花生四烯酸（ARA；20:4n - 6）的保留量。EPA的保留量不受影响，而ARA的保留量则随高温而增加。我们得出结论，在蓝藻水华和全球变暖的情况下，壶菌通过向更高营养级传递PUFA来支持远洋生态系统的功能。
