Heat challenge elicits stronger physiological and gene expression responses than starvation in symbiotic Oculina arbuscula
Heat challenge elicits stronger physiological and gene expression responses than starvation in symbiotic Oculina arbuscula
复制标题
在共生的 Oculina arbuscula 中，热挑战比饥饿引发更强的生理和基因表达反应
DOI：
10.1093/jhered/esac068
复制
发表时间：
2023
影响因子：
3.1
通讯作者：
Davies, Sarah W
中科院分区：
文献类型：
--
作者：
Rivera, Hanny E;Tramonte, Carlos A;Samaroo, Jason;Dickerson, Hayden;Davies, Sarah W
异养已被证明可以减轻热挑战下的珊瑚-藻类生态失调（珊瑚漂白），但这种现象背后的分子机制仍然在很大程度上未被探索。在这里，我们定量珊瑚生理学和基因表达片段的13个基因型的共生Oculina arbuscula后，28天的喂养实验下（1）美联储，环境（24 °C）;（2）unfed，环境;（3）美联储，加热（斜坡到33 °C）;（4）unfed，加热处理。我们在整个实验过程中监测藻类的光合效率，并在28天后，剖析珊瑚和藻类的碳水化合物和蛋白质储备，珊瑚基因表达，藻类细胞密度，叶绿素a和叶绿素c2色素。与以前的研究结果相反，异养并没有减轻温度的影响，我们观察到一些显着的差异，在热的挑战下喂养和不喂养的珊瑚之间的生理。我们的研究结果表明，饥饿和热挑战的持续时间和强度在珊瑚能量学和压力反应中发挥着有意义的作用;迫切需要进一步研究这些阈值以及它们如何影响珊瑚在气候变化下的反应。在喂食和未喂食的珊瑚热挑战下的基因表达模式显示基因本体富集模式与环境应激反应的经典签名一致。虽然喂食和未喂食的珊瑚在热挑战下的基因表达差异是微妙的：未喂食，加热的珊瑚独特地上调与细胞周期功能相关的基因，这表明饥饿可能会诱导先前描述的，温和的“B型”珊瑚应激反应。未来的研究有兴趣解开异养珊瑚漂白的影响将受益于利用这里研究的兼性物种，但使用珊瑚在其共生和非共生状态。
Heterotrophy has been shown to mitigate coral–algal dysbiosis (coral bleaching) under heat challenge, but the molecular mechanisms underlying this phenomenon remain largely unexplored. Here, we quantified coral physiology and gene expression of fragments from 13 genotypes of symbioticOculina arbusculaafter a 28-d feeding experiment under (1) fed, ambient (24 °C); (2) unfed, ambient; (3) fed, heated (ramp to 33 °C); and (4) unfed, heated treatments. We monitored algal photosynthetic efficiency throughout the experiment, and after 28 d, profiled coral and algal carbohydrate and protein reserves, coral gene expression, algal cell densities, and chlorophyll-a and chlorophyll-c2pigments. Contrary to previous findings, heterotrophy did little to mitigate the impacts of temperature, and we observed few significant differences in physiology between fed and unfed corals under heat challenge. Our results suggest the duration and intensity of starvation and thermal challenge play meaningful roles in coral energetics and stress response; future work exploring these thresholds and how they may impact coral responses under changing climate is urgently needed. Gene expression patterns under heat challenge in fed and unfed corals showed gene ontology enrichment patterns consistent with classic signatures of the environmental stress response. While gene expression differences between fed and unfed corals under heat challenge were subtle: Unfed, heated corals uniquely upregulated genes associated with cell cycle functions, an indication that starvation may induce the previously described, milder “type B” coral stress response. Future studies interested in disentangling the influence of heterotrophy on coral bleaching would benefit from leveraging the facultative species studied here, but using the coral in its symbiotic and aposymbiotic states.