Division of Ecology & Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia.
New South Wales Fisheries, National Marine Science Centre, 2 Bay Drive, Coffs Harbour, New South Wales, 2450, Australia.
J Phycol. 2023 Feb;59(1):179-192. doi: 10.1111/jpy.13296. Epub 2022 Dec 20.
Foundation seaweed species are experiencing widespread declines and localized extinctions due to increased instability of sea surface temperature. Characterizing temperature thresholds are useful for predicting patterns of change and identifying species most vulnerable to extremes. Existing methods for characterizing seaweed thermal tolerance produce diverse metrics and are often time-consuming, making comparisons between species and techniques difficult, hindering insight into global patterns of change. Using three kelp species, we adapted a high-throughput method - previously used in terrestrial plant thermal biology - for use on kelps. This method employs temperature-dependent fluorescence (T-F ) curves under heating or cooling regimes to determine the critical temperature (T ) of photosystem II (PSII), i.e., the breakpoint between slow and fast rise fluorescence response to changing temperature, enabling rapid assays of photosynthetic thermal tolerance using a standardized metric. This method enables characterization of T for up to 48 samples per two-hour assay, demonstrating the capacity of T-F curves for high-throughput assays of thermal tolerance. Temperature-dependent fluorescence curves and their derived metric, T , may offer a timely and powerful new method for the field of phycology, enabling characterization and comparison of photosynthetic thermal tolerance of seaweeds across many populations, species, and biomes.
由于海平面温度的不稳定性增加，基础海藻物种正经历着广泛的减少和局部灭绝。描述温度阈值有助于预测变化模式，并确定对极端温度最脆弱的物种。现有的海藻耐热性特征描述方法产生了不同的指标，而且通常耗时耗力，使得物种之间和技术之间的比较变得困难，阻碍了对全球变化模式的深入了解。我们使用三种巨藻物种，对一种高通量的方法进行了改编 - 该方法以前在陆地植物热生物学中使用过 - 用于巨藻。该方法在加热或冷却条件下使用温度依赖性荧光（T-F）曲线来确定光系统 II（PSII）的临界温度（T），即荧光对温度变化的慢和快上升响应之间的转折点，从而能够使用标准化指标快速测定光合作用的耐热性。该方法能够在每两个小时的测定中对多达 48 个样本进行 T 的特征描述，证明了 T-F 曲线在耐热性高通量测定中的应用潜力。温度依赖性荧光曲线及其衍生的指标 T 可能为藻类学领域提供一种及时而强大的新方法，使人们能够对许多种群、物种和生物群落中的海藻光合作用耐热性进行特征描述和比较。
