Bertel Clara, Neuner Gilbert
Department of Botany, University of Innsbruck, Sternwartestr. 15, 6020, Innsbruck, Austria.
Plant Methods. 2025 Jul 1;21(1):89. doi: 10.1186/s13007-025-01404-6.
Global warming is currently occurring at a rapid rate and is having a particularly severe impact on plants, which, as sessile organisms, have a limited ability to escape high temperatures. This requires a better understanding of the thermal limits for different plant species and a better understanding of the processes involved in the development of heat injury in plant leaves. Heat injury results from multiple processes and occurs at the molecular level, involving increased membrane fluidity, lipid peroxidation, and protein aggregation and denaturation.
We have tested whether the DSC method allows the detection of heat-induced denaturation and aggregation of molecules in intact leaves. During controlled heating a consistent and repeatable pattern was observed in the DSC plot, from which critical heat thresholds could be derived. These critical temperatures were in good agreement with the temperatures determined using classical methods and also clearly mark the thermal limits of molecular structures. The advantage of the DCS method is the precise, rapid and easy detection of heat thresholds. Finally, taken all thresholds together, we can draw a better image of the sequence of events associated with heat injury in plant leaves: heat injury begins with membrane leakage and continues with protein denaturation and aggregation at high (sublethal, lethal) temperatures.
Since heat injury results from multiple processes, a holistic understanding requires the acquisition of parameters indicative of different processes. The presented DSC method, which allows the detection of denaturation and aggregation of cellular compounds, therefore complements well the classical methods that reflect photosynthetic impairment and whole leaf tissue damage. The new simple and rapid method requires only a minimal amount of leaf material and allows rapid collection of data on damaging temperatures for different plants, which is particularly important in the face of rapidly progressing climatic changes.
全球变暖目前正在快速发生，对植物产生了特别严重的影响。作为固着生物，植物逃避高温的能力有限。这就需要更好地了解不同植物物种的热极限，以及更好地理解植物叶片热损伤发生过程中所涉及的过程。热损伤是由多种过程导致的，发生在分子水平，涉及膜流动性增加、脂质过氧化以及蛋白质聚集和变性。
我们测试了差示扫描量热法（DSC）是否能够检测完整叶片中热诱导的分子变性和聚集。在控制加热过程中，DSC图谱中观察到了一致且可重复的模式，从中可以得出临界热阈值。这些临界温度与使用经典方法确定的温度高度一致，也清晰地标志着分子结构的热极限。DSC方法的优点是能够精确、快速且容易地检测热阈值。最后，综合所有阈值，我们可以更清楚地描绘出与植物叶片热损伤相关的一系列事件：热损伤始于膜泄漏，在高温（亚致死、致死）下继续发展为蛋白质变性和聚集。
由于热损伤是由多种过程导致的，全面理解需要获取指示不同过程的参数。本文介绍的DSC方法能够检测细胞化合物的变性和聚集，因此很好地补充了反映光合损伤和全叶组织损伤的经典方法。这种新的简单快速方法只需要极少的叶片材料，并且能够快速收集不同植物损伤温度的数据，这在气候变化迅速发展的情况下尤为重要。
