Most plant thermal tolerance studies focus on single critical thresholds, which limit the capacity to generalise across studies and predict heat stress under natural conditions. In animals and microbes, thermal tolerance landscapes describe the more realistic, cumulative effects of temperature. We tested this in plants by measuring the decline in leaf photosynthetic efficiency (FV/FM) following a combination of temperatures and exposure times and then modelled these physiological indices alongside recorded environmental temperatures. We demonstrate that a general relationship between stressful temperatures and exposure durations can be effectively employed to quantify and compare heat tolerance within and across plant species and over time. Importantly, we show how FV/FM curves translate to plants under natural conditions, suggesting that environmental temperatures often impair photosynthetic function. Our findings provide more robust descriptors of heat tolerance in plants and suggest that heat tolerance in disparate groups of organisms can be studied with a single predictive framework.

中文翻译：

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超越单一温度阈值：将累积热应力框架应用于植物耐热性

大多数植物热耐受性研究都集中在单一临界阈值上，这限制了跨研究的泛化能力和预测自然条件下热应激的能力。在动物和微生物中，耐热性景观描述了更现实的温度累积效应。我们通过测量叶片光合效率的下降在植物中进行了测试（FV/F中号）结合温度和暴露时间，然后根据记录的环境温度对这些生理指标进行建模。我们证明，压力温度和暴露持续时间之间的一般关系可以有效地用于量化和比较植物物种内部和跨植物物种之间以及随着时间的推移的耐热性。重要的是，我们展示了如何FV/F中号曲线转化为自然条件下的植物，表明环境温度常常损害光合作用功能。我们的研究结果为植物的耐热性提供了更可靠的描述，并表明可以使用单一的预测框架来研究不同生物群体的耐热性。