Application of the thermal death time model in predicting thermal damage accumulation in plants

Abstract

AbstractThe thermal death time (TDT) model suggests that the duration an organism can tolerate thermal stress decreases exponentially as the intensity of the temperature becomes more extreme. This model has been used to predict damage accumulation in ectotherm animals and plants under fluctuating thermal conditions. However, the critical assumption of the TDT model, which is additive damage accumulation, remains unverified for plants.We assessed thermal damage inThymus vulgarisunder different heat and cold treatments and used TDT models to predict time to thermal failure of PSII. Additionally, thermal tolerance estimates from previous studies were used to create TDT models to assess the applicability of this framework in plants.We show that thermal damage obtained at different stress intensities and durations is additive for both heat and cold stress, and that the TDT model can predict damage accumulation at both temperature extremes. Data from previous studies indicate a broad applicability of this approach across species, traits, and environments.The TDT framework reveals a thermal tolerance landscape describing the exponential relationship between exposure duration, stress intensity and damage accumulation in plants. This thermal sensitivity emphasizes the potential impact of future thermal extremes on the mortality and distribution of plant species.HighlightThis study highlights the applicability of the thermal death time model to plants, unveiling a distinct thermal tolerance landscape, extending across species and traits for assessing thermal stress impacts.