Photosynthetic heat tolerances and extreme leaf temperatures
Photosynthetic heat tolerances and extreme leaf temperatures
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DOI：
10.1111/1365-2435.13658
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发表时间：
2020-09-05
影响因子：
5.2
通讯作者：
Feeley, Kenneth J.
中科院分区：
文献类型：
--
作者：
Perez, Timothy M.;Feeley, Kenneth J.
光合耐热性（PHTs）有几个潜在的应用，包括预测哪些物种将最容易受到气候变化的影响。考虑到植物表现出独特的温度调节特性，影响叶片温度，并将其与环境空气温度分离，我们假设PHTs应该与极端叶片温度而不是空气温度相关。我们测量了生长在费尔柴尔德热带植物园（珊瑚山墙，FL，USA）的19种植物的叶片温度调节特性、最高叶温（T-MO）和两个PHT指标（T（crit）和T（50））。在花园和微环境变量测量的温度调节特性参数化的叶能量平衡模型，估计最高原位叶温度（T-MIS）在13个物种的地理分布。T（MO）、T（MIS）与T（50）呈正相关，与T（crit）无相关性。物种的热安全裕度宽度（T（50）与T（MO）之差）与T（50）呈负相关。我们的研究结果提供了观测和理论支持的基础上的第一性原理的方法的假设，PHTs可能是适应极端的叶温，但反驳的假设，具有较高的PHTs的物种是不太容易受到热损伤。我们的研究还介绍了一种新的方法，通过结合生物物理和物种分布模型研究植物生态生理学，并强调如何使用空气温度与叶温可能会导致相互矛盾的结论物种对热损伤的脆弱性。在本文的支持信息中可以找到一个免费的简明语言摘要。
Photosynthetic heat tolerances (PHTs) have several potential applications including predicting which species will be most vulnerable to climate change. Given that plants exhibit unique thermoregulatory traits that influence leaf temperatures and decouple them from ambient air temperatures, we hypothesized that PHTs should be correlated with extreme leaf temperatures as opposed to air temperatures. We measured leaf thermoregulatory traits, maximum leaf temperatures (T-MO) and two metrics of PHT (T(crit)andT(50)) quantified using the quantum yield of photosystem II for 19 plant species growing in Fairchild Tropical Botanic Garden (Coral Gables, FL, USA). Thermoregulatory traits measured at the Garden and microenvironmental variables were used to parameterize a leaf energy balance model that estimated maximum in situ leaf temperatures (T-MIS) across the geographic distributions of 13 species. T(MO)andT(MIS)were positively correlated withT(50)but were not correlated withT(crit). The breadth of species' thermal safety margins (the difference betweenT(50)andT(MO)) was negatively correlated withT(50). Our results provide observational and theoretical support based on a first principles approach for the hypothesis that PHTs may be adaptations to extreme leaf temperature, but refute the assumption that species with higher PHTs are less susceptible to thermal damage. Our study also introduces a novel method for studying plant ecophysiology by incorporating biophysical and species distribution models, and highlights how the use of air temperature versus leaf temperature can lead to conflicting conclusions about species vulnerability to thermal damage. A freePlain Language Summarycan be found within the Supporting Information of this article.