Quantifying high-temperature stress on soybean canopy photosynthesis: The unique role of sun-induced chlorophyll fluorescence
Quantifying high-temperature stress on soybean canopy photosynthesis: The unique role of sun-induced chlorophyll fluorescence
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DOI：
10.1111/gcb.15603
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发表时间：
2021-04-12
影响因子：
11.6
通讯作者：
Wu, Genghong
中科院分区：
文献类型：
--
作者：
Kimm, Hyungsuk;Guan, Kaiyu;Wu, Genghong
高温和伴随的高水汽压亏缺往往会给植物带来压力，而不会导致植物冠层结构和相应的光谱特征发生明显变化。太阳诱导的叶绿素荧光(SIF)由于其与光合作用的机制联系，可能比依赖于冠层结构变化的光谱反射特征的遥感技术更好地检测这种胁迫。然而，我们对SIF的生理机制及其在生理应激检测中的独特潜力的了解还不是很清楚。在本研究中，我们在高温实验--温度自由空气控制增强实验中测量了SIF，以探索SIF在生理研究中的潜力。试验提供了露地环境下大豆冠层温度的梯度，分别比环境冠层温度高1.5、3.0、4.5和6.0摄氏度。SIF产量与光合作用光能利用效率呈高度相关(r=0.89)，并捕捉到植物对高温条件的动态响应。SIF产量受高温胁迫引起的冠层结构和植株生理变化的影响(偏相关r=0.60和-0.23)。植被的近红外反射率只受冠层结构变化的影响，用来减小冠层结构对SIF产量的影响，并提取生理SIF产量(Phi(F))信号。Phi(F)比SIF产量进一步排除了冠层结构的影响，并指示了植物的生理变异，我们发现Phi(F)对生理胁迫的响应优于SIF产量(r=-0.37)。我们的研究结果表明，Phi(F)对高温下大豆总初级生产力的生理下调做出了敏感的反应。PHI(F)如果可靠地来自卫星SIF，则可以支持在环境胁迫和气候变化下监测区域作物生长和不同生态系统的植被生产力。
High temperature and accompanying high vapor pressure deficit often stress plants without causing distinctive changes in plant canopy structure and consequential spectral signatures. Sun-induced chlorophyll fluorescence (SIF), because of its mechanistic link with photosynthesis, may better detect such stress than remote sensing techniques relying on spectral reflectance signatures of canopy structural changes. However, our understanding about physiological mechanisms of SIF and its unique potential for physiological stress detection remains less clear. In this study, we measured SIF at a high-temperature experiment, Temperature Free-Air Controlled Enhancement, to explore the potential of SIF for physiological investigations. The experiment provided a gradient of soybean canopy temperature with 1.5, 3.0, 4.5, and 6.0 degrees C above the ambient canopy temperature in the open field environments. SIF yield, which is normalized by incident radiation and the fraction of absorbed photosynthetically active radiation, showed a high correlation with photosynthetic light use efficiency (r = 0.89) and captured dynamic plant responses to high-temperature conditions. SIF yield was affected by canopy structural and plant physiological changes associated with high-temperature stress (partial correlation r = 0.60 and -0.23). Near-infrared reflectance of vegetation, only affected by canopy structural changes, was used to minimize the canopy structural impact on SIF yield and to retrieve physiological SIF yield (phi(F)) signals. phi(F) further excludes the canopy structural impact than SIF yield and indicates plant physiological variability, and we found that phi(F) outperformed SIF yield in responding to physiological stress (r = -0.37). Our findings highlight that phi(F) sensitively responded to the physiological downregulation of soybean gross primary productivity under high temperature. phi(F), if reliably derived from satellite SIF, can support monitoring regional crop growth and different ecosystems' vegetation productivity under environmental stress and climate change.