Li Shuangjiang, Yuan Xiangyang, Li Shenglan, Zhou Yuqing, Wang Shenglei, Zhang Kun, Agathokleous Evgenios, Blande James D, Feng Zhaozhong
State Key Laboratory of Climate System Prediction and Risk Management, School of Ecology and Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China.
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science and Technology, Nanjing 210044, China.
Environ Sci Technol. 2025 Jun 24;59(24):12132-12144. doi: 10.1021/acs.est.5c01132. Epub 2025 Jun 13.
Extreme heat and elevated ozone (O) significantly affect plant growth and secondary metabolism, including biogenic volatile organic compound (BVOC) emissions. However, the impact of the extreme heat events (EHs) on the O-induced BVOC emissions remains unclear. Here, (an isoprene emitter) and (a monoterpene emitter) were exposed to five O treatments for three months and subjected to a two-week EH. The emission rates of isoprene and monoterpenes, their synthesis capacities, and reactive oxygen species (ROS) levels were determined to investigate how heat stress modulates O effects. Both BVOC types showed a hormetic response to O, with low doses of O stimulating emissions and high doses suppressing them. Isoprene (Hedges' 2.91) and monoterpene (Hedges' = 2.52) emission rates were inhibited by short-term EH across the five O treatments. However, isoprene emission rates generally recovered during the post-EH period, except under the highest O exposure (NF80). EH also shifted isoprene's response to O from being synthesis-driven to ROS-driven. Although the monoterpene emission rate response to O was driven by synthesis capacity in the pre-EH period, this response became less explainable by either factor post-EH. These findings emphasize the profound effects of EH on the BVOC response to O, providing crucial insights for predicting regional BVOC emissions under future climate scenarios.
极端高温和高浓度臭氧（O）会显著影响植物生长和次生代谢，包括生物源挥发性有机化合物（BVOC）的排放。然而，极端高温事件（EHs）对臭氧诱导的BVOC排放的影响仍不清楚。在此，（一种异戊二烯排放植物）和 （一种单萜排放植物）接受了五种臭氧处理，为期三个月，并经历了为期两周的极端高温处理。测定了异戊二烯和单萜的排放速率、它们的合成能力以及活性氧（ROS）水平，以研究热应激如何调节臭氧的影响。两种BVOC类型对臭氧均表现出 hormetic 响应，低剂量臭氧刺激排放，高剂量则抑制排放。在五种臭氧处理中，短期极端高温均抑制了异戊二烯（Hedges' = 2.91）和单萜（Hedges' = 2.52）的排放速率。然而，除了在最高臭氧暴露水平（NF80）下，异戊二烯排放速率在极端高温处理后通常会恢复。极端高温还使异戊二烯对臭氧的响应从由合成驱动转变为由ROS驱动。尽管在极端高温处理前，单萜排放速率对臭氧的响应是由合成能力驱动的，但在极端高温处理后，这两种因素对该响应的解释力都降低了。这些发现强调了极端高温对BVOC对臭氧响应的深远影响，为预测未来气候情景下的区域BVOC排放提供了关键见解。
