State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, China.
College of Life and Environmental Sciences, Wenzhou University, Wenzhou, 325035, China.
Environ Pollut. 2023 Jan 1;316(Pt 1):120593. doi: 10.1016/j.envpol.2022.120593. Epub 2022 Nov 3.
Green plants in urban environments experience cyclical particulate matter stress. And this history of exhaust exposure may generate stress memory in plants, which may alter their subsequent response. Studies combining urban pollution characteristics and stress memory are limited. Therefore, we selected E. japonicus var. aurea-marginatus, a common urban greening tree species in the Yangtze River Delta, and conducted an experiment in three periods: the initial pollution period (S1: 28 days), the recovery period (R: 14 days) and the secondary pollution period (S2: 28 days). The experimental design consisted of an elevated pollution treatment (173 μg•cm) and an ambient control (34 μg•cm) with three replicates. In S2, the net total particle retention and saturated particle retention decreased by 11.5% and 19.3%, respectively, while PM and PM did not change significantly. E. japonicus var. aurea-marginatus exhibited recovery of chlorophyll levels, slower degradation of carotenoid, faster accumulation of ASA, lower accumulation of MDA, reduced activity of SOD under the second pollution period, and the period had a significant effect on the physiological indicators. Collectively, the effect of autoexhaust exposure history on the particle retention capacity of selected plant varied across particle sizes, and stress memory may confer plant resistance to recurrent exhaust pollution via combined regulations of physiological responses. Fine particles which pose a great risk to human health arise predominantly from vehicular traffic and energy production. So, E. japonicus tends to play a stabilising role in particle retention in industrial, traffic and residential areas.
城市环境中的绿色植物会经历周期性的颗粒物胁迫。而这种尾气暴露史可能会在植物中产生应激记忆，从而改变它们随后的反应。将城市污染特征与应激记忆相结合的研究还很有限。因此，我们选择了长三角地区常见的城市绿化树种金叶瓜子黄杨，在三个时期进行了实验：初始污染期（S1：28 天）、恢复期（R：14 天）和二次污染期（S2：28 天）。实验设计包括一个升高的污染处理（173μg•cm）和一个环境对照（34μg•cm），每个处理重复三次。在 S2 中，净总颗粒物截留和饱和颗粒物截留分别下降了 11.5%和 19.3%，而 PM 和 PM 没有明显变化。金叶瓜子黄杨的叶绿素水平恢复，类胡萝卜素降解速度较慢，ASA 积累速度较快，MDA 积累量较低，SOD 活性在第二次污染期下降，这一时期对生理指标有显著影响。总的来说，自动尾气暴露史对所选植物的颗粒物截留能力的影响因颗粒物大小而异，应激记忆可能通过对生理反应的综合调节赋予植物对反复出现的尾气污染的抗性。对人类健康构成巨大风险的细颗粒物主要来自交通和能源生产。因此，金叶瓜子黄杨在工业、交通和居民区的颗粒物截留中可能起到稳定作用。
