Li Jing, Zhu Guoqing, Liu Hongxia, Sheng Yuanlan, Hu Quanjun, Lin Tiantian, Li Tao
Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Sciences, Sichuan University, Chengdu, 610041, Sichuan, China.
Ministry of Education Key Laboratory for Transboundary Ecosecurity of Southwest China, Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Centre for Invasion Biology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming, 650504, Yunnan, China.
Plant Physiol Biochem. 2025 Mar;220:109467. doi: 10.1016/j.plaphy.2024.109467. Epub 2024 Dec 30.
Soil heavy metal pollution is a major abiotic stressor frequently encountered by plants in conjunction with other biotic stresses like insect herbivory. Yet, it remains largely unexplored how soil metal pollution and insect herbivory act together to influence emissions of plant volatile organic compounds (VOCs), which mediate multiple ecological functions and play crucial roles in atmospheric processes. Here, we assessed the individual and combined effects of soil cadium (Cd) pollution and insect herbivory by Clostera anachoreta on VOC emissions from the seedlings of eastern cottonwood Populus deltoides, and whether these effects depend on plant sex. We found that plant sex notably influenced VOC emission and altered blend compositions, with male seedlings emitting higher amounts of monoterpenes, sesquiterpenes, homoterpenes and green leaf volatiles (GLVs) than females. Soil Cd exposure significantly increased emissions of monoterpenes, GLVs, and nitrogenous VOCs in males but not in females. Comparatively, larval feeding exerted the strongest effects on VOC emissions and their composition, albeit to varying extent between males and females, and among different VOC classes. Importantly, Cd exposure amplified herbivore-induced VOC emissions in males. For instance, under both Cd and herbivory conditions, male seedlings showed a 68.1-fold increase in nitrogenous VOC emissions, almost twice the combined effects of Cd (8.7-fold) and herbivory (26.3-fold). Taken together, these results suggest that soil metal pollution can boost herbivore-induced VOC emissions in a sex-specific manner, with potential implications for ecological interactions and atmospheric processes.
土壤重金属污染是植物经常遇到的主要非生物胁迫因素，同时还伴随着其他生物胁迫，如昆虫取食。然而，土壤金属污染和昆虫取食如何共同作用影响植物挥发性有机化合物（VOCs）的排放，在很大程度上仍未得到充分研究。植物挥发性有机化合物介导多种生态功能，并在大气过程中发挥关键作用。在这里，我们评估了土壤镉（Cd）污染和杨扇舟蛾取食对美洲黑杨幼苗VOC排放的单独和联合影响，以及这些影响是否取决于植物性别。我们发现，植物性别显著影响VOC排放并改变混合成分，雄性幼苗比雌性幼苗释放更多的单萜、倍半萜、高萜和绿叶挥发物（GLVs）。土壤镉暴露显著增加了雄性幼苗中单萜、GLVs和含氮VOC的排放，但雌性幼苗没有。相比之下，幼虫取食对VOC排放及其组成的影响最强，尽管在雄性和雌性之间以及不同VOC类别之间程度不同。重要的是，镉暴露放大了雄性幼苗中食草动物诱导的VOC排放。例如，在镉和食草动物胁迫条件下, 雄性幼苗的含氮VOC排放量增加了68.1倍，几乎是镉（8.7倍）和食草动物（26.3倍）联合作用的两倍。综上所述, 这些结果表明，土壤金属污染可以以性别特异性方式促进食草动物诱导的VOC排放，这对生态相互作用和大气过程具有潜在影响。
