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Li J, Zhu G, Liu H, Sheng Y, Hu Q, Lin T, Li T. Soil cadmium pollution elicits sex-specific plant volatile emissions in response to insect herbivory in eastern cottonwood Populus deltoides. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2025; 220:109467. [PMID: 39755098 DOI: 10.1016/j.plaphy.2024.109467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2024] [Revised: 12/06/2024] [Accepted: 12/29/2024] [Indexed: 01/06/2025]
Abstract
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.
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Affiliation(s)
- Jing Li
- 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
| | - Guoqing Zhu
- 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
| | - Hongxia Liu
- 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
| | - Yuanlan Sheng
- 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
| | - Quanjun Hu
- 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
| | - Tiantian Lin
- 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.
| | - Tao Li
- 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.
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Chen YD, Bu ZJ, Wang M, Zhang MM, Ma JZ, Guo HB. Drought mediates Sphagnum defense response to herbivory. AMERICAN JOURNAL OF BOTANY 2024; 111:e16427. [PMID: 39431323 DOI: 10.1002/ajb2.16427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 07/21/2024] [Accepted: 07/22/2024] [Indexed: 10/22/2024]
Abstract
PREMISE The expected concomitant increase in multiple stressors such as herbivory and drought may threaten peatland ecosystems. How Sphagnum, the ecological engineers of peatlands, responds to combined stressors remains largely unexplored. Here we aimed to clarify resource allocations in Sphagnum during concomitant herbivory and drought. METHODS S. magellanicum and S. fuscum were exposed to drought and herbivory together or separately in laboratory experiments and analyzed for growth (biomass production and net photosynthetic rate), defense (phenolics in leachates and phenolics in extraction) and nonstructural carbohydrates (soluble sugar and starch) in relation to untreated controls. RESULTS Herbivory and drought had significant interactive effects on Sphagnum growth and defense. In both species, drought without herbivory reduced the phenolics in leachate, but with herbivory increased phenolics, indicating a synergistic effect between herbivory and drought on Sphagnum defense. Both stressors significantly decreased biomass production, with the combined stress having a more negative effect. Interestingly, a growth-defense trade-off was found in the drought treatment of both Sphagnum species, but disappeared in the wet treatment. Conversely, a trade-off between soluble sugars and phenolics was found in the wet but not in the drought treatment, suggesting that soluble sugars may play a role in inducing the defense and hence mask the growth-defense trade-off in peat mosses. CONCLUSIONS Our results emphasize that predicting the impact of combined stressors on peat moss traits is complex and challenging. Future models should account for the effects of multiple environmental stressors to guide peatland conservation under climate warming.
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Affiliation(s)
- Yong-Da Chen
- School of Geography and Environmental Engineering, Gannan Normal University, Ganzhou, 341000, China
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, 130024, China
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Institute for Peat and Mire Research, Northeast Normal University, Changchun, 130024, China
- Jilin Provincial Key Laboratory for Wetland Ecological Processes and Environmental Change in the Changbai Mountains, Changchun, 130024, China
| | - Zhao-Jun Bu
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, 130024, China
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Institute for Peat and Mire Research, Northeast Normal University, Changchun, 130024, China
- Jilin Provincial Key Laboratory for Wetland Ecological Processes and Environmental Change in the Changbai Mountains, Changchun, 130024, China
| | - Meng Wang
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, 130024, China
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Institute for Peat and Mire Research, Northeast Normal University, Changchun, 130024, China
- Jilin Provincial Key Laboratory for Wetland Ecological Processes and Environmental Change in the Changbai Mountains, Changchun, 130024, China
| | - Ming-Ming Zhang
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, 130024, China
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Institute for Peat and Mire Research, Northeast Normal University, Changchun, 130024, China
- Jilin Provincial Key Laboratory for Wetland Ecological Processes and Environmental Change in the Changbai Mountains, Changchun, 130024, China
| | - Jin-Ze Ma
- School of Geography and Environmental Engineering, Gannan Normal University, Ganzhou, 341000, China
| | - Hong-Bo Guo
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, 130024, China
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
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Mencuccini M. Downscaling investigations in Tree Physiology: mechanisms and context. TREE PHYSIOLOGY 2024; 44:tpae133. [PMID: 39404083 DOI: 10.1093/treephys/tpae133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2024] [Accepted: 10/12/2024] [Indexed: 11/05/2024]
Affiliation(s)
- Maurizio Mencuccini
- CREAF, Edifici C, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
- ICREA, Passeig de Lluís Companys, 23, 08010 Barcelona, Spain
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Thompson RA. A neutral theory of plant carbon allocation. TREE PHYSIOLOGY 2024; 44:tpad151. [PMID: 38102767 DOI: 10.1093/treephys/tpad151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 12/10/2023] [Indexed: 12/17/2023]
Abstract
How plants use the carbon they gain from photosynthesis remains a key area of study among plant ecologists. Although numerous theories have been presented throughout the years, the field lacks a clear null model. To fill this gap, I have developed the first null model, or neutral theory, of plant carbon allocation using probability theory, plant biochemistry and graph theory at the level of a leaf. Neutral theories have been used to establish a null hypothesis in molecular evolution and community assembly to describe how much of an ecological phenomenon can be described by chance alone. Here, the aim of a neutral theory of plant carbon allocation is to ask: how is carbon partitioned between sinks if one assumes plants do not prioritize certain sinks over others? Using the biochemical network of plant carbon metabolism, I show that, if allocation was strictly random, carbon is more likely to be allocated to storage, defense, respiration and finally growth. This 'neutral hierarchy' suggests that a sink's biochemical distance from photosynthesis plays an important role in carbon allocation patterns, highlighting the potentially adaptive role of this biochemical network for plant survival in variable environments. A brief simulation underscores that our ability to measure the carbon allocation from photosynthesis to a given sink is unreliable due to simple probabilistic rules. While neutral theory may not explain all patterns of carbon allocation, its utility is in the minimal assumptions and role as a null model against which future data should be tested.
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Affiliation(s)
- R Alex Thompson
- School of the Environment, Washington State University, Pullman, WA 99164, USA
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