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Barnett KL, Johnson SN, Facey SL, Gibson-Forty EVJ, Ochoa-Hueso R, Power SA. Altered precipitation and root herbivory affect the productivity and composition of a mesic grassland. BMC Ecol Evol 2021; 21:145. [PMID: 34266378 PMCID: PMC8283849 DOI: 10.1186/s12862-021-01871-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Climate change models predict changes in the amount, frequency and seasonality of precipitation events, all of which have the potential to affect the structure and function of grassland ecosystems. While previous studies have examined plant or herbivore responses to these perturbations, few have examined their interactions; even fewer have included belowground herbivores. Given the ecological, economic and biodiversity value of grasslands, and their importance globally for carbon storage and agriculture, this is an important knowledge gap. To address this, we conducted a precipitation manipulation experiment in a former mesic pasture grassland comprising a mixture of C4 grasses and C3 grasses and forbs, in southeast Australia. Rainfall treatments included a control [ambient], reduced amount [50% ambient] and reduced frequency [ambient rainfall withheld for three weeks, then applied as a single deluge event] manipulations, to simulate predicted changes in both the size and frequency of future rainfall events. In addition, half of all experimental plots were inoculated with adult root herbivores (Scarabaeidae beetles). RESULTS We found strong seasonal dependence in plant community responses to both rainfall and root herbivore treatments. The largest effects were seen in the cool season with lower productivity, cover and diversity in rainfall-manipulated plots, while root herbivore inoculation increased the relative abundance of C3, compared to C4, plants. CONCLUSIONS This study highlights the importance of considering not only the seasonality of plant responses to altered rainfall, but also the important role of interactions between abiotic and biotic drivers of vegetation change when evaluating ecosystem-level responses to future shifts in climatic conditions.
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Affiliation(s)
- Kirk L Barnett
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
| | - Scott N Johnson
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Sarah L Facey
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Eleanor V J Gibson-Forty
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Raul Ochoa-Hueso
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.,Department of Biology, University of Cádiz, Avenida República Árabe Saharaui, 11510, Puerto Real, Cádiz, Spain
| | - Sally A Power
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
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Crawford MS, Schlägel UE, May F, Wurst S, Grimm V, Jeltsch F. While shoot herbivores reduce, root herbivores increase nutrient enrichment's impact on diversity in a grassland model. Ecology 2021; 102:e03333. [PMID: 33710633 DOI: 10.1002/ecy.3333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/04/2020] [Accepted: 01/11/2021] [Indexed: 11/09/2022]
Abstract
Nutrient enrichment is widespread throughout grassland systems and expected to increase during the Anthropocene. Trophic interactions, like aboveground herbivory, have been shown to mitigate its effect on plant diversity. Belowground herbivory may also impact these habitats' response to nutrient enrichment, but its influence is much less understood, and likely to depend on factors such as the herbivores' preference for dominant species and the symmetry of belowground competition. If preferential toward the dominant, fastest growing species, root herbivores may reduce these species' relative fitness and support diversity during nutrient enrichment. However, as plant competition belowground is commonly considered to be symmetric, root herbivores may be less impactful than shoot herbivores because they do not reduce any competitive asymmetry between the dominant and subordinate plants. To better understand this system, we used an established, two-layer, grassland community model to run a full-factorially designed simulation experiment, crossing the complete removal of aboveground herbivores and belowground herbivores with nutrient enrichment. After 100 yr of simulation, we analyzed communities' diversity, competition on the individual level, as well as their resistance and recovery. The model reproduced both observed general effects of nutrient enrichment in grasslands and the short-term trends of specific experiments. We found that belowground herbivores exacerbate the negative influence of nutrient enrichment on Shannon diversity within our model grasslands, while aboveground herbivores mitigate its effect. Indeed, data on individuals' above- and belowground resource uptake reveals that root herbivory reduces resource limitation belowground. As with nutrient enrichment, this shifts competition aboveground. Since shoot competition is asymmetric, with larger, taller individuals gathering disproportionate resources compared to their smaller, shorter counterparts, this shift promotes the exclusion of the smallest species. While increasing the root herbivores' preferences toward dominant species lessens their negative impact, at best they are only mildly advantageous, and they do very little reduce the negative consequences of nutrient enrichment. Because our model's belowground competition is symmetric, we hypothesize that root herbivores may be beneficial when root competition is asymmetric. Future research into belowground herbivory should account for the nature of competition belowground to better understand the herbivores' true influence.
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Affiliation(s)
- Michael S Crawford
- Transformation Pathways, Potsdam Institute for Climate Impact Research (PIK), Building A65 Room 120, P.O. Box 60 12 03, Telegraphenberg, Potsdam, 14412, Germany.,Department of Plant Ecology and Nature Conservation, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Ulrike E Schlägel
- Department of Plant Ecology and Nature Conservation, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Felix May
- Theoretical Ecology, Institute for Biology, Freie Universität, Berlin, Germany
| | - Susanne Wurst
- Functional Biodiversity, Dahlem Centre of Plant Sciences, Institute of Biology, Freie Universität, Berlin, Germany
| | - Volker Grimm
- Department of Plant Ecology and Nature Conservation, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany.,Department of Ecological Modelling, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany.,Biodiversity Economics, German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Florian Jeltsch
- Department of Plant Ecology and Nature Conservation, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany.,Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
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Liu Y, Wang W, Li Y, Liu F, Han W, Li J. Transcriptomic and proteomic responses to brown plant hopper (Nilaparvata lugens) in cultivated and Bt-transgenic rice (Oryza sativa) and wild rice (O. rufipogon). J Proteomics 2020; 232:104051. [PMID: 33217583 DOI: 10.1016/j.jprot.2020.104051] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/27/2020] [Accepted: 11/15/2020] [Indexed: 10/23/2022]
Abstract
Strategies are still employed to reduce insect damage in crop production, including conventional breeding with wild germplasm resources and transgenic technology with foreign genes' insertion. Cultivated and Bt-transgenic rice (Oryza sativa) and two ecotypes of wild rice (O. rufipogon) were treated by a 72 h feeding of brown plant hopper (Nilaparvata lugens). Under the feeding of N. lugens, compared with the cultivated rice (568 and 4), more differentially expressed genes (DEGs) and differentially accumulated proteins (DAPs) were identified in transgenic rice (2098 and 11) and two wild ecotypes (1990, 39 and 1932, 25, respectively). The iTRAQ analysis showed 79 DAPs and confirmed the results of RNA-seq, which showed the least GO terms and KEGG pathways responding to herbivory in the cultivated rice. DAPs significantly enriched two GO terms that are related with Bph14 and Bph33 genes in rice. Most of DEGs and DAPs were related to plant biological processes of plant-pathogen interaction and plant hormone signal transduction, and hormone signaling and transcription factors regulate the immune response of rice to BPH. Our results demonstrated the similarity in the wild rice and Bt-transgenic rice for their transcriptomic and proteomic response to herbivory, while cultivated rice lacked enough pathways in response to herbivory. STATEMENT OF SIGNIFICANCE OF THE STUDY: The iTRAQ analysis and RNA-seq were employed 39 to identify differentially expressed genes (DEGs) and differentially accumulated proteins (DAPs) in seedlings of cultivated, Bt-transgenic and two wild rice ecotypes under feeding of brown plant hopper. Wild rice showed DEGs and DAPs related to biochemical pathways of plant pathogen interactions and plant hormone signal transductions, while cultivated rice lacked enough pathways in response to herbivory. Crop domestication weakened the response of plants to herbivory, while the insertion of Bt gene might promote the response of plants to herbivory. Growing environment plays an important role in regulating gene networks of plant response to herbivory. Our results highlighted the importance of conservation of crop wild species. SIGNIFICANCE: Insect damage is one of main factors in reducing agricultural production, and technologies and methods were employed to control insect pests in agricultural systems. Transgenic technology is developed to produce insect-resistant crops, but receive concerns on biosafety risks. Alternatively, crop wild species are important genetic resource in crop breeding to produce trait-specific varieties. Here, we investigated the molecular mechanisms of plant response to herbivory in wild, Bt-transgenic and cultivated rice, and found crop domestication weakened the response of plants to herbivory. The insertion of foreign Bt gene may promote the expression of other genes. In addition, our results showed growing environment plays an important role in regulating gene networks of plant response to herbivory. These results highlight the importance of wild species conservation, with the strategy of in situ conservation.
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Affiliation(s)
- Yongbo Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Weiqing Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, CAS, Beijing 100093, China
| | - Yonghua Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Fang Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Weijuan Han
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Junsheng Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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Huber M, Bont Z, Fricke J, Brillatz T, Aziz Z, Gershenzon J, Erb M. A below-ground herbivore shapes root defensive chemistry in natural plant populations. Proc Biol Sci 2016; 283:20160285. [PMID: 27009228 DOI: 10.1098/rspb.2016.0285] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 02/22/2016] [Indexed: 01/03/2023] Open
Abstract
Plants display extensive intraspecific variation in secondary metabolites. However, the selective forces shaping this diversity remain often unknown, especially below ground. Using Taraxacum officinale and its major native insect root herbivore Melolontha melolontha, we tested whether below-ground herbivores drive intraspecific variation in root secondary metabolites. We found that high M. melolontha infestation levels over recent decades are associated with high concentrations of major root latex secondary metabolites across 21 central European T. officinale field populations. By cultivating offspring of these populations, we show that both heritable variation and phenotypic plasticity contribute to the observed differences. Furthermore, we demonstrate that the production of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) is costly in the absence, but beneficial in the presence of M. melolontha, resulting in divergent selection of TA-G. Our results highlight the role of soil-dwelling insects for the evolution of plant defences in nature.
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Affiliation(s)
- Meret Huber
- Root Herbivore Interactions Group, Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Zoe Bont
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Julia Fricke
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Théo Brillatz
- Root Herbivore Interactions Group, Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Zohra Aziz
- Root Herbivore Interactions Group, Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Matthias Erb
- Root Herbivore Interactions Group, Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany Institute of Plant Sciences, University of Bern, Bern, Switzerland
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Wurst S, Ohgushi T. Do plant‐ and soil‐mediated legacy effects impact future biotic interactions? Funct Ecol 2015. [DOI: 10.1111/1365-2435.12456] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Susanne Wurst
- Dahlem Centre of Plant Sciences (DCPS) Functional Biodiversity Freie Universität Berlin Königin‐Luise‐Str. 1‐3 14195 Berlin Germany
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