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Chen H, Chen C, Huang S, Zhao M, Wang T, Jiang T, Wang C, Tao Z, Zhang Y, Wang Y, Wang W, Tang Q, Li P. Inactivation of RPX1 in Arabidopsis confers resistance to Plutella xylostella through the accumulation of the homoterpene DMNT. Plant Cell Environ 2023; 46:946-961. [PMID: 36582057 PMCID: PMC10107731 DOI: 10.1111/pce.14528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 12/19/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
The lepidopteran crop pest Plutella xylostella causes severe constraints on Brassica cultivation. Here, we report a novel role for RPX1 (resistance to P. xylostella) in resistance to this pest in Arabidopsis thaliana. The rpx1-1 mutant repels P. xylostella larvae, and feeding on the rpx1-1 mutant severely damages the peritrophic matrix structure in the midgut of the larvae, thereby negatively affecting larval growth and pupation. This resistance results from the accumulation of defence compounds, including the homoterpene (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), due to the upregulation of PENTACYCLIC TRITERPENE SYNTHASE 1 (PEN1), which encodes a key DMNT biosynthetic enzyme. P. xylostella infestation and wounding induce RPX1 protein degradation, which may confer a rapid response to insect infestation. RPX1 inactivation and PEN1 overexpression are not associated with negative trade-offs for plant growth but have much higher seed production than the wild-type in the presence of P. xylostella infestation. This study offers a new strategy for plant molecular breeding against P. xylostella.
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Affiliation(s)
- Hongyi Chen
- The National Engineering Lab of Crop Stress Resistance Breeding, School of Life SciencesAnhui Agricultural UniversityHefeiChina
| | - Chen Chen
- The National Engineering Lab of Crop Stress Resistance Breeding, School of Life SciencesAnhui Agricultural UniversityHefeiChina
- Department of Microbiology, the Key Laboratory of Microbiology and Parasitology of Anhui Province, the Key Laboratory of Zoonoses of High Institutions in Anhui, School of Basic Medical SciencesAnhui Medical UniversityHefeiChina
| | - Shijie Huang
- The National Engineering Lab of Crop Stress Resistance Breeding, School of Life SciencesAnhui Agricultural UniversityHefeiChina
| | - Mengjie Zhao
- The National Engineering Lab of Crop Stress Resistance Breeding, School of Life SciencesAnhui Agricultural UniversityHefeiChina
| | - Tengyue Wang
- The National Engineering Lab of Crop Stress Resistance Breeding, School of Life SciencesAnhui Agricultural UniversityHefeiChina
| | - Taoshan Jiang
- The National Engineering Lab of Crop Stress Resistance Breeding, School of Life SciencesAnhui Agricultural UniversityHefeiChina
| | - Chuanhong Wang
- The National Engineering Lab of Crop Stress Resistance Breeding, School of Life SciencesAnhui Agricultural UniversityHefeiChina
| | - Zhen Tao
- The National Engineering Lab of Crop Stress Resistance Breeding, School of Life SciencesAnhui Agricultural UniversityHefeiChina
| | - Yan Zhang
- The National Engineering Lab of Crop Stress Resistance Breeding, School of Life SciencesAnhui Agricultural UniversityHefeiChina
| | - Yunhe Wang
- The National Engineering Lab of Crop Stress Resistance Breeding, School of Life SciencesAnhui Agricultural UniversityHefeiChina
| | - Wanyi Wang
- The National Engineering Lab of Crop Stress Resistance Breeding, School of Life SciencesAnhui Agricultural UniversityHefeiChina
| | - Qingfeng Tang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant ProtectionAnhui Agricultural UniversityHefeiChina
| | - Peijin Li
- The National Engineering Lab of Crop Stress Resistance Breeding, School of Life SciencesAnhui Agricultural UniversityHefeiChina
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Abstract
Conifers are dominant tree species in boreal forests, but are susceptible to attack by bark beetles. Upon bark beetle attack, conifers release substantial quantities of volatile organic compounds known as herbivore-induced plant volatiles (HIPVs). Earlier studies of broadleaved plants have shown that HIPVs provide information to neighbouring plants, which may enhance their defences. However, the defence responses of HIPV-receiver plants have not been described for conifers. Here we advance knowledge of plant-plant communication in conifers by documenting a suite of receiver-plant responses to bark-feeding-induced volatiles. Scots pine seedlings exposed to HIPVs were more resistant to subsequent weevil feeding and received less damage. Receiver plants had both induced and primed volatile emissions and their resin ducts had an increased epithelial cell (EC) mean area and an increased number of cells located in the second EC layer. Importantly, HIPV exposure increased stomatal conductance and net photosynthesis rate of receiver plants. Receiver-plant responses were also examined under elevated ozone conditions and found to be significantly altered. However, the final defence outcome was not affected. These findings demonstrate that HIPVs modulate conifer metabolism through responses spanning photosynthesis and chemical defence. The responses are adjusted under ozone stress, but the defence benefits remain intact.
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Affiliation(s)
- Hao Yu
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, 70211 Kuopio, Finland
| | - Minna Kivimäenpää
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, 70211 Kuopio, Finland
| | - James D Blande
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, 70211 Kuopio, Finland
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Arce CM, Besomi G, Glauser G, Turlings TCJ. Caterpillar-Induced Volatile Emissions in Cotton: The Relative Importance of Damage and Insect-Derived Factors. Front Plant Sci 2021; 12:709858. [PMID: 34413869 PMCID: PMC8369242 DOI: 10.3389/fpls.2021.709858] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 06/28/2021] [Indexed: 05/25/2023]
Abstract
In response to herbivore attack, plants release large amounts of volatiles that can serve as attractants for the natural enemies of the attacking herbivores. Such responses are typically triggered by damage- and insect-associated factors. Cotton plants are somewhat peculiar because they release specific blends of volatiles in two waves in response to caterpillar attack. They first emit constitutively stored volatile compounds, and after about 24 h a second wave that includes various de novo synthesized compounds. The relative importance of damage-associated and insect associated-factors in this induction of cotton volatile emissions is not yet fully clear. We evaluated how cotton plants respond to mechanical damage and to the application of the oral secretion from the generalist lepidopteran pest Spodoptera exigua, by measuring the local and systemic emissions of volatile compounds from their leaves. Our results confirm that cotton plants respond to damage-associated molecular patterns (DAMPs) as well as to herbivore-associated molecular patterns (HAMPs) present in the caterpillars' oral secretion. Interestingly, a stronger response was observed for cotton plants that were treated with oral secretion from cotton-fed caterpillars than those fed on maize. We tested the possibility that volicitin, a common fatty acid-derived elicitor in caterpillar regurgitant plays a role in this difference. Volicitin and volicitin-like compounds were detected in equal amounts in the oral secretion of S. exigua fed on either cotton or maize leaves. We conclude that other elicitors must be involved. The identification of these eliciting cues is expected to contribute to the development of novel strategies to enhance the resistance of cotton plants to insect pests.
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Affiliation(s)
- Carla M. Arce
- Laboratory of Fundamental and Applied Research in Chemical Ecology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Gaia Besomi
- Laboratory of Fundamental and Applied Research in Chemical Ecology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Gaétan Glauser
- Neuchâtel Platform of Analytical Chemistry, University of Neuchâtel, Neuchâtel, Switzerland
| | - Ted C. J. Turlings
- Laboratory of Fundamental and Applied Research in Chemical Ecology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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Ninkovic V, Markovic D, Rensing M. Plant volatiles as cues and signals in plant communication. Plant Cell Environ 2021; 44:1030-1043. [PMID: 33047347 PMCID: PMC8048923 DOI: 10.1111/pce.13910] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 10/05/2020] [Accepted: 10/05/2020] [Indexed: 05/05/2023]
Abstract
Volatile organic compounds are important mediators of mutualistic interactions between plants and their physical and biological surroundings. Volatiles rapidly indicate competition or potential threat before these can take place, and they regulate and coordinate adaptation responses in neighbouring plants, fine-tuning them to match the exact stress encountered. Ecological specificity and context-dependency of plant-plant communication mediated by volatiles represent important factors that determine plant performance in specific environments. In this review, we synthesise the recent progress made in understanding the role of plant volatiles as mediators of plant interactions at the individual and community levels, highlighting the complexity of the plant receiver response to diverse volatile cues and signals and addressing how specific responses shape plant growth and survival. Finally, we outline the knowledge gaps and provide directions for future research. The complex dialogue between the emitter and receiver based on either volatile cues or signals determines the outcome of information exchange, which shapes the communication pattern between individuals at the community level and determines their ecological implications at other trophic levels.
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Affiliation(s)
- Velemir Ninkovic
- Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
| | - Dimitrije Markovic
- Department of Crop Production EcologySwedish University of Agricultural SciencesUppsalaSweden
- Faculty of Agriculture, University of Banja LukaBanja LukaBosnia and Herzegovina
| | - Merlin Rensing
- Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
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Lin Y, Ruan H, Akutse KS, Lai B, Lin Y, Hou Y, Zhong F. Ethylene and Benzaldehyde Emitted from Postharvest Tomatoes Inhibit Botrytis cinerea via Binding to G-Protein Coupled Receptors and Transmitting with cAMP-Signal Pathway of the Fungus. J Agric Food Chem 2019; 67:13706-13717. [PMID: 31693347 DOI: 10.1021/acs.jafc.9b05778] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Tomato storage conditions are difficult largely due to Botrytis cinerea infection which causes gray mold disease. However, the effects of the volatile organic compounds (VOCs) emitted by postharvest tomatoes on this fungus remain unclear. We analyzed the effects of tomato-emitted VOCs on B. cinerea pathogenicity, germination, and hyphal growth with bioassay, predicted the causative active compounds by principle component analysis, identified G-protein-coupled receptors (GPCRs) which captured chemical signals in the B. cinerea genome by stimulating molecular docking, tested the binding affinities of these receptors for the active compounds by fluorescence binding competition assay, and identified an associated signaling pathway by RNA interfere. The VOCs emitted by postharvest tomatoes inhibited B. cinerea; ethylene and benzaldehyde were the active compounds causing this effect. One of the identified GPCRs in B. cinerea, BcGPR3, bound tightly to both active compounds. Two genes associated with the cAMP signaling pathway (BcRcn1 and BcCnA) were downregulated in wild-type B. cinerea exposed to the active compounds, as well as in the ΔBcgpr3 B. cinerea mutant. Exposure to postharvest tomato VOCs reduces B. cinerea pathogenicity due to ethylene and benzaldehyde volatiles. The BcGPR3 protein is inactivated by the active compounds, and thus fails to transmit signals to the cAMP pathway, thereby inhibiting B. cinerea.
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Affiliation(s)
- Yongwen Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & College of Horticulture , Fujian Agriculture and Forestry University Fujian , 350013 Fuzhou , Fujian , P. R. China
| | - Hongchun Ruan
- Institute of Plant Protection , Fujian Academy of Agricultural Sciences , 350013 Fuzhou , Fujian , P. R. China
| | - Komivi Senyo Akutse
- International Centre of Insect Physiology and Ecology , 30772-00100 Nairobi , Kenya
| | - Baochun Lai
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & College of Horticulture , Fujian Agriculture and Forestry University Fujian , 350013 Fuzhou , Fujian , P. R. China
| | - Yizhang Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & College of Horticulture , Fujian Agriculture and Forestry University Fujian , 350013 Fuzhou , Fujian , P. R. China
| | - Youming Hou
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & College of Horticulture , Fujian Agriculture and Forestry University Fujian , 350013 Fuzhou , Fujian , P. R. China
| | - Fenglin Zhong
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & College of Horticulture , Fujian Agriculture and Forestry University Fujian , 350013 Fuzhou , Fujian , P. R. China
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Forney CF, Fan L, Bezanson GS, Ells TC, LeBlanc DI, Fillmore S. Impact of Listeria Inoculation and Aerated Steam Sanitization on Volatile Emissions of Whole Fresh Cantaloupes. J Food Sci 2018; 83:1017-1024. [PMID: 29660130 DOI: 10.1111/1750-3841.14092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 01/18/2018] [Accepted: 01/29/2018] [Indexed: 11/30/2022]
Abstract
Rapid methods to detect bacterial pathogens on food and strategies to control them are needed to mitigate consumer risk. This study assessed volatile emissions from whole cantaloupe melons (Cucumis melo) as an indicator of Listeria contamination and in response to steam vapor decontamination. Cantaloupe were inoculated with Listeria innocua, a nonpathogenic surrogate for L. monocytogenes, then exposed to 85 °C steam for 240 s (4 min) followed by rapid chilling and storage for 0, 7, 10, or 14 days at 4, 7, or 10 °C. Volatile emissions from whole melons were collected on Carbopack B/Carboxen 1000 headspace collection tubes and analyzed by gas chromatography-mass spectroscopy following thermal desorption. Introduction of L. innocua to cantaloupe rind resulted in a reduction of aromatic compound emission. However, this response was not unique to Listeria contamination in that steam vapor treatment also reduced emission of these compounds. As well, steam vapor treatment diminished the number of viable Listeria and indigenous microflora while causing physiological injury to melon rind. Heat treatment had no significant effects on flesh firmness, color, titratable acidity, or soluble solids, but the production of typical aroma volatiles during postharvest ripening was inhibited. No unique volatile compounds were detected in Listeria contaminated melons. While changes in volatile emissions were associated with Listeria inoculation, they could not be differentiated from heat treatment effects. Results indicate that volatile emissions cannot be used as a diagnostic tool to identify Listeria contamination in whole cantaloupe melons. PRACTICAL APPLICATION The detection of pathogen contamination on fresh produce is a continuing challenge. Using a nondestructive screening method, the presence of surrogate Listeria innocua on fresh whole cantaloupes was shown to alter the emissions of aromatic volatiles from whole cantaloupes. However, these altered emissions were not found to be unique to Listeria spp. and therefore cannot be used as a definitive indicator of Listeria contamination.
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Affiliation(s)
- Charles F Forney
- Agriculture and Agri-Food Canada, Kentville Research and Development Centre, 32 Main Street, Kentville, Nova Scotia, B4N 1J5, Canada
| | - Lihua Fan
- Agriculture and Agri-Food Canada, Kentville Research and Development Centre, 32 Main Street, Kentville, Nova Scotia, B4N 1J5, Canada
| | - Gregory S Bezanson
- Agriculture and Agri-Food Canada, Kentville Research and Development Centre, 32 Main Street, Kentville, Nova Scotia, B4N 1J5, Canada
| | - Timothy C Ells
- Agriculture and Agri-Food Canada, Kentville Research and Development Centre, 32 Main Street, Kentville, Nova Scotia, B4N 1J5, Canada
| | - Denyse I LeBlanc
- Agriculture and Agri-Food Canada, Kentville Research and Development Centre, 32 Main Street, Kentville, Nova Scotia, B4N 1J5, Canada
| | - Sherry Fillmore
- Agriculture and Agri-Food Canada, Kentville Research and Development Centre, 32 Main Street, Kentville, Nova Scotia, B4N 1J5, Canada
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7
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Jardine KJ, Fernandes de Souza V, Oikawa P, Higuchi N, Bill M, Porras R, Niinemets Ü, Chambers JQ. Integration of C₁ and C₂ Metabolism in Trees. Int J Mol Sci 2017; 18:E2045. [PMID: 28946627 DOI: 10.3390/ijms18102045] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 09/16/2017] [Accepted: 09/21/2017] [Indexed: 12/19/2022] Open
Abstract
C1 metabolism in plants is known to be involved in photorespiration, nitrogen and amino acid metabolism, as well as methylation and biosynthesis of metabolites and biopolymers. Although the flux of carbon through the C1 pathway is thought to be large, its intermediates are difficult to measure and relatively little is known about this potentially ubiquitous pathway. In this study, we evaluated the C1 pathway and its integration with the central metabolism using aqueous solutions of 13C-labeled C1 and C2 intermediates delivered to branches of the tropical species Inga edulis via the transpiration stream. Delivery of [13C]methanol and [13C]formaldehyde rapidly stimulated leaf emissions of [13C]methanol, [13C]formaldehyde, [13C]formic acid, and 13CO2, confirming the existence of the C1 pathway and rapid interconversion between methanol and formaldehyde. However, while [13C]formate solutions stimulated emissions of 13CO2, emissions of [13C]methanol or [13C]formaldehyde were not detected, suggesting that once oxidation to formate occurs it is rapidly oxidized to CO2 within chloroplasts. 13C-labeling of isoprene, a known photosynthetic product, was linearly related to 13CO2 across C1 and C2 ([13C2]acetate and [2-13C]glycine) substrates, consistent with reassimilation of C1, respiratory, and photorespiratory CO2. Moreover, [13C]methanol and [13C]formaldehyde induced a quantitative labeling of both carbon atoms of acetic acid emissions, possibly through the rapid turnover of the chloroplastic acetyl-CoA pool via glycolate oxidation. The results support a role of the C1 pathway to provide an alternative carbon source for glycine methylation in photorespiration, enhance CO2 concentrations within chloroplasts, and produce key C2 intermediates (e.g., acetyl-CoA) central to anabolic and catabolic metabolism.
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Jardine KJ, Jardine AB, Holm JA, Lombardozzi DL, Negron-Juarez RI, Martin ST, Beller HR, Gimenez BO, Higuchi N, Chambers JQ. Monoterpene 'thermometer' of tropical forest-atmosphere response to climate warming. Plant Cell Environ 2017; 40:441-452. [PMID: 27943309 DOI: 10.1111/pce.12879] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 11/25/2016] [Accepted: 11/26/2016] [Indexed: 05/24/2023]
Abstract
Tropical forests absorb large amounts of atmospheric CO2 through photosynthesis but elevated temperatures suppress this absorption and promote monoterpene emissions. Using 13 CO2 labeling, here we show that monoterpene emissions from tropical leaves derive from recent photosynthesis and demonstrate distinct temperature optima for five groups (Groups 1-5), potentially corresponding to different enzymatic temperature-dependent reaction mechanisms within β-ocimene synthases. As diurnal and seasonal leaf temperatures increased during the Amazonian 2015 El Niño event, leaf and landscape monoterpene emissions showed strong linear enrichments of β-ocimenes (+4.4% °C-1 ) at the expense of other monoterpene isomers. The observed inverse temperature response of α-pinene (-0.8% °C-1 ), typically assumed to be the dominant monoterpene with moderate reactivity, was not accurately simulated by current global emission models. Given that β-ocimenes are highly reactive with respect to both atmospheric and biological oxidants, the results suggest that highly reactive β-ocimenes may play important roles in the thermotolerance of photosynthesis by functioning as effective antioxidants within plants and as efficient atmospheric precursors of secondary organic aerosols. Thus, monoterpene composition may represent a new sensitive 'thermometer' of leaf oxidative stress and atmospheric reactivity, and therefore a new tool in future studies of warming impacts on tropical biosphere-atmosphere carbon-cycle feedbacks.
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Affiliation(s)
- Kolby J Jardine
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA
| | - Angela B Jardine
- National Institute for Amazon Research (INPA), 69060-001, Manaus, Amazonas, Brazil
| | - Jennifer A Holm
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA
| | - Danica L Lombardozzi
- Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, 80307, Boulder, CO, USA
| | - Robinson I Negron-Juarez
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA
| | - Scot T Martin
- Harvard University, School of Engineering and Applied Sciences, 02138, Cambridge, MA, USA
| | - Harry R Beller
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, 94068, Emeryville, CA, USA
| | - Bruno O Gimenez
- National Institute for Amazon Research (INPA), 69060-001, Manaus, Amazonas, Brazil
| | - Niro Higuchi
- National Institute for Amazon Research (INPA), 69060-001, Manaus, Amazonas, Brazil
| | - Jeffrey Q Chambers
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA
- Department of Geography, University of California, 94720, Berkeley, CA, USA
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Terry LI, Roemer RB, Booth DT, Moore CJ, Walter GH. Thermogenic respiratory processes drive the exponential increase of volatile organic compound emissions in Macrozamia cycad cones. Plant Cell Environ 2016; 39:1588-1600. [PMID: 26924274 DOI: 10.1111/pce.12730] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 02/12/2016] [Accepted: 02/14/2016] [Indexed: 06/05/2023]
Abstract
An important outcome of plant thermogenesis is increased emissions of volatiles that mediate pollinator behaviour. We investigated whether the large increase in emissions, mainly the monoterpene ß-myrcene (>90%), during daily thermogenic events of Macrozamia macleayi and lucida cycad cones are due solely to the influence of high cone temperatures or are, instead, a result of increased respiratory rates during thermogenesis. We concurrently measured temperature, oxygen consumption and ß-myrcene emission profiles during thermogenesis of pollen cones under typical environmental temperatures and during experimental manipulations of cone temperatures and aerobic conditions, all in the dark. The exponential rise in ß-myrcene emissions never occurred without a prior, large increase in respiration, whereas an increase in cone temperature alone did not increase emissions. When respiration during thermogenesis was interrupted by anoxic conditions, ß-myrcene emissions decreased. The increased emission rates are not a result of increased cone temperature per se (through increased enzyme activity or volatilization of stored volatiles) but are dependent on biosynthetic pathways associated with increased respiration during thermogenesis that provide the carbon, energy (ATP) and reducing compounds (NADPH) required for ß-myrcene production through the methylerythritol phosphate (MEP) pathway. These findings establish the significant contribution of respiration to volatile production during thermogenesis.
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Affiliation(s)
- L Irene Terry
- Department of Biology, University of Utah, 257 S. 1400 E., Salt Lake City, UT, 84112, USA
| | - Robert B Roemer
- Department of Mechanical Engineering, University of Utah, 50 S. Central Campus Dr., 2202 Merrill Engineering Bldg, Salt Lake City, UT, 84112, USA
| | - David T Booth
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Queensland, Australia
| | - Chris J Moore
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Queensland, Australia
| | - Gimme H Walter
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Queensland, Australia
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