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Thomas MA, Cooper RL. Building bridges: mycelium-mediated plant-plant electrophysiological communication. PLANT SIGNALING & BEHAVIOR 2022; 17:2129291. [PMID: 36384396 PMCID: PMC9673936 DOI: 10.1080/15592324.2022.2129291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/20/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
Whether through root secretions or by emitting volatile organic compounds, plant communication has been well-documented. While electrical activity has been documented in plants and mycorrhizal bodies on the individual and ramet, electrical propagation as a means of communication between plants has been hypothesized but understudied. This study aimed to test the hypothesis that plants can communicate with one another electrically via conductively isolated mycelial pathways. We created a bio-electric circuit linking two plants using a mycelial network grown from a blend of mycorrhizal fungi which was directly inoculated onto potato dextrose agar, or onto the host plants placed on the agar. The mycelium that grew was forced to cross, or "bridge," an air gap between the two islands of agar - thus forming the isolated conductive pathway between plants. Using this plant-fungal biocircuit we assessed electrical propagation between Pisum sativum and Cucumis sativus. We found that electrical signals were reliably conducted across the mycelial bridges from one plant to another upon the induction of a wound response. Our findings provide evidence that mechanical input can be communicated between plant species and opens the door to testing how this information can affect plant and fungal physiology.
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He C, Lin Y, Zhang Y, Tong L, Ding Y, Yao M, Liu Q, Zeng R, Chen D, Song Y. Aboveground herbivory does not affect mycorrhiza-dependent nitrogen acquisition from soil but inhibits mycorrhizal network-mediated nitrogen interplant transfer in maize. FRONTIERS IN PLANT SCIENCE 2022; 13:1080416. [PMID: 36589048 PMCID: PMC9795027 DOI: 10.3389/fpls.2022.1080416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
Arbuscular mycorrhizal fungi (AMF) are considered biofertilizers for sustainable agriculture due to their ability to facilitate plant uptake of important mineral elements, such as nitrogen (N). However, plant mycorrhiza-dependent N uptake and interplant transfer may be highly context-dependent, and whether it is affected by aboveground herbivory remains largely unknown. Here, we used 15N labeling and tracking to examine the effect of aboveground insect herbivory by Spodoptera frugiperda on mycorrhiza-dependent N uptake in maize (Zea mays L.). To minimize consumption differences and 15N loss due to insect chewing, insect herbivory was simulated by mechanical wounding and oral secretion of S. frugiperda larvae. Inoculation with Rhizophagus irregularis (Rir) significantly improved maize growth, and N/P uptake. The 15N labeling experiment showed that maize plants absorbed N from soils via the extraradical mycelium of mycorrhizal fungi and from neighboring plants transferred by common mycorrhizal networks (CMNs). Simulated aboveground leaf herbivory did not affect mycorrhiza-mediated N acquisition from soil. However, CMN-mediated N transfer from neighboring plants was blocked by leaf simulated herbivory. Our findings suggest that aboveground herbivory inhibits CMN-mediated N transfer between plants but does not affect N acquisition from soil solutions via extraradical mycorrhizal mycelium.
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Affiliation(s)
- Chenling He
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yibin Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yifang Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Lu Tong
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yuanxing Ding
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Min Yao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qian Liu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Rensen Zeng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Institute of Chemical Ecology and Crop Resistance, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Dongmei Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Institute of Chemical Ecology and Crop Resistance, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yuanyuan Song
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Institute of Chemical Ecology and Crop Resistance, Fujian Agriculture and Forestry University, Fuzhou, China
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Phytohormone Profile of Medicago in Response to Mycorrhizal Fungi, Aphids, and Gibberellic Acid. PLANTS 2022; 11:plants11060720. [PMID: 35336602 PMCID: PMC8951282 DOI: 10.3390/plants11060720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 02/20/2022] [Accepted: 03/03/2022] [Indexed: 11/17/2022]
Abstract
Although gibberellic acid (GA) is widely used in agriculture, it is unclear whether exogenous GA makes aphid-infested, mycorrhizal plants more susceptible to herbivory. This study investigates the role of GA in modulating defenses in barrel medic plants (Medicago truncatula) that are infested with pea aphids (Acyrthosiphon pisum) and colonized by the beneficial symbiont Rhizophagus intraradices. Mock- and R. intraradices-inoculated potted plants were grown in a topsoil: sand mix for 42 days and were treated with GA or solvent. Subsequently, plants were exposed to herbivory or no aphid herbivory for 36 h and 7 days. Afterwards, plant growth parameters, aphid fitness, and foliar phytohormone concentrations were measured. The results revealed that GA regulates plant defenses during arbuscular mycorrhizal (AM) fungus–plant–aphid interactions as aphids that fed for 7 days on mycorrhizal, GA-untreated plants weighed more than those that fed on mycorrhizal, GA-treated plants. No major differences were detected in phytohormone levels at 36 h. Overall, mycorrhizal plants showed more shoot biomass compared to non-mycorrhizal controls. The arbuscule density and fungal biomass of R. intraradices were not altered by exogenous GA and aphid herbivory based on molecular markers. This study indicates that exogenous GA may help reduce aphid fitness when feeding on mycorrhizal plants.
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Raut JK, Baral K, Adhikari MK, Jha PK. Interaction of Mycorrhizal Fungi with Rhizospheric Microbes and Their Mode of Action. Fungal Biol 2022. [DOI: 10.1007/978-3-031-04805-0_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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5
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Getman‐Pickering ZL, Stack GM, Thaler JS. Fertilizer quantity and type alter mycorrhizae‐conferred growth and resistance to herbivores. J Appl Ecol 2021. [DOI: 10.1111/1365-2664.13833] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
| | - George M. Stack
- Section of Plant Breeding and Genetics Cornell University Ithaca NY USA
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Alaux PL, Naveau F, Declerck S, Cranenbrouck S. Common Mycorrhizal Network Induced JA/ET Genes Expression in Healthy Potato Plants Connected to Potato Plants Infected by Phytophthora infestans. FRONTIERS IN PLANT SCIENCE 2020; 11:602. [PMID: 32523589 PMCID: PMC7261899 DOI: 10.3389/fpls.2020.00602] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 04/20/2020] [Indexed: 05/20/2023]
Abstract
Most plants are connected belowground via common mycorrhizal networks (CMNs). In their presence, the transmission of warning signals from diseased to uninfected plants has been reported. However, current studies have all been conducted in pots making it difficult to discriminate direct from indirect contribution of hyphae to the transmission of the signals. Here, we conducted an in vitro study with potato plantlets connected by a CMN of the arbuscular mycorrhizal fungus Rhizophagus irregularis. The plantlets were grown in physically separated compartments and their connection ensured only by the CMN. The donor potato plantlets were infected by Phytophthora infestans and defense genes analyzed 24, 48 and 120 h post-infection (hpi) in the uninfected receiver potato plantlets. Twenty-four hpi by the pathogen, PAL, PR-1b, ERF3, and LOX genes were significantly upregulated, whereas no significant transcript variation was noticed 48 and 120 hpi. The exact nature of the warning signals remains unknown but was not associated to microorganisms other than the AMF or to diffusion mechanisms through the growth medium or induced by volatile compounds. The defense response appeared to be transitory and associated with the jasmonic acid or ethylene pathway. These findings demonstrate the direct involvement of hyphae in the transmission of warning signals from diseased to uninfected potato plantlets and their indubitable role in providing a route for activating defense responses in uninfected plants.
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Affiliation(s)
- Pierre-Louis Alaux
- Earth and Life Institute, Applied Microbiology, Mycology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Françoise Naveau
- Earth and Life Institute, Applied Microbiology, Mycology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Stéphane Declerck
- Earth and Life Institute, Applied Microbiology, Mycology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Sylvie Cranenbrouck
- Earth and Life Institute, Applied Microbiology, Mycology, Mycothèque de l’Université catholique de Louvain, Université catholique de Louvain, Louvain-la-Neuve, Belgium
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Volkov AG, Shtessel YB. Underground electrotonic signal transmission between plants. Commun Integr Biol 2020; 13:54-58. [PMID: 32395195 PMCID: PMC7202782 DOI: 10.1080/19420889.2020.1757207] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 10/25/2022] Open
Abstract
Plants can communicate with other plants using wireless pathways above and underground. Some examples of these underground communication pathways are: (1) mycorrhizal networks in the soil; (2) the plants' rhizosphere; (3) acoustic communication; (4) naturally grafting of roots of the same species; (5) signaling chemicals exchange between roots of plants; and (6) electrical signal transmission between plants through the soil. To avoid the possibility of communication between plants using mechanisms (1)-(5), soils in both pots with plants can be connected by Ag/AgCl or platinum wires. Electrostimulation Aloe vera or cabbage plants induces electrotonic potentials transmission in the electro-stimulated plants as well as in the neighboring plants located in the same or different electrically connected pots regardless if plants are the same or different types. The amplitude and sign of electrotonic potentials in both electrostimulated and neighboring plants depend on the amplitude, rise, and fall of the applied voltage. Electrostimulation serves as an important tool for the evaluation of mechanisms of underground communication in the plant-wide web. The previously developed mathematical model of electrotonic potentials transmission within and between tomato plants, which is supported by the experimental data, is generic enough to be used for simulation study and predicting the intercellular and intracellular communication in the form of electrical signals in the electrical networks within and between a variety of plants.
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Affiliation(s)
| | - Yuri B Shtessel
- Department of Electrical and Computer Engineering, University of Alabama in Huntsville, Huntsville, AL, USA
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9
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Volkov AG, Shtessel YB. Electrical signal propagation within and between tomato plants. Bioelectrochemistry 2018; 124:195-205. [DOI: 10.1016/j.bioelechem.2018.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 08/02/2018] [Accepted: 08/04/2018] [Indexed: 12/23/2022]
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10
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Igiehon NO, Babalola OO. Below-ground-above-ground Plant-microbial Interactions: Focusing on Soybean, Rhizobacteria and Mycorrhizal Fungi. Open Microbiol J 2018; 12:261-279. [PMID: 30197700 PMCID: PMC6110075 DOI: 10.2174/1874285801812010261] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 07/10/2018] [Accepted: 07/15/2018] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION Organisms seldom exist in isolation and are usually involved in interactions with several hosts and these interactions in conjunction with the physicochemical parameters of the soil affect plant growth and development. Researches into below and aboveground microbial community are unveiling a myriad of intriguing interactions within the rhizosphere, and many of the interactions are facilitated by exudates that are secreted by plants roots. These interactions can be harnessed for beneficial use in agriculture to enhance crop productivity especially in semi-arid and arid environments. THE RHIZOSPHERE The rhizosphere is the region of soil close to plants roots that contain large number of diverse organisms. Examples of microbial candidates that are found in the rhizosphere include the Arbuscular Mycorrhizal Fungi (AMF) and rhizobacteria. These rhizosphere microorganisms use plant root secretions such as mucilage and flavonoids which are able to influence their diversity and function and also enhance their potential to colonize plants root. NATURAL INTERACTIONS BETWEEN MICROORGANISMS AND PLANT In the natural environments, plants live in interactions with different microorganisms, which thrive belowground in the rhizosphere and aboveground in the phyllosphere. Some of the plant-microbial interactions (which can be in the form of antagonism, amensalism, parasitism and symbiosis) protect the host plants against detrimental microbial and non-microbial invaders and provide nutrients for plants while others negatively affect plants. These interactions can influence below-ground-above-ground plants' biomass development thereby playing significant role in sustaining plants. Therefore, understanding microbial interactions within the rhizosphere and phyllosphere is urgent towards farming practices that are less dependent on conventional chemical fertilizers, which have known negative impacts on the environments. BELOW GROUND RHIZOBACTERIA INTERACTIONS ALLEVIATE DROUGHT STRESS Drought stress is one of the major factors militating against agricultural productivity globally and is likely to further increase. Belowground rhizobacteria interactions could play important role in alleviating drought stress in plants. These beneficial rhizobacterial colonize the rhizosphere of plants and impart drought tolerance by up regulation or down regulation of drought responsive genes such as ascorbate peroxidase, S-adenosyl-methionine synthetase, and heat shock protein. INSIGHTS INTO BELOW AND ABOVE THE GROUND MICROBIAL INTERACTIONS VIA OMIC STUDIES Investigating complex microbial community in the environment is a big challenge. Therefore, omic studies of microorganisms that inhabit the rhizosphere are important since this is where most plant-microbial interactions occur. One of the aims of this review is not to give detailed account of all the present omic techniques, but instead to highlight the current omic techniques that can possibly lead to detection of novel genes and their respective proteins within the rhizosphere which may be of significance in enhancing crop plants (such as soybean) productivity especially in semi-arid and arid environments. FUTURE PROSPECTS AND CONCLUSIONS Plant-microbial interactions are not totally understood, and there is, therefore, the need for further studies on these interactions in order to get more insights that may be useful in sustainable agricultural development. With the emergence of omic techniques, it is now possible to effectively monitor transformations in rhizosphere microbial community together with their effects on plant development. This may pave way for scientists to discover new microbial species that will interact effectively with plants. Such microbial species can be used as biofertilizers and/or bio-pesticides to increase crop yield and enhance global food security.
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Affiliation(s)
- Nicholas O. Igiehon
- Food Security and Safety Niche, Faculty of Natural and Agricultural Sciences, Private Mail Bag X2046, North-West University, Mmabatho 2735, South Africa
| | - Olubukola O. Babalola
- Food Security and Safety Niche, Faculty of Natural and Agricultural Sciences, Private Mail Bag X2046, North-West University, Mmabatho 2735, South Africa
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11
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Mansurova M, Ebert BE, Blank LM, Ibáñez AJ. A breath of information: the volatilome. Curr Genet 2017; 64:959-964. [DOI: 10.1007/s00294-017-0800-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 12/14/2017] [Accepted: 12/18/2017] [Indexed: 01/14/2023]
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12
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G. Volkov A, B. Shtessel Y. Electrotonic signal transduction between Aloe vera plants using underground pathways in soil: Experimental and analytical study. AIMS BIOPHYSICS 2017. [DOI: 10.3934/biophy.2017.4.576] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Pickett JA, Khan ZR. Plant volatile-mediated signalling and its application in agriculture: successes and challenges. THE NEW PHYTOLOGIST 2016; 212:856-870. [PMID: 27874990 DOI: 10.1111/nph.14274] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/04/2016] [Indexed: 05/25/2023]
Abstract
856 I. 856 II. 857 III. 858 IV. 859 V. 860 VI. 862 VII. 863 VIII. 864 IX. 866 866 References 866 SUMMARY: The mediation of volatile secondary metabolites in signalling between plants and other organisms has long been seen as presenting opportunities for sustainable crop protection. Initially, exploitation of interactions between plants and other organisms, particularly insect pests, foundered because of difficulties in delivering, sustainably, the signal systems for crop protection. We now have mounting and, in some cases, clear practical evidence for successful delivery by companion cropping or next-generation genetic modification (GM). At the same time, the type of plant signalling being exploited has expanded to signalling from plants to organisms antagonistic to pests, and to plant stress-induced, or primed, plant-to-plant signalling for defence and growth stimulation.
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Affiliation(s)
- John A Pickett
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Zeyaur R Khan
- Push-Pull Programme, International Centre of Insect Physiology and Ecology, PO Box 30, Mbita, 40305, Kenya
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Anderson JA, Gipmans M, Hurst S, Layton R, Nehra N, Pickett J, Shah DM, Souza TLPO, Tripathi L. Emerging Agricultural Biotechnologies for Sustainable Agriculture and Food Security. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:383-393. [PMID: 26785813 DOI: 10.1021/acs.jafc.5b04543] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
As global populations continue to increase, agricultural productivity will be challenged to keep pace without overtaxing important environmental resources. A dynamic and integrated approach will be required to solve global food insecurity and position agriculture on a trajectory toward sustainability. Genetically modified (GM) crops enhanced through modern biotechnology represent an important set of tools that can promote sustainable agriculture and improve food security. Several emerging biotechnology approaches were discussed in a recent symposium organized at the 13th IUPAC International Congress of Pesticide Chemistry meeting in San Francisco, CA, USA. This paper summarizes the innovative research and several of the new and emerging technologies within the field of agricultural biotechnology that were presented during the symposium. This discussion highlights how agricultural biotechnology fits within the context of sustainable agriculture and improved food security and can be used in support of further development and adoption of beneficial GM crops.
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Affiliation(s)
| | - Martijn Gipmans
- BASF Bioscience Research, c/o metanomics GmbH, Tegeler Weg 33, 10589 Berlin, Germany
| | - Susan Hurst
- Arcadia Biosciences, Seattle, Washington 98119, United States
| | | | - Narender Nehra
- Institute for International Crop Improvement, Donald Danforth Plant Science Center , St. Louis, Missouri 63132, United States
| | - John Pickett
- Rothamsted Research, Harpenden, Herts AL5 2JQ, United Kingdom
| | - Dilip M Shah
- Donald Danforth Plant Science Center , St. Louis, Missouri 63132, United States
| | - Thiago Lívio P O Souza
- Embrapa Arroz e Feijão, Rod. GO-462, km 12, Santo Antônio de Goiás, GO 75.375-000, Brazil
| | - Leena Tripathi
- International Institute of Tropical Agriculture (IITA), Nairobi, Kenya
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Gilbert L, Johnson D. Plant-mediated 'apparent effects' between mycorrhiza and insect herbivores. CURRENT OPINION IN PLANT BIOLOGY 2015; 26:100-105. [PMID: 26190588 DOI: 10.1016/j.pbi.2015.06.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 05/09/2015] [Accepted: 06/06/2015] [Indexed: 06/04/2023]
Abstract
Plants mediate indirect 'apparent' effects between above-ground herbivores and below-ground mutualistic mycorrhizal fungi. The herbivore-plant-mycorrhiza continuum is further complicated because signals produced by plants in response to herbivores can be transmitted to other plants via shared fungal networks below ground. Insect herbivores, such as aphids, probably affect the functioning of mycorrhizal fungi by changing the supply of recent photosynthate from plants to mycorrhizas, whereas there is evidence that mycorrhizas affect aphid fitness by changing plant signalling pathways, rather than only through improved nutrition. New knowledge of the transfer of signals through fungal networks between plant species means we now need a better understanding of how this process occurs in relation to the feeding preferences of herbivores to shape plant community composition and herbivore behaviour in nature.
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Affiliation(s)
- Lucy Gilbert
- Ecological Sciences Group, James Hutton Institute, Cragiebuckler, Aberdeen AB15 8QH, UK
| | - David Johnson
- Institute of Biological and Environmental Sciences, Cruickshank Building, University of Aberdeen, Aberdeen AB24 3UU, UK.
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16
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Johnson D, Gilbert L. Interplant signalling through hyphal networks. THE NEW PHYTOLOGIST 2015; 205:1448-1453. [PMID: 25421970 DOI: 10.1111/nph.13115] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 09/12/2014] [Indexed: 05/08/2023]
Abstract
Mycorrhizal fungi can form common mycelial networks (CMNs) that interconnect plants. Here, we provide an insight into recent findings demonstrating that CMNs can be conduits for interplant signalling, influencing defence against insect herbivores and foliar necrotrophic fungi. A likely mechanism is direct transfer of signalling molecules within hyphae. However, electrical signals, which can be induced by wounding, may also enable signalling over relatively long distances, because the biophysical constraints imposed by liquid transport in hyphae and interaction with soil are relieved. We do not yet understand the ecological, evolutionary and agronomic implications of interplant signalling via CMNs. Identifying the mechanism of interplant signalling will help to address these gaps.
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Affiliation(s)
- David Johnson
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, Aberdeen, AB24 3UU, UK
| | - Lucy Gilbert
- Ecological Sciences Group, The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
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17
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Babikova Z, Gilbert L, Randall KC, Bruce TJA, Pickett JA, Johnson D. Increasing phosphorus supply is not the mechanism by which arbuscular mycorrhiza increase attractiveness of bean (Vicia faba) to aphids. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:5231-41. [PMID: 25200735 PMCID: PMC4157707 DOI: 10.1093/jxb/eru283] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/22/2014] [Accepted: 06/02/2014] [Indexed: 05/04/2023]
Abstract
Arbuscular mycorrhizal (AM) fungi, important plant mutualists, provide plants with nutrients such as phosphorus (P) in return for carbon. AM fungi also enhance the attractiveness of plants to aphids via effects on emissions of plant volatiles used in aphid host location. We tested whether increased P uptake by plants is the mechanism through which AM fungi alter the volatile profile of plants and aphid behavioural responses by manipulating the availability of P and AM fungi to broad beans (Vicia faba L.) in a multi-factorial design. If AM fungi affect plant volatiles only via increased P acquisition, we predicted that the emission of volatiles and the attractiveness of mycorrhizal beans to aphids would be similar to those of non-mycorrhizal beans supplied with additional P. AM fungi and P addition increased leaf P concentrations by 40 and 24%, respectively. The production of naphthalene was less in mycorrhizal plants, regardless of P addition. By contrast, production of (S)-linalool, (E)-caryophyllene and (R)-germacrene D was less in plants colonized by AM fungi but only in the absence of P additions. The attractiveness of plants to pea aphids (Acyrthosiphon pisum Harris) was positively affected by AM fungi and correlated with the extent of root colonization; however, attractiveness was neither affected by P treatment nor correlated with leaf P concentration. These findings suggest that increased P uptake is not the main mechanism by which mycorrhiza increase the attractiveness of plants to aphids. Instead, the mechanism is likely to operate via AM fungi-induced plant systemic signalling.
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Affiliation(s)
- Zdenka Babikova
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank building, St Machar Drive, Aberdeen AB24 3UU, UK James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Lucy Gilbert
- James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Kate C Randall
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Toby J A Bruce
- Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - John A Pickett
- Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - David Johnson
- Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank building, St Machar Drive, Aberdeen AB24 3UU, UK
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Babikova Z, Johnson D, Bruce T, Pickett J, Gilbert L. Underground allies: how and why do mycelial networks help plants defend themselves?: What are the fitness, regulatory, and practical implications of defence-related signaling between plants via common mycelial networks? Bioessays 2013; 36:21-6. [PMID: 24129903 DOI: 10.1002/bies.201300092] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Most land plants associate with mycorrhizal fungi that can connect roots of neighboring plants in common mycelial networks (CMNs). Recent evidence shows that CMNs transfer warning signals of pathogen and aphid attack between plants. However, we do not know how defence-related signaling via CMNs operates or how ubiquitous it is. Nor do we know what the ecological relevance and fitness consequences are, particularly from the perspective of the mycorrhizal fungus. Here, we focus on the potential fitness benefits for mycorrhizal fungi and outline hypothetical scenarios in which signal transfer via CMNs is modulated in order to acquire the most benefit for the fungus (i.e. acquisition of carbon) for minimal cost. We speculate that the signal may be quantitative and may elicit plant defence responses on different levels depending on the distance the signal is transferred. Finally, we discuss the possibility of practical applications of this phenomenon for crop protection.
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Affiliation(s)
- Zdenka Babikova
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK; James Hutton Institute, Aberdeen, UK; Rothamsted Research, Harpenden, UK
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