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Baravalle L. How (not) to Talk to a Plant: An Application of Automata Theory to Plant Communication. Acta Biotheor 2024; 72:8. [PMID: 38949721 PMCID: PMC11217117 DOI: 10.1007/s10441-024-09484-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 06/24/2024] [Indexed: 07/02/2024]
Abstract
Plants are capable of a range of complex interactions with the environment. Over the last decade, some authors have used this as evidence to argue that plants are cognitive agents. While there is no consensus on this view, it is certainly interesting to approach the debate from a comparative perspective, trying to understand whether different lineages of plants show different degrees of responsiveness to environmental cues, and how their responses compare with those of animals or humans. In this paper, I suggest that a potentially fruitful approach to these comparative studies is provided by automata theory. Accordingly, I shall present a possible application of this theory to plant communication. Two tentative results will emerge. First, that different lineages may exhibit different levels of complexity in response to similar stimuli. Second, that current evidence does not allow to infer great cognitive sophistication in plants.
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Affiliation(s)
- Lorenzo Baravalle
- Centro de Filosofia das Ciências, Departamento de História e Filosofia das Ciências, Faculdade de Ciências, Universidade de Lisboa Campo Grande, Edifício C4, 3º Piso, Sala 4.3.24, 1749-016, Lisbon, Portugal.
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2
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Gil AF, Weinbeer M, Gloor PA. Can Plants Perceive Human Gestures? Using AI to Track Eurythmic Human-Plant Interaction. Biomimetics (Basel) 2024; 9:290. [PMID: 38786500 PMCID: PMC11118930 DOI: 10.3390/biomimetics9050290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Revised: 05/09/2024] [Accepted: 05/11/2024] [Indexed: 05/25/2024] Open
Abstract
This paper explores if plants are capable of responding to human movement by changes in their electrical signals. Toward that goal, we conducted a series of experiments, where humans over a period of 6 months were performing different types of eurythmic gestures in the proximity of garden plants, namely salad, basil, and tomatoes. To measure plant perception, we used the plant SpikerBox, which is a device that measures changes in the voltage differentials of plants between roots and leaves. Using machine learning, we found that the voltage differentials over time of the plant predict if (a) eurythmy has been performed, and (b) which kind of eurythmy gestures has been performed. We also find that the signals are different based on the species of the plant. In other words, the perception of a salad, tomato, or basil might differ just as perception of different species of animals differ. This opens new ways of studying plant ecosystems while also paving the way to use plants as biosensors for analyzing human movement.
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Affiliation(s)
- Alvaro Francisco Gil
- MIT Center for Collective Intelligence, Cambridge, MA 02142, USA
- School of Computer Systems Engineering, UPM Technical University of Madrid, 28031 Madrid, Spain
| | | | - Peter A. Gloor
- MIT Center for Collective Intelligence, Cambridge, MA 02142, USA
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3
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Kashyap S, Agarwala N, Sunkar R. Understanding plant stress memory traits can provide a way for sustainable agriculture. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 340:111954. [PMID: 38092267 DOI: 10.1016/j.plantsci.2023.111954] [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: 07/26/2023] [Revised: 12/05/2023] [Accepted: 12/07/2023] [Indexed: 01/01/2024]
Abstract
Being sessile, plants encounter various biotic and abiotic threats in their life cycle. To minimize the damages caused by such threats, plants have acquired sophisticated response mechanisms. One major such response includes memorizing the encountered stimuli in the form of a metabolite, hormone, protein, or epigenetic marks. All of these individually as well as together, facilitate effective transcriptional and post-transcriptional responses upon encountering the stress episode for a second time during the life cycle and in some instances even in the future generations. This review attempts to highlight the recent advances in the area of plant memory. A detailed understanding of plant memory has the potential to offer solutions for developing climate-resilient crops for sustainable agriculture.
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Affiliation(s)
- Sampurna Kashyap
- Department of Botany, Gauhati University, Gopinath Bordoloi Nagar, Jalukbari, Guwahati, Assam, 781014, India
| | - Niraj Agarwala
- Department of Botany, Gauhati University, Gopinath Bordoloi Nagar, Jalukbari, Guwahati, Assam, 781014, India.
| | - Ramanjulu Sunkar
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, United States
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4
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Cosca CM, Haggard JA, Kato HM, Sklavenitis EM, Blumstein DT. Do environmental stimuli modify sensitive plant (Mimosa pudica L.) risk assessment? PLoS One 2023; 18:e0294971. [PMID: 38127910 PMCID: PMC10734946 DOI: 10.1371/journal.pone.0294971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 11/10/2023] [Indexed: 12/23/2023] Open
Abstract
Although plants and animals both assess their environment and respond to stimuli, this reaction is considered a behavior in animals and a response in plants. Responses in plants are seen within various timescales- from the nanosecond stimuli is presented to a lifelong progression. Within this study, we bridge the gap between animal behavioral studies and plant response. Sensitive plants (Mimosa pudica L.) are an ideal subject for this due to the rapid closure of their primary leaflets when touched. We designed a multimodal, or stress combination, experiment to test two hypotheses with sensitive plants: if they could be distracted and if they would alter their risk assessment when exposed to external stimuli (wind and sound). To evaluate the distraction hypothesis, we measured an individual's latency to close, hypothesizing that if the plants were distracted, they would take longer to close. To evaluate the uncertain risk hypothesis, we quantified the latency to reopen, hypothesizing that if the plants were uncertain, they would take longer to reopen. We also quantified the number of pinnae closed on the selected stem to test for changes in risk assessment across treatments. We expected the unimodal treatments would distract or alter risk assessment, and the multimodal treatment would elicit an enhanced response. Multimodal stimuli had a significant effect on the number of pinnae closed before the tap, but we found no evidence that plants were distracted by any stimulus tested. We found that temperature had a significant effect on the latency to close, and that plants modified their risk assessment when exposed to experimental wind stimuli. By manipulating environmental stimuli, we found that sensitive plants trade-off energy and perceived risk much in the way that is commonly found in animals. Framing the study of plants' responses to environmental stimuli as behavioral questions may generate new insights.
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Affiliation(s)
- Charlotte M. Cosca
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Justin A. Haggard
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Halli M. Kato
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Eleni M. Sklavenitis
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Daniel T. Blumstein
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California, United States of America
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5
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de la Cal L, Gloor PA, Weinbeer M. Can Plants Sense Humans? Using Plants as Biosensors to Detect the Presence of Eurythmic Gestures. SENSORS (BASEL, SWITZERLAND) 2023; 23:6971. [PMID: 37571752 PMCID: PMC10422342 DOI: 10.3390/s23156971] [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: 07/03/2023] [Revised: 07/25/2023] [Accepted: 08/02/2023] [Indexed: 08/13/2023]
Abstract
This paper describes the preliminary results of measuring the impact of human body movements on plants. The scope of this project is to investigate if a plant perceives human activity in its vicinity. In particular, we analyze the influence of eurythmic gestures of human actors on lettuce and beans. In an eight-week experiment, we exposed rows of lettuce and beans to weekly eurythmic movements (similar to Qi Gong) of a eurythmist, while at the same time measuring changes in voltage between the roots and leaves of lettuce and beans using the plant spikerbox. We compared this experimental group of vegetables to a control group of vegetables whose voltage differential was also measured while not being exposed to eurythmy. We placed a plant spikerbox connected to lettuce or beans in the vegetable plot while the eurythmist was performing their gestures about 2 m away; a second spikerbox was connected to a control plant 20 m away. Using t-tests, we found a clear difference between the experimental and the control group, which was also verified with a machine learning model. In other words, the vegetables showed a noticeably different pattern in electric potentials in response to eurythmic gestures.
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Affiliation(s)
- Luis de la Cal
- MIT Center for Collective Intelligence, Cambridge, MA 02142, USA;
- Escuela Técnica Superior de Ingeniería de Sistemas Informáticos, UPM Technical University of Madrid, 28031 Madrid, Spain
| | - Peter A. Gloor
- MIT Center for Collective Intelligence, Cambridge, MA 02142, USA;
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6
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Parise AG, Oliveira TFDC, Debono MW, Souza GM. The Electrome of a Parasitic Plant in a Putative State of Attention Increases the Energy of Low Band Frequency Waves: A Comparative Study with Neural Systems. PLANTS (BASEL, SWITZERLAND) 2023; 12:2005. [PMID: 37653922 PMCID: PMC10224360 DOI: 10.3390/plants12102005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 09/02/2023]
Abstract
Selective attention is an important cognitive phenomenon that allows organisms to flexibly engage with certain environmental cues or activities while ignoring others, permitting optimal behaviour. It has been proposed that selective attention can be present in many different animal species and, more recently, in plants. The phenomenon of attention in plants would be reflected in its electrophysiological activity, possibly being observable through electrophytographic (EPG) techniques. Former EPG time series obtained from the parasitic plant Cuscuta racemosa in a putative state of attention towards two different potential hosts, the suitable bean (Phaseolus vulgaris) and the unsuitable wheat (Triticum aestivum), were revisited. Here, we investigated the potential existence of different band frequencies (including low, delta, theta, mu, alpha, beta, and gamma waves) using a protocol adapted from neuroscientific research. Average band power (ABP) was used to analyse the energy distribution of each band frequency in the EPG signals, and time dispersion analysis of features (TDAF) was used to explore the variations in the energy of each band. Our findings indicated that most band waves were centred in the lower frequencies. We also observed that C. racemosa invested more energy in these low-frequency waves when suitable hosts were present. However, we also noted peaks of energy investment in all the band frequencies, which may be linked to extremely low oscillatory electrical signals in the entire tissue. Overall, the presence of suitable hosts induced a higher energy power, which supports the hypothesis of attention in plants. We further discuss and compare our results with generic neural systems.
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Affiliation(s)
| | - Thiago Francisco de Carvalho Oliveira
- Laboratory of Plant Cognition and Electrophysiology (LACEV), Department of Botany, Institute of Biology, Federal University of Pelotas, Capão do Leão 96160-000, RS, Brazil; (T.F.d.C.O.)
| | | | - Gustavo Maia Souza
- Laboratory of Plant Cognition and Electrophysiology (LACEV), Department of Botany, Institute of Biology, Federal University of Pelotas, Capão do Leão 96160-000, RS, Brazil; (T.F.d.C.O.)
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7
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Kambona CM, Koua PA, Léon J, Ballvora A. Stress memory and its regulation in plants experiencing recurrent drought conditions. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:26. [PMID: 36788199 PMCID: PMC9928933 DOI: 10.1007/s00122-023-04313-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
Developing stress-tolerant plants continues to be the goal of breeders due to their realized yields and stability. Plant responses to drought have been studied in many different plant species, but the occurrence of stress memory as well as the potential mechanisms for memory regulation is not yet well described. It has been observed that plants hold on to past events in a way that adjusts their response to new challenges without altering their genetic constitution. This ability could enable training of plants to face future challenges that increase in frequency and intensity. A better understanding of stress memory-associated mechanisms leading to alteration in gene expression and how they link to physiological, biochemical, metabolomic and morphological changes would initiate diverse opportunities to breed stress-tolerant genotypes through molecular breeding or biotechnological approaches. In this perspective, this review discusses different stress memory types and gives an overall view using general examples. Further, focusing on drought stress, we demonstrate coordinated changes in epigenetic and molecular gene expression control mechanisms, the associated transcription memory responses at the genome level and integrated biochemical and physiological responses at cellular level following recurrent drought stress exposures. Indeed, coordinated epigenetic and molecular alterations of expression of specific gene networks link to biochemical and physiological responses that facilitate acclimation and survival of an individual plant during repeated stress.
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Affiliation(s)
- Carolyn Mukiri Kambona
- Department of Plant Breeding, Institut Für Nutzpflanzenwissenschaften Und Ressourcenschutz (INRES), RheinischeFriedrich-Wilhelms-University, Bonn, Germany
| | - Patrice Ahossi Koua
- Department of Plant Breeding, Institut Für Nutzpflanzenwissenschaften Und Ressourcenschutz (INRES), RheinischeFriedrich-Wilhelms-University, Bonn, Germany
- Deutsche Saatveredelung AG, Thüler Str. 30, 33154, Salzkotten-Thüle, Germany
| | - Jens Léon
- Department of Plant Breeding, Institut Für Nutzpflanzenwissenschaften Und Ressourcenschutz (INRES), RheinischeFriedrich-Wilhelms-University, Bonn, Germany
- Field Lab Campus Klein-Altendorf, Rheinische Friedrich-Wilhelms-University, Bonn, Germany
| | - Agim Ballvora
- Department of Plant Breeding, Institut Für Nutzpflanzenwissenschaften Und Ressourcenschutz (INRES), RheinischeFriedrich-Wilhelms-University, Bonn, Germany.
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8
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Rajan D, Makushok T, Kalish A, Acuna L, Bonville A, Correa Almanza K, Garibay B, Tang E, Voss M, Lin A, Barlow K, Harrigan P, Slabodnick MM, Marshall WF. Single-cell analysis of habituation in Stentor coeruleus. Curr Biol 2023; 33:241-251.e4. [PMID: 36435177 PMCID: PMC9877177 DOI: 10.1016/j.cub.2022.11.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 09/26/2022] [Accepted: 11/03/2022] [Indexed: 11/26/2022]
Abstract
Although learning is often viewed as a unique feature of organisms with complex nervous systems, single-celled organisms also demonstrate basic forms of learning. The giant ciliate Stentor coeruleus responds to mechanical stimuli by contracting into a compact shape, presumably as a defense mechanism. When a Stentor cell is repeatedly stimulated at a constant level of force, it will learn to ignore that stimulus but will still respond to stronger stimuli. Prior studies of habituation in Stentor reported a graded response, suggesting that cells transition through a continuous range of response probabilities. By analyzing single cells using an automated apparatus to deliver calibrated stimuli, we find that habituation occurs via a single step-like switch in contraction probability within each cell, with the graded response in a population arising from the random distribution of switching times in individual cells. This step-like response allows Stentor behavior to be represented by a simple two-state model whose parameters can be estimated from experimental measurements. We find that transition rates depend on stimulus force and also on the time between stimuli. The ability to measure the behavior of the same cell to the same stimulus allowed us to quantify the functional heterogeneity among single cells. Together, our results suggest that the behavior of Stentor is governed by a two-state stochastic machine whose transition rates are sensitive to the time series properties of the input stimuli.
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Affiliation(s)
- Deepa Rajan
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Tatyana Makushok
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Asa Kalish
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Lilibeth Acuna
- CCC Summer course, Center for Cellular Construction, San Francisco State University, San Francisco, CA, USA
| | - Alex Bonville
- CCC Summer course, Center for Cellular Construction, San Francisco State University, San Francisco, CA, USA
| | - Kathya Correa Almanza
- CCC Summer course, Center for Cellular Construction, San Francisco State University, San Francisco, CA, USA
| | - Brenda Garibay
- CCC Summer course, Center for Cellular Construction, San Francisco State University, San Francisco, CA, USA
| | - Eric Tang
- CCC Summer course, Center for Cellular Construction, San Francisco State University, San Francisco, CA, USA
| | - Megan Voss
- CCC Summer course, Center for Cellular Construction, San Francisco State University, San Francisco, CA, USA
| | - Athena Lin
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Kyle Barlow
- Integrative Program in Quantitative Biology, University of California, San Francisco, San Francisco, CA, USA
| | - Patrick Harrigan
- Integrative Program in Quantitative Biology, University of California, San Francisco, San Francisco, CA, USA
| | - Mark M Slabodnick
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Wallace F Marshall
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
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9
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Charng YY, Mitra S, Yu SJ. Maintenance of abiotic stress memory in plants: Lessons learned from heat acclimation. THE PLANT CELL 2023; 35:187-200. [PMID: 36271858 PMCID: PMC9806581 DOI: 10.1093/plcell/koac313] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 10/17/2022] [Indexed: 05/23/2023]
Abstract
Plants acquire enhanced tolerance to intermittent abiotic stress by employing information obtained during prior exposure to an environmental disturbance, a process known as acclimation or defense priming. The capacity for stress memory is a critical feature in this process. The number of reports related to plant stress memory (PSM) has recently increased, but few studies have focused on the mechanisms that maintain PSM. Identifying the components involved in maintaining PSM is difficult due in part to the lack of clear criteria to recognize these components. In this review, based on what has been learned from genetic studies on heat acclimation memory, we propose criteria for identifying components of the regulatory networks that maintain PSM. We provide examples of the regulatory circuits formed by effectors and regulators of PSM. We also highlight strategies for assessing PSMs, update the progress in understanding the mechanisms of PSM maintenance, and provide perspectives for the further development of this exciting research field.
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Affiliation(s)
| | - Suma Mitra
- Agricultural Biotechnology Research Center, Academia Sinica, Taiwan, ROC
- Molecular and Biological Agricultural Sciences Program, TIGP, Academia Sinica, Taiwan, ROC
- Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung, Taiwan, ROC
| | - Shih-Jiun Yu
- Agricultural Biotechnology Research Center, Academia Sinica, Taiwan, ROC
- Department of Biochemical Sciences and Technology, National Taiwan University, Taipei, Taiwan, ROC
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10
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Rodriguez-Quintero WD, Moreno-Chacón M, Carrasco-Urra F, Saldaña A. From dark to darkness, negative phototropism influences the support-tree location of the massive woody climber Hydrangea serratifolia (Hydrangeaceae) in a Chilean temperate rainforest. PLANT SIGNALING & BEHAVIOR 2022; 17:2122244. [PMID: 36476262 PMCID: PMC9733698 DOI: 10.1080/15592324.2022.2122244] [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: 04/06/2022] [Revised: 09/02/2022] [Accepted: 09/02/2022] [Indexed: 06/17/2023]
Abstract
Climbing plants rely on suitable support to provide the light conditions they require in the canopy. Negative phototropism is a directional search behavior proposed to detect a support-tree, which indicates growth or movement away from light, based on light attenuation. In a Chilean temperate rainforest, we addressed whether the massive woody climber Hydrangea serratifolia (H. et A.) F. Phil (Hydrangeaceae) presents a support-tree location pattern influenced by light availability. We analyzed direction and light received in two groups of juvenile shoots: searching shoots (SS), with plagiotropic (creeping) growth vs. ascending shoots (AS), with orthotropic growth. We found that, in accordance with light attenuation, SS and AS used directional orientation to search and then ascend host trees. The light available to H. serratifolia searching shoots was less than that of the general forest understory; the directional orientation in both groups showed a significant deviation from a random distribution, with no circular statistical difference between them. Circular-linear regression indicated a relationship between directional orientations and light availability. Negative phototropism encodes the light environment's heterogeneous spatial and temporal information, guiding the shoot apex to the most shaded part of the support-tree base, the climbing start point.
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Affiliation(s)
- W. David Rodriguez-Quintero
- Departamento de Botánica, Universidad de Concepción, Concepción, Chile
- Centro de Ecología Aplicada Ltda, Principe de Gales6465La Reina, Chile
| | | | | | - Alfredo Saldaña
- Departamento de Botánica, Universidad de Concepción, Concepción, Chile
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11
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Zha C, Sossin WS. The molecular diversity of plasticity mechanisms underlying memory: An evolutionary perspective. J Neurochem 2022; 163:444-460. [PMID: 36326567 DOI: 10.1111/jnc.15717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/29/2022] [Accepted: 10/17/2022] [Indexed: 11/06/2022]
Abstract
Experience triggers molecular cascades in organisms (learning) that lead to alterations (memory) to allow the organism to change its behavior based on experience. Understanding the molecular mechanisms underlying memory, particularly in the nervous system of animals, has been an exciting scientific challenge for neuroscience. We review what is known about forms of neuronal plasticity that underlie memory highlighting important issues in the field: (1) the importance of being able to measure how neurons are activated during learning to identify the form of plasticity that underlies memory, (2) the many distinct forms of plasticity important for memories that naturally decay both within and between organisms, and (3) unifying principles underlying the formation and maintenance of long-term memories. Overall, the diversity of molecular mechanisms underlying memories that naturally decay contrasts with more unified molecular mechanisms implicated in long-lasting changes. Despite many advances, important questions remain as to which mechanisms of neuronal plasticity underlie memory.
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Affiliation(s)
- Congyao Zha
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Wayne S Sossin
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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12
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Del Stabile F, Marsili V, Forti L, Arru L. Is There a Role for Sound in Plants? PLANTS 2022; 11:plants11182391. [PMID: 36145791 PMCID: PMC9503271 DOI: 10.3390/plants11182391] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/05/2022] [Accepted: 09/12/2022] [Indexed: 11/16/2022]
Abstract
Plants have long been considered passive, static, and unchanging organisms, but this view is finally changing. More and more knowledge is showing that plants are aware of their surroundings, and they respond to a surprising variety of stimuli by modifying their growth and development. Plants extensively communicate with the world around them, above and below ground. Although communication through mycorrhizal networks and Volatile Organic Compounds has been known for a long time, acoustic perception and communication are somehow a final frontier of research. Perhaps surprisingly, plants not only respond to sound, they actually seem to emit sound as well. Roots emit audible clicks during growth, and sounds are emitted from xylem vessels, although the nature of these acoustic emissions still needs to be clarified. Even more interesting, there is the possibility that these sounds carry information with ecological implications, such as alerting insects of the hydration state of a possible host plant, and technological implications as well. Monitoring sound emissions could possibly allow careful monitoring of the hydration state of crops, which could mean significantly less water used during irrigation. This review summarizes the current knowledge on sound perception communication in plants and illustrates possible implications and technological applications.
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13
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Parise AG, de Toledo GRA, Oliveira TFDC, Souza GM, Castiello U, Gagliano M, Marder M. Do plants pay attention? A possible phenomenological-empirical approach. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 173:11-23. [PMID: 35636584 DOI: 10.1016/j.pbiomolbio.2022.05.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/17/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
Attention is the important ability of flexibly controlling limited cognitive resources. It ensures that organisms engage with the activities and stimuli that are relevant to their survival. Despite the cognitive capabilities of plants and their complex behavioural repertoire, the study of attention in plants has been largely neglected. In this article, we advance the hypothesis that plants are endowed with the ability of attaining attentive states. We depart from a transdisciplinary basis of philosophy, psychology, physics and plant ecophysiology to propose a framework that seeks to explain how plant attention might operate and how it could be studied empirically. In particular, the phenomenological approach seems particularly important to explain plant attention theoretically, and plant electrophysiology seems particularly suited to study it empirically. We propose the use of electrophysiological techniques as a viable way for studying it, and we revisit previous work to support our hypothesis. We conclude this essay with some remarks on future directions for the study of plant attention and its implications to botany.
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Affiliation(s)
- André Geremia Parise
- Laboratory of Plant Cognition and Electrophysiology (LACEV), Department of Botany, Institute of Biology, Federal University of Pelotas, Pelotas, RS, Brazil.
| | - Gabriel Ricardo Aguilera de Toledo
- Laboratory of Plant Cognition and Electrophysiology (LACEV), Department of Botany, Institute of Biology, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Thiago Francisco de Carvalho Oliveira
- Laboratory of Plant Cognition and Electrophysiology (LACEV), Department of Botany, Institute of Biology, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Gustavo Maia Souza
- Laboratory of Plant Cognition and Electrophysiology (LACEV), Department of Botany, Institute of Biology, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Umberto Castiello
- Neuroscience of Movement Laboratory (NEMO), Department of General Psychology, University of Padova, Padova, Italy
| | - Monica Gagliano
- Biological Intelligence Laboratory (BI Lab), School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, Australia
| | - Michael Marder
- Ikerbasque: Basque Foundation for Science & Department of Philosophy, University of the Basque Country (UPV/EHU), Spain
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14
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Memory of plants: present understanding. THE NUCLEUS 2022. [DOI: 10.1007/s13237-022-00399-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022] Open
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15
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Khattar J, Calvo P, Vandebroek I, Pandolfi C, Dahdouh-Guebas F. Understanding interdisciplinary perspectives of plant intelligence: Is it a matter of science, language, or subjectivity? JOURNAL OF ETHNOBIOLOGY AND ETHNOMEDICINE 2022; 18:41. [PMID: 35637487 PMCID: PMC9153103 DOI: 10.1186/s13002-022-00539-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 04/04/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Evidence suggests that plants can behave intelligently by exhibiting the ability to learn, make associations between environmental cues, engage in complex decisions about resource acquisition, memorize, and adapt in flexible ways. However, plant intelligence is a disputed concept in the scientific community. Reasons for lack of consensus can be traced back to the history of Western philosophy, interpretation of terminology, and due to plants lacking neurons and a central nervous system. Plant intelligence thus constitutes a novel paradigm in the plant sciences. Therefore, the perspectives of scientists in plant-related disciplines need to be investigated in order to gain insight into the current state and future development of this concept. METHODS This study analyzed opinions of plant intelligence held by scientists from different plant-related disciplines, including ethnobiology and other biological sciences, through an online questionnaire. RESULTS Our findings show that respondents' personal belief systems and the frequency of taking into account other types of knowledge, such as traditional knowledge, in their own field(s) of study, were associated with their opinions of plant intelligence. Meanwhile, respondents' professional expertise, background (discipline), or familiarity with evidence provided on plant intelligence did not affect their opinions. CONCLUSIONS This study emphasizes the influential role of scientists' own subjective beliefs. In response, two approaches could facilitate transdisciplinary understanding among scientists: (1) effective communication designed to foster change in agreement based on presented information; and (2) holding space for an interdisciplinary dialogue where scientists can express their own subjectivities and open new opportunities for collaboration.
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Affiliation(s)
- Jennifer Khattar
- Systems Ecology and Resource Management, Department of Organism Biology, Faculté des Sciences, Université Libre de Bruxelles - ULB, Avenue F.D. Roosevelt 50, CPi 264/1, 1050, Brussels, Belgium.
- Ecology and Biodiversity, Laboratory of Plant Biology and Nature Management, Biology Department, Vrije Universiteit Brussel - VUB, Pleinlaan 2, VUB-APNA-WE, 1050, Brussels, Belgium.
- International Laboratory of Plant Neurobiology (LINV), Department of Plant, Soil and Environmental Science, Università degli Studi di Firenze, Viale delle Idee 30, 50019, Sesto Fiorentino, Tuscany, Italy.
| | - Paco Calvo
- Minimal Intelligence Lab, Department of Philosophy, University of Murcia, 30100, Murcia, Spain
| | - Ina Vandebroek
- Faculty of Science and Technology, Department of Life Sciences and Natural Products Institute, The University of the West Indies, Mona Campus, Kingston, Jamaica
- Institute of Economic Botany, The New York Botanical Garden, 2900 Southern Boulevard, Bronx, NY, 10458, USA
| | - Camilla Pandolfi
- International Laboratory of Plant Neurobiology (LINV), Department of Plant, Soil and Environmental Science, Università degli Studi di Firenze, Viale delle Idee 30, 50019, Sesto Fiorentino, Tuscany, Italy
| | - Farid Dahdouh-Guebas
- Systems Ecology and Resource Management, Department of Organism Biology, Faculté des Sciences, Université Libre de Bruxelles - ULB, Avenue F.D. Roosevelt 50, CPi 264/1, 1050, Brussels, Belgium
- Ecology and Biodiversity, Laboratory of Plant Biology and Nature Management, Biology Department, Vrije Universiteit Brussel - VUB, Pleinlaan 2, VUB-APNA-WE, 1050, Brussels, Belgium
- Interfaculty Institute of Social-Ecological Transitions - iiTSE, Université Libre de Bruxelles - ULB, Brussels, Belgium
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Perspectives Organize Information in Mind and Nature: Empirical Findings of Point-View Perspective (P) in Cognitive and Material Complexity. SYSTEMS 2022. [DOI: 10.3390/systems10030052] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The importance of perspective-taking crosses disciplines and is foundational to diverse phenomena such as point-of-view, scale, mindset, theory of mind, opinion, belief, empathy, compassion, analysis, and problem solving, etc. This publication gives predictions for and a formal description of point-view Perspectives (P) or the “P-rule”. This makes the P-rule foundational to systems, systems thinking and the consilience of knowledge. It is one of four universals of the organization of information as a whole. This paper presents nine empirical studies in which subjects were asked to complete a task and/or answer a question. The samples vary for each study (ranging from N = 407 to N = 34,398) and are generalizable to a normal distribution of the US population. As was evident in Cabrera, “These studies support—with high statistical significance—the predictions made by DSRP Theory (Distinctions, Systems Relationships, Perspectives) point-view Perspectives including its: universality as an observable phenomenon in both mind (cognitive complexity) and nature (material complexity) (i.e., parallelism); internal structures and dynamics; mutual dependencies on other universals (i.e., Distinctions, Systems, and Relationships); role in structural predictions; and, efficacy as a metacognitive skill”. These data suggest that point-view Perspectives (P) observably and empirically exist, and that universality, efficacy, and parallelism (between cognitive and material complexity) exist as well. The impact of this paper is that it provides empirical evidence for the phenomena of point-view perspective taking (“P-rule”) as a universal pattern/structure of systems thinking, a field in which scholarly debate is often based on invalidated opinioned frameworks; this sets the stage for theory building in the field.
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Brenya E, Pervin M, Chen ZH, Tissue DT, Johnson S, Braam J, Cazzonelli CI. Mechanical stress acclimation in plants: Linking hormones and somatic memory to thigmomorphogenesis. PLANT, CELL & ENVIRONMENT 2022; 45:989-1010. [PMID: 34984703 DOI: 10.1111/pce.14252] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 12/03/2021] [Accepted: 12/09/2021] [Indexed: 06/14/2023]
Abstract
A single event of mechanical stimulation is perceived by mechanoreceptors that transduce rapid transient signalling to regulate gene expression. Prolonged mechanical stress for days to weeks culminates in cellular changes that strengthen the plant architecture leading to thigmomorphogenesis. The convergence of multiple signalling pathways regulates mechanically induced tolerance to numerous biotic and abiotic stresses. Emerging evidence showed prolonged mechanical stimulation can modify the baseline level of gene expression in naive tissues, heighten gene expression, and prime disease resistance upon a subsequent pathogen encounter. The phenotypes of thigmomorphogenesis can persist throughout growth without continued stimulation, revealing somatic-stress memory. Epigenetic processes regulate TOUCH gene expression and could program transcriptional memory in differentiating cells to program thigmomorphogenesis. We discuss the early perception, gene regulatory and phytohormone pathways that facilitate thigmomorphogenesis and mechanical stress acclimation in Arabidopsis and other plant species. We provide insights regarding: (1) the regulatory mechanisms induced by single or prolonged events of mechanical stress, (2) how mechanical stress confers transcriptional memory to induce cross-acclimation to future stress, and (3) why thigmomorphogenesis might resemble an epigenetic phenomenon. Deeper knowledge of how prolonged mechanical stimulation programs somatic memory and primes defence acclimation could transform solutions to improve agricultural sustainability in stressful environments.
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Affiliation(s)
- Eric Brenya
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Mahfuza Pervin
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia
| | - Zhong-Hua Chen
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia
- School of Science, Western Sydney University, Richmond, New South Wales, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia
| | - Scott Johnson
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia
| | - Janet Braam
- Department of Biosciences, Rice University, Houston, Texas, USA
| | - Christopher I Cazzonelli
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia
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18
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The “Fish Tank” Experiments: Metacognitive Awareness of Distinctions, Systems, Relationships, and Perspectives (DSRP) Significantly Increases Cognitive Complexity. SYSTEMS 2022. [DOI: 10.3390/systems10020029] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In the field of systems thinking, there are far too many opinioned frameworks and far too few empirical studies. This could be described as a “gap” in the research but it is more like a dearth in the research. More theory and empirical validation of theory are needed if the field and the phenomenon of systems thinking holds promise and not just popularity. This validation comes in the form of both basic (existential) and applied (efficacy) research studies. This article presents efficacy data for a set of empirical studies of DSRP Theory. According to Cabrera, Cabrera, and Midgley, DSRP Theory has equal or more empirical evidence supporting it than any existing systems theories (including frameworks, which are not theories). Four separate studies show highly statistically relevant findings for the effect of a short (less than one minute) treatment of D, S, R, and P. Subjects’ cognitive complexity and the systemic nature of their thinking increased in all four studies. These findings indicate that even a short treatment in DSRP is effective in increasing systems thinking skills. Based on these results, a longer, more in-depth treatment—such as a one hour or semester long training, such is the norm—would therefore likely garner transformative results and efficacy.
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Abstract
DSRP Theory is now over 25 years old with more empirical evidence supporting it than any other systems thinking framework. Yet, it is often misunderstood and described in ways that are inaccurate. DSRP Theory describes four patterns and their underlying elements—identity (i) and other (o) for Distinctions (D), part (p) and whole (w) for Systems (S), action (a) and reaction (r) for Relationships (R), and point (ρ) and view (v) for Perspectives (P)—that are universal in both cognitive complexity (mind) and material complexity (nature). DSRP Theory provides a basis for systems thinking or cognitive complexity as well as material complexity (systems science). This paper, as a relatively short primer on the theory, provides clarity to those wanting to understand DSRP and its implications.
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20
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Computing within bacteria: Programming of bacterial behavior by means of a plasmid encoding a perceptron neural network. Biosystems 2022; 213:104608. [DOI: 10.1016/j.biosystems.2022.104608] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/07/2021] [Accepted: 01/11/2022] [Indexed: 01/12/2023]
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21
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Brody DC. Open quantum dynamics for plant motions. Sci Rep 2022; 12:3042. [PMID: 35197530 PMCID: PMC8866431 DOI: 10.1038/s41598-022-07102-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 02/11/2022] [Indexed: 12/02/2022] Open
Abstract
Stochastic Schrödinger equations that govern the dynamics of open quantum systems are given by the equations for signal processing. In particular, the Brownian motion that drives the wave function of the system does not represent noise, but provides purely the arrival of new information. Thus the wave function is guided by the optimal signal detection about the conditions of the environments under noisy observations. This behaviour is similar to biological systems that detect environmental cues, process this information, and adapt to them optimally by minimising uncertainties about the conditions of their environments. It is postulated that information-processing capability is a fundamental law of nature, and hence that models describing open quantum systems can equally be applied to biological systems to model their dynamics. For illustration, simple stochastic models are considered to capture heliotropic and gravitropic motions of plants. The advantage of such dynamical models is that they allow for the quantification of information processed by the plants. By considering the consequence of information erasure, it is argued that biological systems can process environmental signals relatively close to the Landauer limit of computation, and that loss of information must lie at the heart of ageing in biological systems.
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Affiliation(s)
- Dorje C Brody
- Department of Mathematics, University of Surrey, Guildford, GU2 7XH, UK. .,St Petersburg National Research University of Information Technologies, Mechanics and Optics, St Petersburg, Russia, 197101.
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22
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Memory and habituation to harmful and non-harmful stimuli in a field population of the sensitive plant, Mimosa pudica. JOURNAL OF TROPICAL ECOLOGY 2021. [DOI: 10.1017/s0266467421000559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractMimosa pudica is a Neotropical legume that closes its leaves rapidly in response to touch stimulation, hypothetically as herbivory defence. Habituation to non-harmful stimuli and long-term memory of past events have been demonstrated in this species, the former with relatively heavy objects and the latter under laboratory conditions. This species should not habituate to harmful stimuli if leaf movement is a response to herbivore damage. We tested in Monteverde, Costa Rica, whether (1) memory occurs in wild plants, (2) whether habituation occurs under harmful stimuli: simulated herbivory, and (3) whether wild plants can habituate to light non-harmful stimuli. The degree of closing of the leaflets and time until reopening was measured in response to repeated harmful and non-harmful stimuli. The results showed habituation to repeated non-harmful very light stimuli and showed lack of habituation to simulated leaf damage. Wild plants also showed faster rehabituation to repeated non-harmful stimuli when they had been exposed 15 days previously, suggesting possible long-term memory. These results indicate that wild plants are capable of (1) distinguishing between harmful and non-harmful stimuli (only habituating to the latter), (2) memorizing previous events, and 3) habituating very light tactile stimuli commonly experienced in the field.
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Abstract
We propose an expansion of neuroecological comparisons to include the capabilities of brainless and non-neural organisms. We begin this enterprise by conducting a systematic search for studies on learning in echinoderms. Echinodermata are marine invertebrates comprising starfish, brittle stars, sea cucumbers, sea urchins, and sea lilies. Animals in this phylum lack any centralized brain and instead possess diffuse neural networks known as nerve nets. The learning abilities of these animals are of particular interest as, within the bilaterian clade, they are close evolutionary neighbors to chordates, a phylum whose members exhibit complex feats in learning and contain highly specialized brains. The learning capacities and limitations of echinoderms can inform the evolution of nervous systems and learning in Bilateria. We find evidence of both non-associative and associative learning (in the form of classical conditioning) in echinoderms, which was primarily focused on starfish. Additional evidence of learning is documented in brittle stars, sand dollars, and sea urchins. We then discuss the evolutionary significance of learning capabilities without a brain, the presence of embodied cognition across multiple groups, and compare the learning present in echinoderms with the impressive cognitive abilities documented in the oldest linage group within vertebrates (the major group within the phylum of chordates), fish.
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24
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Bouteau F, Grésillon E, Chartier D, Arbelet-Bonnin D, Kawano T, Baluška F, Mancuso S, Calvo P, Laurenti P. Our sisters the plants? notes from phylogenetics and botany on plant kinship blindness. PLANT SIGNALING & BEHAVIOR 2021; 16:2004769. [PMID: 34913409 PMCID: PMC9208782 DOI: 10.1080/15592324.2021.2004769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 07/13/2021] [Accepted: 11/08/2021] [Indexed: 05/27/2023]
Abstract
Before the upheaval brought about by phylogenetic classification, classical taxonomy separated living beings into two distinct kingdoms, animals and plants. Rooted in 'naturalist' cosmology, Western science has built its theoretical apparatus on this dichotomy mostly based on ancient Aristotelian ideas. Nowadays, despite the adoption of the Darwinian paradigm that unifies living organisms as a kinship, the concept of the "scale of beings" continues to structure our analysis and understanding of living species. Our aim is to combine developments in phylogeny, recent advances in biology, and renewed interest in plant agency to craft an interdisciplinary stance on the living realm. The lines at the origin of plant or animal have a common evolutionary history dating back to about 3.9 Ga, separating only 1.6 Ga ago. From a phylogenetic perspective of living species history, plants and animals belong to sister groups. With recent data related to the field of Plant Neurobiology, our aim is to discuss some socio-cultural obstacles, mainly in Western naturalist epistemology, that have prevented the integration of living organisms as relatives, while suggesting a few avenues inspired by practices principally from other ontologies that could help overcome these obstacles and build bridges between different ways of connecting to life.
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Affiliation(s)
- François Bouteau
- Laboratoire Interdisciplinaire Des Énergies de Demain, Université de Paris, France
| | - Etienne Grésillon
- Laboratoire Dynamiques Sociales Et Recomposition Des Espaces (Ladyss-umr 7533), Université de Paris, Paris, France
| | - Denis Chartier
- Laboratoire Dynamiques Sociales Et Recomposition Des Espaces (Ladyss-umr 7533), Université de Paris, Paris, France
| | | | - Tomonori Kawano
- Graduate School of Environmental Engineering, University of Kitakyushu 1–1, KitakyushuJapan
| | - František Baluška
- Institute of Cellular and Molecular Botany, University of Bonn, Bonn, Germany
| | - Stefano Mancuso
- LINV-DiSPAA, Department of Agri-Food and Environmental Science, University of Florence, Sesto Fiorentino (FI), Italy
| | - Paco Calvo
- Minimal Intelligence Lab, Department of Philosophy, University of Murcia, Murcia, Spain
| | - Patrick Laurenti
- Laboratoire Interdisciplinaire Des Énergies de Demain, Université de Paris, France
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Wang Q, Guerra S, Ceccarini F, Bonato B, Castiello U. Sowing the seeds of intentionality: Motor intentions in plants. PLANT SIGNALING & BEHAVIOR 2021; 16:1949818. [PMID: 34346847 PMCID: PMC8525965 DOI: 10.1080/15592324.2021.1949818] [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: 04/29/2021] [Revised: 06/25/2021] [Accepted: 06/26/2021] [Indexed: 06/13/2023]
Abstract
Motor intention/intentionality has been investigated from a wide variety of perspectives: some researchers have, for example, been focusing on the purely physical and mechanical aspects underlying the control of action, while others have been concentrating on subjective intentionality. Basically, all approaches ranging from the neuroscientific to phenomenological-inspired ones have been used to investigate motor intentions. The current study set out to examine motor intentions in connection to plant behavior utilizing the final goal of plant action as the definition of its motor intention. Taking a wide-angle approach, the first part of the review is dedicated to examining philosophical and psychological studies on motor intentions. Recent data demonstrating that plant behavior does indeed seem goal-directed will then be reviewed as we ponder the possibility of purposeful or intentional plant responses to stimuli and stress conditions in their environment. The article will draw to a close as we examine current theories attempting to explain plants' overt behavior and corresponding covert representations.
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Affiliation(s)
- Qiuran Wang
- Department of General Psychology, University of Padua, Padua, Italy
| | - Silvia Guerra
- Department of General Psychology, University of Padua, Padua, Italy
| | | | - Bianca Bonato
- Department of General Psychology, University of Padua, Padua, Italy
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26
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Reyes-Jiménez D, Iglesias-Parro S, Abad MJF, Paredes-Olay C. Effects of pre-exposure and post-exposure of the context in habituation of the retraction response in earthworms (Lumbricidae). Behav Processes 2021; 193:104527. [PMID: 34601052 DOI: 10.1016/j.beproc.2021.104527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 09/08/2021] [Accepted: 09/28/2021] [Indexed: 11/19/2022]
Abstract
The context specificity of habituation has been demonstrated in earthworms. After the habituation of the retraction response to a light, a recovery of the response was observed when subjects are re-habituated in a different context. Some theories assume that an association between the context and the unconditioned stimulus could underlie this result. A series of experiments were conducted in order to test this issue. We assessed the potential disruptive effects of post-exposure (extinction effect) and pre-exposure of the context (latent inhibition effect) on the establishment of a context-US association. A recovery of response during subsequent rehabituation test was expected. The results of Experiment 1 showed that the extinction was effective, the post-exposure of the context after habituation produced a recovery of the retraction response. This result was replicated in Experiment 2 where the post-exposure condition was compared with a pre-exposure one. However, the pre-exposure to the context did not result in a recovery of the response in the rehabituation test, but also produced a general decrement on the response during the habituation training, that it has been interpreted as decrement in context's salience. In summary, these results suggest the involvement of associative and nonassociative processes in habituation learning.
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Affiliation(s)
- David Reyes-Jiménez
- Department of Psychology, Universidad de Jaén, Paraje las Lagunillas s/n, 23071 Jaén, Spain.
| | - Sergio Iglesias-Parro
- Department of Psychology, Universidad de Jaén, Paraje las Lagunillas s/n, 23071 Jaén, Spain.
| | - María J F Abad
- Department of Psychology, Universidad de Jaén, Paraje las Lagunillas s/n, 23071 Jaén, Spain.
| | - Concepción Paredes-Olay
- Department of Psychology, Universidad de Jaén, Paraje las Lagunillas s/n, 23071 Jaén, Spain.
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27
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Miguel-Tomé S, Llinás RR. Broadening the definition of a nervous system to better understand the evolution of plants and animals. PLANT SIGNALING & BEHAVIOR 2021; 16:1927562. [PMID: 34120565 PMCID: PMC8331040 DOI: 10.1080/15592324.2021.1927562] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 04/30/2021] [Accepted: 05/03/2021] [Indexed: 05/10/2023]
Abstract
Most textbook definitions recognize only animals as having nervous systems. However, for the past couple decades, botanists have been meticulously studying long-distance signaling systems in plants, and some researchers have stated that plants have a simple nervous system. Thus, an academic conflict has emerged between those who defend and those who deny the existence of a nervous system in plants. This article analyses that debate, and we propose an alternative to answering yes or no: broadening the definition of a nervous system to include plants. We claim that a definition broader than the current one, which is based only on a phylogenetic viewpoint, would be helpful in obtaining a deeper understanding of how evolution has driven the features of signal generation, transmission and processing in multicellular beings. Also, we propose two possible definitions and exemplify how broader a definition allows for new viewpoints on the evolution of plants, animals and the nervous system.
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Affiliation(s)
- Sergio Miguel-Tomé
- Grupo De Investigación En Minería De Datos (Mida), Universidad De Salamanca, Salamanca, Spain
| | - Rodolfo R. Llinás
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, USA
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28
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Segundo-Ortin M, Calvo P. Consciousness and cognition in plants. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2021; 13:e1578. [PMID: 34558231 DOI: 10.1002/wcs.1578] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 08/26/2021] [Accepted: 08/30/2021] [Indexed: 12/17/2022]
Abstract
Unlike animal behavior, behavior in plants is traditionally assumed to be completely determined either genetically or environmentally. Under this assumption, plants are usually considered to be noncognitive organisms. This view nonetheless clashes with a growing body of empirical research that shows that many sophisticated cognitive capabilities traditionally assumed to be exclusive to animals are exhibited by plants too. Yet, if plants can be considered cognitive, even in a minimal sense, can they also be considered conscious? Some authors defend that the quest for plant consciousness is worth pursuing, under the premise that sentience can play a role in facilitating plant's sophisticated behavior. The goal of this article is not to provide a positive argument for plant cognition and consciousness, but to invite a constructive, empirically informed debate about it. After reviewing the empirical literature concerning plant cognition, we introduce the reader to the emerging field of plant neurobiology. Research on plant electrical and chemical signaling can help shed light into the biological bases for plant sentience. To conclude, we shall present a series of approaches to scientifically investigate plant consciousness. In sum, we invite the reader to consider the idea that if consciousness boils down to some form of biological adaptation, we should not exclude a priori the possibility that plants have evolved their own phenomenal experience of the world. This article is categorized under: Cognitive Biology > Evolutionary Roots of Cognition Philosophy > Consciousness Neuroscience > Cognition.
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Affiliation(s)
- Miguel Segundo-Ortin
- Department of Philosophy and Religious Studies, Faculty of Humanities, Utrecht University, Utrecht, The Netherlands
| | - Paco Calvo
- Minimal Intelligence Laboratory, Universidad de Murcia, Murcia, Spain
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Fey SB, Kremer CT, Layden TJ, Vasseur DA. Resolving the consequences of gradual phenotypic plasticity for populations in variable environments. ECOL MONOGR 2021. [DOI: 10.1002/ecm.1478] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Samuel B. Fey
- Department of Biology Reed College Portland Oregon 97202 USA
| | - Colin T. Kremer
- W.K. Kellogg Biological Station Michigan State University Hickory Corners Michigan 49060 USA
- Department of Ecology and Evolutionary Biology University of California Los Angeles Los Angeles California 90096 USA
| | | | - David A. Vasseur
- Department of Ecology and Evolutionary Biology Yale University 165 Prospect Street New Haven Connecticut 06520 USA
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Zhang X, Li C, Tie D, Quan J, Yue M, Liu X. Epigenetic memory and growth responses of the clonal plant Glechoma longituba to parental recurrent UV-B stress. FUNCTIONAL PLANT BIOLOGY : FPB 2021; 48:827-838. [PMID: 33820599 DOI: 10.1071/fp20303] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 03/10/2021] [Indexed: 06/12/2023]
Abstract
The responses of plants to recurrent stress may differ from their responses to a single stress event. In this study, we investigated whether clonal plants can remember past environments. Parental ramets of Glechoma longituba (Nakai) Kuprian were exposed to UV-B stress treatments either once or repeatedly (20 and 40 repetitions). Differences in DNA methylation levels and growth parameters among parents, offspring ramets and genets were analysed. Our results showed that UV-B stress reduced the DNA methylation level of parental ramets, and the reduction was enhanced by increasing the number of UV-B treatments. The epigenetic variation exhibited by recurrently stressed parents was maintained for a long time, but that of singly stressed parents was only short-term. Moreover, clonal plants responded to different UV-B stress treatments with different growth strategies. The one-time stress was a eustress that increased genet biomass by increasing offspring leaf allocation and defensive allocation in comparison to the older offspring. In contrast, recurring stress was a distress that reduced genet biomass, increased the biomass of storage stolons, and allocated more defensive substances to the younger ramets. This study demonstrated that the growth of offspring and genets was clearly affected by parental experience, and parental epigenetic memory and the transgenerational effect may play important roles in this effect.
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Affiliation(s)
- Xiaoyin Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, China
| | - Cunxia Li
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, China
| | - Dan Tie
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, China
| | - Jiaxin Quan
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, China
| | - Ming Yue
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, China
| | - Xiao Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, China; and Corresponding author.
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Relational health: Theorizing plants as health-supporting actors. Soc Sci Med 2021; 281:114083. [PMID: 34130074 DOI: 10.1016/j.socscimed.2021.114083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/21/2021] [Accepted: 05/24/2021] [Indexed: 11/20/2022]
Abstract
'Plant blindness' stops people from recognizing the important role that plants play in society, and is acute when it comes to seeing how plants support health. The social sciences are beginning to explore how plants are imbricated in sociopolitical processes, including ones that produce health. This paper theorizes people-plant relations and the agency of plants in the production of health, drawing on data from a multispecies ethnography conducted in Toronto's largest social housing community during the 2018 growing season. The paper applies a posthumanist lens to find that food-producing plants in the area exert their agency and are health-supporting actors when collaborating with residents to advocate for community gardens and influence neighbourhood design. By arguing that plants are actual agents of change in sociopolitical processes, the article deepens an understanding of the health-supporting role of plants and provides empirical evidence for a view of health as a process, as opposed to a status, that is produced through relationships. The paper suggests that the term 'relational health' be used to describe a conception of health that recognizes that health is produced through interconnections and interdependencies, including between people and plants. The article contributes to discourses exploring the human health relationship to nature, including One Health.
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Ribeiro RV, Vitti KA, Marcos FCC, Souza GM, Pissolato MD, Almeida LFR, Machado EC. Proposal of an index of stability for evaluating plant drought memory: A case study in sugarcane. JOURNAL OF PLANT PHYSIOLOGY 2021; 260:153397. [PMID: 33721569 DOI: 10.1016/j.jplph.2021.153397] [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: 02/08/2021] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 06/12/2023]
Abstract
Stability is a key trait for plant growth and development in a changing environment, involving homeostasis and resilience. While homeostasis refers to the maintenance of the internal structural and functional plant integrity, resilience is associated with the plant ability in returning to the initial conditions after a given disturbance. Such concepts are especially relevant for perennial and semi-perennial plants facing seasonal and frequent stress conditions. Although plant memory is closely associated with plant performance under recurrent stresses, to date, there is no study evaluating how stress memory is linked to stability under varying water conditions. Herein, we evaluated the association between drought stability and memory in sugarcane plants and proposed a new stability index to evaluate plant memory. Two datasets were analyzed, the first deals with leaf gas exchange and photochemistry of sugarcane plants grown in nutrient solution and exposed to one, two or three water deficit cycles. The second takes into account the physiological performance of sugarcane propagules obtained by vegetative propagation from plants that faced drought. To quantify sugarcane stability, we estimated the drought impact, the disturbance rate (DR), drought perturbation, and recovery rate (RR) for plants from both datasets. Drought memory - given by improved performance after previous stress events or when origin material faced drought - was detected in both datasets, changing either DR or RR. Based on these indices, we proposed the overall stability (OSt), defined as the ratio between RR and DR. While DR is associated to plant homeostasis, RR is a measure of plant resilience. Sugarcane plants exposed to three cycles of water deficit or those propagules originated from stressed plants presented the highest OSt values, showing higher RR and/or lower DR when compared to well-watered plants or to propagules from well-watered plants. Regarding the physiological traits evaluated, leaf CO2 assimilation and stomatal conductance were the most consistent variables in revealing drought stability and memory. Concluding, OSt revealed consistently patterns of response associated with plant memory, besides quantifying plant stability under stressful conditions.
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Affiliation(s)
- Rafael V Ribeiro
- Laboratory of Crop Physiology (LCroP), Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil.
| | - Karine A Vitti
- Laboratory of Plant Physiology 'Coaracy M. Franco', Center for Research and Development in Ecophysiology and Biophysics, Agronomic Institute (IAC), Campinas, SP, Brazil
| | - Fernanda C C Marcos
- Department of Natural Sciences and Mathematics, Limeira Technical High School, University of Campinas (Unicamp), Limeira, SP, Brazil
| | - Gustavo M Souza
- Laboratory of Plant Cognition and Electrophysiology, Department of Botany, Federal University of Pelotas (UFPel), Capão do Leão, RS, Brazil
| | - Maria D Pissolato
- Laboratory of Crop Physiology (LCroP), Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Luiz Fernando R Almeida
- Section of Plant Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu, SP, Brazil
| | - Eduardo C Machado
- Laboratory of Plant Physiology 'Coaracy M. Franco', Center for Research and Development in Ecophysiology and Biophysics, Agronomic Institute (IAC), Campinas, SP, Brazil
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Van Volkenburgh E, Mirzaei K, Ybarra Y. Understanding Plant Behavior: A Student Perspective. TRENDS IN PLANT SCIENCE 2021; 26:423-425. [PMID: 33744160 DOI: 10.1016/j.tplants.2021.02.012] [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: 10/03/2020] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 06/12/2023]
Abstract
Biology students need special incentive to learn plant physiology. Framing plant function as 'behavior' analogous to animal neurobiology and behavior and integrating active learning methods is a successful way to generate an inclusive space for a wide range of learning styles, cultural backgrounds, and scientific contributions.
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Affiliation(s)
| | - Kaaren Mirzaei
- Biology Department, University of Washington, Seattle, WA 98195, USA
| | - Yesenia Ybarra
- Biology Department, University of Washington, Seattle, WA 98195, USA
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Yamashita F, Rodrigues AL, Rodrigues TM, Palermo FH, Baluška F, de Almeida LFR. Potential Plant-Plant Communication Induced by Infochemical Methyl Jasmonate in Sorghum ( Sorghum bicolor). PLANTS 2021; 10:plants10030485. [PMID: 33806670 PMCID: PMC8001897 DOI: 10.3390/plants10030485] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 02/26/2021] [Accepted: 02/27/2021] [Indexed: 11/25/2022]
Abstract
Despite the fact that they are sessile organisms, plants actively move their organs and also use these movements to manipulate the surrounding biotic and abiotic environments. Plants maintain communication with neighboring plants, herbivores, and predators through the emission of diverse chemical compounds by their shoots and roots. These infochemicals modify the environment occupied by plants. Moreover, some infochemicals may induce morphophysiological changes of neighboring plants. We have used methyl-jasmonate (MeJa), a plant natural infochemical, to trigger communication between emitters and receivers Sorghum bicolor plants. The split roots of two plants were allocated to three different pots, with the middle pot containing the roots of both plants. We scored low stomatal conductance (gS) and low CO2 net assimilation (A) using the plants that had contact with the infochemical for the first time. During the second contact, these parameters showed no significant differences, indicating a memory effect. We also observed that the plants that had direct leaf contact with MeJa transmitted sensory information through their roots to neighboring plants. This resulted in higher maximum fluorescence (FM) and structural changes in root anatomy. In conclusion, MeJa emerges as possible trigger for communication between neighboring sorghum plants, in response to the environmental challenges.
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Affiliation(s)
- Felipe Yamashita
- Section of Plant Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (A.L.R.); (T.M.R.); (F.H.P.); (L.F.R.d.A.)
- Institute of Cellular and Molecular Botany, University of Bonn, 53115 Bonn, Germany;
- Correspondence:
| | - Angélica Lino Rodrigues
- Section of Plant Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (A.L.R.); (T.M.R.); (F.H.P.); (L.F.R.d.A.)
| | - Tatiane Maria Rodrigues
- Section of Plant Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (A.L.R.); (T.M.R.); (F.H.P.); (L.F.R.d.A.)
| | - Fernanda Helena Palermo
- Section of Plant Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (A.L.R.); (T.M.R.); (F.H.P.); (L.F.R.d.A.)
| | - František Baluška
- Institute of Cellular and Molecular Botany, University of Bonn, 53115 Bonn, Germany;
| | - Luiz Fernando Rolim de Almeida
- Section of Plant Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 18618-689, Brazil; (A.L.R.); (T.M.R.); (F.H.P.); (L.F.R.d.A.)
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Dussutour A. Learning in single cell organisms. Biochem Biophys Res Commun 2021; 564:92-102. [PMID: 33632547 DOI: 10.1016/j.bbrc.2021.02.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/02/2021] [Accepted: 02/04/2021] [Indexed: 12/12/2022]
Abstract
The survival of all species requires appropriate behavioral responses to environmental challenges. Learning is one of the key processes to acquire information about the environment and adapt to changing and uncertain conditions. Learning has long been acknowledged in animals from invertebrates to vertebrates but remains a subject of debate in non-animal systems such a plants and single cell organisms. In this review I will attempt to answer the following question: are single cell organisms capable of learning? I will first briefly discuss the concept of learning and argue that the ability to acquire and store information through learning is pervasive and may be found in single cell organisms. Second, by focusing on habituation, the simplest form of learning, I will review a series of experiments showing that single cell organisms such as slime molds and ciliates display habituation and follow most of the criteria adopted by neuroscientists to define habituation. Then I will discuss disputed evidence suggesting that single cell organisms might also undergo more sophisticated forms of learning such as associative learning. Finally, I will stress out that the challenge for the future is less about whether or not to single cell organisms fulfill the definition of learning established from extensive studies in animal systems and more about acknowledging and understanding the range of behavioral plasticity exhibited by such fascinating organisms.
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Affiliation(s)
- Audrey Dussutour
- Research Centre on Animal Cognition (CRCA), Centre for Integrative Biology (CBI), Toulouse University, CNRS, UPS, Toulouse, 31062, AD, France.
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Mayer BF, Charron J. Transcriptional memories mediate the plasticity of cold stress responses to enable morphological acclimation in Brachypodium distachyon. THE NEW PHYTOLOGIST 2021; 229:1615-1634. [PMID: 32966623 PMCID: PMC7820978 DOI: 10.1111/nph.16945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/04/2020] [Indexed: 05/03/2023]
Abstract
Plants that successfully acclimate to stress can resume growth under stressful conditions. The grass Brachypodium distachyon can grow a cold-adaptive morphology during cold acclimation. Studies on transcriptional memory (TM) have revealed that plants can be primed for stress by adjusting their transcriptional responses, but the function of TM in stress acclimation is not well understood. We investigated the function of TM during cold acclimation in B. distachyon. Quantitative polymerase chain reaction (qPCR), RNA-seq and chromatin immunoprecipitation qPCR analyses were performed on plants exposed to repeated episodes of cold to characterize the presence and stability of TM during the stress and growth responses of cold acclimation. Transcriptional memory mainly dampened stress responses as growth resumed and as B. distachyon became habituated to cold stress. Although permanent on vernalization gene VRN1, TMs were short-term and reversible on cold-stress genes. Growing under cold conditions also coincided with the acquisition of new and targeted cold-induced transcriptional responses. Overall, TM provided plasticity to cold stress responses during cold acclimation in B. distachyon, leading to stress habituation, acquired stress responses, and resumed growth. Our study shows that chromatin-associated TMs are involved in tuning plant responses to environmental change and, as such, regulate both stress and developmental components that characterize cold-climate adaptation in B. distachyon.
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Affiliation(s)
- Boris F. Mayer
- Department of Plant ScienceMcGill University21, 111 LakeshoreSainte‐Anne‐de‐BellevueCanada
| | - Jean‐Benoit Charron
- Department of Plant ScienceMcGill University21, 111 LakeshoreSainte‐Anne‐de‐BellevueCanada
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Abstract
Using the database Web of Science, a systematic search for literature on learning in Cnidaria, both non-associative and associative, was conducted. Cnidaria comprise hydras, box jellies, (true) jellyfish, corals, and sea anemones, a group of animals possessing diffuse networks of nerves known as nerve nets or neural nets. Being neighbors on the animal evolutionary tree to bilaterian animals, the vast collection of (mostly) bilaterally symmetric animals with brains ranging from tiny worms to giant whales, the cognitive capacities of Cnidaria inform the evolution of nervous systems and cognition in bilateria. I failed to find literature on learning in corals and box jellies. Habituation has been amply shown in hydras, jellyfish, and sea anemones, while sensitization has been studied in detail in sea anemones, including some neurobiological details in the release of nematocysts or poisoned darts for capturing prey. One well-controlled study found evidence for classical conditioning with shock in sea anemones, in addition to two other lesser-controlled demonstrations. The relevance of associative learning in sea anemones, embodied cognition, and representationsal issues when it comes to animals without central brains is discussed.
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Fransson P, Brännström Å, Franklin O. A tree's quest for light-optimal height and diameter growth under a shading canopy. TREE PHYSIOLOGY 2021; 41:1-11. [PMID: 32879970 PMCID: PMC7868666 DOI: 10.1093/treephys/tpaa110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 07/30/2019] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
For trees in forests, striving for light is matter of life and death, either by growing taller toward brighter conditions or by expanding the crown to capture more of the available light. Here, we present a mechanistic model for the development path of stem height and crown size, accounting for light capture and growth, as well as mortality risk. We determine the optimal growth path among all possible trajectories using dynamic programming. The optimal growth path follows a sequence of distinct phases: (i) initial crown size expansion, (ii) stem height growth toward the canopy, (iii) final expansion of the crown in the canopy and (iv) seed production without further increase in size. The transition points between these phases can be optimized by maximizing fitness, defined as expected lifetime reproductive production. The results imply that to reach the canopy in an optimal way, trees must consider the full profile of expected increasing light levels toward the canopy. A shortsighted maximization of growth based on initial light conditions can result in arrested height growth, preventing the tree from reaching the canopy. The previous result can explain canopy stratification, and why canopy species often get stuck at a certain size under a shading canopy. The model explains why trees with lower wood density have a larger diameter at a given tree height and grow taller than trees with higher wood density. The model can be used to implement plasticity in height versus diameter growth in individual-based vegetation and forestry models.
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Affiliation(s)
- Peter Fransson
- Department of Mathematics and Mathematical Statistics, Umeå University, Linneaus väg 49, Umeå, SE-901 87, Sweden
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd 17, SE-901 83 Umeå, Sweden
| | - Åke Brännström
- Department of Mathematics and Mathematical Statistics, Umeå University, Linneaus väg 49, Umeå, SE-901 87, Sweden
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, A-2361, Austria
| | - Oskar Franklin
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, A-2361, Austria
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd 17, SE-901 83 Umeå, Sweden
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Hung TW. Nonhuman rationality: a predictive coding perspective. Cogn Process 2021; 22:353-362. [PMID: 33404900 DOI: 10.1007/s10339-020-01009-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 12/07/2020] [Indexed: 10/22/2022]
Abstract
How can we rethink 'rationality' in the wake of animal and artificial intelligence studies? Can nonhuman systems be rational in any nontrivial sense? In this paper, we propose that all organisms, under certain circumstances, exhibit rationality to a diverse degree and aspect in the sense of the standard picture (SP): Their inferential processes conform to logic and probability rules. We first show that according to Calvo and Friston (J R Soc Interface 14(131):20170096, 2017) and Orlandi (2018), all biological systems must embody a top-down process (active inference) to minimize free energy. Next, based on Maddy's (Second philosophy, Oxford University Press, Oxford, 2007; The logical must: Wittgenstein on logic, Oxford University Press, Oxford, 2014) analysis, we argue that this inferential process conforms to logic and probability rules; thus, it satisfies the SP, which explains the rudimentary logic and arithmetic (e.g., categorizing and numbering) found among pigeons and mice. We also hold that the mammalian brain is only one among many ways of implementing rationality. Finally, we discuss data from microorganisms to support this view.
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Affiliation(s)
- Tzu-Wei Hung
- Institute of European and American Studies, Academia Sinica, Taipei City, Taiwan.
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Brenya E, Chen ZH, Tissue D, Papanicolaou A, Cazzonelli CI. Prior exposure of Arabidopsis seedlings to mechanical stress heightens jasmonic acid-mediated defense against necrotrophic pathogens. BMC PLANT BIOLOGY 2020; 20:548. [PMID: 33287718 PMCID: PMC7720613 DOI: 10.1186/s12870-020-02759-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 11/26/2020] [Indexed: 05/27/2023]
Abstract
BACKGROUND Prolonged mechanical stress (MS) causes thigmomorphogenesis, a stress acclimation response associated with increased disease resistance. What remains unclear is if; 1) plants pre-exposed to a short period of repetitive MS can prime defence responses upon subsequent challenge with necrotrophic pathogens, 2) MS mediates plant immunity via jasmonic acid (JA) signalling, and 3) a short period of repetitive MS can cause long-term changes in gene expression resembling a stress-induced memory. To address these points, 10-days old juvenile Arabidopsis seedlings were mechanically stressed for 7-days using a soft brush and subsequently challenged with the necrotrophic pathogens, Alternaria brassicicola, and Botrytis cinerea. Here we assessed how MS impacted structural cell wall appositions, disease symptoms and altered gene expression in response to infection. RESULTS The MS-treated plants exhibited enhanced cell wall appositions and jasmonic acid (JA) accumulation that correlated with a reduction in disease progression compared to unstressed plants. The expression of genes involved in JA signalling, callose deposition, peroxidase and phytoalexin biosynthesis and reactive oxygen species detoxification were hyper-induced 4-days post-infection in MS-treated plants. The loss-of-function in JA signalling mediated by the JA-insensitive coronatine-insensitive 1 (coi1) mutant impaired the hyper-induction of defense gene expression and promoted pathogen proliferation in MS-treated plants subject to infection. The basal expression level of PATHOGENESIS-RELATED GENE 1 and PLANT DEFENSIN 1.2 defense marker genes were constitutively upregulated in rosette leaves for 5-days post-MS, as well as in naïve cauline leaves that differentiated from the inflorescence meristem well after ceasing MS. CONCLUSION This study reveals that exposure of juvenile Arabidopsis plants to a short repetitive period of MS can alter gene expression and prime plant resistance upon subsequent challenge with necrotrophic pathogens via the JA-mediated COI1 signalling pathway. MS may facilitate a stress-induced memory to modulate the plant's response to future stress encounters. These data advance our understanding of how MS primes plant immunity against necrotrophic pathogens and how that could be utilised in sustainable agricultural practices.
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Affiliation(s)
- Eric Brenya
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Present address: Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Hesler Biology Building. 1441 Circle Drive, Knoxville, TN, 37996, USA
| | - Zhong-Hua Chen
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- School of Science, Western Sydney University, Penrith, NSW, 2751, Australia
| | - David Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Alexie Papanicolaou
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Christopher Ian Cazzonelli
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
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Kumar A, Memo M, Mastinu A. Plant behaviour: an evolutionary response to the environment? PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22:961-970. [PMID: 32557960 DOI: 10.1111/plb.13149] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 06/01/2020] [Indexed: 05/21/2023]
Abstract
Plants are not just passive living beings that exist in nature. They are complex and highly adaptable species that react sensitively to environmental forces/stimuli with movement, morphological changes and through the communication via volatile molecules. In a way, plants mimic some traits of animal and human behaviour; they compete for limited resources by gaining more area for more sunlight and spread their roots underground. Furthermore, in order to survive and thrive, they evolve and 'learn' to control various environmental stress factors in order to increase the yield of flowering, fertilization and germination processes. The concept of associating complex behaviour, such as intelligence, with plants is still a highly debatable topic among researchers worldwide. Recent studies have shown that plants are able to discriminate between positive and negative experiences and 'learn' from them. Some botanists have interpreted these behavioural data as a form of primitive cognitive processes. Others have evaluated these responses as biological automatisms of plants determined by adaptation to the environment and absence of intelligence. This review aims to explore adaptive behavioural aspects of various plant species distributed in different ecosystems by emphasizing their biological complexity and survival instincts.
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Affiliation(s)
- A Kumar
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Huddinge, Sweden
| | - M Memo
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - A Mastinu
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
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Cognition in some surprising places. Biochem Biophys Res Commun 2020; 564:150-157. [PMID: 32950231 DOI: 10.1016/j.bbrc.2020.08.115] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/17/2020] [Accepted: 08/20/2020] [Indexed: 02/06/2023]
Abstract
The most widely accepted view in the biopsychological sciences is that the cognitive functions that are diagnostic of mental operations, sentience or, more commonly, consciousness emerged fairly late in evolution, most likely in the Cambrian period. Our position dovetails with James's below - subjectivity, feeling, consciousness has a much longer evolutionary history, one that goes back to the first appearance of life. The Cellular Basis of Consciousness (CBC) model is founded on the presumption that sentience and life are coterminous; that all organisms, based on inherent cellular activities via processes that take place in excitable membranes of their cells, are sentient, have subjective experiences and feelings. These, in turn, guide the context-relevant behaviors essential for their survival in often hostile environments in constant flux. The CBC framework is reductionistic, mechanistic, and calls for bottom-up research programs into the evolutionary origin of biological consciousness.
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Go forth and replicate. NATURE PLANTS 2020; 6:901. [PMID: 32782409 DOI: 10.1038/s41477-020-00759-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
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Abstract
A substrate does not have to be solid to compute. It is possible to make a computer purely from a liquid. I demonstrate this using a variety of experimental prototypes where a liquid carries signals, actuates mechanical computing devices and hosts chemical reactions. We show hydraulic mathematical machines that compute functions based on mass transfer analogies. I discuss several prototypes of computing devices that employ fluid flows and jets. They are fluid mappers, where the fluid flow explores a geometrically constrained space to find an optimal way around, e.g. the shortest path in a maze, and fluid logic devices where fluid jet streams interact at the junctions of inlets and results of the computation are represented by fluid jets at selected outlets. Fluid mappers and fluidic logic devices compute continuously valued functions albeit discretized. There is also an opportunity to do discrete operation directly by representing information by droplets and liquid marbles (droplets coated by hydrophobic powder). There, computation is implemented at the sites, in time and space, where droplets collide one with another. The liquid computers mentioned above use liquid as signal carrier or actuator: the exact nature of the liquid is not that important. What is inside the liquid becomes crucial when reaction-diffusion liquid-phase computing devices come into play: there, the liquid hosts families of chemical species that interact with each other in a massive-parallel fashion. I shall illustrate a range of computational tasks, including computational geometry, implementable by excitation wave fronts in nonlinear active chemical medium. The overview will enable scientists and engineers to understand how vast is the variety of liquid computers and will inspire them to design their own experimental laboratory prototypes. This article is part of the theme issue 'Liquid brains, solid brains: How distributed cognitive architectures process information'.
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Affiliation(s)
- Andrew Adamatzky
- Unconventional Computing Lab, Department of Computer Science and Creative Technologies, University of the West of England , Bristol , UK
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Boussard A, Delescluse J, Pérez-Escudero A, Dussutour A. Memory inception and preservation in slime moulds: the quest for a common mechanism. Philos Trans R Soc Lond B Biol Sci 2020; 374:20180368. [PMID: 31006372 DOI: 10.1098/rstb.2018.0368] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Learning and memory are indisputably key features of animal success. Using information about past experiences is critical for optimal decision-making in a fluctuating environment. Those abilities are usually believed to be limited to organisms with a nervous system, precluding their existence in non-neural organisms. However, recent studies showed that the slime mould Physarum polycephalum, despite being unicellular, displays habituation, a simple form of learning. In this paper, we studied the possible substrate of both short- and long-term habituation in slime moulds. We habituated slime moulds to sodium, a known repellent, using a 6 day training and turned them into a dormant state named sclerotia. Those slime moulds were then revived and tested for habituation. We showed that information acquired during the training was preserved through the dormant stage as slime moulds still showed habituation after a one-month dormancy period. Chemical analyses indicated a continuous uptake of sodium during the process of habituation and showed that sodium was retained throughout the dormant stage. Lastly, we showed that memory inception via constrained absorption of sodium for 2 h elicited habituation. Our results suggest that slime moulds absorbed the repellent and used it as a 'circulating memory'. This article is part of the theme issue 'Liquid brains, solid brains: How distributed cognitive architectures process information'.
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Affiliation(s)
- A Boussard
- Research Centre on Animal Cognition (CRCA), Centre for Integrative Biology (CBI), Toulouse University, CNRS, UPS , Toulouse 31062 , France
| | - J Delescluse
- Research Centre on Animal Cognition (CRCA), Centre for Integrative Biology (CBI), Toulouse University, CNRS, UPS , Toulouse 31062 , France
| | - A Pérez-Escudero
- Research Centre on Animal Cognition (CRCA), Centre for Integrative Biology (CBI), Toulouse University, CNRS, UPS , Toulouse 31062 , France
| | - A Dussutour
- Research Centre on Animal Cognition (CRCA), Centre for Integrative Biology (CBI), Toulouse University, CNRS, UPS , Toulouse 31062 , France
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Calvo P, Gagliano M, Souza GM, Trewavas A. Plants are intelligent, here's how. ANNALS OF BOTANY 2020; 125:11-28. [PMID: 31563953 PMCID: PMC6948212 DOI: 10.1093/aob/mcz155] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 07/01/2019] [Accepted: 09/26/2019] [Indexed: 05/07/2023]
Abstract
HYPOTHESES The drive to survive is a biological universal. Intelligent behaviour is usually recognized when individual organisms including plants, in the face of fiercely competitive or adverse, real-world circumstances, change their behaviour to improve their probability of survival. SCOPE This article explains the potential relationship of intelligence to adaptability and emphasizes the need to recognize individual variation in intelligence showing it to be goal directed and thus being purposeful. Intelligent behaviour in single cells and microbes is frequently reported. Individual variation might be underpinned by a novel learning mechanism, described here in detail. The requirements for real-world circumstances are outlined, and the relationship to organic selection is indicated together with niche construction as a good example of intentional behaviour that should improve survival. Adaptability is important in crop development but the term may be complex incorporating numerous behavioural traits some of which are indicated. CONCLUSION There is real biological benefit to regarding plants as intelligent both from the fundamental issue of understanding plant life but also from providing a direction for fundamental future research and in crop breeding.
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Affiliation(s)
- Paco Calvo
- Minimal Intelligence Laboratory, Universidad de Murcia, Murcia, Spain
| | - Monica Gagliano
- Biological Intelligence Laboratory, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Gustavo M Souza
- Laboratory of Plant Cognition and Electrophysiology, Federal University of Pelotas, Pelotas - RS, Brazil
| | - Anthony Trewavas
- Institute of Molecular Plant Science, Kings Buildings, University of Edinburgh, Edinburgh, UK
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Schemann M, Frieling T, Enck P. To learn, to remember, to forget-How smart is the gut? Acta Physiol (Oxf) 2020; 228:e13296. [PMID: 31063665 DOI: 10.1111/apha.13296] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 04/29/2019] [Accepted: 05/02/2019] [Indexed: 12/19/2022]
Abstract
The enteric nervous system (ENS) resides within the gut wall and autonomously controls gut functions through coordinated activation of sensory, inter and motor neurons. Its activity is modulated by the enteric immune and endocrine system as well as by afferent and efferent nerves of the parasympathetic and sympathetic nervous system. The ENS is often referred to as the second brain and hence is able to perform sophisticated tasks. We review the evidence that the "smartness" of the ENS may even extend to its ability to learn and to memorize. Examples for habituation, sensitization, conditioned behaviour and long-term facilitation are evidence for various forms of implicit learning. Moreover, we discuss how this may change not only basic Neurogastroenterology but also our understanding of development of gut diseases and chronic disorders in gut functions. At the same time, we identify open questions and future challenges to confirm learning, memory and memory deficits in the gut. Despite some remaining experimental challenges, we are convinced that the gut is able to learn and are tempted to answer the question with: Yes, the gut is smart.
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Affiliation(s)
| | | | - Paul Enck
- Department of Internal Medicine VI, Psychosomatic Medicine and Psychotherapy University Hospital Tübingen Tübingen Germany
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Abstract
Plants do not possess brains or neurons. However, they present astonishingly complex behaviors such as information acquisition, memory, learning, decision making, etc., which helps these sessile organisms deal with their ever-changing environments. As a consequence, they have been proposed to be cognitive and intelligent, an idea which is becoming increasingly accepted. However, how plant cognition could operate without a nervous central system remains poorly understood and new insights on this topic are urgently needed. According to the Extended Cognition hypothesis, cognition may also occur beyond the limits of the body, encompassing objects from the environment. This was shown possible in humans and spiders, who actively manipulate their external environment to extend their cognitive capacity. Here, we propose that extended cognition may also be found in plants and could partly explain the complexity of plant behavior. We suggest that plants can extend their cognitive abilities to the environment they manipulate through the root influence zone and the mycorrhizal fungi that associate with them. The possibility of a cognitive process involving organisms from different kingdoms is exciting and worthwhile exploring as it may provide key insights into the origin and evolution of cognition.
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Affiliation(s)
- André Geremia Parise
- Laboratory of Plant Cognition and Electrophysiology (LACEV), Department of Botany, Institute of Biology, Federal University of Pelotas, Pelotas, Brazil
- CONTACT André Geremia Parise Laboratory of Plant Cognition and Electrophysiology (LACEV), Department of Botany, Institute of Biology, Federal University of Pelotas, Pelotas, Brazil
| | - Monica Gagliano
- Biological Intelligence (BI) Laboratory, School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
- Sydney Environment Institute (SEI), The University of Sydney, Sydney, Australia
| | - Gustavo Maia Souza
- Laboratory of Plant Cognition and Electrophysiology (LACEV), Department of Botany, Institute of Biology, Federal University of Pelotas, Pelotas, Brazil
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Taiz L, Alkon D, Draguhn A, Murphy A, Blatt M, Hawes C, Thiel G, Robinson DG. Plants Neither Possess nor Require Consciousness. TRENDS IN PLANT SCIENCE 2019; 24:677-687. [PMID: 31279732 DOI: 10.1016/j.tplants.2019.05.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 05/08/2019] [Accepted: 05/20/2019] [Indexed: 05/07/2023]
Abstract
In claiming that plants have consciousness, 'plant neurobiologists' have consistently glossed over the remarkable degree of structural and functional complexity that the brain had to evolve for consciousness to emerge. Here, we outline a new hypothesis proposed by Feinberg and Mallat for the evolution of consciousness in animals. Based on a survey of the brain anatomy, functional complexity, and behaviors of a broad spectrum of animals, criteria were established for the emergence of consciousness. The only animals that satisfied these criteria were the vertebrates (including fish), arthropods (e.g., insects, crabs), and cephalopods (e.g., octopuses, squids). In light of Feinberg and Mallat's analysis, we consider the likelihood that plants, with their relative organizational simplicity and lack of neurons and brains, have consciousness to be effectively nil.
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Affiliation(s)
- Lincoln Taiz
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
| | - Daniel Alkon
- Neurotrope, Inc., 1185 Avenue of the Americas, 3rd Floor, New York, NY 10036, USA
| | - Andreas Draguhn
- Institut für Physiologie und Pathophysiologie, Medizinische Fakultät Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany
| | - Angus Murphy
- Department of Plant Science and Landscape Architecture, 2104 Plant Sciences Building, College Park, MD 20742, USA
| | - Michael Blatt
- Laboratory of Plant Physiology and Biophysics, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Chris Hawes
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Gerhard Thiel
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstraße 3, 64287, Darmstadt, Germany
| | - David G Robinson
- Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
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