Plant cognition
Plant cognition also known as plant neurobiology is a field of plant biology which aims to understand how plants process the information they obtain from their environment.[1][2] Plant neurobiological researchers claim that plants possess abilities associated with cognition including anticipation, decision making, learning and memory.[2][3][4]
Terminology used in plant neurobiology is rejected by many botanists as misleading as plants do not possess consciousness or neurons.[5][6][7][8]
History
[edit]The idea of cognition in plants was explored by Charles Darwin in the late 1800s in the book The Power of Movement in Plants, co-authored with his son Francis. Using a neurological metaphor, he described the sensitivity of plant roots in proposing that the tip of roots acts like the brain of some lower animals. This involves reacting to sensation in order to determine their next movement[9] even though plants possess neither brains nor nerves. Thomas G. Gentry was one of the earliest writers to author a book on plant intelligence.[10] Maurice Maeterlinck wrote about the intelligence of flowers.[11]
Jagadish Chandra Bose is considered an important forerunner of plant neurobiology by proponents of plant cognition.[12][13][14] Bose was the author of The Nervous Mechanism of Plants, published in 1926.
Anthony Trewavas is credited with reintroducing the idea of plant intelligence in the early 2000s.[11][15][16] Modern research on plant cognition is conducted by researchers associated with the Society for Plant Neurobiology that was established in 2005.[4] Due to criticisms from botanists and complaints from early members that affiliations with the Society were negatively impacting their careers, the Society was renamed the Society of Plant Signaling and Behavior (SPSB) in 2009.[4][17]
A minority of researchers within the field of plant neurobiology argue that plants are conscious organisms.[18][19][20] František Baluška argues for a model called the Cellular Basis of Consciousness (CBC) which proposes that all cells are conscious.[18] The model has been criticized for being based on only speculation and lacking empirical evidence for its claim that cells have consciousness.[21][22]
Types
[edit]The study of plant cognition stems from the idea that plants are able to learn and adapt to their environment with only a stimulus, integration, and response system. While proven that plants do indeed lack a brain and the function of a conscious working nervous system, plants are still somehow capable of adapting to their environment and changing the integration pathway that would ultimately lead to how a plant responds to a presented stimulus.[3]
Plant memory
[edit]In a study done by Monica Gagliano from the University of Western Australia’s Centre for Evolutionary Biology, Mimosa pudica (sensitive plant) was tested for habituation to repeatedly being dropped. After multiple drops, it was found that the plants eventually became habituated, opening their leaves more quickly compared to the first time they were dropped.[23] While the mechanism of this plant behavior is still not fully understood, it is strongly linked to changes in the flux within calcium channels.[24]
Associative learning
[edit]In 2016, a research team led by Monica Gagliano set out to test whether plants learn to respond to predicted events in their environment. The research demonstrated that plants were capable of learning the association between the occurrence of one event and the anticipation of another event (i.e. Pavlovian learning).[25] By experimentally demonstrating associative learning in plants, this finding qualified plants as proper subjects of cognitive research.[25] In this study, it was hypothesized that plants have the capability to associate one type of stimulus with another. To test this hypothesis, pea plants were exposed to two different stimuli. For the training phase, one group of pea plants was exposed to both wind and light, and the other group of plants was exposed to wind without light as a control. In the experimental phase, the plants were exposed only to the wind stimulus. The pea plants that were only ever exposed to wind without light grew away from the wind in both the training and experimental phases. In contrast, the pea plants exposed to both wind and light in the training phase exhibited growth toward a wind stimulus without the presence of light, demonstrating an apparent learned association between wind and light. The mechanism for this response is not entirely understood, though it is hypothesized that sensory inputs from mechanoreceptors and photoreceptors were somehow integrated within the plants. This explains why a non-light stimulus would trigger a growth response in the trained pea plant that is typically only triggered by the activation of photoreceptors.[26]
A replication study with a larger sample size, published in 2020, found no evidence of associative learning in pea plants.[27] However, it also failed to replicate the finding that light functioned effectively as an unconditioned stimulus. Pea plants in this study displayed only a slight trend rather than a reliable directional growth response towards previously presented light. The replicated experimental setup differed from the original in the presence of higher levels of ambient and reflected light, which may have randomised directional growth somewhat and prevented replication.[28]
Further research
[edit]In 2003, Anthony Trewavas led a study to see how the roots interact with one another and study their signal transduction methods. He was able to draw similarities between water stress signals in plants affecting developmental changes and signal transductions in neural networks causing responses in muscle.[15] Particularly, when plants are under water stress, there are abscisic acid dependent and independent effects on development.[29] This brings to light further possibilities of plant decision-making based on its environmental stresses. The integration of multiple chemical interactions show evidence of the complexity in these root systems.[30]
In 2012, Paco Calvo Garzón and Fred Keijzer speculated that plants exhibited structures equivalent to (1) action potentials (2) neurotransmitters and (3) synapses. Also, they stated that a large part of plant activity takes place underground, and that the notion of a 'root brain' was first mooted by Charles Darwin in 1880. Free movement was not necessarily a criterion of cognition, they held. The authors gave five conditions of minimal cognition in living beings, and concluded that 'plants are cognitive in a minimal, embodied sense that also applies to many animals and even bacteria.'[31] In 2017 biologists from University of Birmingham announced that they found a "decision-making center" in the root tip of dormant Arabidopsis seeds.[32]
In 2014, Anthony Trewavas released a book called Plant Behavior and Intelligence that highlighted a plant's cognition through its colonial-organization skills reflecting insect swarm behaviors.[33] This organizational skill reflects the plant's ability to interact with its surroundings to improve its survivability, and a plant's ability to identify exterior factors. Evidence of the plant's minimal cognition of spatial awareness can be seen in their root allocation relative to neighboring plants.[31] The organization of these roots have been found to originate from the root tip of plants.[34]
On the other hand, Peter A. Crisp and his colleagues proposed a different view on plant memory in their review: plant memory could be advantageous under recurring and predictable stress; however, resetting or forgetting about the brief period of stress may be more beneficial for plants to grow as soon as the desirable condition returns.[35]
Affifi (2018) proposed an empirical approach to examining the ways plants model coordinate goal-based behaviour to environmental contingency as a way of understanding plant learning.[36] According to this author, associative learning will only demonstrate intelligence if it is seen as part of teleologically integrated activity. Otherwise, it can be reduced to mechanistic explanation.
Raja et al (2020) found that potted French bean plants, when planted 30 centimetres from a garden cane, would adjust their growth patterns to enable themselves to use the cane as a support in the future. Raja later stated that "If the movement of plants is controlled and affected by objects in their vicinity, then we are talking about more complex behaviours (rather than simple) reactions". Raja proposed that researchers should look for corresponding cognitive signatures.[37][38]
In 2017 Yokawa, K. et al. found that, when exposed to anesthetics, a number of plants lost both their autonomous and touch-induced movements. Venus flytraps no longer generate electrical signals and their traps remain open when trigger hairs were touched, and growing pea tendrils stopped their autonomous movements and were immobilized in a curled shape.[39]
Criticism
[edit]The idea of plant cognition is a source of controversy and is rejected by the majority of plant scientists.[5][6][7][40] Plant neurobiology has been criticized for misleading the public.[41]
Amadeo Alpi and 35 other scientists published an article in 2007 titled "Plant Neurobiology: No Brain, No Gain?" in Trends in Plant Science.[5] In this article, they argue that since there is no evidence for the presence of neurons in plants, the idea of plant neurobiology and cognition is unfounded and needs to be redefined.[5] In response to this article, Francisco Calvo Garzón published an article in Plant Signaling and Behavior.[3] He states that, while plants do not have neurons as animals do, they do possess an information-processing system composed of cells. He argues that this system can be used as a basis for discussing the cognitive abilities of plants.
See also
[edit]References
[edit]- ^ Brenner ED, Stahlberg R, Mancuso S, Vivanco J, Baluska F, Van Volkenburgh E. (2006). "Plant neurobiology: an integrated view of plant signaling". Trends Plant Sci. 11 (8): 413–419. doi:10.1016/j.tplants.2006.06.009. PMID 16843034.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ a b Lee, Jonny (2023). "What is cognitive about 'plant cognition'?". Biology & Philosophy. 38 (18). doi:10.1007/s10539-023-09907-z.
- ^ a b c Garzón FC (July 2007). "The quest for cognition in plant neurobiology". Plant Signaling & Behavior. 2 (4): 208–11. Bibcode:2007PlSiB...2..208C. doi:10.4161/psb.2.4.4470. PMC 2634130. PMID 19516990.
- ^ a b c Minorsky, Peter V. (2024). "The "plant neurobiology" revolution". Plant Signaling & Behavior. 19 (1). doi:10.1080/15592324.2024.2345413. PMC 11085955. PMID 38709727.
- ^ a b c d Alpi A, Amrhein N, Bertl A, Blatt MR, Blumwald E, Cervone F, et al. (April 2007). "Plant Neurobiology: No Brain, No Gain?". Trends in Plant Science. 12 (4): 135–6. Bibcode:2007TPS....12..135A. doi:10.1016/j.tplants.2007.03.002. PMID 17368081.
- ^ a b Taiz, Lincoln; Alkon, Daniel; Draguhn, Andreas; Murphy, Angus; Blatt, Michael; Hawes, Chris; Thiel, Gerhard; Robinson, David G. (2019). "Plants Neither Possess nor Require Consciousness". Trends in Plant Science. 24 (8): 677–687. doi:10.1016/j.tplants.2019.05.008. PMID 31279732.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ a b Mallatt J, Blatt MR, Draguhn A, Robinson DG, Taiz L. (2020). "Debunking a myth: plant consciousness". Protoplasma. 258 (3): 459–476. doi:10.1007/s00709-020-01579-w. PMC 8052213. PMID 33196907.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ Pigliucci, Massimo (2024). "Are Plants Conscious?". Skeptical Inquirer. 48 (5).
- ^ Darwin, C. (1880). The Power of Movement in Plants. London: John Murray. Darwin Online : "The course pursued by the radicle in penetrating the ground must be determined by the tip; hence it has acquired such diverse kinds of sensitiveness. It is hardly an exaggeration to say that the tip of the radicle thus endowed, and having the power of directing the movements of the adjoining parts, acts like the brain of one of the lower animals; the brain being seated within the anterior end of the body, receiving impressions from the sense-organs, and directing the several movements."
- ^ Folsom, Ed (1983). "The Mystical Ornithologist and the Iowa Tufthunter: Two Unpublished Whitman Letters and Some Identifications" (PDF). Walt Whitman Quarterly Review. 1: 18–29. doi:10.13008/2153-3695.1003. Archived from the original (PDF) on 24 October 2021.
- ^ a b Cvrcková F, Lipavská H, Zárský V. (2009). "Plant intelligence: Why, why not or where?". Plant Signal Behav. 4 (5). doi:10.4161/psb.4.5.8276. PMID 19816094.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ Kingsland, Sharon E; Taiz, Lincoln (2024). "Plant "intelligence" and the misuse of historical sources as evidence". Protoplasma. doi:10.1007/s00709-024-01988-1. PMID 39276228.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ Tandon PN (2019). "Jagdish Chandra Bose & plant neurobiology". Indian J Med Res. 149 (5): 593–599. doi:10.4103/ijmr.IJMR_392_19. PMC 6702694. PMID 31417026.
- ^ Minorsky, Peter V. (2021). "American racism and the lost legacy of Sir Jagadis Chandra Bose, the father of plant neurobiology". Plant Signal Behav. 16 (1): 1818030. doi:10.1080/15592324.2020.1818030. PMC 7781790. PMID 33275072.
- ^ a b Trewavas A (July 2003). "Aspects of plant intelligence". Annals of Botany. 92 (1): 1–20. doi:10.1093/aob/mcg101. PMC 4243628. PMID 12740212.
- ^ Trewavas, Anthony (2002). "Plant intelligence: Mindless mastery". Nature. 415 (841). doi:10.1038/415841a.
- ^ Nasser, Latif (2012). "The long, strange quest to detect plant consciousness". The Boston Globe. Archived from the original on November 30, 2024.
- ^ a b Reber, Arthur S; Baluška, František (2021). "Cognition in some surprising places". Biochemical and Biophysical Research Communications. 564: 150–157. doi:10.1016/j.bbrc.2020.08.115.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ Mallatt J, Taiz L, Draguhn A, Blatt MR, Robinson DG. (2021). "Integrated information theory does not make plant consciousness more convincing". Biochem Biophys Res Commun. 564: 166–169. doi:10.1016/j.bbrc.2021.01.022. PMID 33485631.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ Hansen, Mads Jørgensen (2024). "A critical review of plant sentience: moving beyond traditional approaches". Biology & Philosophy. 39 (13). doi:10.1007/s10539-024-09953-1.
- ^ Key, Brian (2016). ""Cellular basis of consciousness": Not just radical but wrong". Animal Sentience. 11 (5): 1–2. doi:10.51291/2377-7478.1163.
- ^ Robinson DG, Mallatt J, Peer WA, Sourjik V, Taiz L. (2024). "Cell consciousness: a dissenting opinion: The cellular basis of consciousness theory lacks empirical evidence for its claims that all cells have consciousness". EMBO Reports. 25 (5): 2162–2167. doi:10.1038/s44319-024-00127-4. PMID 38548972.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ Gagliano M, Renton M, Depczynski M, Mancuso S (May 2014). "Experience teaches plants to learn faster and forget slower in environments where it matters". Oecologia. 175 (1): 63–72. Bibcode:2014Oecol.175...63G. doi:10.1007/s00442-013-2873-7. PMID 24390479. S2CID 5038227.
- ^ Cahill J, Bao T, Maloney M, Kolenosky C (June 4, 2012). "Mechanical leaf damage causes localized, but not systemic, changes in leaf movement behavior of the Sensitive Plant, Mimosa pudica". Botany. doi:10.1139/cjb-2012-0131.
- ^ a b Gagliano M, Vyazovskiy VV, Borbély AA, Grimonprez M, Depczynski M (December 2016). "Learning by Association in Plants". Scientific Reports. 6 (1): 38427. Bibcode:2016NatSR...638427G. doi:10.1038/srep38427. PMC 5133544. PMID 27910933.
- ^ Mawphlang OI, Kharshiing EV (July 11, 2017). "Photoreceptor Mediated Plant Growth Responses: Implications for Photoreceptor Engineering toward Improved Performance in Crops". Frontiers in Plant Science. 8: 1181. doi:10.3389/fpls.2017.01181. PMC 5504655. PMID 28744290.
- ^ Markel K (June 2020). "Lack of evidence for associative learning in pea plants". eLife. 9: e57614. doi:10.7554/eLife.57614. PMC 7311169. PMID 32573434.
- ^ Gagliano, Monica; Vyazovskiy, Vladyslav V; Borbély, Alexander A; Depczynski, Martial; Radford, Ben (2020-09-10). Lee, Daeyeol; Hardtke, Christian S (eds.). "Comment on 'Lack of evidence for associative learning in pea plants'". eLife. 9: e61141. doi:10.7554/eLife.61141. ISSN 2050-084X. PMC 7556858. PMID 32909941.
- ^ Shinozaki K (2000). "Molecular responses to dehydration and low temperature: differences and cross-talk between two stress signaling pathways". Current Opinion in Plant Biology. 3 (3): 217–223. doi:10.1016/s1369-5266(00)00067-4. PMID 10837265.
- ^ McCully ME (June 1999). "ROOTS IN SOIL: Unearthing the Complexities of Roots and Their Rhizospheres". Annual Review of Plant Physiology and Plant Molecular Biology. 50: 695–718. doi:10.1146/annurev.arplant.50.1.695. PMID 15012224.
- ^ a b Garzon P, Keijzer F (2011). "Plants: Adaptive behavior, root-brains, and minimal cognition" (PDF). Adaptive Behavior. 19 (3): 155–171. doi:10.1177/1059712311409446. S2CID 5060470.
- ^ Topham AT, Taylor RE, Yan D, Nambara E, Johnston IG, Bassel GW (June 2017). "Temperature variability is integrated by a spatially embedded decision-making center to break dormancy in Arabidopsis seeds". Proceedings of the National Academy of Sciences of the United States of America. 114 (25): 6629–6634. Bibcode:2017PNAS..114.6629T. doi:10.1073/pnas.1704745114. PMC 5488954. PMID 28584126.
- ^ Trewavas 2014, p. 95-96.
- ^ Trewavas 2014, p. 140.
- ^ Crisp PA, Ganguly D, Eichten SR, Borevitz JO, Pogson BJ (February 2016). "Reconsidering plant memory: Intersections between stress recovery, RNA turnover, and epigenetics". Science Advances. 2 (2): e1501340. Bibcode:2016SciA....2E1340C. doi:10.1126/sciadv.1501340. PMC 4788475. PMID 26989783.
- ^ Affifi R (2018). "Deweyan Psychology in Plant Intelligence Research: Transforming Stimulus and Response". In Baluska F, Gagliano M, Witzany G (eds.). Memory and Learning in Plants. Signaling and Communication in Plants. Cham.: Springer. pp. 17–33. doi:10.1007/978-3-319-75596-0_2. ISBN 978-3-319-75595-3.
- ^ "Plants: Are they conscious?". BBC Science Focus Magazine. 5 February 2021. Retrieved 6 February 2021.
- ^ Raja, Vicente; Silva, Paula L.; Holghoomi, Roghaieh; Calvo, Paco (December 2020). "The dynamics of plant nutation". Scientific Reports. 10 (1): 19465. Bibcode:2020NatSR..1019465R. doi:10.1038/s41598-020-76588-z. PMC 7655864. PMID 33173160.
- ^ Yokawa, K; Kagenishi, T; Pavlovič, A; Gall, S; Weiland, M; Mancuso, S; Baluška, F (11 December 2017). "Anaesthetics stop diverse plant organ movements, affect endocytic vesicle recycling and ROS homeostasis, and block action potentials in Venus flytraps". Annals of Botany. 122 (5): 747–756. doi:10.1093/aob/mcx155. PMC 6215046. PMID 29236942.
- ^ Draguhn A, Mallatt JM, Robinson DG. (2021). "Anesthetics and plants: no pain, no brain, and therefore no consciousness". Protoplasma. 258 (2): 239–248. doi:10.1007/s00709-020-01550-9. PMC 7907021. PMID 32880005.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - ^ Robinson, David G; Draguhn, Andreas; Taiz, Lincoln (2020). "Plant "intelligence" changes nothing". EMBO Reports. 21 (5): e50395. doi:10.15252/embr.202050395. PMC 7202214. PMID 32301219.
{{cite journal}}
: CS1 maint: multiple names: authors list (link)
Further reading
[edit]Plant cognition and neurobiology
[edit]- Baluska F, Mancuso S. (2009). "Plant neurobiology: from sensory biology, via plant communication, to social plant behavior". Cogn Process. 1: S3-7. doi:10.1007/s10339-008-0239-6. PMID 18998182.
- Calvo P, Gagliano M, Souza GM, Trewavas A. (2020). "Plants are intelligent, here's how". Annals of Botany. 125 (1): 11–28. doi:10.1093/aob/mcz155. PMID 31563953.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - Ferretti, Gabriele (2024). Philosophy of Plant Cognition: Interdisciplinary Perspectives. Routledge. ISBN 978-1032493510.
- Garzón FC (July 2007). "The quest for cognition in plant neurobiology". Plant Signaling & Behavior. 2 (4): 208–11. Bibcode:2007PlSiB...2..208C. doi:10.4161/psb.2.4.4470. PMC 2634130. PMID 19516990.
- Mancuso, Stefano (2019). Brilliant Green: The Surprising History and Science of Plant Intelligence. Island Press. ISBN 978-1610917315.
- Minorsky, Peter V. (2024). "The "plant neurobiology" revolution". Plant Signaling & Behavior. 19 (1). doi:10.1080/15592324.2024.2345413. PMC 11085955. PMID 38709727.
- Schlanger, Zoë (2024). The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth. New York: Harper. ISBN 9780063073852. OCLC 1421933387. Archived from the original on 16 April 2024. Retrieved 6 May 2024.
- Segundo-Ortin M, Calvo P. (2022). "Consciousness and cognition in plants". Wiley Interdiscip Rev Cogn Sci. 13 (2): e1578. doi:10.1002/wcs.1578. PMID 34558231.
- Trewavas AJ (2014). Plant Behaviour and Intelligence. Oxford: Oxford University Press. ISBN 978-0-19-953954-3. OCLC 890389682.
- Trewavas, Anthony (2003). "Aspects of Plant Intelligence". Annals of Botany. 92 (1): 1–20. doi:10.1093/aob/mcg101. PMC 4243628. PMID 12740212.
Criticism
[edit]- Firn, Richard (2004). "Plant Intelligence: An Alternative Point of View". Annals of Botany. 93 (4): 345–351. doi:10.1093/aob/mch058. PMC 4242337. PMID 15023701.
- Galston, Arthur W; Slayman, Clifford L. "The Not-So-Secret Life of Plants" (PDF). American Scientist. 67 (3): 337–344. JSTOR 27849226.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - Kingsland, Sharon E; Taiz, Lincoln (2024). "Plant "intelligence" and the misuse of historical sources as evidence". Protoplasma. doi:10.1007/s00709-024-01988-1. PMID 39276228.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - Mallatt J, Blatt MR, Draguhn A, Robinson DG, Taiz L. (2020). "Debunking a myth: plant consciousness". Protoplasma. 258 (3): 459–476. doi:10.1007/s00709-020-01579-w. PMC 8052213. PMID 33196907.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - Mallatt, Jon; Robinson, David G; Blatt, Michael R; Draguhn, Andreas; and Taiz, Lincoln (2023). "Plant sentience: The burden of proof". Animal Sentience. 33 (15): 1–10. doi:10.51291/2377-7478.1802.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - Robinson DG, Draguhn A. (2021). "Plants have neither synapses nor a nervous system". J Plant Physiol. 263: 153467. doi:10.1016/j.jplph.2021.153467. PMID 34247030.
- Taiz, Lincoln; Alkon, Daniel; Draguhn, Andreas; Murphy, Angus; Blatt, Michael; Hawes, Chris; Thiel, Gerhard; Robinson, David G. (2019). "Plants Neither Possess nor Require Consciousness". Trends in Plant Science. 24 (8): 677–687. doi:10.1016/j.tplants.2019.05.008. PMID 31279732.
{{cite journal}}
: CS1 maint: multiple names: authors list (link)