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The leaf closing after touch in Mimosa pudica depends on electrical signals.
Vine tendril. Note how the plant reaches for and wraps around the galvanised wire provided for the purpose. This is a very tough twig and appears to have no other purpose than support for the plant. Nothing else grows from it. It must reach out softly, then wrap around and then dry and toughen. See more at thigmotropism.

Plant perception or Plant Gnosophysiology[1] is the ability of plants to sense and respond to the environment to adjust their morphology, physiology, and phenotype accordingly.[2] Other disciplines such as plant physiology, ecology and molecular biology are used to assess this ability. Plants react to chemicals, gravity, light, moisture, infections, temperature, oxygen and carbon dioxide concentrations, parasite infestation, disease, physical disruption, sound,[3][4][5][6] and touch.




Displacement can be detected by plants.[7] Poplar stems can detect reorientation and inclination (equilibrioception).[8]

Pathway signalsEdit

Wounded tomatoes are known to produce the volatile odour methyl jasmonate as an alarm signal.[9] Neighbouring plants can then detect the chemical and prepare for the attack by producing chemicals that defend against insects or attract predators.[9]

Plants systematically use hormonal signalling pathways to coordinate their own development and morphology.


Plants produce several proteins found in the animal neuron systems such as acetylcholine esterase, glutamate receptors, GABA receptors, and endocannabinoid signaling components. They also use ATP, NO, and ROS like animals for signaling.[10]


Although plant cells are not neurons, they can be electrically excitable and can display rapid electrical responses (action potentials) to environmental stimuli. These action potentials can influence processes such as actin-based cytoplasmic streaming, plant organ movements, wound responses, respiration, photosynthesis, and flowering.[11][12][13][14] These electrical responses can cause the synthesis of numerous organic molecules, including ones that act as neuroactive substances in other organisms.[citation needed] Thus, plants accomplish behavioural responses in environmental, communicative, and ecological contexts.

Signal responseEdit

A plant's concomitant reactive behavior is mediated by phytochromes, kinins, hormones, antibiotic or other chemical release, changes of water and chemical transport, and other means. These responses are generally slow, taking at minimum a number of hours to accomplish, and can best be observed with time-lapse cinematography, but rapid movements can occur as well. Plants respond to volatile signals produced by other plants.[15][16] Jasmonate levels also increase rapidly in response to mechanical perturbations such as tendril coiling.[17]

Plants have many strategies to fight off pests. For example, they can produce different toxins (phytoalexins) against invaders or they can induce rapid cell death in invading cells to hinder the pests from spreading out.

Some plants are capable of rapid movement: the mimosa plant (Mimosa pudica) makes its thin leaves point down at the slightest touch[citation needed] and carnivorous plants such as the Venus flytrap snap shut by the touch of insects. In the Venus flytrap, touch is detected by cilia that generate an action potential that stimulates motor cells, by which movement occurs.[18]

In plants, the mechanism responsible for adaptation is signal transduction.[19][20][21][22]

Adaptive responses include:

Aspects of perceptionEdit


The sunflower, a common heliotropic plant which perceives and reacts to sunlight by slow turning movement

Many plant organs contain photo-sensitive compounds (phototropins, cryptochromes and phytochromes), each reacting very specifically to certain wavelengths of light.[citation needed] These light sensors tell the plant if it is day or night, how long the day is, how much light is available and from where the light comes. Shoots grow towards light and roots usually grow away from light. These responses are called phototropism and skototropism respectively. They are brought about by light sensitive pigments like phototropins and phytochromes and the plant hormone auxin[citation needed]. Many plants exhibit certain phenomena at specific times of the day; for example, certain flowers open only in the mornings. Plants keep track of the time of day with a circadian clock.[citation needed] This internal clock is set to solar time every day using sunlight, temperature and other cues, similar to the biological clocks of other organisms. The internal clock coupled with the ability to perceive light also allows plants to measure the time of the day and so find the season of the year. This is how many plants know when to flower.[citation needed] (see photoperiodism) The seeds of many plants sprout only after they are exposed to light. This response is carried out by phytochrome signalling. Plants are also able to sense the quality of light and respond appropriately. For example, in low light conditions, plants produce more photosynthetic pigments. If the light is very bright or if the levels of harmful UV increase, plants produce more of their protective pigments that act as sunscreens.[30]


To orient themselves correctly, plants must have an adequate sense of the direction of gravity’s unidirectional pull. The subsequent response plant movement is known as gravitropism. Typically, in the root this works as gravity is sensed and translated in the root tip, and subsequently roots grow towards gravity via elongation of the cells. In the shoot, similar effects are happening, but gravity is perceived and then growth occurs in the opposite direction, as the above ground part of the plant experiences negative gravitropism.[31]

At the root tip, there are amyloplasts containing starch granules that fall in the direction of gravity. This weight activates secondary receptors, which signal to the plant the direction of gravitational pull. After this occurs, auxin is redistributed through polar auxin transport and differential growth towards gravity begins. In the shoots, auxin redistribution occurs in a way to produce differential growth away from gravity.

For perception to happen, the plant must sense, perceive and translate the direction of gravity. Without gravity, proper orientation will not occur and the plant will not effectively grow. The root will not be able to uptake nutrients or water, and the shoot will not grow towards the sky to maximize photosynthesis.[32]

Plant intelligenceEdit

Plants do not have a brain or neuronal network, but reactions within signalling pathways may provide a biochemical basis for learning and memory in addition to computation and problem solving.[33] Controversially, the brain is used as a metaphor in plant intelligence to provide an integrated view of signalling.[34]

Plants respond to environmental stimuli by movement and changes in morphology. They communicate while actively competing for resources. In addition, plants accurately compute their circumstances, use sophisticated cost–benefit analysis and take tightly controlled actions to mitigate and control diverse environmental stressors. Plants are also capable of discriminating positive and negative experiences and of learning by registering memories from their past experiences.[35][36][37][38][39] Plants use this information to update their behaviour in order to survive present and future challenges of their environment.

Plant physiology studies the role of signalling to integrate data obtained at the genetic, biochemical, cellular and physiological levels to understand plant development and behaviour. The neurobiological view sees plants as information-processing organisms with rather complex processes of communication occurring throughout the individual plant organism. It studies how environmental information is gathered, processed, integrated and shared (sensory plant biology) to enable these adaptive and coordinated responses (plant behaviour); and how sensory perceptions and behavioural events are 'remembered' in order to allow predictions of future activities upon the basis of past experiences. Plants, it is claimed by some plant physiologists, are as sophisticated in behaviour as animals but this sophistication has been masked by the time scales of plants' response to stimuli, many orders of magnitude slower than animals'.[citation needed]

It has been argued that although plants are capable of adaptation, it should not be called intelligence, as plant neurobiologists are relying primarily on metaphors and analogies to argue that complex responses in plants can only be produced by intelligence.[40] "A bacterium can monitor its environment and instigate developmental processes appropriate to the prevailing circumstances, but is that intelligence? Such simple adaptation behaviour might be bacterial intelligence but is clearly not animal intelligence."[41] However, plant intelligence fits a definition of intelligence proposed by David Stenhouse in a book about evolution and animal intelligence where he described it as "adaptively variable behaviour during the lifetime of the individual".[42] Critics of the concept have also argued that a plant cannot have goals once it is past the development stage of seedling because, as a modular organism, each module seeks its own survival goals and the resulting organism level behavior is not centrally controlled.[41] This view, however, necessarily accommodates the possibility that a tree is a collection of individually intelligent modules cooperating, competing and influencing each other to determine behavior in a bottom-up fashion. The development into a larger organism whose modules must deal with different environmental conditions and challenges is not universal across plant species however, as smaller organisms might be subject to the same conditions across their bodies, at least, when the below and above ground parts are considered separately. Moreover, the claim that central control of development is completely absent from plants is readily falsified by apical dominance.

The Italian botanist Federico Delpino wrote on the idea of plant intelligence in 1867.[43] Charles Darwin studied the movement of plants and in 1880 published a book The Power of Movement in Plants. In the book he concludes:

It is hardly an exaggeration to say that the tip of the radicle thus endowed [..] acts like the brain of one of the lower animals; the brain being situated within the anterior end of the body, receiving impressions from the sense-organs, and directing the several movements.

In philosophy, there are few studies of the implications of plant perception. Michael Marder put forth a phenomenology of plant life based on the physiology of plant perception.[44] Paco Calvo Garzon offers a philosophical take on plant perception based on the cognitive sciences and the computational modeling of consciousness.[45]

Comparison to neurobiologyEdit

A plant's sensory and response system has been compared to the neurobiological processes of animals. Plant neurobiology, an unfamiliar misnomer, concerns mostly the sensory adaptive behaviour of plants and plant electrophysiology. Indian scientist J. C. Bose is credited as the first person to research and talk about neurobiology of plants. Many plant scientists and neuroscientists, however, view this as inaccurate, because plants do not have neurons.[40]

The ideas behind plant neurobiology were criticised in a 2007 article[40] published in Trends in Plant Science by Amedeo Alpi and 35 other scientists, including such eminent plant biologists as Gerd Jürgens, Ben Scheres, and Chris Sommerville. The breadth of fields of plant science represented by these researchers reflects the fact that the vast majority of the plant science research community reject plant neurobiology. Their main arguments are that:[40]

  • "Plant neurobiology does not add to our understanding of plant physiology, plant cell biology or signaling".
  • "There is no evidence for structures such as neurons, synapses or a brain in plants".
  • The common occurrence of plasmodesmata in plants which "poses a problem for signaling from an electrophysiological point of view" since extensive electrical coupling would preclude the need for any cell-to-cell transport of a ‘neurotransmitter-like’ compounds.

The authors call for an end to "superficial analogies and questionable extrapolations" if the concept of "plant neurobiology" is to benefit the research community.[40]

There were several responses to the criticism clarifying that the term "plant neurobiology" is a metaphor and metaphors have proved useful on several previous occasions.[46][47] Plant ecophysiology describes this phenomenon.

Parallels in other taxaEdit

As described above in the case of a plant, similar mechanisms exist in a bacterial cell, a choanoflagellate, a fungal hypha, or a sponge, among the many other examples. All of these individual organisms of the respective taxa, despite being devoid of a brain or nervous system, are capable of sensing their immediate and momentary environment and responding accordingly. In the case of single-celled life, the sensory pathways are even more primitive in the sense that they take place on the surface of a single cell, as opposed to a network of many cells.

See alsoEdit


  1. ^ Michmizos D, Chilioti Z (January 2019). "A roadmap towards a functional paradigm for learning & memory in plants". Journal of Plant Physiology. 232 (1): 209–215.
  2. ^ Trewavas A (September 2005). "Green plants as intelligent organisms". Trends in Plant Science. 10 (9): 413–9. doi:10.1016/j.tplants.2005.07.005. PMID 16054860.
  3. ^ Gagliano M, Mancuso S, Robert D (June 2012). "Towards understanding plant bioacoustics". Trends in Plant Science. 17 (6): 323–5. doi:10.1016/j.tplants.2012.03.002. PMID 22445066.
  4. ^ Gagliano M (July 2013). "Green symphonies: a call for studies on acoustic communication in plants". Behavioral Ecology. 24 (4): 789–796. doi:10.1093/beheco/ars206. PMC 3677178. PMID 23754865.
  5. ^ Gagliano M, Grimonprez M, Depczynski M, Renton M (May 2017). "Tuned in: plant roots use sound to locate water". Oecologia. 184 (1): 151–160. doi:10.1007/s00442-017-3862-z. PMID 28382479.
  6. ^ Mishra RC, Ghosh R, Bae H (August 2016). "Plant acoustics: in the search of a sound mechanism for sound signaling in plants". Journal of Experimental Botany. 67 (15): 4483–94. doi:10.1093/jxb/erw235. PMID 27342223.
  7. ^ Jaffe MJ, Forbes S (February 1993). "Thigmomorphogenesis: the effect of mechanical perturbation on plants". Plant Growth Regulation. 12 (3): 313–24. doi:10.1007/BF00027213. PMID 11541741.
  8. ^ Azri W, Chambon C, Herbette S, Brunel N, Coutand C, Leplé JC, Ben Rejeb I, Ammar S, Julien JL, Roeckel-Drevet P (June 2009). "Proteome analysis of apical and basal regions of poplar stems under gravitropic stimulation". Physiologia Plantarum. 136 (2): 193–208. doi:10.1111/j.1399-3054.2009.01230.x. PMID 19453506.
  9. ^ a b Farmer EE, Ryan CA (October 1990). "Interplant communication: airborne methyl jasmonate induces synthesis of proteinase inhibitors in plant leaves". Proceedings of the National Academy of Sciences of the United States of America. 87 (19): 7713–6. PMC 54818. PMID 11607107.
  10. ^ Baluška F, Volkmann D, Mancuso S (2006). Communication in Plants: Neuronal Aspects of Plant Life. Springer Verlag. ISBN 978-3-540-28475-8.
  11. ^ Wagner E, Lehner L, Normann J, Veit J, Albrechtova J (2006). "Hydroelectrochemical integration of the higher plant—basis for electrogenic flower induction". In Baluska F, Mancuso S, Volkmann D. Communication in plants: neuronal aspects of plant life. Berlin: Springer. pp. 369–389.
  12. ^ Fromm J, Lautner S (March 2007). "Electrical signals and their physiological significance in plants". Plant, Cell & Environment. 30 (3): 249–257. doi:10.1111/j.1365-3040.2006.01614.x. PMID 17263772.
  13. ^ Zimmermann MR, Maischak H, Mithöfer A, Boland W, Felle HH (March 2009). "System potentials, a novel electrical long-distance apoplastic signal in plants, induced by wounding". Plant Physiology. 149 (3): 1593–600. doi:10.1104/pp.108.133884. PMC 2649404. PMID 19129416.
  14. ^ Pickard BG (1973). "Action Potentials in Higher Plants". Botanical Review. 39 (2): 172–201. doi:10.1007/BF02859299. JSTOR 4353850.
  15. ^ Farmer EE, Ryan CA (October 1990). "Interplant communication: airborne methyl jasmonate induces synthesis of proteinase inhibitors in plant leaves". Proceedings of the National Academy of Sciences of the United States of America. 87 (19): 7713–6. Bibcode:1990PNAS...87.7713F. doi:10.1073/pnas.87.19.7713. PMC 54818. PMID 11607107.
  16. ^ Karban R, Baxter KJ (2001). "Induced Resistance in Wild Tobacco with Clipped Sagebrush Neighbors: The Role of Herbivore Behavior". Journal of Insect Behavior. 14 (2): 147–156. doi:10.1023/A:1007893626166.
  17. ^ Falkenstein E, Groth B, Mithöfer A, Weiler EW (October 1991). "Methyljasmonate and α-linolenic acid are potent inducers of tendril coiling". Planta. 185 (3): 316–22. doi:10.1007/BF00201050. PMID 24186412.
  18. ^ Volkov AG, Adesina T, Jovanov E (May 1, 2007). "Closing of Venus Flytrap by Electrical Stimulation of Motor Cells". Plant Signaling & Behavior. 2: 139–145. doi:10.4161/psb.2.3.4217 – via Taylor & Francis Group.
  19. ^ Scheel D, Wasternack C (2002). Plant signal transduction. Oxford: Oxford University Press. ISBN 0-19-963879-9.
  20. ^ Xiong L, Zhu JK (June 2001). "Abiotic stress signal transduction in plants: Molecular and genetic perspectives". Physiologia Plantarum. 112 (2): 152–166. doi:10.1034/j.1399-3054.2001.1120202.x. PMID 11454221.
  21. ^ Clark GB, Thompson G, Roux SJ (January 2001). "Signal transduction mechanisms in plants: an overview". Current Science. 80 (2): 170–7. PMID 12194182.
  22. ^ Trewavas A (April 1999). "How plants learn". Proceedings of the National Academy of Sciences of the United States of America. 96 (8): 4216–8. Bibcode:1999PNAS...96.4216T. doi:10.1073/pnas.96.8.4216. PMC 33554. PMID 10200239.
  23. ^ a b De Kroon H, Hutchings MJ (1995). "Morphological plasticity in clonal plants: the foraging concept reconsidered". J. Ecol. 83: 143–152. JSTOR 2261158.
  24. ^ Grime JP, MacKey JM (2002). "The role of plasticity in resource capture by plants". Evolutionary Ecology. 16 (3): 299–307. doi:10.1023/A:1019640813676.
  25. ^ Hutchings M, Dekroon H (1994). "Foraging in Plants: the Role of Morphological Plasticity in Resource Acquisition". Advances in Ecological Research. 25: 159–238. doi:10.1016/S0065-2504(08)60215-9.
  26. ^ Honda H, Fisher JB (February 1978). "Tree branch angle: maximizing effective leaf area". Science. 199 (4331): 888–90. Bibcode:1978Sci...199..888H. doi:10.1126/science.199.4331.888. PMID 17757590.
  27. ^ McConnaughay KD, Bazzaz FA (1991). "Is Physical Space a Soil Resource?". Ecology. 72 (1): 94–103. doi:10.2307/1938905. JSTOR 1938905.
  28. ^ McConnaughay KD, Bazzaz FA (1992). "The Occupation and Fragmentation of Space: Consequences of Neighbouring Shoots". Functional Ecology. 6 (6): 711–718. doi:10.2307/2389968. JSTOR 2389968.
  29. ^ Schenk H, Callaway R, Mahall B (1999). "Spatial Root Segregation: Are Plants Territorial?". Advances in Ecological Research. 28: 145–180. doi:10.1016/S0065-2504(08)60032-X.
  30. ^ Strid Å, Porra RJ (1992). "Alterations in Pigment Content in Leaves of Pisum sativum After Exposure to Supplementary UV-B". Plant and Cell Physiology. 33 (7): 1015–1023.
  31. ^ Freeman S (2014). Biological science. Illinois: Pearson. p. 803. ISBN 978-0-321-74367-1. OCLC 821271420.
  32. ^ Perrin RM, Young LS, Murthy UM, Harrison BR, Wang Y, Will JL, Masson PH (October 2005). "Gravity signal transduction in primary roots". Annals of Botany. 96 (5): 737–43. doi:10.1093/aob/mci227. PMC 4247041. PMID 16033778.
  33. ^ Bhalla US, Iyengar R (January 1999). "Emergent properties of networks of biological signaling pathways". Science. 283 (5400): 381–7. Bibcode:1999Sci...283..381B. doi:10.1126/science.283.5400.381. PMID 9888852.
  34. ^ Brenner ED, Stahlberg R, Mancuso S, Vivanco J, Baluska F, Van Volkenburgh E (August 2006). "Plant neurobiology: an integrated view of plant signaling". Trends in Plant Science. 11 (8): 413–9. doi:10.1016/j.tplants.2006.06.009. PMID 16843034.
  35. ^ Goh CH, Nam HG, Park YS (October 2003). "Stress memory in plants: a negative regulation of stomatal response and transient induction of rd22 gene to light in abscisic acid-entrained Arabidopsis plants". The Plant Journal. 36 (2): 240–55. doi:10.1046/j.1365-313X.2003.01872.x. PMID 14535888.
  36. ^ Volkov AG, Carrell H, Baldwin A, Markin VS (June 2009). "Electrical memory in Venus flytrap". Bioelectrochemistry. 75 (2): 142–7. doi:10.1016/j.bioelechem.2009.03.005. PMID 19356999.
  37. ^ Rensing L, Koch M, Becker A (December 2009). "A comparative approach to the principal mechanisms of different memory systems". Die Naturwissenschaften. 96 (12): 1373–84. Bibcode:2009NW.....96.1373R. doi:10.1007/s00114-009-0591-0. PMID 19680619.
  38. ^ 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. doi:10.1007/s00442-013-2873-7. PMID 24390479.
  39. ^ Gagliano M, Vyazovskiy VV, Borbély AA, Grimonprez M, Depczynski M (December 2016). "Learning by Association in Plants". Scientific Reports. 6 (1): 38427. doi:10.1038/srep38427. PMID 27910933.
  40. ^ a b c d e Alpi A, Amrhein N, Bertl A, Blatt MR, Blumwald E, Cervone F, Dainty J, De Michelis MI, Epstein E, Galston AW, Goldsmith MH, Hawes C, Hell R, Hetherington A, Hofte H, Juergens G, Leaver CJ, Moroni A, Murphy A, Oparka K, Perata P, Quader H, Rausch T, Ritzenthaler C, Rivetta A, Robinson DG, Sanders D, Scheres B, Schumacher K, Sentenac H, Slayman CL, Soave C, Somerville C, Taiz L, Thiel G, Wagner R (April 2007). "Plant neurobiology: no brain, no gain?". Trends in Plant Science. 12 (4): 135–6. doi:10.1016/j.tplants.2007.03.002. PMID 17368081.
  41. ^ a b Firn R (April 2004). "Plant intelligence: an alternative point of view". Annals of Botany. 93 (4): 345–51. doi:10.1093/aob/mch058. PMC 4242337. PMID 15023701.
  42. ^ Phillips H (27 July 2002). "Not just a pretty face". New Scientist.
  43. ^ Mancuso S (September 2010). "Federico Delpino and the foundation of plant biology". Plant Signaling & Behavior. 5 (9): 1067–71. doi:10.4161/psb.5.9.12102. PMC 3115070. PMID 21490417.
  44. ^ Marder M (November 2012). "Plant intentionality and the phenomenological framework of plant intelligence". Plant Signaling & Behavior. 7 (11): 1365–72. doi:10.4161/psb.21954. PMC 3548850. PMID 22951403.
  45. ^ Garzón FC (July 2007). "The quest for cognition in plant neurobiology". Plant Signaling & Behavior. 2 (4): 208–11. doi:10.4161/psb.2.4.4470. PMC 2634130. PMID 19516990.
  46. ^ Trewavas A (June 2007). "Response to Alpi et al.: Plant neurobiology--all metaphors have value". Trends in Plant Science. 12 (6): 231–3. doi:10.1016/j.tplants.2007.04.006. PMID 17499006.
  47. ^ Brenner ED, Stahlberg R, Mancuso S, Baluska F, Van Volkenburgh E (July 2007). "Response to Alpi et al.: plant neurobiology: the gain is more than the name". Trends in Plant Science. 12 (7): 285–6. doi:10.1016/j.tplants.2007.06.005. PMID 17591455.

Further readingEdit

External linksEdit