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The Growth Oscillator and Plant Stomata: An Open and Shut Case

Since Darwin’s “Power of Movement in Plants” the precise mechanism of oscillatory plant growth remains elusive. Hence the search continues for the hypothetical growth oscillator that regulates a huge range of growth phenomena ranging from circumnutation to pollen tube tip growth and stomatal movemen...

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Autor principal: Lamport, Derek T. A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10347134/
https://www.ncbi.nlm.nih.gov/pubmed/37447091
http://dx.doi.org/10.3390/plants12132531
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author Lamport, Derek T. A.
author_facet Lamport, Derek T. A.
author_sort Lamport, Derek T. A.
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description Since Darwin’s “Power of Movement in Plants” the precise mechanism of oscillatory plant growth remains elusive. Hence the search continues for the hypothetical growth oscillator that regulates a huge range of growth phenomena ranging from circumnutation to pollen tube tip growth and stomatal movements. Oscillators are essentially simple devices with few components. A universal growth oscillator with only four major components became apparent recently with the discovery of a missing component, notably arabinogalactan glycoproteins (AGPs) that store dynamic Ca(2+) at the cell surface. Demonstrably, auxin-activated proton pumps, AGPs, Ca(2+) channels, and auxin efflux “PIN” proteins, embedded in the plasma membrane, combine to generate cytosolic Ca(2+) oscillations that ultimately regulate oscillatory growth: Hechtian adhesion of the plasma membrane to the cell wall and auxin-activated proton pumps trigger the release of dynamic Ca(2+) stored in periplasmic AGP monolayers. These four major components represent a molecular PINball machine a strong visual metaphor that also recognises auxin efflux “PIN” proteins as an essential component. Proton “pinballs” dissociate Ca(2+) ions bound by paired glucuronic acid residues of AGP glycomodules, hence reassessing the role of proton pumps. It shifts the prevalent paradigm away from the recalcitrant “acid growth” theory that proposes direct action on cell wall properties, with an alternative explanation that connects proton pumps to Ca(2+) signalling with dynamic Ca(2+) storage by AGPs, auxin transport by auxin-efflux PIN proteins and Ca(2+) channels. The extensive Ca(2+) signalling literature of plants ignores arabinogalactan proteins (AGPs). Such scepticism leads us to reconsider the validity of the universal growth oscillator proposed here with some exceptions that involve marine plants and perhaps the most complex stress test, stomatal regulation.
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spelling pubmed-103471342023-07-15 The Growth Oscillator and Plant Stomata: An Open and Shut Case Lamport, Derek T. A. Plants (Basel) Review Since Darwin’s “Power of Movement in Plants” the precise mechanism of oscillatory plant growth remains elusive. Hence the search continues for the hypothetical growth oscillator that regulates a huge range of growth phenomena ranging from circumnutation to pollen tube tip growth and stomatal movements. Oscillators are essentially simple devices with few components. A universal growth oscillator with only four major components became apparent recently with the discovery of a missing component, notably arabinogalactan glycoproteins (AGPs) that store dynamic Ca(2+) at the cell surface. Demonstrably, auxin-activated proton pumps, AGPs, Ca(2+) channels, and auxin efflux “PIN” proteins, embedded in the plasma membrane, combine to generate cytosolic Ca(2+) oscillations that ultimately regulate oscillatory growth: Hechtian adhesion of the plasma membrane to the cell wall and auxin-activated proton pumps trigger the release of dynamic Ca(2+) stored in periplasmic AGP monolayers. These four major components represent a molecular PINball machine a strong visual metaphor that also recognises auxin efflux “PIN” proteins as an essential component. Proton “pinballs” dissociate Ca(2+) ions bound by paired glucuronic acid residues of AGP glycomodules, hence reassessing the role of proton pumps. It shifts the prevalent paradigm away from the recalcitrant “acid growth” theory that proposes direct action on cell wall properties, with an alternative explanation that connects proton pumps to Ca(2+) signalling with dynamic Ca(2+) storage by AGPs, auxin transport by auxin-efflux PIN proteins and Ca(2+) channels. The extensive Ca(2+) signalling literature of plants ignores arabinogalactan proteins (AGPs). Such scepticism leads us to reconsider the validity of the universal growth oscillator proposed here with some exceptions that involve marine plants and perhaps the most complex stress test, stomatal regulation. MDPI 2023-07-03 /pmc/articles/PMC10347134/ /pubmed/37447091 http://dx.doi.org/10.3390/plants12132531 Text en © 2023 by the author. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Review
Lamport, Derek T. A.
The Growth Oscillator and Plant Stomata: An Open and Shut Case
title The Growth Oscillator and Plant Stomata: An Open and Shut Case
title_full The Growth Oscillator and Plant Stomata: An Open and Shut Case
title_fullStr The Growth Oscillator and Plant Stomata: An Open and Shut Case
title_full_unstemmed The Growth Oscillator and Plant Stomata: An Open and Shut Case
title_short The Growth Oscillator and Plant Stomata: An Open and Shut Case
title_sort growth oscillator and plant stomata: an open and shut case
topic Review
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10347134/
https://www.ncbi.nlm.nih.gov/pubmed/37447091
http://dx.doi.org/10.3390/plants12132531
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