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Huang X, Tanveer M, Min Y, Shabala S. Melatonin as a regulator of plant ionic homeostasis: implications for abiotic stress tolerance. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:5886-5902. [PMID: 35640481 DOI: 10.1093/jxb/erac224] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/23/2022] [Indexed: 06/15/2023]
Abstract
Melatonin is a highly conserved and ubiquitous molecule that operates upstream of a broad array of receptors in animal systems. Since melatonin was discovered in plants in 1995, hundreds of papers have been published revealing its role in plant growth, development, and adaptive responses to the environment. This paper summarizes the current state of knowledge of melatonin's involvement in regulating plant ion homeostasis and abiotic stress tolerance. The major topics covered here are: (i) melatonin's control of H+-ATPase activity and its implication for plant adaptive responses to various abiotic stresses; (ii) regulation of the reactive oxygen species (ROS)-Ca2+ hub by melatonin and its role in stress signaling; and (iii) melatonin's regulation of ionic homeostasis via hormonal cross-talk. We also show that the properties of the melatonin molecule allow its direct scavenging of ROS, thus preventing negative effects of ROS-induced activation of ion channels. The above 'desensitization' may play a critical role in preventing stress-induced K+ loss from the cytosol as well as maintaining basic levels of cytosolic Ca2+ required for optimal cell operation. Future studies should focus on revealing the molecular identity of transporters that could be directly regulated by melatonin and providing a bioinformatic analysis of evolutionary aspects of melatonin sensing and signaling.
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Affiliation(s)
- Xin Huang
- International Research Center for Environmental Membrane Biology, Foshan University, Foshan, Guangdong, China
| | - Mohsin Tanveer
- Tasmanian Institute of Agriculture, University of Tasmania, Tas, Hobart, Australia
| | - Yu Min
- International Research Center for Environmental Membrane Biology, Foshan University, Foshan, Guangdong, China
| | - Sergey Shabala
- International Research Center for Environmental Membrane Biology, Foshan University, Foshan, Guangdong, China
- Tasmanian Institute of Agriculture, University of Tasmania, Tas, Hobart, Australia
- School of Biological Sciences, University of Western Australia, Perth, WA, Australia
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2
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Quade BN, Parker MD, Hoepflinger MC, Phipps S, Bisson MA, Foissner I, Beilby MJ. The molecular identity of the characean OH - transporter: a candidate related to the SLC4 family of animal pH regulators. PROTOPLASMA 2022; 259:615-626. [PMID: 34232395 PMCID: PMC8738779 DOI: 10.1007/s00709-021-01677-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/01/2021] [Indexed: 06/13/2023]
Abstract
Characeae are closely related to the ancient algal ancestors of all land plants. The long characean cells display a pH banding pattern to facilitate inorganic carbon import in the acid zones for photosynthetic efficiency. The excess OH-, generated in the cytoplasm after CO2 is taken into the chloroplasts, is disposed of in the alkaline band. To identify the transporter responsible, we searched the Chara australis transcriptome for homologues of mouse Slc4a11, which functions as OH-/H+ transporter. We found a single Slc4-like sequence CL5060.2 (named CaSLOT). When CaSLOT was expressed in Xenopus oocytes, an increase in membrane conductance and hyperpolarization of resting potential difference (PD) was observed with external pH increase to 9.5. These features recall the behavior of Slc4a11 in oocytes and are consistent with the action of a pH-dependent OH-/H+ conductance. The large scatter in the data might reflect intrinsic variability of CaSLOT transporter activation, inefficient expression in the oocyte due to evolutionary distance between ancient algae and frogs, or absence of putative activating factor present in Chara cytoplasm. CaSLOT homologues were found in chlorophyte and charophyte algae, but surprisingly not in related charophytes Zygnematophyceae or Coleochaetophyceae.
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Affiliation(s)
- Bianca N Quade
- Department of Physiology and Biophysics, The State University of New York: The University at Buffalo, Buffalo, NY, USA
| | - Mark D Parker
- Department of Physiology and Biophysics, The State University of New York: The University at Buffalo, Buffalo, NY, USA
| | - Marion C Hoepflinger
- Department of Biosciences, University of Salzburg, Hellbrunner Str. 34, 5020, Salzburg, Austria
| | - Shaunna Phipps
- Department of Biological Sciences and Program in Evolution, Ecology, and Behavior, The State University of New York: The University at Buffalo, Hochstetter 623, Buffalo, NY, USA
| | - Mary A Bisson
- Department of Biological Sciences and Program in Evolution, Ecology, and Behavior, The State University of New York: The University at Buffalo, Hochstetter 623, Buffalo, NY, USA
| | - Ilse Foissner
- Department of Biosciences, University of Salzburg, Hellbrunner Str. 34, 5020, Salzburg, Austria
| | - Mary J Beilby
- School of Physics, The University of NSW, Kensington, Sydney, NSW, 2052, Australia.
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Altaf MA, Shahid R, Ren MX, Mora-Poblete F, Arnao MB, Naz S, Anwar M, Altaf MM, Shahid S, Shakoor A, Sohail H, Ahmar S, Kamran M, Chen JT. Phytomelatonin: An overview of the importance and mediating functions of melatonin against environmental stresses. PHYSIOLOGIA PLANTARUM 2021; 172:820-846. [PMID: 33159319 DOI: 10.1111/ppl.13262] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/09/2020] [Accepted: 10/27/2020] [Indexed: 05/06/2023]
Abstract
Recently, melatonin has gained significant importance in plant research. The presence of melatonin in the plant kingdom has been known since 1995. It is a molecule that is conserved in a wide array of evolutionary distant organisms. Its functions and characteristics have been found to be similar in both plants and animals. The review focuses on the role of melatonin pertaining to physiological functions in higher plants. Melatonin regulates physiological functions regarding auxin activity, root, shoot, and explant growth, activates germination of seeds, promotes rhizogenesis (growth of adventitious and lateral roots), and holds up impelled leaf senescence. Melatonin is a natural bio-stimulant that creates resistance in field crops against various abiotic stress, including heat, chemical pollutants, cold, drought, salinity, and harmful ultra-violet radiation. The full potential of melatonin in regulating physiological functions in higher plants still needs to be explored by further research.
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Affiliation(s)
| | - Rabia Shahid
- School of Economics, Hainan University, Haikou, China
| | - Ming-Xun Ren
- Center for Terrestrial Biodiversity of the South China Sea, College of Ecology and Environment, Hainan University, Haikou, China
| | | | - Marino B Arnao
- Department of Plant Biology (Plant Physiology), Faculty of Biology, University of Murcia, Murcia, Spain
| | - Safina Naz
- Department of Horticulture, Faculty of Agricultural Science and Technology, Bahauddin Zakariya University, Multan, Pakistan
| | - Muhammad Anwar
- College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | | | - Sidra Shahid
- Institute for Clinical Chemistry, University Medical Center Goettingen, Goettingen, Germany
| | - Awais Shakoor
- Department of Environment and Soil Sciences, University of Lleida, Lleida, Spain
| | - Hamza Sohail
- College of Horticulture and Forestry Sciences, Huazhong Agricultural University/Key Laboratory of Horticultural Plant Biology, Ministry of Education, Wuhan, China
| | - Sunny Ahmar
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Muhammad Kamran
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Jen-Tsung Chen
- Department of Life Sciences, National University of Kaohsiung, Kaohsiung, Taiwan
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4
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Phipps S, Delwiche CF, Bisson MA. Salinity-induced Changes in Gene Expression in the Streptophyte Alga Chara: The Critical Role of a Rare Na + -ATPase. JOURNAL OF PHYCOLOGY 2021; 57:1004-1013. [PMID: 33713364 DOI: 10.1111/jpy.13166] [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: 07/30/2020] [Accepted: 01/13/2021] [Indexed: 06/12/2023]
Abstract
The primarily freshwater genus Chara is comprised of many species that exhibit a wide range of salinity tolerance. The range of salt tolerance provides a good platform for investigating the role of transport mechanisms in response to salt stress, and the close evolutionary relationship between Charophytes and land plants can provide broader insights. We investigated the response to salt stress of previously identified transport mechanisms in two species of Chara, Chara longifolia (salt-tolerant), and Chara australis (salt-sensitive): a cation transporter (HKT), a Na+ /H+ antiport (NHX), H+ -ATPase (AHA), and a Na+ -ATPase (ENA). The presence of these candidate genes has been confirmed in both species of Chara, with the exception of the Na+ -ATPase, which is present only in salt-tolerant Chara longifolia. Time-course Illumina transcriptomes were created using RNA from multiple time points (0, 6, 12, 24 and 48 h) after freshwater cultures for each species were exposed to salt stress. These transcriptomes verified our hypotheses of these mechanisms conferring salt tolerance in the two species examined and also aided in identification of specific transcripts representing our genes of interest in both species. The expression of these transcripts was validated through use of qPCR, in a similar experimental set-up used for the RNAseq data described above. The RNAseq and qPCR data showed significant changes of expression mechanisms in C. longifolia (respectively), a down-regulation of HKT and a substantial up-regulation of ENA. Significant responses to salt stress in salt-sensitive C. australis show up-regulation of NHX and AHA.
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Affiliation(s)
- Shaunna Phipps
- Department of Environment & Sustainability, State University at Buffalo, Buffalo, New York, USA
- Department of Biological Sciences, State University at Buffalo, Buffalo, New York, USA
| | - Charles F Delwiche
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
| | - Mary A Bisson
- Department of Environment & Sustainability, State University at Buffalo, Buffalo, New York, USA
- Department of Biological Sciences, State University at Buffalo, Buffalo, New York, USA
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Liu J, Shabala S, Zhang J, Ma G, Chen D, Shabala L, Zeng F, Chen ZH, Zhou M, Venkataraman G, Zhao Q. Melatonin improves rice salinity stress tolerance by NADPH oxidase-dependent control of the plasma membrane K + transporters and K + homeostasis. PLANT, CELL & ENVIRONMENT 2020; 43:2591-2605. [PMID: 32196121 DOI: 10.1111/pce.13759] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/29/2020] [Accepted: 03/02/2020] [Indexed: 05/18/2023]
Abstract
This study aimed to reveal the mechanistic basis of the melatonin-mediated amelioration of salinity stress in plants. Electrophysiological experiments revealed that melatonin decreased salt-induced K+ efflux (a critical determinant of plant salt tolerance) in a dose- and time-dependent manner and reduced sensitivity of the plasma membrane K+ -permeable channels to hydroxyl radicals. These beneficial effects of melatonin were abolished by NADPH oxidase blocker DPI. Transcriptome analyses revealed that melatonin induced 585 (448 up- and 137 down-regulated) and 59 (54 up- and 5 down-regulated) differentially expressed genes (DEGs) in the root tip and mature zone, respectively. The most noticeable changes in the root tip were melatonin-induced increase in the expression of several DEGs encoding respiratory burst NADPH oxidases (OsRBOHA and OsRBOHF), calcineurin B-like/calcineurin B-like-interacting protein kinase (OsCBL/OsCIPK), and calcium-dependent protein kinase (OsCDPK) under salt stress. Melatonin also enhanced the expression of potassium transporter genes (OsAKT1, OsHAK1, and OsHAK5). Taken together, these results indicate that melatonin improves salt tolerance in rice by enabling K+ retention in roots, and that the latter process is conferred by melatonin scavenging of hydroxyl radicals and a concurrent OsRBOHF-dependent ROS signalling required to activate stress-responsive genes and increase the expression of K+ uptake transporters in the root tip.
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Affiliation(s)
- Juan Liu
- Collaborative Innovation Centre of Henan Grain Crops, Henan Key Laboratory of Rice Biology, Henan Agricultural University, Zhengzhou, China
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tasmania, Australia
| | - Sergey Shabala
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tasmania, Australia
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan, China
| | - Jing Zhang
- Collaborative Innovation Centre of Henan Grain Crops, Henan Key Laboratory of Rice Biology, Henan Agricultural University, Zhengzhou, China
| | - Guohui Ma
- State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, China
| | - Dandan Chen
- Collaborative Innovation Centre of Henan Grain Crops, Henan Key Laboratory of Rice Biology, Henan Agricultural University, Zhengzhou, China
| | - Lana Shabala
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tasmania, Australia
| | - Fanrong Zeng
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Zhong-Hua Chen
- School of Science, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
- Collaborative Innovation Centre for Grain Industry, College of Agriculture, Yangtze University, Jingzhou, China
| | - Meixue Zhou
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tasmania, Australia
| | - Gayatri Venkataraman
- Plant Molecular Biology Laboratory, M.S. Swaminathan Research Foundation, III Cross Street, Taramani Institutional Area, Chennai, India
| | - Quanzhi Zhao
- Collaborative Innovation Centre of Henan Grain Crops, Henan Key Laboratory of Rice Biology, Henan Agricultural University, Zhengzhou, China
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Melatonin: A Small Molecule but Important for Salt Stress Tolerance in Plants. Int J Mol Sci 2019; 20:ijms20030709. [PMID: 30736409 PMCID: PMC6387279 DOI: 10.3390/ijms20030709] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 02/03/2019] [Accepted: 02/04/2019] [Indexed: 01/09/2023] Open
Abstract
Salt stress is one of the most serious limiting factors in worldwide agricultural production, resulting in huge annual yield loss. Since 1995, melatonin (N-acetyl-5-methoxytryptamine)—an ancient multi-functional molecule in eukaryotes and prokaryotes—has been extensively validated as a regulator of plant growth and development, as well as various stress responses, especially its crucial role in plant salt tolerance. Salt stress and exogenous melatonin lead to an increase in endogenous melatonin levels, partly via the phyto-melatonin receptor CAND2/PMTR1. Melatonin plays important roles, as a free radical scavenger and antioxidant, in the improvement of antioxidant systems under salt stress. These functions improve photosynthesis, ion homeostasis, and activate a series of downstream signals, such as hormones, nitric oxide (NO) and polyamine metabolism. Melatonin also regulates gene expression responses to salt stress. In this study, we review recent literature and summarize the regulatory roles and signaling networks involving melatonin in response to salt stress in plants. We also discuss genes and gene families involved in the melatonin-mediated salt stress tolerance.
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Absolonova M, Beilby MJ, Sommer A, Hoepflinger MC, Foissner I. Surface pH changes suggest a role for H +/OH - channels in salinity response of Chara australis. PROTOPLASMA 2018; 255:851-862. [PMID: 29247277 PMCID: PMC5904247 DOI: 10.1007/s00709-017-1191-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 11/27/2017] [Indexed: 05/16/2023]
Abstract
To understand salt stress, the full impact of salinity on plant cell physiology has to be resolved. Electrical measurements suggest that salinity inhibits the proton pump and opens putative H+/OH- channels all over the cell surface of salt sensitive Chara australis (Beilby and Al Khazaaly 2009; Al Khazaaly and Beilby 2012). The channels open transiently at first, causing a characteristic noise in membrane potential difference (PD), and after longer exposure remain open with a typical current-voltage (I/V) profile, both abolished by the addition of 1 mM ZnCl2, the main known blocker of animal H+ channels. The cells were imaged with confocal microscopy, using fluorescein isothiocyanate (FITC) coupled to dextran 70 to illuminate the pH changes outside the cell wall in artificial fresh water (AFW) and in saline medium. In the early saline exposure, we observed alkaline patches (bright fluorescent spots) appearing transiently in random spatial distribution. After longer exposure, some of the spots became fixed in space. Saline also abolished or diminished the pH banding pattern observed in the untreated control cells. ZnCl2 suppressed the alkaline spot formation in saline and the pH banding pattern in AFW. The osmotic component of the saline stress did not produce transient bright spots or affect banding. The displacement of H+ from the cell wall charges, the H+/OH- channel conductance/density, and self-organization are discussed. No homologies to animal H+ channels were found. Salinity activation of the H+/OH- channels might contribute to saline response in roots of land plants and leaves of aquatic angiosperms.
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Affiliation(s)
- Marketa Absolonova
- Department of Cell Biology and Physiology/Plant Physiology, University of Salzburg, Salzburg, Austria
| | - Mary J Beilby
- School of Physics, The University of NSW, Sydney, NSW, 2052, Australia.
| | - Aniela Sommer
- Department of Cell Biology and Physiology/Plant Physiology, University of Salzburg, Salzburg, Austria
| | - Marion C Hoepflinger
- Department of Cell Biology and Physiology/Plant Physiology, University of Salzburg, Salzburg, Austria
| | - Ilse Foissner
- Department of Cell Biology and Physiology/Plant Physiology, University of Salzburg, Salzburg, Austria
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Arnao MB, Hernández-Ruiz J. Functions of melatonin in plants: a review. J Pineal Res 2015; 59:133-50. [PMID: 26094813 DOI: 10.1111/jpi.12253] [Citation(s) in RCA: 425] [Impact Index Per Article: 47.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 06/05/2015] [Indexed: 02/06/2023]
Abstract
The number of studies on melatonin in plants has increased significantly in recent years. This molecule, with a large set of functions in animals, has also shown great potential in plant physiology. This review outlines the main functions of melatonin in the physiology of higher plants. Its role as antistress agent against abiotic stressors, such as drought, salinity, low and high ambient temperatures, UV radiation and toxic chemicals, is analyzed. The latest data on their role in plant-pathogen interactions are also discussed. Both abiotic and biotic stresses produce a significant increase in endogenous melatonin levels, indicating its possible role as effector in these situations. The existence of endogenous circadian rhythms in melatonin levels has been demonstrated in some species, and the data, although limited, suggest a central role of this molecule in the day/night cycles in plants. Finally, another aspect that has led to a large volume of research is the involvement of melatonin in aspects of plant development regulation. Although its role as a plant hormone is still far of from being fully established, its involvement in processes such as growth, rhizogenesis, and photosynthesis seems evident. The multiple changes in gene expression caused by melatonin point to its role as a multiregulatory molecule capable of coordinating many aspects of plant development. This last aspect, together with its role as an alleviating-stressor agent, suggests that melatonin is an excellent prospect for crop improvement.
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Affiliation(s)
- Marino B Arnao
- Department of Plant Biology (Plant Physiology), Faculty of Biology, University of Murcia, Murcia, Spain
| | - Josefa Hernández-Ruiz
- Department of Plant Biology (Plant Physiology), Faculty of Biology, University of Murcia, Murcia, Spain
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Beilby MJ. Salt tolerance at single cell level in giant-celled Characeae. FRONTIERS IN PLANT SCIENCE 2015; 6:226. [PMID: 25972875 PMCID: PMC4412000 DOI: 10.3389/fpls.2015.00226] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Indexed: 05/20/2023]
Abstract
Characean plants provide an excellent experimental system for electrophysiology and physiology due to: (i) very large cell size, (ii) position on phylogenetic tree near the origin of land plants and (iii) continuous spectrum from very salt sensitive to very salt tolerant species. A range of experimental techniques is described, some unique to characean plants. Application of these methods provided electrical characteristics of membrane transporters, which dominate the membrane conductance under different outside conditions. With this considerable background knowledge the electrophysiology of salt sensitive and salt tolerant genera can be compared under salt and/or osmotic stress. Both salt tolerant and salt sensitive Characeae show a rise in membrane conductance and simultaneous increase in Na(+) influx upon exposure to saline medium. Salt tolerant Chara longifolia and Lamprothamnium sp. exhibit proton pump stimulation upon both turgor decrease and salinity increase, allowing the membrane PD to remain negative. The turgor is regulated through the inward K(+) rectifier and 2H(+)/Cl(-) symporter. Lamprothamnium plants can survive in hypersaline media up to twice seawater strength and withstand large sudden changes in salinity. Salt sensitive C. australis succumbs to 50-100 mM NaCl in few days. Cells exhibit no pump stimulation upon turgor decrease and at best transient pump stimulation upon salinity increase. Turgor is not regulated. The membrane PD exhibits characteristic noise upon exposure to salinity. Depolarization of membrane PD to excitation threshold sets off trains of action potentials, leading to further loses of K(+) and Cl(-). In final stages of salt damage the H(+)/OH(-) channels are thought to become the dominant transporter, dissipating the proton gradient and bringing the cell PD close to 0. The differences in transporter electrophysiology and their synergy under osmotic and/or saline stress in salt sensitive and salt tolerant characean cells are discussed in detail.
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Affiliation(s)
- Mary J. Beilby
- Plant Membrane Biophysics, Physics/Biophysics, School of Physics, University of New South Wales, Sydney, NSWAustralia
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Beilby MJ, Turi CE, Baker TC, Tymm FJM, Murch SJ. Circadian changes in endogenous concentrations of indole-3-acetic acid, melatonin, serotonin, abscisic acid and jasmonic acid in Characeae (Chara australis Brown). PLANT SIGNALING & BEHAVIOR 2015; 10:e1082697. [PMID: 26382914 PMCID: PMC4883837 DOI: 10.1080/15592324.2015.1082697] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Giant-celled Characeae (Chara australis Brown), grown for 4 months on 12/12 hr day/night cycle and summer/autumn temperatures, exhibited distinct concentration maxima in auxin (indole-3-acetic acid; IAA), melatonin and serotonin about 4 hr after subjective daybreak. These concentration peaks persisted after 3 day pretreatment in continuous darkness: confirming a circadian rhythm, rather than a response to "light on." The plants pretreated for 3 d in continuous light exhibited several large IAA concentration maxima throughout the 24 hr. The melatonin and serotonin concentrations decreased and were less synchronized with IAA. Chara plants grown on 9/15 hr day/night cycle for 4 months and winter/spring temperatures contained much smaller concentrations of IAA, melatonin and serotonin. The IAA concentration maxima were observed in subjective dark phase. Serotonin concentration peaks were weakly correlated with those of IAA. Melatonin concentration was low and mostly independent of circadian cycle. The "dark" IAA concentration peaks persisted in plants treated for 3 d in the dark. The plants pretreated for 3 d in the light again developed more IAA concentration peaks. In this case the concentration maxima in melatonin and serotonin became more synchronous with those in IAA. The abscisic acid (ABA) and jasmonic acid (JA) concentrations were also measured in plants on winter regime. The ABA concentration did not exhibit circadian pattern, while JA concentration peaks were out of phase with those of IAA. The data are discussed in terms of crosstalk between metabolic pathways.
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Affiliation(s)
- Mary J Beilby
- School of Physics; University of NSW; Sydney, Australia
- Correspondence to: Mary J Beilby;
| | - Christina E Turi
- Department of Chemistry; University of British Columbia; Kelowna, Canada
| | - Teesha C Baker
- Department of Chemistry; University of British Columbia; Kelowna, Canada
| | - Fiona JM Tymm
- Department of Chemistry; University of British Columbia; Kelowna, Canada
| | - Susan J Murch
- Department of Chemistry; University of British Columbia; Kelowna, Canada
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11
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Erland LAE, Murch SJ, Reiter RJ, Saxena PK. A new balancing act: The many roles of melatonin and serotonin in plant growth and development. PLANT SIGNALING & BEHAVIOR 2015; 10:e1096469. [PMID: 26418957 PMCID: PMC4883872 DOI: 10.1080/15592324.2015.1096469] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 09/11/2015] [Accepted: 09/14/2015] [Indexed: 05/20/2023]
Abstract
Melatonin and serotonin are indoleamines first identified as neurotransmitters in vertebrates; they have now been found to be ubiquitously present across all forms of life. Both melatonin and serotonin were discovered in plants several years after their discovery in mammals, but their presence has now been confirmed in almost all plant families. The mechanisms of action of melatonin and serotonin are still poorly defined. Melatonin and serotonin possess important roles in plant growth and development, including functions in chronoregulation and modulation of reproductive development, control of root and shoot organogenesis, maintenance of plant tissues, delay of senescence, and responses to biotic and abiotic stresses. This review focuses on the roles of melatonin and serotonin as a novel class of plant growth regulators. Their roles in reproductive and vegetative plant growth will be examined including an overview of current hypotheses and knowledge regarding their mechanisms of action in specific responses.
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Affiliation(s)
- Lauren A E Erland
- Department of Plant Agriculture; University of Guelph; Guelph, Canada
| | - Susan J Murch
- Department of Chemistry; University of British Columbia; Kelowna, Canada
| | - Russel J Reiter
- Department of Cellular and Structural Biology; University of Texas Health Center; San Antonio, TX USA
| | - Praveen K Saxena
- Department of Plant Agriculture; University of Guelph; Guelph, Canada
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