Table Of ContentN eurotransmitters
in
Plant Life
VICTORIA V. ROSHCHINA
Russian Academy of Sciences
Institute of Cell Biophysics
Pushchino, Moscow Region
Russia
Science Publishers, Inc.
Enfield (NH), USA Plymouth, UK
SCIENCE PUBLISHERS, lNc.
Post Office Box 699
Enfield, New Hampshire 037 48
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© 2001, Copyright Reserved
Library of Congress Cataloging-in-Publication Data
Roshchina, V. V. {Viktoriia Vladimirovna)
[Biomediatory v rasteniiakh. English]
Neurotrasmitters in plant life/Victoria V. Roschina.
p. cm.
Includes bibliographical references {p. ) .
ISBN 1-57808-142-4
1. Biogenic amines. 2. Acetylcholine. 3. Plant cells and
tissues. 4. Plant physiology. 5. Neurotrasmitters. I. Title.
QK898.B56 R6713 2001
572'. 5482--dc21
2001020173
All rights reserved. No part of this publication may be reproduced, stored
in a retrieval system, or transmitted in any form or by any means, elec-
tronic, mechanical, photocopying or otherwise, without the prior permis-
sion from the publisher. The request to produce certain material should
include a statement of the purpose and extent of the reproduction.
Published by Science Publishers Inc., Enfield, NH, USA
ISBN 13: 978-1-57808-142-4 (hbk)
Preface
The neutrotransmitters acetylcholine and biogenic amines dopamine,
noradrenaline, serotonin, and histamine are present not only in ani
mals, but also in plants. What are the functions of these compounds
in plant organisms? How many plant reactions are sensitive to
neurotransmitters? What is their significance in the field of medi
cine? This book is a first attempt to answer these questions.
The synthesis, content, and role of acetylcholine, catecholamines,
serotonin, and histamine in plants have been reviewed in this work
on the basis of world literature and the author's data. The papers
describe participation of the components of animal cholinergic and
aminergic regulatory systems in the functioning of many plant proc
esses within and outside the cell: from changes in ion permeability
of membranes, energetics, and metabolism to complex processes
such as a fertilization, motility and finally germination, growth, and
morphogenesis. In plants, enzymes of the neurotransmitters' syn
thesis and catabolism are present as well as some functional
analogs of cholino- and aminoreceptors.
In plants, neurotransmitters serve as chemical signallers, trigger
seed and pollen germination, regulate ion permeability, energetics,
metabolism, and movements (of roots, leaves, and stomata cells),
protect against stresses, and participate in intercellular and intracellular
relations. The stimulatory effects of some neurotransmitters on plant
growth reactions may be commercially useful both in laboratories
and in agriculture. Medicinal plants enriched in some neuromediators
could be used in pharmacology and medicine as alternatives to
purified chemical drugs.
An evolutionary approach to the role of neurotransmitters re
veals the presence of the compounds at all steps of evolutionary
development, from unicellular organisms to highly organized ani
mals. This shows that non-synaptic functions of substances have
arisen earlier than synaptic functions in animals with developed
nervous system, and so may play a universal role as elementary
molecular agents of irritation in any living cell.
Contents
Preface iii
Introduction 1
1. Neuromediators, Their Synthesis and Metabolism 4
1.1. Acetylcholine 4
1.1.1. Occurrence of Acetylcholine in Plants 4
1.1.2. Metabolism of Acetylcholine 13
1.1.3. Effect of External Factors on Metabolism of
Acetylcholine 17
1.2. Catecholamines 20
1.2.1 Occurrence in Plants 20
1.2.2. Metabolism in Plants 25
1.3. Serotonin 34
1.3.1. Occurrence in Plants 34
1.3.2. Metabolism in Plants 39
1.4. Histamine 43
1.4.1. Occurrence in Plants 43
1.4.2. Metabolism in Plants 48
2. Response of Plants to Acetylcholine and Biogenic Amines 52
2.1. Growth, development and movements of plants 52
2.1.1. Growth 52
2.1.2. Germination of Seeds, Pollen, and Spores 54
2.1.3. Development of Plants 56
2.1.4. Influence of Environmental Factors on
the Activity of Neurotransmitters 57
2.1.5. Mechanism of Action on Growth and Development 58
2.1.6. Movements and Motility Reactions of Plants 60
2.2. Membrane Processes 63
2.2.1. Ion Permeability and Membrane Potential of
Whole Cells 63
2.2.2. Ion Permeability and Membrane Potential of
Organelles 67
vi Structure of Silk Yarn
2.3. Energetic and Metabolic Reactions 69
2.3.1. Electron Transport and Coupled Phosphorylation 70
2.3.2. Redox Reactions 71
2.3.3. Fluorescence of Individual Cellular Components
and Intact Cells 76
2.3.4. Effects on Metabolic Processes 80
3. The Regulatory Systems with Participation of Neuromediators 82
3.1. Cholinergic System of Regulation 84
3.1.1. Cholinoreception 85
3.1.1.1. Main Features of Cholinoreception 85
3.1.1.2. Cholinoreception in Plants 88
3.1.2. Choline Acetyltransferase 98
3.1.3. Cholinesterase 99
3.1.3.1. Main Characteristics of Animal
Cholinesterases 99
3.1.3.2. Occurrence of Cholinesterase
Activity in Plants 100
3.1.3.3. Kinetic Parameters of Cholinesterases
Found in Plant Extracts 115
3.1.3.4. Localization of Cholinesterase in Plant Cells 120
3.1.3.5. Isolation and Purification of Cholinesterases 126
3.1.3.6. Regulation of Cholinesterase Activity 139
3.1.3.7. Effects of Pesticides and Growth Regulators
with Anticholinesterase Activity on Plant
Reactions 146
3.1.3.8. Special Roles of Cholinesterases 147
3.2. Other Regulatory Systems (Adrenergic, Dopaminergic,
Serotoninergic, Histaminergic) 150
3.2.1. Reception of Catecholamines, Serotonin and
Histamine 150
3.2.1.1. Main Features of Aminoreception 150
3.2.1.2. Aminoreception in Plants 152
3.2.2. Enzymes Participating in Biosynthesis of
Biogenic Amines 159
3.2.3. Enzymes Participating in Catabolism of
Biogenic Amines 164
3.3. Systems of Secondary Messengers Coupling with
Receptors 168
4. Physiological Role of Neuromediatorsi n Plants 178
4.1. Mediatory Function 179
4.1.1. Intracellular and Intercellular Chemical
Signaling in Plants 183
Contents vii
4.1.2. Electric Potentials in Plants and Possible
Role of Neuromediators 187
4.1.3. Neuromediators as Possible Triggers of Secondary
Messenger Systems 191
4.2. Non-mediatory Functions 192
4.2.1. Mediators as Regulators of Energetic and
Metabolic Processes 194
4.2.2. Role of Neuro Mediators in Growth and
Morphogenetic Reactions 196
4.2.3. Protective Role of Neuro Mediators 197
4.3. Evolution of Regulatory System with Participation of
Neuromediators 199
4.4. Perspectives in Practical Use of Neurotransmitters
in Plants 205
4.4.1. Medicine and Pharmacology 205
4.4.2. Agriculture and Protection of the Environment 205
Conclusion 207
Appendix: 1. Pharmacological Effects of Neurotransmitters 211
Lists of some pharmacologically important plants,
containing neuromediators and their derivatives
Appendix: 2. Methods for Plants Assays 215
Bibliography 221
Subject Index 257
Latin Index 276
Introduction
The problem of information transmission within and between living cells
is as significant as the problem of genetic code because it is a major
aspect of irritability, one of the important features of life. Just as genetic
code has a common basis in all living organisms in the form of the se
quence and combination of several purine and pyrimidine bases, the
mechanism of irritability appears to have a common basis in the form of
chemical signals, that are uniform for every cell.
In the 19th century, the animal physiologist Claude Bernard, when
considering irritability (excitability) as one of the main characteristics of
all living things, predicted the occurrence of common mechanisms of
perception and fast reaction of organisms to external factors. In his book
(Bernard, 1878), he has written that there exists common basis of excita
tion in all living organisms. He reached this conclusion after experiments
on the rapid closing of mechanically irritated Mimosa leaves. He
demonstrated that anaesthetics block the conducting of excitation im
pulses in plants, as also observed in animals. However, the molecular
mechanism of excitability, including the perception of external stimulus,
transmission of information about this stimulus, and responses, were
studied only in the 20th century. Electric events in the form of changes of
electric potential have been demonstrated to be the basis of the impulse
spreading in both animals and plants. Moreover, Jagadish Chandra Bose
(1926) proposed even the existence of the nervous mechanisms in plants.
Further investigations were motivated by the search for anaesthetics
and sedative drugs. Investigation of the mechanisms by which excitation
is transmitted from cell to cell in animals having a nervous system led to
the discovery of the low-molecular chemical transmitters (mediators)
cholinic ester acetylcholine, the biogenic amines dopamine, noradrenaline,
adrenaline, serotonin, histamine, and other compounds at the beginning
of the 20th century. In the nerve cell, these compounds are stored in
special secretory vesicles and on irritation are liberated in a narrow space
(1 nm) between contacting cells: the synaptic chink or synapse. The free
