Physiological Plant Pathology

908 Pages·1976·29.767 MB·English

by  W. H. Fuchs (auth.), R. Heitefuss, P. H. Williams (eds.)

Encyclopedia of
Plant Physiology
New Series Volume 4
Editors
A. Pirson, Gottingen
M. H. Zimmermann, Harvard
Physiological
Plant Pathology
Edited by
R. Hei tefuss and P. H. Williams
Contributors
J.R.Aist P.J.Allen H.G.Basham D.FBateman
J. M. Daly H. M. Dekhuijzen V H. Dropkin J. M. Duniway
A. H. Ellingboe F Fric W H. Fuchs D. G. Gilchrist
R. N. Goodman R. Heitefuss E. C. Hislop D. S. Ingram
T. Kosuge J. A. Kuc B. B. Lippincott J. A. Lippincott
K.Maramorosch J. E. Mitchell G. F Pegg D. Pitt K.Rudolph
R. P. Scheffer E. SchlOsser F Schonbeck K. J. Scott
R. C. Staples 1. Uritani H. E. Wheeler G. Wolf Z. Yaniv
C. E. Yarwood G. A. De Zoeten
Springer-Verlag Berlin Heidelberg New York 1976
With 92 Figures
ISBN- 13: 978-3-642-66281-2 e-ISBN-13: 978-3-642-66279-9
DOl: 10.1007/978-3-642-66279-9
Library of Congress Cataloging in Publication Data. Main entry under title: Physiological plant pathology. (Encyclope
dia of plant physiology: v. 4) Includes bibliographical references and indexes. 1. Plant diseases. 2. Plant physiology.
I. Heitefuss. Rudolf. II. Williams, Paul. H., 1938 - .SB731.P53. 581.2.76-3724.
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by Springer-Verlag Berlin· Heidelberg 1976
Softcover reprint of the hardcover 1st edition 1976
The use of registered names, trademarks, etc. in this pUblication does not imply, even in the absence of a specific
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general use.
Preface
Plant pathology embraces all aspects of biological and scientific activity which are
concerned with understanding the complex phenomena of diseases in plants.
Physiological plant pathology represents those specialities within plant pathology
which focus on the physiological and biochemical activities of pathogens and
on the response of host plant tissues.
Today there is an increasing recognition on the part of the scientific agri
cultural community that only through a deeper and more fundamental under
standing of all the interacting components of the agricultural biota can we expect
to improve our capabilities of feeding an expanding world population. It is in this
context that physiological plant pathology has assumed new significance within
the broader field of plant pathology. No longer are studies on the biochemistry
and physiology of pathogens and pathogenesis merely isolated academic exercises;
rather, a substantial coherent body of knowledge is accumulating upon which our
understanding of the process of disease developmen t and host resistance is being
founded. It is from these foundations of knowledge that ultimately new insights
into the control of plant diseases may be expected to grow.
It seems appropriate, therefore, that at regular intervals those involved in the
various subspecialities encompassing the broadest aspects of physiological plant
pathology reassess the contributions within the particular specialities in the light of
new knowledge and technologies for the purpose of articulating new and productive
directions for the future.
It has become increasingly apparent in all areas of biology that a full under
standing of any particular phenomenon lies at the interfaces of knowledge from
diverse disciplines. Thus, only by bringing together the insights of disciplines such
as genetics, physiology, cytology, biochemistry and biophysics will the complexities
and significance of host-pathogen relations be fully understood. With the publication
of this volume, we hope to have provided researchers and students with the
opportunity of assessing the state of our knowledge in diverse aspects of physiological
plant pathology, ranging from the physiology and ultrastructural cytology of
various pathogens to the biochemistry of pathogenesis and resistance. From
throughout the world we have selected active researchers and asked them to review
the past, to evaluate the present knowledge and to assess the future potential for
their respective disciplines.
We have selected two authors with especially long and thorough experience in
the field of physiological plant pathology to introduce the volume. In a historical
chapter we hope to provide the reader with a view of the beginnings and philo
sophical roots from which modern physiological plant pathology has grown. In
the following chapter, some of the principal aspects of host-pathogen interactions
VI Preface
in need of modem biochemical technology and analytical objectivity are critically
evaluated. We have avoided dwelling on definitions and terminology in the
intfoductory chapters but instead refer to the phytopathological paper No. 17
(1973) of the Commonwealth Mycological Institute as "a guide to the use of terms
in plant pathology".
The main part of the volume is structured with the realization that host-pathogen
interactions progress through a series of stages before and during pathogenesis
which are ultimately expressed as susceptibility or resistance of the plant. Before
the parasite enters the host, physiological events occur which may be decisive in
determining the ultimate success of the attack. Normally, these activities take place
in the rhizosphere or phyllosphere and the relationship of the chemical and physical
environments of these regions may be of great importance to the regulation of
germination and penetration.
Although most of the emphasis in this volume is on the reactions of higher
plants with fungi and bacteria; viruses, nematodes and mycoplasm-like organisms
have also been included. The specialist in these latter fields may miss some important
aspects, as the scope of the volume has not permitted complete coverage. Our
intention has been to focus on various similarities and differences within the
different groups and in their reactions with the host. This should be especially
evident in the section on physiology and cytology of penetration and establishment,
an area in which the progress in knowledge depends primarily on the careful
investigation and interpretation of structure and function.
1\ study of pathogenesis involves not only an understanding of the alteration
in normal plant metabolism, water balance, and growth responses, but also a
knowledge of those factors used by pathogens to aid or assist in the attack and
colonization of host tissues. A number of chapters, therefore, are directed to the
activities of toxins, enzymes, and growth regulators as factors involved in patho
genesis and to alterations in metabolic pathways, water balance, and growth
responses in the diseased plant.
Of great interest today in studies of physiological plant pathology are the events
which result in resistance to pathogens or in manifestations of specificity in
particular combinations of host and pathogen genotypes. The chapters on pre
formed and induced determinants of resistance and specificity review major research
in these areas. Strongly complementing these discussions on resistance are chapters
on the genetic basis for specificity and the role of metabolic regulation in the
infected host tissue.
Any consideration of the diseased plant must take into account possible factors
which may have had an effect in predisposing that plant to disease. The influence
of predisposition is often neglected by pathologists viewing diseases under conditions
designed for physiological studies. For this reason, we thought it particularly
important to include a chapter on predisposing factors in plant disease.
Technological advances in the past 1O~15 years have now permitted the routine
cultivation of a number of biotrophic parasites in axenic and monoxenic culture
on host callus. The implications of these methodologies to cytological, physiological,
and biochemical analysis of obligate parasitism are very great and it seemed
appropriate to review the status of these emerging specialities.
Outside the scope of this volume are the diseases or disorders of plants caused by
non-parasitic agents. Therefore the physiology of disorders due to deficiency, excess
Preface VII
or imbalance of elements essential to plant growth has not been treated. It is
hoped that these problems will be included in a later volume of this series. The
same applies to injury of plants by phytotoxic air pollutants and other chemical
agents.
Just as it is expected that a knowledge of the physiological processes of disease
in plants can be gained only after understanding the normal physiology in the
plant, so it is appropriate to include in this New Series of the Encyclopedia of
Plant Physiology a volume of Physiological Plant Pathology. Indeed, in such a setting
as this series, the study of disease processes in plants may not only receive closer
scrutiny by plant physiologists and biochemists, but physiological plant pathologists
may be directed to new insights of the plant which provide solutions to their
particular problems.
Our thanks are due to the authors of this volume for their contributions and
for their patience during the preparation of this book, which has taken longer
than we had originally anticipated. We thank Professor Dr. W.H. FUCHS and
Professor Dr. A. PIRSON, both in G6ttingen, for valuable suggestions on the outline
and scope of this volume. Further thanks are extended to Mrs. KAUNA TH for her
technical assistance. We appreciate the assistance by various members of the
Springer-Verlag for the final preparation of the book.
G6ttingen and Madison, R. HEITEFUSS
May 1976 P.H. WILLIAMS
Contents
1. General
1.1 History of Physiological Plant Pathology
W.H. FUCHS ........... .
1.2 Some Aspects of Host-Pathogen Interactions
1.M. DALY (With 1 Figure)
1. Introduction . . . . . . 27
2. The Response of the Host 27
2.1 Resistance . . . . . 28
2.2 Susceptibility . . . . 30
2.3 Economic Damage and Tolerance to Disease 30
2.4 Symptom Expression and Spurious Effects . 31
3. Pathogenicity and Virulence . . . . . . . . . 32
4. The Influence of Disease in the Design of Experimental Procedures 34
5. The Control of Host-Pathogen Interactions. 35
5.1 Genetic Control. . . . . . . . 35
5.2 Flor's Gene-for-gene Hypothesis. . . . 36
5.3 Metabolic Control. . . . . . . . . . 37
5.4 Modes of Inheritance and Induced Resistance versus Induced Susceptibility 39
5.5 Recognition Phenomena in Specificity . . . . . . 40
5.6 The Influence of Environment. . . . . . . . . . 41
6. Special Topics . . . . . . . . . . . . . . . . . . 41
6.1 Quantitative Measures of Disease and of Pathogens 41
6.2 Genetic Control of Experimental Material 43
6.3 Model Systems . . . 44
6.4 Challenge Inoculations 45
References . . . . . . . . 47
2. Spore Germination and Its Regulation
2.1 Control of Spore Germination and Infection Structure Formation in the Fungi
P.l. ALLEN
1. Introduction . . . . . . . . . . . . . . . . . . 51
2. Self-Inhibition and Stimulation of Gennination . . . 54
2.1 Gennination Inhibitors from the Parent Colony . 54
2.2 Gennination Inhibitors in Spores . . . . . . . 55
2.3 Self-Stimulation of Gennination. . . . . . . . 66
3. Inhibitors and Stimulants of Gennination in Soil. .. 68
3.1 Soil Fungistasis . . . . . . . . . . . . . . . 68
3.2 Stimulants in Soil . . . . . . . . . . . . . . 71
4. Stimulants and Inhibitors of Gennination at Plant Surfaces 73
4.1 Inhibitors 73
4.2 Stimulants . . . . . . . . . . . . . . . . . . . . 75
x
Contents
5. Fonnation of Infection Structures. . . . . . . . . . . 76
5.1 Genetic Basis of Infection Structure Fonnation . . . 76
5.2 Experimental Studies on Infection Structure Fonnation 76
6. Conclusions 77
References . . . . . . . . . . . . . . . . . . . . . 78
2.2 Protein and Nucleic Acid Metabolism during Germination
R.C. STAPLES and Z. Y ANIV (With 2 Figures)
1. Introduction . . . . . . . 86
2. Facultative Parasites 86
2.1 Gennination of Conidia 86
2.2 Gennination of Zoospores 93
2.3 Gennination of Basidiospores 95
3. Obligate Parasites. . . . . . . 96
3.1 Introduction ...... . 96
3.2 Changes in Proteins and Nucleic Acids during Gennination 96
3.3 Changes in Ribosome Activity during Spore Gennination 97
3.4 Differentiation 98
3.5 Conclusions. 99
References . . . . . 101
2.3 The Effect of Roots on the Activity of Soil-borne Plant Pathogens
J .E. MITCHELL
1. Introduction . . . . . . 104
2. The Pathogen in the Soil . 105
3. The Root-Soil Interface 106
3.1 The Rhizosphere ... 106
3.2 The Rhizoplane . . . 107
4. The Mechanism of the Root Effect 108
4.1 Root Tissue Debris . . . . 108
4.2 Root Exudates . . . . . . . 108
4.3 Oxygen and Carbon Dioxide . 110
4.4 Volatile Emanations from Roots. 111
4.5 Root Surface Effects . . . . . . III
5. Methods of StUdying Response of Pathogens to Roots 112
6. Behavior of Specific Pathogens 113
7. Discussion 122
References . . . . . . . . . . 123
3. Cytology and Physiology of Penetration and Establishment
3.1 Cytology of Virus Infection and Virus Transport
G.A. DE ZOETEN (With 8 Figures)
1. Introduction . . . 129
2. Methods of Study. . . . . . 130
3. Infection. . . . . . . . . . 132
4. Cytology of Virus Multiplication 136
5. Virus Aggregation, Anomalous Inclusions and Structural Changes in Infected Cells 141
6. Transport . 143
7. Conclusions 145
References . . 146
3.2 Plant Mycoplasma Diseases
K. MARAMOROSCH (With 1 Figure)
1. Introduction . . . . . . . 150
2. Historical Background. . . 150
3. Tenninology and Definitions 152
Contents XI
4. Methodology. . . . . . . . . 154
5. Effects of MLO on Plants . . . 159
6. Effects of MLO on Insect Vectors 161
7. Chemotherapy and Heat Therapy 162
8. Unsolved Problems . . . 164
9. Summary and Conclusions . . . 165
References . . . . . . . . . . . 166
3.3 Physiological and Cytological Aspects of the Bacterial Infection Process
R.N. GOODMAN (With 5 Figures)
I. Introduction . . . . . . . . . . . . 172
2. Pre-penetration . . . . . . . . . . . 172
2.1 Motility, Aerotaxis and Chemotaxis 172
2.2 Predisposing Environmental Features. 174
2.3 Morphological Barriers to Infection 179
3. Penetration. . . . . 180
3.1 Natural Openings . . 180
3.2 Wounds . . . . . . 183
4. Growth of the Bacteria in vivo 186
4.1 Inoculum Size Required to Establish an Infection 186
4.2 The Sites of Bacterial Multiplication. . . . . . 186
4.3 Bacterial Proliferation in Connection with the Hypersensitive Reaction 190
4.4 Growth of Saprophytic Bacteria in Plant Tissue 190
5. Microbiological Antagonism and Commensalism 191
6. Summing-up 192
References . . . . . . . . . . . . . . . . 193
3.4 Cytology of Penetration and Infection - Fungi
1.R. AIST (With 12 Figures)
I. Introduction . . 197
2. The Use of Modem Methodology 197
3. Primary Penetration. . . . . . 201
3.1 Primary Penetration Types . 201
3.2 The Mechanism(s) of Primary Penetration 206
4. Infection. . . . . . . . . . . . . . . . . 209
4.1 Specialized Structures Associated with Infection 209
4.2 Effects of Infection on Susceptible Host Cytology 213
5. Relating Structure to Function 215
References . . . . . . . . . . . . . . . . . . . . 216
3.5 Nematode Parasites of Plants, Their Ecology and the Process of Infection
V.H. DROPKIN (With 3 Figures)
1. Introduction . . . . . . . . . . . . . . . 222
2. Physiology of Nematodes outside Their Hosts 223
3. Attraction and Penetration 229
3.1 Attraction . . . . . . 229
3.2 Feeding Behavior . . . 230
3.3 Wall-degrading Enzymes 232
4. Nutrition . . . . . . 232
4.1 Cultures . . . . . 232
4.2 Sex Determination. 233
4.3 Growth Rates. . . 234
4.4 Mineral Nutrition of Host 234
5. Cyto- and Histopathology . . . . . . 234
6. Biochemical Changes in Infected Tissues 240
7. Remarks on Breeding for Resistance 241
References . . . . . . . . . . . . . . 242
XII Contents
4. Forces by Which the Pathogen Attacks the Host Plant
4.1 Host-specific Toxins in Relation to Pathogenesis and Disease Resistance
R.P. SCHEFFER (With 1 Figure)
1. Introduction . . . . . . . . . . . . . .247
2. The Agronomic Background . . . . . . 248
3. Development and Use of Toxin Bioassays 250
4. Genetic Studies of the Toxin Problem . . 254
5. Isolation and Characterization of Toxins . 255
6. Comparative Effects of the Fungi and Their Toxins on Susceptible Cells and
Tissues . . . . . . . . . . . . . . 258
7. The Resistant Cell in Relation to Toxin 264
8. Summary 265
References . . . . . . . . . . . . . . 265
4.2 Non-specific Toxins
K. RUDOLPH (With I Figure)
I. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 270
2. Definitions. . . . . . . . . . . . . . . . . . . . . . . . . 271
3. Production of Phytotoxic Compounds in vitro by Plant Pathogens 272
4. Assay Systems for Phytotoxicity. . . . 274
5. Purification of Toxins . . . . . . . . 276
6. Lowest Effective Concentration or Doses 277
7. Chemistry of Phytotoxic Compounds. . 277
8. Mode of Action of Phytotoxic Compounds 283
9. Toxins in Relation to Pathogenesis . . 289
10. Biosynthesis and Degradation of Toxins . 294
11. Uses of Phytotoxic Compounds 295
12. Phytopathogens Which Produce Phytotoxic Compounds 296
13. Concluding Remarks 301
References. . . . . . . . . . . . . . . . . . . . . . 301
4.3 Degradation of Plant Cell Walls and Membranes by Microbial Enzymes
D.F. BATEMAN and H.G. BASHAM (With 6 Figures)
1. Introduction . . . . . . . . . . . . . . . . . 316
2. Structural Components . . . . . . . . . . . . 316
3. Enzymes Which Degrade Plant Structural Elements 321
3.1 Cell Wall Degradation . . . . . . . . . . . . 321
3.2 Membrane Degradation . . . . . . . . . . . 327
4. Relationships of Enzymatic Alterations of Structural Constituents to Pathogenesis 329
4.1 Alterations of Cell Wall Constituents . 330
4.2 Enzymatic Degradation of Membranes. 342
5. Summary and Additional Considerations. 344
References . . . . . . . . . . . . . . . . 345
4.4 Morphogenic Determinants as Exemplified by the Crown-gall Disease
1.A. LIPPINCOTT and B.B. LIPPINCOTT (With I Figure)
1. Introduction . . . . . . . . . . . . . . . . 356
1.1 Historical Background and Related Diseases 356
1.2 Gall Morphology and Structure . . . . . . 357
1.3 General Concepts . . . . . . . . . . .. 357
2. The Causal Agent . . . . . . . . . . . . . . 360
2.1 Taxonomic Relationships of the Agrobacteria 361
2.2 Agrobacterium Genetics . . . . . . . . . 362