This book deals with Plant Bacteriology/Phytobacteriology, which is a sub-discipline of Plant Pathology. Phytobacteriology deals with plant diseases caused by Phytopathogenic Procaryotes or plant pathogenic bacteria, their prevention and control. Some of these diseases, namely, bacterial wilt of solanaceous plants, soft rot of fleshy fruits and vegetables, bacterial blight of rice, fire blight of pome fruits, crown gall of plants, citrus canker, citrus huanglongbing, etc. This book will serve as a text book for UG and PG students from the discipline of Plant Pathology and Plant Bacteriology. It will also serve as a Reference book for research workers engaged in the discipline of Plant Pathology and Plant Bacteriology.

 Part One: GENERAL ASPECTS

1 Introduction
1.1. Phytobacteriology
1.2. Phytopathogenic procaryotes
1.2.1. Bacteria
1.2.1.1. Gram-negative bacteria having cell walls
1.2.1.2. Gram-positive bacteria having cell walls
1.2.1.3. Bacteria lacking cell walls
1.2.2. Archaea
1.3. Economic importance of phytopathogenic procaryotes
1.4. Historical review of plant bacteriology

2 The Procaryotic Cell
2.1. Size
2.2. Shape
2.3. Arrangement
2.4. Cell structure
2.4.1. Flagella and pili
2.4.2. Surface layers (capsule and slime layer)
2.4.3. Cell wall
2.4.3.1. Cell wall of Gram-positive bacteria
2.4.3.2. Cell wall of Gram-negative bacteria
2.4.3.3. Gram staining
2.4.4. Cytoplasmic (plasma) membrane
2.4.5. Cytoplasm
2.4.6. Ribosomes
2.4.7. Inclusion and storage products
2.4.8. Gas vesicles
2.4.9. Nucleoplasm (genophore)
2.4.10. Plasmids
2.4.11. Dormant forms
2.4.11.1. Spores
2.4.11.2. Cysts

3 Growth and Nutrition of Bacteria
3.1. Growth
3.1.1. Growth rate
3.1.2. Generation time
3.1.3. Growth curve of unicellular microorganisms
3.1.3.1. Lag phase
3.1.3.2. Log phase
3.1.3.3. Stationary phase
3.1.3.4. Decline phase
3.1.4. Measurement of growth
3.1.4.1. Cell count
3.1.4.1.1. Microscopic count
3.1.4.1.2. Colony count
3.1.4.2. Cell weight/mass
3.2. Factors affecting growth of bacterial cultures
3.2.1. Physical factors
3.2.1.1. Temperature
3.2.1.1.1. Psychrophiles
3.2.1.1.2. Psychrotrophs
3.2.1.1.3. Mesophiles
3.2.1.1.4 Thermophiles
3.2.1.1.5. Hyperthermophiles
3.2.1.2. Gaseous environment
3.2.1.2.1. Aerobes
3.2.1.2.2. Facultative anaerobes
3.2.1.2.3. Anaerobes
3.2.1.2.4. Microaerophiles
3.2.1.3. Hydrogen ion concentration (pH)
3.2.1.4. Water availability
3.2.1.5. Light
3.2.1.6. Nutritional factors (requirements)
3.2.1.6.1. Major elements
3.2.1.6.1.1. Carbon
3.2.1.6.1.2. Oxygen
3.2.1.6.1.3. Nitrogen
3.2.1.6.1.4. Hydrogen
3.2.1.6.1.5. Sulphur
3.2.1.6.1.6. Phosphorus
3.2.1.6.1.7. Metal ions
3.2.1.6.2. Trace elements
3.2.1.6.3. Growth factors
3.2.1.6.4. Carbon and energy sources
3.2.1.6.4.1. Photoautotrophs
3.2.1.6.4.2. Photoheterotrophs
3.2.1.6.4.3. Chemoautotrophs
3.2.1.6.4.4. Chemoheterotrophs

 4 Variation in Bacteria
4.1. Mutation
4.1.1. Selection
4.1.2. Screening
4.2. Recombination
4.2.1. Transformation
4.2.2. Conjugation
4.2.2.1. F+ ´ F– mating
4.2.2.2. Hfr conjugation
4.2.2.3. F' ´ F– mating
4.2.3. Transduction
4.2.3.1. Generalized transduction
4.2.3.2. Specialized or restricted transduction
4.3. Plasmids

5 Classification of Bacteria
5.1. Nomenclature code
5.2. Species
5.3. Classification
5.3.1. Classification of plant pathogenic bacteria
5.3.1.1. Pathovar concept
5.3.1.2. International Standards for Naming Pathovars of
Phytopathogenic Bacteria
5.3.1.3. Genera of phytopathogenic bacteria
5.3.1.3.1. Acetobacter
5.3.1.3.2. Acidovorax
5.3.1.3.3. Agrobacterium
5.3.1.3.4. Arthrobacter
5.3.1.3.5. Bacillus
5.3.1.3.6. Brenneria
5.3.1.3.7. Burkholderia
5.3.1.3.8. ‘Candidatus Liberibacter’
5.3.1.3.9. ‘Candidatus Phlomobacter’
5.3.1.3.10. ‘Candidatus Phytoplasma’
5.3.1.3.11. Clavibacter
5.3.1.3.12. Clostridium
5.3.1.3.13. Corynebacterium
5.3.1.3.14. Curtobacterium
5.3.1.3.15. Dickeya
5.3.1.3.16. Enterobacter
5.3.1.3.17. Erwinia
5.3.1.3.18. Gluconobacter
5.3.1.3.19. Herbaspirillum
5.3.1.3.20. Janibacter
5.3.1.3.21. Janthinobacterium
5.3.1.3.22. Leifsonia
5.3.1.3.23. Nocardia
5.3.1.3.24. Pantoea
5.3.1.3.25. Pectobacterium
5.3.1.3.26. Pseudoalteromonas
5.3.1.3.27. Pseudomonas
5.3.1.3.28. Ralstonia
5.3.1.3.29. Rathayibacter
5.3.1.3.30. Rhizobacter
5.3.1.3.31. Rhizobium
5.3.1.3.32. Rhodococcus
5.3.1.3.33. Samsonia
5.3.1.3.34. Serratia
5.3.1.3.35. Sphingomonas
5.3.1.3.36. Spiroplasma
5.3.1.3.37. Streptomyces
5.3.1.3.38. Xanthomonas
5.3.1.3.39. Xylella
5.3.1.3.40. Xylophilus

6 Genome Evolution of Phytopathogenic Procaryotes
6.1. Bacterial genome
6.2. Pathogenicity islands
6.3. Horizontal gene transfer
6.4. Gall-forming Pantoea agglomerans- a case study
6.5. Evolution in Streptomyces species
6.6. Xa. oryzae pv. oryzae- a case of rapid evolution

7 Fastidious Phytopathogenic Procaryotes: Their
Cultivation and Characterization, and Plant Diseases
Caused by Them
7.1. Fastidious phytopathogenic procaryotes
7.2. Phytoplasma
7.3. Spiroplasma
7.4. Fastidious phloem-colonizing bacteria
7.5. Fastidious xylem-limited bacteria

8 Interactions among Plant Pathogenic
Bacteria and Other Microorganisms
8.1. Soil inhabitants/invaders
8.2. Plant growth-promoting rhizobacteria
8.3. Phylloplane
8.4. Endophytes
8.5. Interaction between fungal and bacterial plant pathogens
8.6. Interaction between bacterial plant pathogens

8.7. Interaction between plant pathogenic bacteria and nematodes

8.8. Interaction between bacterial and viral plant pathogens

9 Bacteriophages

9.1. Definition

9.2. Types of phages

9.3. Classification of phages

9.4. Phage or lysogenic conversion

9.5. Replication of phages

9.5.1. Adsorption or attachment of phage to host cell

9.5.2. Transfer of phage nucleic acid into bacterial cell

9.5.3. Replication of phage nucleic acid and proteins

9.5.4. Assembly of phage particles

9.5.5. Release of phage particles

9.6. Uses of phages

9.6.1. Phage therapy

9.6.2. Use in food industry

9.6.3. Identification of bacteria

9.6.4. Detection of bacteria from substrate

9.6.5. Disease forecasting

9.6.6. Control of bacterial plant diseases

10 Host-pathogen Relationship

10.1. Gene-for-gene hypothesis

10.2. Avirulence genes

10.3. Recognition of Avr proteins of pathogens by the host plant

10.4. Hypersensitive response and pathogenicity genes

10.5. Harpins

10.6. Bacterial secretion systems

10.6.1. Type I secretion system

10.6.2. Type II secretion system

10.6.3. Type III secretion system

10.6.4. Type IV secretion system

10.6.5. Type V (autotransporters) and VI (two-partner secretion) secretion systems

10.7. Pathogen effectors

10.8. Quorum sensing

10.8.1. Ag. tumefaciens

10.8.2. Pe. carotovorum subsp. carotovorum

10.8.3. Ral. solanacearum

10.8.4. Pa. stewartii subsp. stewartii

10.9. Role of toxins, enzymes and auxins in plant disease development

10.9.1. Toxins

10.9.1.1. Tabtoxin

10.9.1.2. Phaseolotoxin

10.9.1.3. Tagetoxin

10.9.2. Growth regulators

10.9.3. Enzymes

10.9.3.1. Pectinases

10.9.3.2. Cellulases

10.9.4. Extracellular polysaccharides

11 Diagnosis of Bacterial Diseases of Plants

11.1. Diagnosis

11.2. Monoclonal antibodies

11.3. Flow cytometry

11.4. Genomic techniques

11.5. Enrichment techniques

12 Disease Management with Biocontrol Agents, Bacteriophages, Bacteriocins and Siderophores

12.1. Biological control

12.2. Plant growth-promoting rhizobacteria

12.3. Induced systemic resistance

12.4. Bacteriophages

12.5. Bacteriocins

12.6. Siderophores

Part Two: SPECIFIC PLANT DISEASES

13 Description of Plant Diseases

13.1. Bacterial blight of rice

13.2. Bacterial leaf streak of rice

13.3. Yellow ear rot of wheat

13.4. Bacterial stripe and black chaff of barley

13.5. Bacterial stalk rot of maize

13.6. Bacterial leaf stripe of maize

13.7. Stewart’s wilt of corn

13.8. Red stripe of sugarcane

13.9. Ratoon stunting disease of sugarcane

13.10. Gummosis of sugarcane

13.11. Leaf scald of sugarcane

13.12. Bacterial wilt of solanaceous plants

13.13. Soft rot of fleshy vegetables and fruits

13.14. Blackleg of potato

13.15. Common scab of potato

13.16. Ring rot of potato

13.17. Black rot of crucifers

13.18. Bacterial spot of tomato and pepper

13.19. Bacterial canker of tomato

13.20. Bacterial speck of tomato

13.21. Bacterial blight of pea

13.22. Bacterial wilt of cucurbits

13.23. Angular leaf spot of cucurbits

13.24. Bacterial blight of cotton

13.25. Common and fuscous blights of bean

13.26. Halo blight of bean

13.27. Bacterial brown spot of bean

13.28. Soybean pustule

13.29. Bacterial blight of soybean

13.30. Bacterial blight of cowpea

13.31. Bacterial leaf spot of green gram

13.32. Halo blight of green gram

13.33. Bacterial leaf spot of black gram

13.34. Bacterial blight of moth bean

13.35. Bacterial blight of clusterbean

13.36. Bacterial leaf spot of hyacinth bean

13.37. Bacterial leaf spot and stem canker of pigeon pea

13.38. Bacterial blight of sesame

13.39. Bacterial leaf spot of sesame

13.40. Crown gall of plants

13.41. Hairy root of apple

13.42. Fire blight of pome fruit trees

13.43. Citrus canker

13.44. Citrus huanglongbing

13.45. Citrus stubborn disease

13.46. Bacterial canker and gummosis of stone fruit trees

13.47. Bacterial canker of mango

13.48. Pierce’s disease of grapevine

13.49. Bacterial canker of grapevine

13.50. Bacterial canker of kiwi

13.51. Bacterial blight of mulberry

13.52. Angular leaf spot of peepal

Index

Coloured Photographs of Symptoms of Plant Diseases