Screening,Identification,Characterization and Exploration of Antibiotic Potential of Volatile Compounds Produced by Endophytic Bacillus Species Against Necrotrophic Phytopathogen Sclerotinia Sclerotiorum

目录

声明

Table of Contents

List of acronyms

ABSTRACT

摘要

CHAPTER 1 Research background

1．2 Endophytic bacteria

1．2．1 Production of Hpopeptides

1．2．2 Extracellular products

1．2．3 VOCs production and their antibiotic potential

1．2．4 Functions of bacterial volatiles

1．2．5 Influence of bacterial volatiles on fungi physiological functions

1．3 Necrotrophic phytopathogens

1．3．1 Economic impact of diseases caused by necrotrophic pathogens

1．3．2 Disease cycle and epidemiology of S．sclerotiorum

1．3．3 Infection strategies of S．sclerotiorum

1．3．4 The role of toxins and necrosis-inducing proteins secreted by necrotrophic pathogens

1．4 Aims and objectives of the study

1．4．1 Specific objectives generated from the main objective of the study

References

CHAPTER 2 Endophytic Bacillus species produce metabolites which mediate inhibitory activity against Sclerotinia sclerotiorum

2．1 Abstract

2．2 Introduction

2．3 Material and methods

2．3．1 Strains culture growth and seeds procurement

2．3．2 Bacterial isolation

2．3．3 Antibiotic activity of secondary metabolites produced by Bacillus endophytes

2．3．4 Biochemical characterization and antibiotic sensitivity of Bacillus endophytes

2．3．5 Molecular identification of endophytie bacteria

2．3．6 MALDI-TOF Analysis

2．3．7 Data analysis

2．4 Results

2．4．1 Secondary metabolites mediated antifungal activity against S．sclerotiorum

2．4．2 Phenotypic and biochemical characterization of bacterial endophytes

2．4．3 Molecular identification and phylogeny trend of bacterial endophytes

2．4．4 Lipopeptides detection by MALDI-TOF analysis

2．5 Discussion

2．6 Conclusion

References

CHAPTER 3 Volatile organic compounds of endophytic Bacillus spp·have biocontrol activity against Sclerotinia sclerotiorum

3．1 Abstract

3．2 Introduction

3．3 Material and methods

3．3．3 GC-MS analysis

3．3．4 Effects of Bacillus VOCs on sclerotia production，viability，and development

3．3．5 Antifungal activity of synthetic chemicals on S．sclerotiorum

3．3．6 Reactive oxygen species accumulation

3．3．7 SEM and TEM analysis

3．3．8 Virulence and pathogenicity assays on detached leaves

3．3．9 Medium acidification assays

3．3．10 Temperature stability for inhibitory activity of endophytic Bacillus spp．against S．sclerotiorum

3．3．11 Data analysis

3．4 Results

3．4．1 Effect of bacterial VOCs on fungal mycelia growth

3．4．2 Sclerotia production was affected by Baciilus endophytes VOCs

3．4．3 Antibiotic activity pure chemical volatiles on S．sclerotiorum

3．4．4 Analysis of ROS induction

3．4．5 Morphological and ultrastructural damage in S．sclerotiorum hyphae

3．4．6 Pathogenicity test OR host-plant leaves

3．4．7 Bacterial volatiles lowered OA produced by S．sclerotiorum

3．4．8 Temperature stability of bacterial VOCs in controlling S．sclerotiorum

3．5 Discussion

3．6 Conclusion

References

APPENDICES

PUBLICATIONS

ACKNOWLEDGEMENTS