Ebook: Microbial Activity in the Rhizoshere

The rhizosphere is a very complex environment in which the effects of the plant on soil microorganisms and the effects of the microorganisms on the plant are interacting and are interdependent. Plant root exudates and breakdownproducts attract microbes and feed them and, in turn, the plants often bene?t from the microbes. Interactions among microorg- ismsandplantrootsareessentialfornutritionalrequirementsoftheplant. Plant growth, development and productivity are largely dependent on the soil environment in the root region rhizosphere. The new techniques of studying the rhizosphere enables us to get a much better understanding of the dynamics of the rhizosphere population, such rhizosphere studies beingofinteresttoagriculturists,soilbiologists,chemists,microbiologists andmolecularbiologists. The rhizosphere microbes in?uence the root environment in several ways. They may change the oxidation-reduction potential, in?uence the availabilityofmoistureandnutrients,producegrowthinhibitingorgrowth promoting substances in the form of exudates, provide competition and possiblyinducemanyothereffects.Mycorrhizalassociationsarebene?cial in mineral uptake and in increasing root surface area for effective ion absorption. Antagonism,competitionandsynergisminsoilandtherhizoplane(r- zosphere) are the most important microbial interactions to consider in the study of rhizosphere biology. With the growing information on the production of growth regulators, competitiveness of the microbes in the rhizosphere, microsymbionts, and other factors, their effect upon plant growth will become more evident. Experiments on the introduction of microbes or their products in the rhizosphere will help to improve our understandingofthebiologyoftherhizosphere.

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The rhizosphere is a very complex environment. The interactions among microorganisms and the plant roots are essential for the nutrition, growth and productivity of the plant. On the other hand, the microorganisms also benefit from their interactions with the plant. Rhizosphere studies are of interest to agriculturists, soil biologists, chemists, microbiologists and molecular biologists.

Microbial Activity in the Rhizosphere will be useful to the beginner as well as to experienced scientists. It starts with contributions dealing with the basic concepts in rhizosphere biology and the techniques used in these studies. Further topics include the bacterial community composition, rhizosphere of arbuscular mycorrhizal roots, significance of AM fungi in relation to form and functioning of the root system, the role of microsymbionts in plant growth and health, and the impact of rhizosphere environment on pre-infection behaviour of Oomycetous plant pathogens like Aphanomyces, Phytophthora and Pythium.

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The rhizosphere is a very complex environment. The interactions among microorganisms and the plant roots are essential for the nutrition, growth and productivity of the plant. On the other hand, the microorganisms also benefit from their interactions with the plant. Rhizosphere studies are of interest to agriculturists, soil biologists, chemists, microbiologists and molecular biologists.

Microbial Activity in the Rhizosphere will be useful to the beginner as well as to experienced scientists. It starts with contributions dealing with the basic concepts in rhizosphere biology and the techniques used in these studies. Further topics include the bacterial community composition, rhizosphere of arbuscular mycorrhizal roots, significance of AM fungi in relation to form and functioning of the root system, the role of microsymbionts in plant growth and health, and the impact of rhizosphere environment on pre-infection behaviour of Oomycetous plant pathogens like Aphanomyces, Phytophthora and Pythium.

Content:
Front Matter....Pages I-XVI
Rhizosphere Biology – an Overview....Pages 1-15
Methods and Techniques for Isolation, Enumeration and Characterization of Rhizosphere Microorganisms....Pages 17-38
Root Exudates as Determinant of Rhizospheric Microbial Biodiversity....Pages 39-53
Rhizosphere Microbial Community Dynamics....Pages 55-69
The Role of Rhizotrons and Minirhizotrons in Evaluating the Dynamics of Rhizoplane-Rhizosphere Microflora....Pages 71-87
Significance of Bacteria in the Rhizosphere....Pages 89-119
Interactions Among Beneficial Microorganisms....Pages 121-137
Bacterial Community Composition and Activity in Rhizosphere of Roots Colonized by Arbuscular Mycorrhizal Fungi....Pages 139-154
Mycorrhizosphere Concept....Pages 155-172
Molecular Techniques for Understanding the Microbial Community Structure in Mycorrhizosphere....Pages 173-198
Arbuscular Mycorrhizal Fungi and the Formand Functioning of the Root System....Pages 199-222
Fungal Recognition Responses to Host Derived Signals by Arbuscular Mycorrhizal Fungi....Pages 223-243
Interactions Between Ectomycorrhizal Fungi and Rhizospheric Microbes....Pages 245-263
Role of Beneficial Microsymbionts on the Plant Performance and Plant Fitness....Pages 265-296
Bacteria Helping Mycorrhiza Development....Pages 297-310
Rhizosphere Regulation of Preinfection Behavior of Oomycete Plant Pathogens....Pages 311-343
Back Matter....Pages 345-349

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The rhizosphere is a very complex environment. The interactions among microorganisms and the plant roots are essential for the nutrition, growth and productivity of the plant. On the other hand, the microorganisms also benefit from their interactions with the plant. Rhizosphere studies are of interest to agriculturists, soil biologists, chemists, microbiologists and molecular biologists.

Microbial Activity in the Rhizosphere will be useful to the beginner as well as to experienced scientists. It starts with contributions dealing with the basic concepts in rhizosphere biology and the techniques used in these studies. Further topics include the bacterial community composition, rhizosphere of arbuscular mycorrhizal roots, significance of AM fungi in relation to form and functioning of the root system, the role of microsymbionts in plant growth and health, and the impact of rhizosphere environment on pre-infection behaviour of Oomycetous plant pathogens like Aphanomyces, Phytophthora and Pythium.

Content:
Front Matter....Pages I-XVI
Rhizosphere Biology – an Overview....Pages 1-15
Methods and Techniques for Isolation, Enumeration and Characterization of Rhizosphere Microorganisms....Pages 17-38
Root Exudates as Determinant of Rhizospheric Microbial Biodiversity....Pages 39-53
Rhizosphere Microbial Community Dynamics....Pages 55-69
The Role of Rhizotrons and Minirhizotrons in Evaluating the Dynamics of Rhizoplane-Rhizosphere Microflora....Pages 71-87
Significance of Bacteria in the Rhizosphere....Pages 89-119
Interactions Among Beneficial Microorganisms....Pages 121-137
Bacterial Community Composition and Activity in Rhizosphere of Roots Colonized by Arbuscular Mycorrhizal Fungi....Pages 139-154
Mycorrhizosphere Concept....Pages 155-172
Molecular Techniques for Understanding the Microbial Community Structure in Mycorrhizosphere....Pages 173-198
Arbuscular Mycorrhizal Fungi and the Formand Functioning of the Root System....Pages 199-222
Fungal Recognition Responses to Host Derived Signals by Arbuscular Mycorrhizal Fungi....Pages 223-243
Interactions Between Ectomycorrhizal Fungi and Rhizospheric Microbes....Pages 245-263
Role of Beneficial Microsymbionts on the Plant Performance and Plant Fitness....Pages 265-296
Bacteria Helping Mycorrhiza Development....Pages 297-310
Rhizosphere Regulation of Preinfection Behavior of Oomycete Plant Pathogens....Pages 311-343
Back Matter....Pages 345-349
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