The document discusses the rhizosphere and phyllosphere, emphasizing the microbial activity, types of organisms, and their roles in plant growth. It describes the chemical substances in root exudates that enhance microbial proliferation, as well as the effects of environmental factors on these communities. The conclusion highlights the ecological and economic significance of studying these habitats and their contributions to biogeochemical cycles.

1. SHRI SHANKARACHARYA
MAHAVIDYALAYA, JUNWANI,BHILAI
TOPIC:- RHIZOSPHERE & PHYLLOSPHERE
Dr. Rachana Choudhary
Asstt. Prof. Department of Microbiology

2. SYNOPSIS
 Introduction on Rhizosphere
 Reasons of increased Microbial activity in Rhizosphere
 Type of Rhizosphere Region
 Rhizosphere Micro-organism
 Rhizosphere Effect
 Nitrogen Fixation In The Rhizosphere
 Alternation of Rhizosphere Microflora
 Introduction on phyllosphere
 Microbial Communities of Phyllosphere
 Phyllosphere Micro-organism
 Microbiology of Phyllosphere
 Modification of Phyllosphere Habitat
 Conclusion
 References 2

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4. INTRODUCTION
 The region of the soil around roots in which the
maximum microbial growth & activities operate is
called “Rhizosphere”.
 Root surface together with closely adhering soil
particles is called “Rhizoplane”.
 Soil which is not part of rhizosphere is called bulk
soil.
 The rhizosphere contains many bacteria that feed on
sloughed-off plants cells, termed rhizodeposition,
and the proteins and sugar released by roots.
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5. REASONS OF INCREASED MICROBIALACTIVITY IN
RHIZOSPHERE
 Accumulation of Organic & inorganic
Compounds
 Composition of Root Exudates
 Factors Affecting Exudation
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6. TYPE OF RHIZOSPHERE REGION
• Inner region
which is an closed vicinity of roots.
• Outer region
immediate adjacent soil.
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Sr.
No.
Root
Exudates
Chemical Substances
1. AminoAcids All naturally occurring amino acids.
2. Organic acids Acetic, Butyric, Citric, Fumaric, Lactic, Malic
Propionic, Succinic etc
3. Carbohydrates
sugars
Arabinose, Fructose,Galactose,Glucose, Maltose, Mannose,
Oligosaccharides, Raffinose, Ribose, Sucrose, Xylose etc.
4. Nucleic acid
derivatives
Adenine, Cystidine, Guanine, Uridine
5. Growth factors
(phytohormones)
Biotin, Choline, Inositol, Pyridoxineetc
6. Vitamins Thiamine, Nicotinic Acid, Biotin etc.
7. Enzymes Amylase, Invertase, Protease, Phosphatase etc
8. Other
Compounds
Auxins, glutamine,glycosides,hydrocyanic acid peptides,
Uv-absorbing compounds,nematode attracting factors,
spore germination stimulators, spore inhibitors etc.

9. RHIZOSPHERE MICRO-ORGANISMS
• Microbial population in the rhizosphere also have
pronounced direct & indirect effects on growth of plants
in different ways.
• Chief bacteria genera in rhizosphere are:-
Pseudomonas
Bacillus
Streptomyces
• Chief fungi genera are:-
• Trichoderma
• Penicillium
• Glioladium
• Fusarium
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10. RHIZOSPHERE EFFECT
 The term rhizosphere effect indicate overall influence of
plants roots on soil micro-organism.
 Compared to non-rooted bulk soil , the rhizospheric soil
around the plant root contains much larger population of
microorganism.
 A stimulation that can be put on a quantitative basis by
the use of the R：S ratio
 Where
R number of microorganisms in the rhizosphere soil
S number of microorganisms in the non-rhizosphere soil.
R/S > 1, Good stimulation
R/S = 1, No stimulation
R/S < 1, Inhibition 10

11. Factors Affecting Microbial Flora of the Rhizosphere /
Rhizosphere Effect
A. Soil type and its moisture
B. Soil amendments and fertilizers
C. Soil PH/ Rhizosphere PH
D. Root / exudates /excretion
E. Proximity of root with Soil
F. Age of Plant
G. Plant Species
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12. NITROGEN FIXATION IN THE RHIZOSPHERE
• With the advent of acetylene reduction technique,
it has been possible to measure nitrogenase
activity in the rhizosphere.
• This fixation is a cumulative effect of
Rhodopseudomonas, BGA, both free living as
well as symbiotic.
• It is also now known that nitrogen fixing bacteria
occurs in rhizosphere stalk & phyllosphere of
sugarcane plants.
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13. • Following nitrogen fixing bacteria have been
isolated from roots region of sugarcane:-
 Azotobacter
 Enterobacter
 Azospirillum
 Bacillus
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14. ALTERATION OF RHIZOSPHERE MICROFLORA
• There are the reports of changes in the
rhizosphere micro flora by:-
• Soil amendments
• Foliar application of nutrients
• Artificial inoculation of seed or soil with
preparation containing live micro-organism
specially bacteria.
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16. INTRODUCTION
• The phyllosphere is termed used in microbiology to
refer to the total above-ground portions of plants as
habitat for micro-organism.
• The phyllosphere can be further sub-divided in to the
• Caulosphere(stems)
• Phylloplane(leaves)
• Anthosphere(flowers)
• Carposphere(fruits).
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17. MICROBIAL COMMUNITIES OF
PHYLLOSPHERE
• The microbial communities of phyllosphere are
diverse and include many different genera of
bacteria, filamentous fungi, yeast, algae & less
frequently protozoa and nematodes.
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18. PHYLLOSPHERE MICRO-ORGANISM
• The common genera of bacteria are:-
• Pseudomonas
• Bacillus
• Erwinia
• Some of the fungi are:-
• Aspergillus
• Actinomycetes
• Streptomyces
• Trichoderma
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19. MICROBIOLOGY OF PHYLLOSPHERE
• Phyllosphere microbiology has focused on leaves,
a more dominant aerial plant structure.
• Bacteria are by far the most numerous colonies of
leaves.
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20. MODIFICATION OF PHYLLOSPHERE
HABITAT
• Alteration of plant surface properties.
Multiple physical & chemical factors limit
bacterial growth and survival in the phyllosphere.
• Cell-Density Dependent modification.
• Plant-microbe interaction.
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21. CONCLUSION
• The concept of the rhizosphere has been
significant to ecological, biological,
agronomical, and forestry science.
• The phyllosphere is both scientifically &
economically an important habitat in which to
study microbial ecology.
• Epiphytes are involved in processes in large
scale as the carbon cycle and the nitrogen cycle.
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22. REFERENCES
• Microbiology By Dubey & Maheshwari.
• Microbiology By R. P. Singh
• Soil Microbiology By N.S. Subba Rao
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