Science

1. JAWAHARLAL NEHRU KRISHI VISHWAVIDHYALAYA,
JABALPUR (M.P.)
Seminar on :-
ENDOPHYTES WITH SPECIAL REFERENCE TO
FUNGI AND BACTERIA
Seminar Incharge:- Presented by:-
Dr.(Mrs.) Om Gupta Nisha kumari
M.Sc (Ag)
Plant pathology
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2. ENDOPHYTES with special
reference to Fungi and
Bacteria

3. Introduction
Endophyte means an organism, with “endo”
means “inside” and “phyte” means “plants”.
Fungi and bacteria are the most common
organisms associated with the term
endophyte.
An endophyte is an endosymbiont, often a
bacterium or fungus, that lives within a plant
for at least part of its life without causing
apparent disease.

4. Introduction
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Plants
Directly or indirectly
interactions
Mutualism
Parasitism

5. Endophytes
 All plants are infested with microbes
Symptomless
•Epiphytes/Endophytes
• Balanced status of symbiosis
Disease
• Pathogens
• Unbalanced status of symbiosis

6. Endoparasitic fungi found in grass species
(mycelium of fungal endophyte in a grass leaf)

7. Endophyte /Plant relationship
–Endophyte gains
• Shelter and Nutrients
–Plant cost
• Nutrients and Resources
– (eg. more susceptible to pests and diseases)
–Plant gains
• Growth Promotion
– (enhanced nutrient uptake)
• Increased Tolerance to harsh environments
– (eg. drought tolerance)
• Induced Resistance to Pests and Diseases

8. Endophytes
1.Ecological significance
2.Importance of the
microorganism in this habitat

9. Ecological Significance
Endophytic organisms associated with plants
are varied and complex.
Contribute to plant health.
Protect plants against biotic stresses.
Co-evolution may exist between endophytes
and their host in resist to environmental
stresses.
Endophytes have been targeted as valuable
sources of new bioactive compounds.

10. Physical environment
Endophytic microorganisms depend on the
nutrient supplied by host plants.
Physical factors
• affect indirectly (rainfall, temperature and UV
Radiation)
Soil physical and chemical factors
• affect indirectly (soil pH, salinity and soil texture)

11. Microbial Community
Fungi
 Every plant species is found to be at least host one
fungal Endophytes, but usually asymptomatic and
sometimes systemically.
 Endophytes of roots will initiate colonies by hyphal
extension from existing resources.
 Endophytes are transmitted horizontally and
vertically.
Eg.Neothyphodium and some related species
 Most aerial endophytes will be carried in the air
and colonise plant tissue directly.

12. Endophyte Life Cycle

13. Bacteria
Detected from inside surface-disinfested plants
or extracted from inside plants .
Have no visibly harmful
effects on the Plants
extracted from inside
plants .
Contribute to plant
growth with
rhizospheric bacteria.

14. Biological interactions
Every plant found so far associate with at
least one kind of endophytic microbes.
Variety of interactions are going on
ranging from microbe-host interaction to
microbe-microbe interaction.
Endophytes colonizing inside plant tissues
contribute to the fitness of host and in
return, they gain nutrient and protection
from the host.

15. Mycorrhizal roots and the associated networks of hyphae

16. Mycorrhizas produced by
fine Endophytes
Mycorrhizas produced by
Glomus species

17. Fungi-Host Interaction
 Found within the leaves and stems of plants.
 Systemic Endophytic fungi are able to produce
physiologically active alkaloids in host plant tissues.
 Nutrients are cycled between the host and fungus.
 Endophytic fungi are traditionally thought to
interact with host mutualistically.
 The endophytic fungus gains a protected and long-
lived environment in which nutrients are readily
available.
 Plant tissues remain entire and functional.

18. Bacteria-Host Interaction
In general endophytic bacteria occur at lower
population densities than rhizospheric bacteria
or bacterial pathogens.
Endophytic bacteria could be better protected
from biotic and abiotic stresses than rhizospheric
bacteria.
Obligate or facultative
Endophytic bacteria living with in plant tissue as
biotrophic symbionts.
Enhance the nutrient ability and fix nitrogen for
plants.
Produce plant hormones necessary for bryophyte
development .

19. Endophyte - plant interaction

20. Endophytes - pathogen
Interactions
 Endophytic bacteria and fungi coexist with many other
microorganisms, such as virus, other bacteria and fungi.
 Competitions between endophytic bacteria and
pathogens are observed due to the limited nutrient
supply inside plant tissue.
 Bacteria colonizing the plant interior are able to improve
plant growth and suppress pathogen.
 Endophytic bacteria reducing the negative impact of plant
pathogen.
 Both endophytic fungi and bacteria produce antibiotic
agents.

21. Natural Products of Endophytes
 The bioactive natural products from endophytes are
promising resources for medicine, agriculture and
industry.
 Produce alkaloids raise plants’resistance to
environmental stress.
 Produce metabolite product which toxic to insect but
not to mammals.
Eg. Indole-3-acetic acid
 Produce extracellular hydrolyases establish resistance
mechanism against plant invasion.
 Produce a wide range of phytohormones, such as Auxins,
Cytokinins, and the Gibberellins .

22. Endophytic n2-fixing bacteria
 Rhizobia inside root nodules fix nitrogen, and export to
the leguminous plants.
 In root nodules, the bacteria infect, inhabit, and
construct a co-metabolic system with the legumes, so as
to form a well-developed symbiosis.
 Rhizobia that can become endosymbionts, reducing
atmospheric nitrogen into ammonia within nodules
formed on the roots of legume plants.
 N2-fixation processes also exist in some non-legumes
particularly sugar cane, rice and maize.
Eg. Azoarcus sp. strain BH72 with sugarcane
 The nitrogen fixation rate is relatively lower comparing
to legumes.

23. Symbiotic relationship

24. Endophytes in Biotechnology
 Interact with the host biochemically and genetically.
 Once they are established, other microorganisms would
offer less competition.
 In Genetically modified endophyte strains with genes for
fluorescent colors.
 In production of biofule.
 The anticancer properties of several secondary
metabolites from endophytes have been investigated
recently.
Eg.“Taxol” from Taxomyces andreanae and “Ergoflavin”
from endophytic fungi growing on the leaves of an
Indian medicinal plant Mimusops elengi.

25. Expression of nitrogenase genes by the endophyte
Azoarcus sp. strain BH72 inside rice roots.

26. Plant Yield and Growth Promotion
Enhanced nutrient/mineral availability and uptake
• Phosphate, nitrogen
Phosphate solubilization
Siderophore production
• Minerals made more bioavailable; solubilized by
siderophore
Osmotic adjustment
Stomatal regulation

27. Plant Health and Protection
Lessen/prevent effects of pathogens on
plants
• Fungal, bacterial, viral diseases less
harmful after inoculation of endophytes
• Endophytes trigger Induced Systemic
Resistance (ISR)
Immune-like response by plants

28. Benefits of Endophytes
Help to enhance the nutrient ability.
Control at low levels or doses.
Fix nitrogen for plants.
Increase resistant against pathogens.
Remove contaminants.
Promote plant growth and yield.
Produce anticancer compounds.
Help to produce biofule.

29.  Increasing resistance todrought, insect herbivores,
or fungal pathogens.
 Solubilize phosphate or contribute assimilable
nitrogen to plants.
 Produce plant growth regulators (PGRs),
siderophores and HCN.
 Increase host resistance to rust pathogens in wheat.
eg. Chaetomium globosum
 Reduce the feeding by aphids from leaves of cotton.
eg. Lecanicillium lecanii
 Reduces needle attack by borers.
eg. Rhabdocline parkeri

30. DISADVANTAGEs
Majority fungal endophytes, especially those
horizontal transmitted, do not show obvious
or show even no impact to the host growth
and resistance.
Produce some alkaloides which are used in
drugs and harmful to mammels.

31. Current Research
 Biofuel plants
Eg. Miscanthus and Switch grass ,
maize and sugar cane
 Antibiotic substence
Eg.Beauveria bassiana
and Lecanicillium spp.
 Rice endophyte metagenome
Eg. Azoarcus sp. strain BH72

32. THANK