This document summarizes symbiotic associations between lichens, mycorrhizal fungi, and plants. It discusses the structure and morphology of lichen thalli composed of a fungal mycobiont and photosynthetic photobiont. Mycorrhizae form associations between fungi and roots of 90% of plant species. There are three main types of mycorrhizae - ectomycorrhizae, endomycorrhizae, and ectendomycorrhizae - which differ in how the fungal hyphae interact with the plant roots. Lichens and mycorrhizal fungi provide benefits to plants like nutrient exchange and are important ecologically and for human

2. .
Teacher – Dr. Sarika Torawane Madam
SYMBIOTIC ASSOCIATIONS OF LICHEN
AND MYCORRHIZA AND THEIR
SIGNIFICANCE
BY
Sanket Dnyanoba Singapure

4. Contents ……..
1. Symbiotic Assosiation of lichen and their Significance ……
• Structure of thallus
• Morphology and anatomy of Lichen
• Reproduction in lichen
• Significance of lichen
2. Symbiotic Association of Mycorrhiza and their Significance …..
• Types of Mycorrhizae
• Ectomycorrhizae
• Endomycorrhizae
• Ectendomycorrhizae
• Significance of Mycorrhizae .

5. Symbiotic Associations Of Lichen
And Their Significance
• Lichens are the symbiotic organism composed of fungal
partner called mycobiont and one or more photosynthetic
partner called as photobiont , which is either algal or
cyanobacteria .
• Swiss botanist schwendener in 1968 discovered the dual
nature of lichen .
Lichens of arctic

6. • There are four parts of structure of thallus :
1. Cortex
2. photobiont : algal layer
3. Mycobiont
4. medulla

7. a . Cortex :
• Most of the Lichens are having both upper as
well as lower cortex .
• Similar to epidermis of leaf with varied
thickness and are tight structure of two types
of tissues .
• In foliose lichen lower cortex is well
developed .function of cortex is protection of
photobiont and medullar layer.
Cortex formation in plants

8. b. Photobiont : [
Algal Layer ]
• Nearly 40 genera of algae and cyanobacteria are reported as a
photobiont of lichens - out of which 25 genera of algae and 15
genera of cyanobacteria .
• Most common genera are Trebouxia , Trentepohlia , are belonging to
green alga and are eukaryotic in nature and Nostoc , belongs to
cyanobacteria .
• The main function of photobiont is photosynthesis , symbitic partner
establishment .
• The photobiont are multiply by mitosis and by aplanospore
formation .
• Sexual reproduction of photobiont is not observed in lichen
symbiosis.

9. C . Mycobiont
• Mycobionts are also called as lichen forming fungi ,
mycobiont belongs mostly to Ascomycota [98%]
rarely to Basidiomycota [0.3].
• Ecologically lichen forming fungi are obligate , but
physiologically they are facultative biotrophs .

10. D. Medulla
• Consist of loosely interwoven hyphae forming
weakly gelatinized and cottony layer with internal
spaces .
• Strengthen due to para or Plactenchymatous tissues
.
• This region generally produced lichen substances
and calcium oxalate crystal .
1. Function : Greater water holding , food storage
region , exchange of gases
Pith [ medulla ] formation and function in plants

11. • Thalli fasten to substratum and lower cortex developed attachment to the substrate .
• In crustose lichens a prothallus formed by Prosoplectenchymatous tissue around and below the
main thallus and established the attachment with substrate .
• In foliose lichens attachment to the substrate is by Prosoplectenchymatous hyphae called
Rhizines .
• In fruticose lichen , hyphae fasten to the substratum and attached to it by forming holdfast .
• Another type of attachment is cilia , fibrillar outgrowth emerging from margin , unbranched /
branched , simple and Bulbate .

12. • The varied morphology of lichen thallus is primarily determined by
peculiar structure and mycobiont , a very few lichens habit morphology is
determined by photobiont .
• Morphologically lichens are classified in to three main morphological
growth forms :
1. Crustose lichen
2. Foliose lichen
3. Fruticose lichens

13. 1. Crustose lichen :
• Thallus is tightly attached to the substrate with their lower surface .
• The thallus is either homoiomerous i.e. primitive type in which the
algal and fungal partner partners are forming distinct zone .
• Crustose lichens are generally endolithic and endophloeodic.
• Crustose lichen thallus producing areoles , is a polygonal part of
thallus containing both the symboionts .

14. • Partially attached to the surface of substrate , flattened leaf like
structure, flattened leaf like structure, dorsiventral, with distinct
upper and lower surface, either homoiomerous or
heteroiomerous .
• The margin is lobed and branching, two types of forms are
observed in foliose lichen, Lanciniate type of foliose lichen is
lobate, homoiomerous or heteromerous .
• The lower surface of thallus is attached to substrate by rhizines,
cilia to tomentum .
• Umbilicate type lichens unbranched single lobed, circular thalli
or multilobed thalli with limited branching patterns and
depressions on the upper side of thallus .
2. Foliose Lichen

15. • Vegetative Reproduction :
1. Simple Fragmentation : It is natural type where fragment of
thallus is detached from parent thallus and gives rise to new
thallii .
2. Bulbil Formation : parenchymatous globular multilayer
outgrowth having algal partners only can propagate in to
new thallii .

16. Vegetative Diaspore
1. Isidia :
• Isidia are formed on the upper surface of thallus simple, stalked,
cylindrical or branched outgrowth .
• Isidia is composed of both the partner algal and fungal partners covered
with cortex .
• Different shapes of isidia are observed in lichens .
• Under favourable condition, isidia gives rise to new substratum .
Different shapes of Isidia

17. 2. Soredium :
• Soredium formed small protuberance on the upper surface of thallus .
• Soredium is pustule like structure containing few algal cells surrounded by fungal hyphae .
• Under favourable condition sorelia developed in to new thallus on new substratum .

18. Sexual Organs :
• Carpogonium is a female reproductive structure developed coiled structure in the
medulla region and it form a tube which is growing upto the surface of thallus .
• The male reproductive structure is spermogonium which is flask shaped structure .
• The hyphae of spermogonium produced number of non-motile male gamete called
spermatium .
Sexual organs of lichen

19. Food :
• In india, some species of parmelia are used as curry powder or whole thallus used in food dishes such as gharam
masala, meat masala and sambar masala.
• Invertebrate such as termites, caterpillars,snails,slugs feed on some gelatinous lichen .
• Lichens like lecanora Saxicola and aspicilia calcarea etc. are used as food by snails, caterpillars,termites,slugs etc .
Fodder :
• Ramalina traxinea, R. fastigiate, Evernia prunastri, lobaria pulmonaria are used as fodder for animals, due to the
presence of lichenin,a polysaccharide .
• Most useful species for grazing are reindeer lichen such as cladonia rangifera and cl. Alpestris .
# The lichens are useful to human beings in various ways such as food , fodder,
used in industry , medicine and ecological importance .

20. Medicine :
• In Atharveda [ 1500 B.C. ] , first record of the use of a lichen , shipal
as a medicine .
• In india Charila lichen is widely used in ayurveda from ancient
system of medicine for various disease and disorders e.g. skin
diseases, urinary troubles,vomiting, heart trouble cough,fever etc.
• SHAILAYA and SHILAPUSHP are the Sanskrit names of species of
parmeloid lichens have been described in sushruta Samhita,
charaka Samhita and several Nighantu.
• Usnic acid active compound from usnea sp. Are good antimicrobial
effects against various fungal and bacterial pathogens .
• Lichens are modulating the cancer associated molecular
mechanisms leads to anticancer effects in various cancers .

21. The industrial uses are ……..
1. Brewery and Distillation
2. Preparation of dye
3. Litmus paper
4. Lichen In perfume

22. 1. Brewery and Distillation
The countries such as Russia and Siberia
used Lobaria pulmonaria in brewing of beer
.
Cladonia rangiferina produced 176-282cc of
alcohol per kg material .

23. 2. Preparation of dye :
• In Europe the lichen substances are the source of
dyes for cotton and wool .
• Roceella and Ochrolechia are the lichen
producing purple and red dyes .
• The yarn immersed in the mixture of purple and
red dye which is dissolved in human urine ,
ammonia salts in the urine functioned as
mordants to make permanent dye .

24. • It is an acid-base indicator prepared from
tinctorial property of lichen secondary
metabolite from different lichen like R. tinctoria
and Lecanora tartarea .
• Mixture of coloured compound is called as
chromogen , which under combine treatment of
ammonia and oxygen produced colour
component of litmus .

25. • In india,past 800 years a small town of Utter Pradesh called
Kannauj famous for perfume production, today also lichen is
used in the preparation of a perfume called Hina Attar .
• The species of Ramalina and Evernia are used for extraction of oil
and further used for cosmetic soap .
• Two combine lichens,Evernia are used for perfume industry
because of its sweet and mossy fragrance .
• In France, Morocco and South eastern Europe countries, these
two species are harvested in tons for perfume preparation .

26. # Lichenometry
• Lichenometry is a technique used to
determine the surfaces age by using size of
lichen colonies on the rock surface .
• Lichenometry is a dating technique useful
only 500 years approximately .
• The Rhizocarpon sp. And Xanthoria sp. Of
lichens are most commonly used for study of
lichenometry .
Study of lichenometry

27. Pollution tolerance and heavy metal homeostasis by Lichen
• Lichen secondary metabolites play a role in metal
homeostasis and pollution tolerance.
• Lichens are also used as a bio-indicators .
• Depends upon environmental conditions,lichens are
growing e.g. in clean air, leafy, hairy shruby lichens are
growing abundantly .
• In high pollution environment, lichens are not growing .
• Various studies showed that the level of lichen secondary
metabolites produced by lichen is depends on external
environment .

28. Lichen Substances :
• Lichen produced variety of secondary metabolites, also called
as lichen substances or lichen acid produced extracellularly by
mycobient .
• These compounds are deposited on hyphae within cortex or
medulla of thalli in amorphous or crystalline forms .
• The lichen produced lichen compounds by three important
pathways :
1. Shikimic acid pathway
2. Mevalonic acid pathway
3. Acetyl palymalonyl pathway
Bioactive Lichen Substances

29. SYMBIOTIC ASSOCIATIONS OF
MYCORRHIZA AND THEIR SIGNIFICANCE
• Symbiosis is a phenomenon of two or more dissimilar organism live together .
• There are different forms of the symbiosis observed in nature viz ., Mutualism and
Parasitism .
• Mutualism, both the partners are benefited from each other and parasitism, one of
the partners live at the expense of the other .

30. • The term `Mycorrhiza` was first comes from German researcher
and inverts from greeks .
• Mycos meaning fungus and rhiza meaning roots .
• German botanist, Frank, in 1885 discovered mycorrhizae, as a
mutualistic symbiotic beneficial, non-pathogenic association with
plant root .
• Mycorrhizas are located in the 90% of the roots of plants .
• The most common type arbuscular mycorrhizae is present in 70%
of crop plants like Wheat and Rice .

31. 1. Types of Mycorrhizae
• Mycorrhizae are commonly divided into six types :
A. Ectomycorrhiza
B. Vesicular arbuscular mycorrhiza
C. Ericoid mycorrhiza
D. Orchid mycorrhiza
E. Arbutoid mycorrhiza
F. Monotropoid mycorrhiza
• These six type of mycorrhizae divided in to the three main
classes :
i. Ectomycorrhizae
ii. Endomycorrhizae
iii. Ectendomycorrhizae
Types of Mycorrhizae

32. i. Ectomycorrhizae
• In this type of mycorrhizae, the fungus forms a fungal sheath around the roots and also enters into the roots
of the host plants and forming in the outer cortex, an intracellular net of hyphae called hertig net .
• The ectomycorrhizae found only in 3% of plant species, majority 90% of which are temperate forest trees .
• This type of association found by the members of Basidiomycota, Ascomycota and Zygomycota .
• The ectomycorrhizae are easily recognizeable .
• The fungal sheath gives a swollen and stumpy look .

33. • The whole root, including the apex of the root is often
surrounded by the fungal sheath, so there is not direct
contact between the young roots and the soil .
• Thus the sheath insulates the host from the soil and all
the minerals from the soil absorbed by the
mycorrhizal roots and pass through the sheath .
Ectomycorrhizae

34. • While the unaffected roots remain unbranched and short lived,
mycorrhizal roots by repeated branching, form a crowded cluster of swollen
persist for many more years .
• The fungus and the roots of host plants grow in an organized way .
• During the spring season some of the root apices grow out of the hyphal
sheath and extend beyond it .
• After the region of the cell division, the hypae from the inner sheath,
penetrate into the root cortical cells and producing network of hyphae
called Hertig net .
• But these hyphae never enter into the cortical cells .

35. 2. Endomycorrhizae
• The fungi in the endomycorrhizae invade the cells of
the root cortex, with a portion lying externally as a
loose mass of hyphae in the soil .
• Endomycorrhizas have been further divided in to three
classes :-
a. Arbuscular
b. Ericoid
c. Orchid mycorrhiza

36. Arbuscular mycorrhizae
• Arbuscular mycorrhizae are mycorrhizas whose mycelium enters in to the cells of host plant, producing the
balloon-like structure called vesicles and tree like structures called arbuscule for exchanging the nutrients .
• The fungal hyphae do not penetrate into the cell wall but invading the plasma membrane of the cell
• The arbuscules developed in the cell and established the bridge between the arbuscule hypha and the plasma
membrane of cell for transferring the nutrients .
• This type of plant fungus association is found in a wide range of plant including angiosperm, gymnosperm, and
pteridophytes, mosses etc .
• Arbuscular mycorrhizal fungi recently placed in a new phylum, Glomeromycota, with a presumed origin at least
460 million years ago .

37. This mycorrhiza formed the two characteristic structures in the root
cortex .
1] Arbuscules :- Dichotomously branched and bush like haustoria
structure called arbuscule . These are formed shortly after infection,
and these are later digested by host cell. Firstly the tips are eroded and
then whole arbuscule is degraded and digested .
2] Vesicles :- These are spherical and oval, and thick walled structures
formed terminally in the intercellular spaces on in the cortical cells.
Vesicles contain fat granules and serve as storage organ .

38. Ericoid mycorrhizae :-
• They are formed between ascomycetous fungi and family
of the plants Ericaceae and Epacridaceae .
• The important plant genera showing ericoid mycorrhizae
are Calluna, Erica, Rhododendron, and Viccinium .
• The fungus grows over the lateral root hairs and hyphae
penetrate the single layer of the cortical cells and fill them
with hyphal coils called peletones .
• The fungus can occupy 80% of total volume of colonised
roots .
• There are some evidence, the species of calluna and
vaccinium have very high tolerance to the some stresses .

39. Orchid Mycorrhiza :-
• These mycorrhizae formed between roots of plants
belongs to family Orchidaceae and fungal partners
belong to Basidiomycota and rarely in Ascomycota .
• These mycorrhizae lack external sheath, but hyphae
penetrate the soil around the infected roots .
• During the symbiosis, the fungus develops
structures called pelotons within the root cortex of
the orchid .
• Peloton has short life, it degenerates and digested
by orchid cells .
• Host plant growth and uptake of nutrients are
enhanced in mycorrhizal orchids .

40. 3. Ectendomycorrhizae
• Ectendomycorrhizae is a association of both
the type ecto and endomycorrhizal to the
roots .
• There are two type of Ectendomycorrhizae :-
1. Arbutoid mycorrhiza
2. Monotropoid mycorrhizae

41. • This type of association is formed between the members of
the plants families Ericaceae and pyrolaceae, of the order
Ericales and the fungi belonging with basidiomycota, that
are mainly species that form ectomycorrhizae with the
forest trees .
• There is well developed fungal sheath and hertig net in
between the outer cells .
• But it differs from ectomycorrhiza, where some of the
hyphae penetrate into the root cells and forming
ectendomycorrhizal association .

42. • One of the most important examples of
ectendomycorrhizae, is the mycorrhizal association
in the Monotropa indica, the Indian pipe which
grows on forest grounds under Fagas, Pinus,
Carpinus and other trees .
• Families belong to subfamily of Monotropoideae of
the Ericaceae some genera of Orchidaceae showed
this type of association .
• This is a non-mutualistic, parasitic type of
mycorrhizal symbiosis .

43. • In Monotropa, the fungus forms an external hyphal sheath
and the hertig net, one cell deep into the root cortex .
• It also formed invaginated structures called hyphal pegs,
inside the cortex cell .
• This look like transfer cell formed in a variety of plant species,
when there is need rapid short distance transport of minerals
.
• Bjorkaman, by using tracer carbon technique, proved that the
mycorrhizal fungus receives nutrients from the trees and
transfer the mycorrhizae .

44. Significance of mycorrhizae
1. Mycorrhizal association with plants established network of
hyphae within soil and hyphae access water and nutrients
from the soil and transport them to the plants . Plants
increase absorption area resulting in to increase the plant
root biomass .
2. Mycorrhizal hyphae absorb the nutrients especially
Nitrogen, Phosphate, Potassium and micronutrients and
delivered to plant roots. This helps the plant to better
growth performance .

45. 3. Mycorrhizal fungi increased the survival and
establishment at seedling and transplanting .
4. Mycorrrhizal fungi increased flowering and fruiting .
5. Mycorrhizal fungi improved the tolerance to various
biotic and abiotic stresses .
6. Mycorrhizal fungi maintain soil quality and water
holding capacity .

46. 7. Mycorrhizal fungi reduced the use of
fertilizers .
8. Mycorrhizal fungi improved crop quality and
yield .
9. Mycorrhizal fungi reduced the growth of
pathogen due to barrier effect of hyphae and
competitiveness .

47. Referance :-
1. cryptogamic botany book .
2. Braincart.com
3. Mycorrhiza.com
4. Lichen.in
5. http://www.davidmoore.org.uk/