Symbiotic Relationship between Fungi

1. SYMBIONTIC
RELATIONSHIP
DR. JUVERIA SAMAR

2. CONTENTS
LICHENS
• What is Lichens?
• Components
• Occurrence
• Thallus
• Reproduction
MYCORRHIZA
• What is mycorrhiza
• Types of mycorrhizae
• Ectomycorrhiza
• Endomycorrhiza
• Importance

3. LICHENS

4. What is Lichens ?
• Association of an algae and a fungus
• According to international association of Lichenology define as
“A Lichens is an association of a fungus and a photosynthetic symbiont, resulting in a
stable thallus of specific structure.”
• In 1983 Dictionary of fungi may defined as
“A stable self supporting association of a mycobiont and phoobiont”

5. COMPONENTS
LICHENS
MYCOBIONT
Ascomycotina
[COMMON)
Basidiomycotina
[UNCOMMON)
Deuteromycotina
[RARE]
PHOTOBIONT/
PHYCOBIONT
Cyanophyceae
[BLUE-GREEN ALGAE]
Chlorophyceae
[GREEN-ALGAE]

6. OCCURRENCE
•
CORTICOLOUS: bark of tree,
Usnea, Parmelia
LIGNICOLOUS: develop on
wood, e.g. Calicicum,
Cyphelium
SAXICOLOUS: rocky substrata,
Dermatocarpon, Xanthora
TERRICOLOUS: grow on
ground, e.g. Collema tenax,
Cladonia floerkeana

7. Leprose
Crustose
Crustose
Foliose
(homolomerous)
Foliose
(Heteromerous)

8. THALLUS
LEPROSE LICHENS
• Fungal hyphae envelop either small or cluster of algal cell
• Powdery appearance
CRUSTOSE LICHENS
• Adhere to substratumand provide crust like appearance, photobiont are covered by distinct layer of fungal layer.
• Outer surface is smooth
FOLIOSE LICHENS
• Flat, leaf like well branched lobed attached to the substratum with rhizoid called rhizines crinkled and twisted leaves
shapes
• Separate upper cortex, followed by algal layer and thick medulla, well organized lower cortex.
FRUTICOSE LICHENS
• Well branched, generally erect structure provide shruby appearance e.g. Usnea
• Heteromerous structure internally, thick outer cortex, and specialized central elastic axis
FILAMENTOUS LICHENS
• Lichens thallus is dominated by algae
• Coenogonium, Ephebe, Racodium genra have ensheathed or covered by few fungal hyphaewith having a well developed
filamentous algal partner

9. REPRODUCTION
VEGETATIVE
FRAGMENTATION
ISIDIUM
SOREDIUM
A SEXUAL CONIDIA
OIDIA
SEXUAL ASCOGONIUM
SPERMATIUM
ASCOCARP

10. VEGETATIVE
FRAGMENTATION: Foliose & fruticose lichens break into small
fragments.
ISIDIUM: Small corticated outgrowths, made up of fungal hyphae
and algal cells situated on upper side of thallus. Isidia are smooth,
corticated coral petal like outgrowth. e.g. Parmelia
SOREDIUM : Soredia are small, non corticated, bud like powdery
masses outgrowth made up of only a few algal cell surrounded by as
few fungal hyphae. Entire upper surface or in special pustle like area
called soralia. e.g. Bryoria.

11. A SEXUAL REPRODUCTION
• CONIDIA :
• E.g. Rocella, Cladonia
• OIDIA:

12. ASCOGONIUM
• Hyphae situated deep in the algal
layer.
• Ascogonia are multicellular, lower
portion is coiled.
• Upper portion of ascogonium
above the level of cortex.
• Such projected portion reprersent
trichogyne.
SPERMATIUM
• Conidia produced in pycnidia also
function as male cells
• Such conidia with a sexual function
are called spermatia
ASCOCARP
• Ascogenous hyphae develop from
basal portion of ascogonium.
• Freely branched ascogenous
hyphae develop the asci.
• 2 nuclei of ascus cell fuse to form
diploid nucleus.
SEXUAL REPRODUCTION

13. ECONOMIC IMPORTANCE
• BIOCHEMICAL WEATHERING : crustose lichens , secreation of organic acids, oxalic acid
• PEDOGENESIS: honey comb like structure on rocks, disintegration of rocks into soil particles
• NATURAL PRODUCTS : 550 natural products, Salazinic acid, squamatic acid, usnic acid
• DRUGS: 1. Usnic acid: antibiotic products , effective against gram positive bacteria
2. Erythrin: angina treatment, from Roccella montagnei
3. Evosin: well known for tumor inhibiting
• PERFUMES: Pseudevernia furfuracea widely used in perfume industry.
• DYES: Red & purple dye obtained from Ochrolechia androgyna
• FOODS: Cladonia raniferina serve as food in tudra region for many animals reindeer
• POISION: Letharia vulpine (wolf moss) used as poison for wolf

14. MYCORRHIZA

15. What is mycorrhiza?
• Greek μύκης mýkēs, "fungus", and ῥίζα rhiza, "root“
• Symbiotic association between a fungus and a plant
• • Fungi gets carbohydrates from plants
• • Plant gets nutrients from the soil with the help of mycorrhizae
• • Sometimes parasitic association
• • Mycorrhiza-like associations also occur in bryophytes

16. TYPES OF MYCORRHIZAE

17. ECTOMYCORRHIZA
• Plants : >6,000 (10 %)
• Ectomycorrhizal fungi includes
7750 species
• Estimated species are 20,000 -
25,000 (0.7%
• Up to 90% of the forest tree
species form ectomycorrhizal
• Mantle layer
• Hartig net
• Formed on the fine root tips of
the host
• Abundant in top layers of humus
rich soils
• Root morphology changes
• Root hair are absent

18. COMPONENTS
Epigeous fruiting bodies
MUSHROOMS
Hypogeous fruiting bodies
TRUFFLES
ER Morphotypes various
shapes
MORPHOTYPES

24. Nomenclature of Ectomycorrhiza
• Characterization is based on morphological features
– Structure of morphotype
– Mantle layer type
– Emanating hyphae
– Cystidia
• Generic name was based on host
• Specific epithet according to plant nomenclature
• Not followed due to advent of molecular techniques

25. Formation of Ectomycorrhiza
• Hyphal contact to the root
• Mycelial proliferation
• Hyphal penetration between epidermal cells
• Occurrence of active mycorrhizal zone
• Formation of storage structures and propagules

26. Groups involved
FUNGI
• Basidiomycota
• Gomphales
• Thelephorales
• Boletales
• Agaricales
– Amanitaceae
– Cantharellaceae
– Cortinariaceae
– Inocybaceae
– Russulaceae
– Tricholomataceae
• Ascomycota
• Ascomycetes
- Pezizales
• • Mucormycota
• Endogonaceae
-Endogone
PLANTS
• Dipterocarpaceae
• Fagaceae
• Myrtaceae
• Pinaceae
• Salicaceae

27. Ectomycorrhizal Pakistani species
Amanita pakistanica Tulloss, S. H. Iqbal &
Khalid Boletus himalayensis Jabeen, S.
Sarwar & Khalid
Hortiboletus rubellus (Kromb.)
Simonini, Vizzini & Gelardi
Peziza succosella (Le Gal &
Romagn.

28. ENDOMYCORRHIZA
Fungus penetrates the cortical
cells of the roots
• Mostly found in field crops
•Also called
– Arbuscular mycorrhiza (AM)
– Vesicular arbuscular
mycorrhiza (VAM)
• Components
– Soil hyphae
– Spores
– Auxillary bodies
– Arbuscules
– Vesicles

31. ANATOMY

32. Formation of endomycorrhiza
• Hyphae respond to the root and establish contact
• Root penetration occurs between adjacent epidermal cells and penetrate these cells
• One or more hyphae manage to penetrate the hypodermis
• Aseptate hyphae spread along the cortex in both directions
• Arbuscules grow within cortex cells
• Vesicles develop to accumulate storage
• In later stages, arbuscules collapse and hyphae in the root cortex develop crosswalls in
old associations

33. TYPES OF MYCORRHIZA
Arbuscular
Ericoid Orchid
Arbutoid Monotropoid

35. Arbuscular mycorrhiza
• Hyphae penetrate plant cells
• Form vesicles and arbuscules
• Arbuscules increase surface area for
absorption
• Formed by members in Glomeromycota
• 85% of all plant families, and occur in many
crop species
• Appeared 400-460 million years ago
• Fungi produce the glycoprotein glomalin
• Mostly reproduce by asexual means

36. Monotropoid mycorrhiza
• Occurs in Monotropoideae and members
of Orchidaceae
• Plats are achlorophyllus
• They are heterotrophic or mixotrophic
• Non-mutualistic, parasitic type of
mycorrhizal symbiosis

37. Arbutoid mycorrhiza
• Host plants belong to Ericaceae
(Arbutoideae)
• Resembles to ectomycorrhiza
• Forms a mantle layer
• Hyphae penetrate into the root
cells

38. Orchid mycorrhiza
• Formed by members of Orchidaceae
• All orchids are mycohetrotrophs at some
stage
• Orchid seeds lack endosperm
• They form association with fungus present
in the soil
• Fungal partner belong to basidiomycete
fungi
• Hyphae penetrate into the root cells and
form coils for nutrient exchange

39. Ericoid mycorrhiza
• Intracellular hyphae make dense coils
• Restricted to outermost layer of root cells.
• There is no intercellular and extracellular
phase
• Hyphae do not extend very far into the
surrounding soil
• They might form sporocarps
• Fungi also have saprotrophic capabilities

40. IMPORTANCE
ECTOMYCORHIZA
• Tree survival
• Fungal life cycle
• Nutrient acquisition
• Protect against root diseases
• Mitigate the effect of abiotic stresses
• Help to increase forest cover
• Functioning and maintenance of
biodiversity
ENDOMYCORRHIZA
• Obligatory for geminating seed
(Rhizoctonia repens)
• P-deficient soils needs inoculation of VAM .
• First tree invaders as wastelands and
pioneers in barren lands
• Root colonization's provide protection
• Crops like onion, strawberry depends on
mycorrhiza in absence of P
• Help in uptake of mineral