Lecture 7b: Fungal Ecology

Question 1

How do decomposing fungi spread?

Answer 1

• spore
• scelortia
• mycelia

Question 2

Mycelial cords

Answer 2

Aggregations of predominantly parallel, longitudinally aligned hyphae

Question 3

Short-range branching patterns of mycelium

Answer 3

Dense hyphae and mycelia

Question 4

Long-range branching patterns of mycelia

Answer 4

When a new recourse is encountered there is a reallocation of mycelia biomass

Question 5

‘Sit-and-wait’ strategy

Answer 5

Waits for leaves and branches to fall on the network

Question 6

‘Active-search’ strategy

Answer 6

Grow from one leaf to the next

Question 7

Foraging strategies vary among species and can alter depending on:

Answer 7

• Resource quantity and quality
• Presents of other organisms
• Microclimatic conditions

Question 8

Fungal spores and/or mycelia will colonise, establish and grow until:

Answer 8

• Outcompeted by another fungus
• Encounter adverse abiotic conditions
• Used the available resources

Question 9

Abiotic conditions

Answer 9

Fungi alter the physical and chemical properties of the environment; they metabolise the resource and alter the chemistry of wood which leads to a change in pH and the water content

Question 10

Exploitatoin competition

Answer 10

They use up the resources

Question 11

Interference competition

Answer 11

Inhibit access

Question 12

Competition at a distance VOCs

Answer 12

Volatile organic compounds can act over greater distances

Question 13

Competition at a distance DOCs

Answer 13

Diffusible organic compounds accumulate and diffuse through the substrate

Question 14

What do VOCs and DOCs do?

Answer 14

They can alter sporulation, mycelia morphology and enzyme production of its target species

Question 15

Mycoparasitism

Answer 15

One mycelia gains nutrition from another mycelium

Question 16

Necrotrophy

Answer 16

Cause death of the mycelia and utilise nutrients from dead or decaying hyphae

Question 17

Biotrophy

Answer 17

Derive nutrients from living mycelia

Question 18

Non-invasive necrotrophs

Answer 18

Grow close to host hyphae which they attack by secreting nonenzymatic diffusible toxins

Question 19

Result of non-invasive necrotrophs on the host hyphae

Answer 19

• Loss of membrane function
• Lysis of organelleses
• Deaths of hyphal compartments
• Multiple contacts= whole mycelia die

Question 20

Invasive necrotrophs

Answer 20

Coil around and penetrate host hyphae and produces antifungal

Question 21

Results of invasive necrotrophs on the host

Answer 21

• Lysis of hyphal walls and organelles
• disrupts host cytoplasm

Question 22

Intracellular biotrophs

Answer 22

• entire thallus enter and develop within host cells
• obtain nutrients directly from the cytoplasm

Question 23

Haustoria biotrophs

Answer 23

• Penetrate host cell by production of appresoria
• Develop abortive branches that invades the host plasma membrane

Question 24

Fusion or contact biotrophs

Answer 24

Specialised hyphae forms channels of microspores in the cell wall that absorbs nutrients

Question 25

Gross mycelium contact

Answer 25

A way in which mycelium maximise territory by replacing other mycelium and defending themselves from replacement

Question 26

Hyphae stained with CMFDA

Answer 26

This accumulates in fungal vacuoles and shows as bright green fluorescence

Question 27

Hyphae treated with Cellufluor

Answer 27

This binds to chitin in fungal walls and fluoresces blue

Question 28

Hyphae stained with Dil and DiO

Answer 28

Give green or red fluorescence of fungal membranes

Question 29

Hyphae stained with CMAC

Answer 29

Give blue fluorescence of the vacuoles

Question 30

Hyphae stained with Nile red

Answer 30

Show intense yellow fluorescence of lipid droplets, while the cytoplasm fluoresces orange

Question 31

Fungal Ecology using PCR method

Answer 31

• Isolate DNA/RNA directly from soil
• Target specific core and/or housekeeping genes using fungal specific primers
• Profile the community using electrophoresis methods or cloning and DNA-sequencing

Question 32

Fungal ecology using Next generation sequencing

Answer 32

• Isolate DNA/RNA directly from soil
  Target specific core and/or housekeeping genes using fungal specific primers
• Sequencing in the illumine platform
• Assemble sequence reads
• Analyse the sequence data