Week 15 L3: Plant-Microbes - PHOSPHORUS

Question 1

What is the limit with synthetic phosphorus as fertiliser?

Answer 1

rocks where phosphorus is found are limited

Question 2

What are the 2 types of interactions mycorrhizal with plants?

Answer 2

ecto and endo

proliferate inside or outside cell

Question 3

What do the majority of land plants associate with?

Answer 3

AMF and proliferate endo

Question 4

what are AMF?

Answer 4

fungi not bacteria

Question 5

What apparatus us used to penetrate the plant root?

Answer 5

pre-penetrative apparatus

Question 6

What is the microbe which that trades soil nutrients for carbon?

Answer 6

Mycorrhizal fungi

Question 7

What are the 2 forms of Mycorrhizal fungi?

Answer 7

ectomycorrhizal fungi

endomycorrhizal fungi

Question 8

What is the difference between endo- and ecto-mycorrhizal fungi?

Answer 8

can proliferate within or between cells

Question 9

What do the endo and ectomycorrhizal form?

Answer 9

develop multicellular, 
vegetative bodies (Mycelia, Mycelium sing., ) both within and outside the roots

Question 10

What interaction do most of the land plants form with mycorrhizal?

Answer 10

~80% form endo

Question 11

What type of mycorrhizal fungi forms inside plants cells?

Answer 11

arbuscular mycorrhizal fungi

AMF

Question 12

What lifestyle are AMFs?

Answer 12

obligate biotrophs, cant live without their root partners

Question 13

What new organ is developed in plant cells due to interaction between plant and arbuscular mycorrhizal fungi?

Answer 13

arbuscules

Question 14

What is the first step in the interaction between fungus and plant?

Answer 14

Mutual regognition: signalling between AMF and plants.

The plant prepares to permit the fungi to penetrate its cells

Question 15

What chemical does the plant root secrete?

Answer 15

strigolactones

Question 16

What does strigolactones initiate in the fungus?

Answer 16

branching in fungal hyphae.

The fungus produces a Myc factor which identifies it symbiont.

Question 17

What is the second stage in fungal-plant interaction?

Answer 17

fungal penetration

Question 18

What is the pre-penetrative apparatus in th eplant?

Answer 18

-The pre-penetration apparatus (PPA) is a cytoplasmatic bridge across the vacuole of a plant cell that forms in 
anticipation of fungal infection
- The PPA contains a hollow tube
- Only when the PPA is formed, the 
fungus enter the PPA (no root hair 
curling)

Question 19

When can the fungus enter the PPA?

Answer 19

only when it is fully formed

Question 20

When does the development of the arbuscule begin?

Answer 20

when the fungus reaches the root cortex via the PPA

Question 21

When the fungus penetrates the plant, what occurs?

Answer 21

A plant-derived, perifungal membrane encloses the penetrating fungus and
prevents microbial contact with the plant cytoplasm

Question 22

What is the third stage of plant-fungus interaction?

Answer 22

arbuscule development.

Question 23

What is the purpose of the arbuscule?

Answer 23

used to trade organic compounds between the fungus and plant.

Question 24

What is the arbuscule reminiscent of?

Answer 24

the haustorium, the arbuscules are specialized hyphae of fungus

Question 25

What is the haustorium?

Answer 25

penetrates the tissues of a host and absorbs nutrients and water.

Question 26

Does the fungus make new arbuscules?

Answer 26

YES, one will last for a certain amount of time and then it will degrade so the fungus forms a new one.

Question 27

How are resources exchanged between plants and AMF?

Answer 27

Mineral nutrient are 
released into plant 
cells thanks to 
specific transporters 
“embedded” into the 
periarbusculalar 
membrane (PAM)

The fungus contributes nitrogen and phosphate into the plants arbuscules

Question 28

What is PAM?

Answer 28

periarbusculalar

membrane

Question 29

Where does nutrient uptake take place for AMF?

Answer 29

EXTRA-RADIAL MTCELIUM