Week 15 L3: Plant-Microbes - PHOSPHORUS Flashcards
What is the limit with synthetic phosphorus as fertiliser?
rocks where phosphorus is found are limited
What are the 2 types of interactions mycorrhizal with plants?
ecto and endo
proliferate inside or outside cell
What do the majority of land plants associate with?
AMF and proliferate endo
what are AMF?
fungi not bacteria
What apparatus us used to penetrate the plant root?
pre-penetrative apparatus
What is the microbe which that trades soil nutrients for carbon?
Mycorrhizal fungi
What are the 2 forms of Mycorrhizal fungi?
ectomycorrhizal fungi
endomycorrhizal fungi
What is the difference between endo- and ecto-mycorrhizal fungi?
can proliferate within or between cells
What do the endo and ectomycorrhizal form?
develop multicellular, vegetative bodies (Mycelia, Mycelium sing., ) both within and outside the roots
What interaction do most of the land plants form with mycorrhizal?
~80% form endo
What type of mycorrhizal fungi forms inside plants cells?
arbuscular mycorrhizal fungi
AMF
What lifestyle are AMFs?
obligate biotrophs, cant live without their root partners
What new organ is developed in plant cells due to interaction between plant and arbuscular mycorrhizal fungi?
arbuscules
What is the first step in the interaction between fungus and plant?
Mutual regognition: signalling between AMF and plants.
The plant prepares to permit the fungi to penetrate its cells
What chemical does the plant root secrete?
strigolactones
What does strigolactones initiate in the fungus?
branching in fungal hyphae.
The fungus produces a Myc factor which identifies it symbiont.
What is the second stage in fungal-plant interaction?
fungal penetration
What is the pre-penetrative apparatus in th eplant?
-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)
When can the fungus enter the PPA?
only when it is fully formed
When does the development of the arbuscule begin?
when the fungus reaches the root cortex via the PPA
When the fungus penetrates the plant, what occurs?
A plant-derived, perifungal membrane encloses the penetrating fungus and
prevents microbial contact with the plant cytoplasm
What is the third stage of plant-fungus interaction?
arbuscule development.
What is the purpose of the arbuscule?
used to trade organic compounds between the fungus and plant.
What is the arbuscule reminiscent of?
the haustorium, the arbuscules are specialized hyphae of fungus
What is the haustorium?
penetrates the tissues of a host and absorbs nutrients and water.
Does the fungus make new arbuscules?
YES, one will last for a certain amount of time and then it will degrade so the fungus forms a new one.
How are resources exchanged between plants and AMF?
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
What is PAM?
periarbusculalar
membrane
Where does nutrient uptake take place for AMF?
EXTRA-RADIAL MTCELIUM
