Mycorrhizae Rhizobia

Question 1

what is the core plant microbiota

Answer 1

the microbiota associated with a specific species or genotypes, independant of environmental conditions

Question 2

what are core plant microbiota believed to be

Answer 2

microvial taxa

crucial if not required for growth and survival of species

Question 3

2 groups of core microbiota

Answer 3

mycorrhizae

rhizobia

Question 4

what is mycorrhizae

Answer 4

fungal species which associate with plant roots in a symbiotic relationship

Question 5

when do mycorrhizae occur

Answer 5

when the hyphae of mycorrhizae enter the root organ

Question 6

what is hyphae

Answer 6

main tissue of a fungal species

the body

Question 7

what do the plant and fungi both get out of a mycorrhizal association

Answer 7

• fungus is receiving carbohydrates from the plant

- plant benefits from increased absorption area for water and minerals since mycorrhizae acts as extended root system

Question 8

role of hyphae with roots

Answer 8

fungus absorbs water and minerals through cell surface

more surface area= greater interface with which to absorb water and minerals

Question 9

what are the 2 classes of mycorrhizal associations

Answer 9

ectomycorrhizae

endomycorrhizae

Question 10

what is ectomycorrizae

Answer 10

a mycorrhizal association which does not penetrate into cells of the host

Question 11

what is ectomycorrhizae

Answer 11

association which forms a complex sheath of hyphae around the root tip (mantle)

Question 12

what is believed to be the main fungal group responsible for tree to tree communication

Answer 12

ectomycorrhizae

Question 13

what is endomycorrhizae

Answer 13

mycorrhizae association where hyphae penetrates the host cell

Question 14

what is the most common type of endomycorrhizae

Answer 14

arbuscular mycorrhizae

Question 15

what is arbuscular mycorrhizae

Answer 15

a form of endomycorrhizae where the hyphae of the fungus penetrates the cells of the cortex

Question 16

what are strucutes of penetrated arbuscular mycorrhizae

Answer 16

arbuscules

vesicles

Question 17

what are arbuscules

Answer 17

highly branching hyphae that enters the plasma membrane of the cell and increases surface area of the hyphae inside the cell

Question 18

what are vesicles

Answer 18

large spherical growths of fungal hyphae within the plant cell

Question 19

what are the other mycorrhizae

Answer 19

ericoid
orchid
arbutoid

Question 20

what is ericoid mycorrhizae

Answer 20

special class of endomycorrhizae found only in the ericaceae family

Question 21

what is the ericaeae family

Answer 21

mainly wtland plants: blueberries, cranberries, rhododendrons

Question 22

what do ericoid mycorrhizae specialize in

Answer 22

nitrogen acquisition

Question 23

what is the unique form of ericoid mycorrhizae

Answer 23

the hyphae form coils

Question 24

what is orchid mycorrhizae

Answer 24

a mycorrhizal association unique to orchid species

Question 25

how do seeds in orchidaceae with no endosperm get energy for growth

Answer 25

mycorrhizal symbiont

Question 26

what is the growth pattern of the orchid mycorrhizae

Answer 26

hyphae penetrate the cortical cells and the plasma membranes of the cortical cells

Question 27

what are pelotons

Answer 27

very dense fungal groupings

Question 28

what do orchid mycorrhizae provide early in the association

Answer 28

carbon and minerals

Question 29

what do orchid mycorrhizae provide when plant is mature and photosynthesizes

Answer 29

minerals

Question 30

what are arbutoid mycorrhizae

Answer 30

very rare form of mycorrhizal association only found in 2 groups of the ericeae family

Question 31

what are the rhizobia symbioses

Answer 31

group of bacterial species that associate mainly with members of the fabaceae family

Question 32

what happens when rhizobia is associated with a plant host

Answer 32

it can express genes to fix atmospheric nitrogen into a form that the plant can absorb

Question 33

what does plant provide to rhizobia in return

Answer 33

sugars

Question 34

what is nodulation

Answer 34

process of symbioses with rhizobia

Question 35

what are the steps of rhizobial symbioses

Answer 35

1. rhizobia bacteria associate with an emerging root hair 2. bacteria release signals to tell the plant that the bacterial cells are present 3. in response, the root hairs elongate and begin to form coiled structures trapping the bacteria 4. cell walls of the root hair then begin to collapse inward creating a passage from the soil surface to the cortex cells 5. in the cortex, rhizobia cells travel to cortex cells and inscide the cell they begin to multiply enlarge and form a nodule

Question 36

what is an infection thread

Answer 36

passage from the soil to the surface of the cortex cells

Question 37

what is a nodule

Answer 37

a plant cortex cell filled with nitrogen fixing bacteroids that is connected to the vasculature of the root

Question 38

what are bacteroids

Answer 38

mature rhizobia cells actively fixing nitrogen

Question 39

what is the symbioses relationship in plant master

Answer 39

plant initiates the symbiosis | plant gives sugar to symbiont in exchange for minerals