Flashcards in Lecture 13 - Microbe-Plant Interactions Deck (67)
What are the 2 types of microbe-plant associations that plants benefit from?
mutualistic and commensalism
What are some examples of mutualistic activities between plant-microbe interactions?
they are highly specialized such as fungal interaction with root system or bacteria producing nodules
Where do most plant-microbe interactions occur?
in the rhizosphere
What is a rhizosphere?
soil bits still attached to plant's roots
What are the 3 different groups of microbes found in the rhizosphere?
beneficial, commensal, and pathogenic
How does a beneficial microbe interact with the plant within the rhizosphere?
mutualistic interaction, it uses nutrients released from plant roots
How does a commensal microbe interact with the plant within the rhizosphere?
plant doesn't benefit (researchers claim) but organism benefits from released nutrients of plant
How does a pathogenic microbe interact with the plant within the rhizosphere?
benefits from released nutrients of plant but has negative affect on plant, commensal and/or beneficial microbes
What type of interaction is between the water fern and cyanobacteria? (positive or negative?
How can water ferns be used as a biofertilizer?
considered as "green manure" because it is nitrogen rich
Explain the interaction between water ferns and cyanobacteria. Who benefits what?
cyanobacteria grow in the cavities/holes on water fern leaves as well as provides it nutrients and sugars IN TURN cyanobacteria fixes N2 to NH3 for water fern
What are mycorrhizae? What type of interaction is this?
relationship between fungus and root and are endo- or ectomycorrhizae | mutualistic interaction
Which is more prevalent in the rhizosphere? Gram+ or Gram–
What are the 3 benefits of mycorrhizae?
make plants capable of survival in low-nutrient soils, higher plant growth rates, more disease-resistance
What are ectomycorrhizae?
fungus is associated with roots which are shorter, thicker, and more branched | no breaking of root cells
What are the structures that develop the ectomycorrhizae?
Hartig nets and fungal sheath
What are Hartig nets?
where the fungus has gone in and surrounds root cells
What are fungal sheaths?
what surrounds the whole root
Explain the ectomycorrhizae interaction. Who benefits what?
fungus provides essential nutrients/minerals for plant IN TURN plant provides sugars for fungus
Where are ectomycorrhizae commonly seen in (type of plants)?
What are endomycorrhizae?
fungus penetrates root cells via arbuscules
What are arbuscules?
fungal structures used to uptake nutrients
What is the benefit of the arbuscule penetration of root cells?
enhanced root uptake of minerals
Explain the endomycorrhizal interaction. Who benefits what?
endomycorrhizal fungus provides plant with nutrients/minerals and enhances uptake IN TURN plant provides sugars for fungus
Which mycorrhizae is more common, endo- or ecto-?
What are hyphae?
branching filaments of fungal cells
Which organisms are the only ones that contain nitrogen fixation genes?
What is nitrogen fixation?
taking nitrogen from the atmosphere and fixing it into ammonia
Within mutualistic plant-bacteria interactions, what does the plant usually provide?
carbon and energy sources