28: plant-microbe interactions and plant defense

Nitrogen-fixing bacteria

live in root nodules (bubbles in roots)

converts N2 into usable nitrogen forms

receives plant carbon and habitat

Mycorrhizal Fungi

extend absorptive surface beyond roots

increases phosphorus and water uptake

receive plant carbon

Is root mutualism beneficial?

SOMETIMES

if plant is not getting any light, its already low sugars gonna be used up by the partner, so not beneficial

otherwise if it has light and there is low N/P, then yes

How do leaves scorch?

pathogens enter tissues, blocking xylem