Ecological Strategies Flashcards
(13 cards)
How do maize plants defend against caterpillars using airborne signals?
They release volatiles that attract parasitic wasps, which lay eggs in the caterpillars
What is a tritrophic interaction?
An interaction involving plants, herbivores and natural enemies
How do plants recruit beneficial microbes when attacked?
By producing secondary metabolites that act as recruitment signals for disease suppressive microbes
What are two major microbial mechanisms for suppressing disease?
- Antibiotic production
- Iron sequestration (limiting pathogen access to iron)
What was revealed using PhyloChip analysis on Arabidopsis?
What was the effect of these bacteria?
Downy mildew infection alters soil microbiota, enriching specific bacteria:
- Stenotrophomonas sp.
- Xanthomonas sp.
- Microbacterium sp.
Effect of bacteria:
Induced systemic resistance (ISR) and slight growth promotion
What is soil conditioning?
When infected plants modify soil microbiota, leading to disease-suppressive feedback for the next plant generation
What is DIMBOA?
A bezoxazinoid compound exuded by young maize roots, derived from tryptophan, involved in defence against pests
What does DIMBOA do aboveground and below?
Above: acts as an anti-herbivore compound against aphids and caterpillars
Below: helps recruit beneficial microbes, like P. putida KT2440
How does P. putida respond to DIMBOA?
It is tolerant and activates detoxification and chemotaxis genes in its presence
What does chemotaxis mean in the context related to DIMBOA?
P. putida moves toward chemical cues like DIMBOA in the root zone
What does the DIMBOA bx1 mutant show about microbial colonisation?
bx1 mutants lose the ability to recruit P. putida, showing DIMBOA is required for recruitment
What happens with BX biosynthesis is disrupted?
Root colonisation by beneficial bacteria is reduced
What is the soil legacy effect of benzoxazinoids like MBOA?
Soils conditioned by BX producing plants reduce caterpillar growth, indicating long-lasting ISR
