9/10: Cameron et al 2007

Question 1

in what host is host quality thought to be linked to expression of defences against parasite?

Answer 1

forb

Question 2

what were the hosts used and what was supplied to them and why?

Answer 2

C.Cristatus grass
L.vulgare + P.lanceolata forbs
- 15 N tracers supplied to know efficacy of defence responses

Question 3

how much of the tracer was taken up when R.minor penetrated xylem of C.cristatus?

Answer 3

17%

Question 4

why are forbs considered poor hosts?

Answer 4

effective resistance mechanisms to prevent parasite from directly accessing xylem solutes

Question 5

what does R.minor use to attack host xylem and how?

Answer 5

haustoria to access host vascular tissue

- pulling host xylem sap to parasite by mass flow

Question 6

how can striga and rhinanthus sustain high transpiration rates?

Answer 6

stomata relatively insensitive to water loss

Question 7

on which of the species is the Haustorium most developed ? and what do the other 2 lack?

Answer 7

C.cristatus

- others lack secondary xylem and hyaline body with parasite not penetrating xylem

Question 8

when did R.minor have the lower biomass?

Answer 8

when grown on forb species

Question 9

how may forbs can prevent direct access to their xylem?

Answer 9

lignin

hypersensitive cell death at point of parasite contact

Question 10

when may a parasite be found in close proximity to the host

Answer 10

if it can’t sequester enough resources to overcome cost of competition