plant pathogens

Question 1

what is potato blight plant pathogen
-why is it difficult to control
-synthesis of what

Answer 1

casued by phytophthora infestans which is a water mold.
synthesis of celluose cell walls

control: high challenging as p. infestans rapidly adapts to control measures due to repetitive genome

Question 2

what is fusarium wilt of banana
-how temporary protection can be offered

Answer 2

fungas that casues banana wilt (panama disease)

control: hard to eradicate. prior exposure to avirulent TR1 strain from Brazil can offer temporary protection from TR4

Question 3

name some environmental challenges faced by plant pathogens-

Answer 3

-vary in temperature
-very basic transport/ communication systum
-surface and root microbes

Question 4

the challenges faced by plant pathogens in terms of plant defences and immune system.
1) (PAMP) and pattern triggered immunity (PTI)
-resistence it offers

2) effector triggered immunity (ETI)
-what it recognises
-resistence it offers

Answer 4

1) PAMPS are recognised by plant pattern recognition receptors (PRR).
poor resistence as some pathogens produce avirulence (Avr) effector proteins to avoid PTI.

2) recognise pathogen effector molecules leading to a stronger ETI response.
plant resistence proteins can also trigger ETI by sensing damaged plant molecules (DAMPS)

Question 5

different types of plant resistence when DAMPS triggered?
-calcium e.g. phytoalexins
-hypersensitive response
-salicylic acid and jasmonic acid (what can lead to)

Answer 5

1) triggers calcium signalling, ROS, accumulation of pathogenesis e.g. phytoalexins
2) programmed cell death at infection site
3) chnages in plant hormone levels (salicylic acid and jasmonic acid) lead to SAR (systemic aquired resistence)

Question 6

5 results of pathogen detection to protect themselves?

Answer 6

1) cell wall modification
2) closure of stomata
3) production of ROS
4) hypersensitive response
5) production of anti-parasite compounds and proteins

Question 7

how plant pathogens can be exploited for industry, genetic modification and biotechnology
1) pseudomonas spp.
2) tobacco mosaic virus
3) agrobacterium tumefaciens

Answer 7

1) lethal to mosquitos and there larvae
2) can be genetically modified to display vaccine for malaria
3) bacteria casues crown gall disease (tumours). can be genetically engineered to insert genes into plant genomes via Ti plasmid

Question 8

give a cultural control strategy for plant pathogens

Answer 8

crop rotation to break pathogen life cycle

Question 9

how does puccinia graminis spread and what does it infect

Answer 9

airborne spores, infects wheat

Question 10

dutch elm disease
-what fungi pathogen
-how is it spread
-pathogeneis

Answer 10

-ophiostoma ulmi
-spread by elm bark bettles
-pathogenesis includes fungas blocks water conduction channels (xylem) causing wilt.

Question 11

ash dieback disease
-kind of fungas

Answer 11

windborn fungas
hymenoscyphus fraxineus

Question 12

meaning of plant pathologies
1) necrosis
2) blight
3) cankers
4) gall
5) wilt

Answer 12

1) death of cell
2) discolouration and death of foilage
3) dead section of bark
4) tumour growth
5) loss of turgor in leaves