jörg kämper mpi für terrestrische mikrobiologie marburg
DESCRIPTION
Zeae maydis morbus ad ustilaginem vulgo relatus F.J.Imhof, 1784. Regulating networks and pathogenicity in Ustilago maydis. Jörg Kämper MPI für terrestrische Mikrobiologie Marburg. Economical losses by smut fungi: - high annual losses, local losses sometimes more than 25% - PowerPoint PPT PresentationTRANSCRIPT
Jörg KämperMPI für terrestrische Mikrobiologie
Marburg
Zeae maydis morbus ad ustilaginem vulgo relatus F.J.Imhof, 1784
Regulating networks and
pathogenicity in Ustilago maydis
Economical losses by smut fungi:
- high annual losses, local losses sometimes more than 25%
Ustilago hordei: 0.7 - 1,4% loss/year (Canada)appr. 17.6 Mio US $/year
Ustilago maydis: usually less than 2%, but up to 70%2% in USA equals about 380 Mio US $!!!
Economical losses by smut fungi:
- high annual losses, local losses sometimes more than 25%
Ustilago hordei: 0.7 - 1,4% loss/year (Canada)appr. 17.6 Mio US $/year
Ustilago maydis: usually less than 2%, but up to 70%2% in USA equals about 380 Mio US $!!!
Related to rust fungi (obligat biotroph)
- extremly high annual losses- Epidemics
Life cycle of Ustilago maydisLife cycle of Ustilago maydis
saprophyticphase
Life cycle of Ustilago maydisLife cycle of Ustilago maydis
Saprophytic phase:Simple cultivation under lab conditionsVarious molecular techniques:
- gene replacement- ARS plasmids- regulatable promoters- GFP reporter- REMI- transposon tagging- fast infection model
saprophyticphase
4 days
Pant infection with Ustilago maydis
7 days
Pant infection with Ustilago maydis
Life cycle of Ustilago maydisLife cycle of Ustilago maydis
Life cycle of Ustilago maydisLife cycle of Ustilago maydis
Life cycle of Ustilago maydisLife cycle of Ustilago maydis
Life cycle of Ustilago maydisLife cycle of Ustilago maydis
Life cycle of Ustilago maydisLife cycle of Ustilago maydis
Life cycle of Ustilago maydisLife cycle of Ustilago maydis
plant signals?
pathogenic developmentsexual developmentNuclear fusionSpore formation
b:
pheromone signallinga:
autocrineresponse
filamentous growth
a:b:
Function of the a and b mating type loci
a1b1 a2b2
a1b1 a2b2
a1a2b1b2
sexual reproduction
50 % 50 %
Problems in mating populations
50 % 50 %
Zur Anzeige wird der QuickTime™ Dekompressor „TIFF (Unkomprimiert)“
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sexual reproduction
Problems in mating populations
50 % 50 %
Zur Anzeige wird der QuickTime™ Dekompressor „TIFF (Unkomprimiert)“
benötigt.
sexual reproduction
Problems in mating populations
50 % 50 %
Zur Anzeige wird der QuickTime™ Dekompressor „TIFF (Unkomprimiert)“
benötigt.Zur Anzeige wird der QuickTime™
Dekompressor „TIFF (Unkomprimiert)“ benötigt.
sexual reproduction
- some restrictions may apply.....
Problems in mating populations
25 % 25 %
sexual reproduction
Problems in mating populations
a1b1 a2b1
a1b2 a2b2
25 % 25 %
sexual reproduction
self/nonself recognition systems
Fungi:tetrapolar mating systemsvegetative incompatibilityPlants: pollen rejectionAnimals: MHC
Problems in mating populations
a1b1 a2b1
a1b2 a2b2
Podospora anserina
sexual reproduction
self/nonself recognition systems
Fungi:tetrapolar mating systemsvegetative incompatibilityPlants: pollen rejectionAnimals: MHC
Problems in mating populations
sexual reproduction
self/nonself recognition systems
Fungi:tetrapolar mating systemsvegetative incompatibilityPlants: pollen rejectionAnimals: MHC
< 50 % < 50 %
Problems in mating populations
sexual reproduction
self/nonself recognition systems
Fungi:tetrapolar mating systemsvegetative incompatibilityPlants: pollen rejectionAnimals: MHC
Two component self/nonself discrimination systems
self
non-self
Mutation
Two component self/nonself discrimination systems
Consequences:plants: self-pollinationfungi: cell death
self-fertility
Recognition as: non-self
Mutation
Two component self/nonself discrimination systems
Recognition as: non-self
?
The b mating type encodes the central regulator for pathogenic development
The b mating type encodes the central regulator for pathogenic development
- specificity is determined within the variable domains
- variable domains are sufficient for dimerization- mutations within the variable domain alter
dimerization AND specificity
- sequencing: 18 strains from ATCC- screening of > 200 field isolates for novel RFLP- identification of one novel specificity
342
b4b
b2 b10 b2b2 b10 b2
b8 b16 b8
b5
bW3 bE3
bW4 bE4
resistence gene
PCR-based system*:homologous recombination up to 100%
Genetic manipulations: gene replacement
*Schreier, P und Kämper, J: European Patent 1 279 741 A1
PCR-knockout
a
a
PCR-knockout
SfiI: ggccnnnn nggcc
resistance cassette
PCR-knockout
PCR-knockout
rb2.2nrb2.1n
283 Eco RI •597 Pst I •
1296 Sfi I •
1584 Pst I •1594 Not I •
2271 Nco I •2290 Pst I •
2380 Eco RI •
2625 Nco I •
3180 Sfi I •
3767 Eco RI •
• Sna BI 4121• Eco RI 4230
• Pst I 4235• Not I 4256
• Pst I 5402
• Nco I 5785
pCR-b-ko-neu(+)
7837 bp
lb
rb
hph