Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Og for group meeting 23march10


Published on

  • Be the first to comment

  • Be the first to like this

Og for group meeting 23march10

  1. 1. Oligogalacturonide (OG) Signalling in Plant Innate Immunity 23 March 2010
  2. 2. Background <ul><li>Activation of plant innate immunity </li></ul><ul><ul><li>Specific detection of pathogen-associated molecular patterns (PAMPs) </li></ul></ul><ul><ul><li>Host encoded pattern-recognition receptors (PRRs) </li></ul></ul><ul><li>Perception of PAMPs </li></ul><ul><ul><li>signaling cascades </li></ul></ul><ul><ul><ul><li>activation of plant defenses and enhancement of basal immunity towards potential pathogens </li></ul></ul></ul>
  3. 3. Background <ul><li>Recognition of modified-self including damage-associated molecular patterns (DAMPs) </li></ul><ul><li>Plant cell-wall fragments </li></ul><ul><ul><li>Degrading enzymes secreted by the pathogen during the infection process </li></ul></ul><ul><ul><li>Recognised as DAMPs </li></ul></ul><ul><li>None of the hypothetical DAMP receptors have yet been identified </li></ul><ul><ul><li>Signaling processes not properly characterized. </li></ul></ul>
  4. 4. Background <ul><li>Pectin </li></ul><ul><ul><li>Central component in plant cell walls </li></ul></ul><ul><li>Release of oligogalacturonide (OG) fragments from plant cell walls </li></ul><ul><li>Many plant pathogens produce pectin degrading enzymes as crucial virulence factors </li></ul><ul><li>Recognition as DAMP </li></ul><ul><li>Activation of immune responses </li></ul>
  5. 5. Previous work in the group <ul><li>Activation tagging - Karen </li></ul><ul><li>35,000 BASTA resistant plants selected from 1 million seeds </li></ul><ul><li>1500 pools of 24 plants collected </li></ul><ul><li>Germinated on Whatman paper with water </li></ul><ul><li>Infiltrated with OGs </li></ul><ul><li>Selection for oligogalacturonide-tolerant seedlings </li></ul><ul><ul><ul><li>OGs of DP 2-6(8) : 300 putants </li></ul></ul></ul><ul><li>Reselection of putants (2x) : 30 ”mutants ” </li></ul>BAR 4 x 35S enh
  6. 6. Repeating Karen´s results <ul><li>On 6 and 12 well plates with MQ water </li></ul><ul><li>Problems: </li></ul><ul><ul><li>Seedling germination and growth rate </li></ul></ul><ul><ul><ul><li>Several lines very slow </li></ul></ul></ul><ul><ul><ul><li>Start to die before they are “ready” </li></ul></ul></ul>7 days old 9 days old
  7. 7. <ul><li>Solutions </li></ul><ul><ul><li>New “fresher” seeds </li></ul></ul><ul><ul><li>Grow in MS media from the start? </li></ul></ul><ul><ul><li>One line per plate? </li></ul></ul><ul><ul><ul><li>Infiltrate when “standard” size? </li></ul></ul></ul>
  8. 8. New screen <ul><li>Previous test to germinate on plates then move to liquid medium containing OGs. </li></ul><ul><li>Try to grow in 96-well plates. </li></ul><ul><li>Germinate in liquid ½ MS medium </li></ul><ul><ul><li>Low amount of liquid so seed can grow ”out” of liquid </li></ul></ul><ul><ul><li>After germination: add OGs </li></ul></ul><ul><ul><li>Selection for tolerant seedlings </li></ul></ul>
  9. 9. <ul><li>Problems </li></ul><ul><ul><li>Drying out at the edges of the plates </li></ul></ul><ul><ul><li>Time consuming to transfer seeds one by one </li></ul></ul><ul><ul><ul><li>Seed loader? </li></ul></ul></ul><ul><ul><li>Insufficient oxygen? </li></ul></ul>New screen 8 days old – Grown in different volumes of media ( μl indicated on the right side)