Cell to Cell signalling and communication during the establishment - - PowerPoint PPT Presentation

“Cell to Cell signalling and communication during the establishment

• f the nitrogen-fixing symbiosis”

Martina Beck Incoming fellow

1

PhD 2006-2009

IZMB, University Bonn, Germany Supervision: J. Samaj

Root cell signalling

Research background: Studying the dynamics of plant signalling processes

Immune receptor signalling PostDoc 2010-2014 TSL, Norwich, U.K. Supervision: S. Robatzek

PhD 2006-2009

IZMB, University Bonn, Germany Supervision: J. Samaj

Root cell signalling

Research background: Studying the dynamics of plant signalling processes

Immune receptor signalling PostDoc 2010-2014 TSL, Norwich, U.K. Supervision: S. Robatzek

AgreenSkills Project

LIPM, Toulouse

Group: D. Barker and P. Gamas

Root cell signalling during symbiotic plant-microbe interaction

• Nitrogen is a limiting factor for plant growth represents 50% of fertilizer demand

to improve crop yield

• Legumes represent a natural solution to increase nitrogen conc. in plants and soil
• M. truncatula

Legume Rhizobia

N2 fixing nodule

Root Hair Infection CO

2

NH

3

N2

ATP ADP

Symbiotic plant-microbe interaction

• M. truncatula

Legume Rhizobia Root Hair Infection CO

2

NH

3

N2

ATP ADP

Symbiotic plant-microbe interaction

root hair cortical cells

Cell wall invagination Tubular structure

rhizobia epidermis cortical cells

• Symbiont entry via Infection thread

N2 fixing nodule

Rhizobia

N2 fixing nodule

Root Hair Infection

Signals involved in host cell reprogramming prior infection

root hair cortical cells rhizobia epidermis cortical cells

• Specific host cell reprogramming prior to IT entry

Cell reorganisation Ca2+ spiking Gene expresssion

Do intercellular connections control molecular flux between cells ?

How is signalling controlled during infection ?

root hair epidermis cortical cells cortical cells

• Connection ?
• Separation ?

ONLY cortical cells connected to RH are signalling

Intercellular connection Cytoplasma Cell wall Plasmodesmata Changes in number and distribution Cytoplasma Cytoplasma Changes in pore size

How is signalling controlled during infection ?

root hair epidermis cortical cells cortical cells

Role of symplastic connections

(1) Live cell imaging approach  PD localisation, distribution, structure  Molecular flux studies (GFP,Dyes)

How is signalling controlled during infection ?

root hair epidermis cortical cells cortical cells

Identification of new regulators for cell-to-cell communication

(1) Live cell imaging approach  PD localisation, distribution, structure  Molecular flux studies (GFP,Dyes) (2) Gene Candidate approach

• Transcriptomic data of

symbiotic tissue  Expression pattern/ Localization  Functional studies  PD localized and regulatory protein