Way of Transport
Apoplastic: Ions, Auxin, Peptides
Symplastic Connection: Plasmodesmata
Plasmodesmata
Cilia & Jackson (2004) COCB 16, 500
Transport to/through Plasmodesmata
Oparka (2004) TIPS 9, 33-41
Basal and
dynamic
Size
Exclusion
Limit
Development of Plasmodesmata
simple complex
Pickard & Beachy (2005) Cell 98, 5-8
PD-localisated Proteins
AtRGP2-GFP
Sagi et al. (2005) Plant Cell 17, 1788
RGP = reversibly glycosylated protein
STM::GFP STM ::(GFP)2 STM::(GFP)3 MSG2::(GFP)2
Size exclusion limit - GFP Transport in Embryos
Kim et al. (2005) PNAS 102, 2227
Dynamic size exclusion limit
in root epidermis cells
Kurata et al. (2005) Development 132, 5387-5398
CPC::GFP CPC::CPC:GFP
CPC::CPC:(GFP)3 CPC::CPC:(GFP)4
Identification
of Plasmodesmata–based Signals
Kim et al. (2005) G&D 19, 788
Idea
Constructs
Results
Tassetto et al. (2005) EMBO Rep. 6, 885–890
Homeo domain of KN1 mediates trafficking
KN1 domains
homeo domain
GFP GUS
gl1; GL2::GUS
+ RbcS::GL1-GFP-KN1
KN1 fragments
fused to GL1
TF trafficking mediated by some HDs
Class I KNOX
homeo domains
class I
mediate
trafficking
Root: Radial Patterning
Detective story of moving transcription factors
Cortex + Endodermis CortexMixed (Cx+En)
SCR and SHR Expression + SHR Proteintransport
Expression
in Stele
Protein
in Endodermis + QC
SCR Expression SHR Expression SHR Protein
Expression and Protein
in Endodermis + QC
Model for SHR und SCR Function
SCRp::SHR Expression: Mehr Endodermis
Interzellulärer Transport der Signale
- Importance of intercellular signals in totipotent plant
cells with cell walls
- Diversity of signals: small molecules, RNAs, viroids,
Peptides, Transcription factors
- Plasmodesmata: special Organelles for connecting cells
- static and dynamic „size exclusion limit“
- modification of plasmodesmata during
plant development
- Examples of intercellular signalling (e.g. Endodermis,
Root hair Specification)