11. Plasmodesmata and intercellular transport

Question 1

What can be detected in the electron micorscope regarding the plasmodesmata?

Answer 1

Various forms of Plasmodesmata detected in the transmission electron microscope and viral movement proteins at plasmodesmata

Question 2

How does a plamsodesmata look like?

Answer 2

ER (through), actin (at the side of the ER, can be seen with immunogold lableing), myosin (in the gap on actin), neck structure (in the cell, made of callose)
Beginning: cytoplasmic channel

Question 3

How does the formation of the primary plasmodesmata takes place?

Answer 3

New cell material (stippling) is laid down at the cell plate
Cell wall deposition continues
ER becomes trapped during cell wall deposition forming the desmotubule of the plasmodesma

Question 4

How does the formation of seccondary plamodesmata takes place?

Answer 4

1. Cell is loosed during cell expansation during auxin mediated acidification (+), expansins and enzymes such as xyloglycan endotransglucosylase/hydrolase
2. the cell streches the wall and thinner the wall that underwent local loosening
3. the cell wall in thinnered by the tugor preassure of the 2 cells and ER enters into the space generated
4. after a time, well wall breaks and the 2 ER becomes continous. ER and other cell components fill up the space and reestablish a balanced tugor.