A second lateral cambium, called the phellogen or cork cambium, is the source of the periderm, a protective tissue that replaces the epidermis when the secondary growth displaces, and ultimately destroys, the epidermis of the primary plant body.
The secondary structures of B. scorzonerifolium roots consist of the periderm, pericycle ring and secondary vascular tissue.
These findings indicate that molecular architecture of tight junctions of the periderm is different from that of the maculae occludentes of the epidermis, and that claudin-6 is important in the formation of tight junctions of the periderm.
Then the isolated periderm membranes, comprising exclusively the suberized cell walls of the phellem (cork) layer of the periderm, were washed with deionized water and dried at 35 °C.
The phelloderm cells are the innermost layer of the periderm and contain actively dividing cells during tuber maturation.
At 13 14 weeks, K10 was expressed in the intermediate layers and in some parts of the periderm (Table 2).
Nonetheless, we found that all cells of the periderm and some scattered dermal cells in prenatal skin expressed TLR3.
In contrast, similar analyses in Irf6R84C/R84C homozygous mice failed to reveal any periderm formation within the oral epithelia suggesting that normal IRF6 function may be an absolute requirement for oral periderm formation from the basal cells; indeed, our initial analyses suggest that IRF6 may play a central role in the formation of the periderm more widely.
In potato tubers, fragmentation of rhamnogalacturonan I by a fungal rhamnogalaturononan lyase induced radial swelling of the periderm cells and the development of cortical intercellular air spaces [ 53].
Genetically modified potato plants provide effective investigative probes of the individual contributions of the suberin components to the mechanical performance of the periderm.
