Equisetum Cell Walls
The crude cell extracts of all Equisetum species tested contain mixed-linkage glucan : xyloglucan endotransglucosylase (MXE) activity. This is a novel enzyme and is not known to occur in any other plants. In addition, the cell walls of all Equisetum species tested contain mixed-linkage glucan (MLG), a polysaccharide which, until recently, was thought to be confined to the Poales. The evolutionary distance between Equisetum and the Poales suggests that each evolved MLG independently. The presence of MXE activity in Equisetum suggests that they have evolved MLG along with some mechanism of cell wall modification. The lack of MXE in the Poales suggests that there it must play some other, currently unknown, role. Due to the correlation between MXE activity and cell age, MXE has been proposed to promote the cessation of cell expansion.
Read more about this topic: Equisetum
Famous quotes containing the words cell and/or walls:
“I turn and turn in my cell like a fly that doesn’t know where to die.”
—Antonio Gramsci (1891–1937)
“Nor stony tower, nor walls of beaten brass,
Nor airless dungeon, nor strong links of iron,
Can be retentive to the strength of spirit.”
—William Shakespeare (1564–1616)