The mechanics of cell separation during plant organ abscission

Jerry Roberts

The shedding of plant organs such as leaves, flowers and fruit is the culmination of a highly co-ordinated sequence of cellular and molecular events that take place at discrete positions termed abscission zones. The final process results in the breakdown of the pectin-rich middle lamellar region that cements cells together and is thought to be mediated by enzymes secreted into the cell wall by the abscission zone cells. Our studies have shown that in flowers of Arabidopsis the abscission zone comprises two layers of cells. After shedding one of these is retained by the parent plant whilst the other remains at the base of the petal, sepal or anther filament that is shed. We know that both layers of cells express genes encoding pectin degrading enzymes.

Proceedings of the 2nd Mathematics in the Plant Sciences Study Group