This is caused by incomplete development of the abscission layer. This binding brings Bro1 to the site of membrane abscission. They inhibit root growth and leaf abscission. Similarly in Drosophila, RNAi knockdown of Citron-K results in a failure of cellular abscission. The process of abscission physically cleaves the midbody into two. Exhaustion of auxin makes the abscission zone sensitive to ethylene. Cells under the abscission zone divide and form a layer of cork cells. The deadwooding process speeds up the tree's natural abscission process. This mediation of abscission occurs through interactions with the centralspindlin complex. It was so named because it was originally thought to control abscission. The loss of chlorophyll may also contribute to the abscission process. As the auxin levels decrease, the flux of auxin to the abscission zone is reduced. In peach, PG activity was only detected in fruit abscission zones. The abscission layer is a greenish-grayish color. This natural shedding is called abscission.