Controlled free radical attack in the apoplast: A hypothesis for roles of O, N and S species in regulatory and polysaccharide cleavage events during rapid abscission by Azolla

- Abscission of plant organs requires cell wall loosening.
- Rapid cell wall loosening occurs via free radical attack of structural polymers.
- Free radicals are formed in the apoplast by a variety of potential mechanisms.
- Thiol modifications and Ca2+ influence in rapid abscission of Azolla water ferns.
- O, N and S molecular species potentially function in regulating rapid abscission.