Whats the role of Abscisic acid in stomatal movement? plz explain in detail?

Question

Whats the role of Abscisic acid in stomatal movement? plz explain in detail?

Answer 1

The guard cell membrane has a cell surface receptor. ABA is present and triggers the guard cell's closure by binding the cell surface G-coupled signaling protein.  Inside the cell the protein signals to multiple pathways. The pH is raise from one path and calcium ions are moved from the central vacuole to the cytosol by another pathway. Cytosol changes cascade as a resulting in the osmotic pressure shifting inside the guard cell. Cell turgor is lost and the stomata close. Responses vary with differing rates of closure in different species.

http://www.pubmedcentral.nih.gov/article...

http://users.rcn.com/jkimball.ma.ultrane...