Stomatal control during dessication in the resurrection plant Xerophyta humilis

Stomatal apertures on leaves of the resurrection plant Xerophyta humilis were monitored microscopically in order to characterize stomatal regulation during a dehydration time course. In addition, the effect of exogenous application of the stress hormone ABA on stomatal regulation was followed. X humilis stomatal regulation appears to be initially similar to that typical of desiccation sensitive plants, but differed in that stomata did not all close at once but at a slower rate to control the drying rate of the plant, this gave time for protection mechanisms to be laid down. The signal hormone ABA was found to have strong stomatal control on the adaxial surfaces of leaves but weak control on the abaxial leaf surfaces, thus it is difficult to say that ABA regulates the process until RWC of below 50%, where stomatal apertures open as a result of shrinkage of guard cells due to loss of water.

Grantor dc:publisher.institution

Department of Biological Sciences

Year dc:date.issued

2007

Author dc:creator

• Chireshe, Nyaradzo

Advisor dc:contributor.advisor

• Farrant, Jill M

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/24964

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/24964