Guard Cell Regulation of Stomatal Response: Chloroplast Function and Abscisic Acid Metabolism in Guard Cells of Commelina Communis and Vicia Faba

Techniques were evaluated for obtaining viable, purified guard cells by sonication of epidermal peels of Vicia faba L. and by treatment at pH 4 of epidermal peels of Commelina communis L. The guard cells were free of mesophyll cells and chloroplasts and of living epidermal cells as shown by fluorescence microscopy and uptake of neutral red. The guard cells of Vicia were 98% free of non-guard cell chlorophyll. These cells were used to measure the light-induced electrochromic absorbance changes indicative of the electrical component of the high energy state in guard cell chloroplasts. The guard cells exhibited DCMU-sensitive photosystem 2 activity, DBMIB-sensitive electron transport and DCCD-sensitive relaxation of the electric field associated with photophosphorylation. These results indicate that guard cell chloroplasts, although reported to lack Calvin-Benson cycle enzymes, are photosynthetically competent with respect to electron transport and photophosphorylation.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Botany

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Grantz, David Arthur

• Biology, Plant Physiology

Language dc:language

eng

Identifier

(UMI)AAI8409936

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/77655