Digital Repository

Characterization of the state transition in the cyanobacterium synechococcus sp. 7002 and a phycobilisome-less Mutant

DSpace/Manakin Repository

Show simple item record Brimble, K. Scott. en_US 2009-10-02T13:19:55Z 2009-10-02T13:19:55Z 1989-10-02T13:19:55Z
dc.description.abstract ABSTRACT Photosynthetic state transitions were investigated in the cyanobacterium Synechococcus sp. PCC 7002 in both wild-type cells and mutant cells lacking phycobilisomes. Preillumination in the presence of DCMU (3(3,4 dichlorophenyl) 1,1 dimethyl urea) induced state 1 and dark adaptation induced state 2 in both wild-type and mutant cells as determined by 77K fluorescence emission spectroscopy. Light-induced transitions were observed in the wildtype after preferential excitation of phycocyanin (state 2) or preferential excitation of chlorophyll .a. (state 1). The state 1 and 2 transitions in the wild-type had half-times of approximately 10 seconds. Cytochrome f and P-700 oxidation kinetics could not be correlated with any current state transition model as cells in state 1 showed faster oxidation kinetics regardless of excitation wavelength. Light-induced transitions were also observed in the phycobilisomeless mutant after preferential excitation of short wavelength chlorophyll !l. (state 2) or carotenoids and long wavelength chlorophyll it (state 1). One-dimensional electrophoresis revealed no significant differences in phosphorylation patterns of resolved proteins between wild-type cells in state 1 and state 2. It is concluded that the mechanism of the light state transition in cyanobacteria does not require the presence of the phycobilisome. The results contradict proposed models for the state transition which require an active role for the phycobilisome. en_US
dc.language.iso eng en_US
dc.publisher Brock University en_US
dc.subject Cyanobacteria. en_US
dc.subject Synechococcus. en_US
dc.subject Photosynthesis. en_US
dc.subject Phycobilins. en_US
dc.title Characterization of the state transition in the cyanobacterium synechococcus sp. 7002 and a phycobilisome-less Mutant en_US
dc.type Electronic Thesis or Dissertation en_US M.Sc. Biological Sciences en_US Masters en_US
dc.contributor.department Department of Biological Sciences en_US Faculty of Mathematics and Science en_US

Files in this item

This item appears in the following Collection(s)

Show simple item record

Search The Repository


My Account


About the Digital Repository