Plant and Cell Physiology, 1999, Vol. 40, No. 12 1194-1202
© 1999
Light Regulation of Phycobilisome Structure and Gene Expression in Spirulina platensis C1 (Arthrospira sp. PCC 9438)
1 School of Bioresources and Technology, King Mongkut's University of Technology Thonburi Bangkok 10140, Thailand
2 Unité de Physiologie Microbienne, Institut Pasteur 75724 Paris Cedex 15, France
3 Laboratoire de Photorégulation et Dynamique des Membranes Végétales, CNRS URA 1810, Ecole Normale Supérieure Paris Cedex 05, France
4 National Center for Genetic Engineering and Biotechnology Bangkok 10400, Thailand
Light intensity is the most significant environmental factor influencing the light harvesting complexes (phycobilisomes) in cyanobacteria. Spirulina platensis C1, a filamentous cyanobacterium, was grown in batch culture under low (50 µE m–2s–1) and high (500 µE m–2s–1) photosynthetic photon flux density. Phycobilisomes were isolated, purified and analyzed by spectrophotometry, gel electrophoresis and electron microscopy. The absorption spectra in conjunction with the electron micrographs revealed that they are hemidiscoidal with three allophycocyanin cylindrical cores and six phycocyanin rods radiating from the core. The 33 kDa linker polypeptide normally found in low light cells disappeared under high light resulting in smaller phycobilisomes. The decrease in the number of phycobilisomes correlated well with the decrease in phycocyanin and allophycocyanin content from cells shifted from low to high light. The phycobiliprotein transcripts exhibited different pattern in response to different light intensities. Three species of phycocyanin mRNA of sizes 1.4, 1.5 and 3.5 kb and two species of allophycocyanin of 1.4 and 1.7 kb were found in low light grown cells. However in high light, the 3.5 kb phycocyanin transcript disappeared while the others remained with subtle changes. This observation indicates that the largest transcript encoding for phycocyanin subunits and linker polypeptides and the phycobilisome structure are modulated by light intensity.
(Received January 21, 1999; Accepted October 12, 1999)
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  C. Six, J.-C. Thomas, L. Thion, Y. Lemoine, F. Zal, and F. Partensky Two Novel Phycoerythrin-Associated Linker Proteins in the Marine Cyanobacterium Synechococcus sp. Strain WH8102 J. Bacteriol., March 1, 2005; 187(5): 1685 - 1694. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Miskiewicz, A. G. Ivanov, and N. P.A. Huner Stoichiometry of the Photosynthetic Apparatus and Phycobilisome Structure of the Cyanobacterium Plectonema boryanum UTEX 485 Are Regulated by Both Light and Temperature Plant Physiology, November 1, 2002; 130(3): 1414 - 1425. [Abstract] [Full Text] [PDF]
|
|