SS2.03 Phytoplankton Ecology Using Molecular Approach
Date: Thursday, June 13, 2002
Time: 2:45:00 PM
Location: Colwood
Zhang, H, , University of Connecticut, Groton, USA,
LinS, University of Connecticut, Groton, USA,
Rubisco in Prorocentrum minimum (Dinophyceae): Does it indicate photosynthetic rate?
Rubisco has been extensively used to indicate photosynthetic rate for marine phytoplankton. However, Rubisco in dinoflagellates (form II) is different from counterparts in other algae (form I) in origin and gene structure and whether its expression is correlated with photosynthetic rate is unknown. To characterize this unusual form of Rubisco, a full-length cDNA (Pmrbc) was isolated from Prorocentrum minimum (Parvillard) Schiller. A recombinant fusion protein was expressed in E. coli and purified, and antisera were produced. Western blot using these antisera revealed one single protein band and whole cell immunofluorescence demonstrated that this enzyme was distributed diffusely in plastids in some cells and highly concentrated as one or two foci in others. To examine the effects of light dark conditions on the expression of Pmrbc, cultures were grown under 12:12 L:D photocycle in one experiment and were shifted from the light to the dark in another experiment. Results of reverse transcription- polymerase chain reaction (RT-PCR) and western blot analyses for samples collected from the light and the dark showed that Pmrbc is expressed independent of light dark conditions.