Phycobilisome composition in Chondrus crispus (Gigartinales, Rhodophyta) from a wild type strain and its vegetatively derived green mutant

Abstract

Intact phycobilisomes from a wild-type red Chondrus crispus and its vegetatively derived green mutant were isolated by centrifugation through a discontinuous sucrose density gradient. Pigment composition was subsequently characterized by spectrophotometry. Vegetative thalli of the two strains grown together for six months in the laboratory resulted in different pigment profiles. Two pigmented phycobilisome bands appeared in the sucrose gradient of the wild-type alga, a purple coloured one, and a pink one, whereas only a single blue band appeared in the gradient of the green mutant. Spectrophotometric and fluorescence analyses identified the phycobiliprotein composition of the purple band as the typical phycoerythrin-phycocyanin-allophycocyanin complement in the wild-type, but there was no detectable phycoerythrin present in the blue band of the green mutant. Sodium dodecyl sulphate, preparative polyacrylamide gel electrophoresis analysis confirmed the presence of allophycocyanin subunits in all extracts, but firm evidence of an R-phycoerythrin linker polypeptide in the blue band was missing. These results highlight the ability of C. crispus to adapt to a phycoerythrin deficiency by adjusting light harvesting pigment ratios.

Influence of structural colour on the photoprotective mechanism in the gametophyte phase of the red alga Chondrus crispus

“…The attenuation given by structural coloration in the case of the gametophytes was simulated on the traces of the tetrasporophytes. As the photosynthetic system resides beneath the structural colour multi-layers, which are on the surface, there are fewer photons at around 400 nm that reach the [44] assigned to chlorophyll (Chl) [45,46], phycoerythrin (PE), phycocyanin (PC), and allophycocyanin (APC) [43,47] and the fitted spectrum using the spectra of the individual pigments. The violet, orange, blue and red lines are the spectra of PE, PC, APC and Chl with the amplitudes obtained by fitting to the experimental data and the dashed line is the spectrum generated by the superposition of these spectra.…”

“…( b ) Reflectivity spectra of gametophytes (35 replicas from 11 samples, multiple tips were used for measurements from a single sample) and tetrasporophytes (35 replicas from seven samples) with the associated standard deviation shown as a pink and purple area, respectively. Time-resolved fluorescence maps of ( c ) gametophyte and ( d ) tetrasporophyte tips upon excitation at 400 nm and ( e,f ) spectra integrated over a 2 ns window and spectra of the individual pigments of the algae [44] assigned to chlorophyll (Chl) [45,46], phycoerythrin (PE), phycocyanin (PC), and allophycocyanin (APC) [43,47] and the fitted spectrum using the spectra of the individual pigments. The violet, orange, blue and red lines are the spectra of PE, PC, APC and Chl with the amplitudes obtained by fitting to the experimental data and the dashed line is the spectrum generated by the superposition of these spectra.…”

The freshwater red algaBatrachospermum turfosum(Florideophyceae) can acclimate to a wide range of light and temperature conditions

“…The phycobiliproteins R-phycoerythrin (PE), R-phycocyanin (PC) and R allophycocyanin (APC) were extracted according to Cornish et al (2013) with minor modifications. Briefly, ground material was suspended at 4°C in 500 μl extraction solution consisting of 74.5 ml Sørensen's phosphate buffer (50 mM, pH 7), 0.5 ml Triton X-100, 10.5 μl β-mercaptoethanol and 10 protease inhibitor tablets (cOmplete, Roche Diagnostics GmbH, Mannheim, Germany).…”

Chondrus crispus – A Present and Historical Model Organism for Red Seaweeds

“…Tank culture permits close control of crop traceability and management. Some of these may possess unique characteristics of commercial value and colour mutations enriched in blue pigment is an example (Cornish, O'Leary, & Garbary, 2013). Some of these may possess unique characteristics of commercial value and colour mutations enriched in blue pigment is an example (Cornish, O'Leary, & Garbary, 2013).…”