Response of Audouinella saviana (Meneghini) Woelkerling (Nemaliales, Rhodophyta) cultures to monochromatic light

Abstract

Audouinella saviana (Meneghini) Woelkerling was cultured at a constant temperature (24 °C) and different irradiances (from 1 mol to 30 ,mol photons m-2 s -') of blue (430-470 nm) and green (500-560 nm) light in order to study its adaptive response. Modifications in colour, morphology and ultrastructure of the thalli, together with changes in pigment composition and in the spectral properties of chlorophyll a and R-phycoerythrin, were observed both by means of light and electron microscopy (TEM, SEM) and spectrophotometric and spectrofluorimetric analyses. In this paper we report the adaptive response of the seaweed to blue and green radiation by focussing on the cell wall and on the photosynthetic apparatus, particularly on phycobilisomes in situ and on R-PE after extraction. PBSs were fully structured only under blue light at low irradiance whilst they were absent under green light, whatever the irradiance, in spite of the high R-PE content. This fact, together with the spectral changes of R-PE, suggests adaptation at a molecular level, presumably referable to changes in aggregation state.

Ultrastructure of the vegetative gametophytic cells of Porphyra leucosticta (Rhodophyta) grown in red, blue and green light

“…1989;Lüning 1992;Grossman et al . 1993;Talarico and Cortese 1993;Figueroa et al . 1995a,b;Talarico 1996).…”

Influences of cadmium on fine structure and metabolism of Hypnea musciformis (Rhodophyta, Gigartinales) cultivated in vitro

“…The control plants (no Cd) were cultivated as described above, and for the treated plants, CdCl 2 was added at graded concentrations of 50, 100, 200, and 300 μM to the culture medium, as previously suggested by Talarico et al (1997) and Xia et al (2004) for Gracilaria lemaneiformis (Bory de Saint-Vincent) Greville during a 4-day cadmium treatment. Four replicates were made for each experimental group.…”

Photoecophysiology of Marine Macroalgae

“…These include variations in phycobiliprotein content and in the ratio of the chromophores of phycobilins, i.e. phycourobilidphycoerythrobilin and changes in the apoprotein aggregation state (153,154). This aggregation alters the absorption properties.…”