Algae. 1996; 11(3): 309-315.

Characterization of Light-harvesting Pigments in Spores of Ulva fasciata Delile

Hyun-Woung Shin, Celia M. Smith

Department of Botany, University of Hawaii

Results of in vivo absorbance spectra, high-performance liquid chromatography (HPLC) and in vivo fluorescence spectra were compared to characterize pigments in spores and vegetative tissues of Ulva fasciata. In vivo absorbance spectra of these spored revealed a broad absorbance capacity from 470 to 550 nm not observed in vegetative tissue of the same thalli. Calculation of the 4th derivative of the absorbance spectrum corresponds with wavelength to an absorbance peak of one of the pigments present in the sample. The chlorophyll and carotenoid composition, determined by standard HPLC methods with a three solvent gradient system and C sub(18) reversed-phase column chromatography revealed that lutein and β-carotene were th main novel contributors in the blue-green region (475 to 495 nm). The ratio of β-carotene/ Chlorophyll a in spores was 3- to 4-fold higher than in vegetative tissues; the ratio of lutein/ Chl a in spores was 1.5- to 2-fold higher than in vegetative tissues. In vivo fluorescence spectra for from temperature PSII emission in these unicells revealed a broad spectral range for light-harvesting capacity, with enhanced harvesting from 470 nm to 495 nm, a 5 nm shift to longer wavelengths for spores when compared with vegetative tissues of the same thalli. The enhanced in in vivo absorbance and in vivo fluorescence by spores suggests that distinct carotenoids function in light-harvesting.

Keywords : high-performance liquid chromatography, in vivo absorbance spectra, in vivo fluorescence spectra, light-harvesting pigments, Ulva fasciata