Characterization of the photosynthetic conditions and pigment profiles of the colour strains of Hypnea musciformis from field-collected and in vitro cultured samples

Abstract

Abstract:Hypnea musciformis (Wulfen) JV Lamour. is a species of great economic interest as it produces κ-carrageenan and has shown biological activities against HIV and HSV viruses. This species displays different colour strains in its natural habitat, which may have implications for the biotechnological potential of the species. The aim of this study was to characterize the photosynthetic apparatus and pigment profile of three colour strains of H. musciformis (green, brown and red) in their natural habitat and in culture. Chlorophyll a fluorescence of photosystem II was measured with a pulse-amplitude modulated fluorometer and pigments were quantified by spectrofluorimetry (chlorophyll a) and spectrophotometry (phycobiliproteins). In the natural habitat, we detected significant differences between the colour strains for the following photochemical parameters: the green strain had a higher effective quantum yield (ΦPSII) than the red strain and a higher maximum relative electron transport rate (rETRmax) than the brown and red strains. Saturation irradiances were 1000 μE.m -2 .s -1 (green) and 500 μE.m -2 .s -1 (brown and red). Concerning in vitro culture, the green strain presented the lowest ΦPSII, rETRmax, and α rETR, while the brown strain presented the highest values for these same parameters. The chlorophyll a content of the cultured green strain was the lowest. The phycoerythrin contents of the three colour strains were unchanged by either natural of in vitro conditions: lower in green, intermediate in brown and higher in the red strain, ensuring the chromatic identity of the strains. Our results suggest that the green strain has a better performance when exposed to high irradiance, but a lower efficiency under low irradiance compared to the brown and red strains.

Photosystem II fluorescence and growth in cabbage plants (Brassica oleracea var. capitata) grown under waterlogging stress

“…The effective quantum yield of photosystem II (ΦPSII) was reduced by 50% in the waterlogged plants, compared to the control plants. Determination of ΦPSII has an advantage, since this variable is more sensitive to a large number of stressors than the Fv/Fm value, according to Fernandes et al (2012) since it has been found that the reduced plant health under prolonged soaking may result in biochemical alterations such as restriction of ribulose bisphosphate carboxylase (RuBPC), phosphoglycollate and glycollate oxidase activity, as well as severe damage to chloroplast membranes. These alterations restrict the electron transport chain during photosynthesis and negatively alter the efficiency of PSII (Ashraf, 2012).…”

Composición pigmentar de variantes amarillas y rojas de Ahnfeltia plicata (Ahnfeltiaceae, Rhodophyta) en la Región de Magallanes

“…Además de ser una de las reservas más importantes de nitrógeno en las algas (Martinez & Rico, 2006). Los resultados del presente estudio coinciden con los obtenidos en el trabajo realizado por Fernandes et al (2012), en Hypnea musciformes (Wulfen) J. V. Lamouroux, 1813, cuya concentración de ficoeritrina es predominante tanto en condiciones de cultivo como en condiciones naturales. En el estudio realizado por Costa et al (2001), los ejemplares de Gracilaria birdae de coloración roja, verdemarrón y verde, colectados en un mismo ambiente y posteriormente sometidos a un cultivo, se obtuvo que los ejemplares de mayor crecimiento fueron los de coloración roja.…”

Definindo espécies e sua distribuiação: um estudo de caso em Hypnea (Gigartinales, Rhodophyta)

“…have similar growth rates (although in different optimal light conditions). Martins et al (2009) and Fernandes et al (2012) also conducted studies related to two color variants, were they showed that both of those variants could be selected for aquaculture. The only taxonomic study using cultures of Hypnea species was held by .…”