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

Abstract

production of chlorophyll a, phycoerythrin, phycocyanin and soluble proteins, while intense production of polysaccharidic material is attributed to red light.

Effects of light quality on reproduction, growth and pigment content of <em>Gracilaria birdiae</em> (Rhodophyta: Gracilariales)

“…The increase of phycobiliproteins that occurred in G. birdiae cultivated under BL and GR light could be related to improved energy absorption, which is transferred to Chl a to make up for the absence of other light qualities that are usually absorbed by chlorophyll. The same observation was shown in Porphyra leucosticta (Tsekos et al 2002). Additional evidence of this optimization of light energy and possible rearrangement of phycobilisome structure in G. birdiae was achieved by the same proportion of pigment content that could be seen in algae cultivated in WH, GR, and RD light, irrespective of photoperiod, although the amounts of these pigments were higher in GR-cultivated samples.…”

“…Considering the high PE and PC contents in G. birdiae, a higher BL-enhanced production in pigment proteins is suggested, similar to Chondrus crispus (López-Figueroa 1991) and P. umbilicalis (Figueroa et al 1995a). BL could also stimulate the accumulation of nitrogen compounds in G. birdiae, such as PE and PC, and the resultant higher density of phycobilisomes under BL than that observed under RD and GR, as reported in P. leucosticta (Tsekos et al 2002). Because of the relatively rapid accumulation of PE, this photosynthetic pigment has been suggested as an Nstore compound, as in cyanobacteria and red macroalgae (Lapointe et al 1984, Figueroa et al 1995a.…”

Efeitos da radiação ultravioleta solar em algas de importância econômica da região subantártica do Chile durante a primavera

“…As características ultraestruturais das células de Porphyra columbina são semelhantes às observadas em outras espécies do gênero Porphyra (DELIVOPOULUS et al, 1999;TSEKOS et al, 2002;OURIQUES et al, 2011 (GUIMARÃES & PLASTINOS, 1999;NAVARRO et al, 2010a). Essas associações parecem ser comuns nessas algas, proporcionando uma maior eficiência no metabolismo celular (OATES & COLE, 1989).…”

“…A diminuição do volume do protoplasto promoveu uma compressão das organelas celulares, que foi evidenciada pela formação de grandes vesículas mucilaginosas, principalmente em indivíduos expostos à UV-B. A presença de um grande número dessas vesículas já foi referida para P. lecosticta, quando exposta à luz azul e vermelha (TSEKOS et al, 2002). Estruturas similares, sugeridas como vacúolos, foram identificadas em carpósporos de P. spiralis var.…”

“…amplifolia (OURIQUES et al, 2011). Essas vesículas teriam origem a partir do RE ou de corpos membranosos concêntricos que liberam seu conteúdo na parede celular (TSEKOS et al, 2002).…”