TY - JOUR
T1 - Responses of the macroalgae Hypnea musciformis after in vitro exposure to UV-B
AU - Schmidt, Éder C.
AU - Pereira, Beatriz
AU - dos Santos, Rodrigo W.
AU - Gouveia, Claudiane
AU - Costa, Giulia Burle
AU - Faria, Gabriel S M
AU - Scherner, Fernando
AU - Horta, Paulo A.
AU - Martins, Roberta de Paula
AU - Latini, Alexandra
AU - Ramlov, Fernanda
AU - Maraschin, Marcelo
AU - Bouzon, Zenilda L.
PY - 2012/7
Y1 - 2012/7
N2 - The in vitro effects of UVBR were investigated in apical segments of Hypnea musciformis. The plants were cultivated and exposed to photosynthetically active radiation (PAR) at 80μmolphotonsm -2s -1 and PAR+UVBR at 1.6Wm -2 at 3h per day for 7 days. Toluidine Blue reaction showed metachromatic granulations in vacuole, and Periodic Acid Schiff stain showed a decrease in the number of floridean starch grains. UVBR also caused changes in the ultrastructure of cortical cells, which included increased thickness of the cell wall, reduced intracellular spaces, changes in the cell contour, destruction of chloroplast internal organization, and rough endoplasmic reticula increase. The algae cultivated under PAR-only showed growth rates of 9.7%day -1, while algae exposed to PAR+UVBR grew only 3.2%day -1. Furthermore, compared with control algae, phycobiliprotein contents (phycoerythrin, phycocyanin, and allophycocyanin) were observed to decrease after PAR+UVBR. However, chlorophyll a levels were not significantly different (ANOVA, P=0.52) after exposure to PAR+UVBR. As a photoprotective adaptation strategy against UVB damage, an increase of 58.9% phenolic compounds and 3.6% of carotenoids was observed. Overall, these results lead to the conclusion that both ultrastructural damage and observable changes in metabolism occurred in H. musciformis after only 3h of daily UVB exposure over a 7-d experimental period.
AB - The in vitro effects of UVBR were investigated in apical segments of Hypnea musciformis. The plants were cultivated and exposed to photosynthetically active radiation (PAR) at 80μmolphotonsm -2s -1 and PAR+UVBR at 1.6Wm -2 at 3h per day for 7 days. Toluidine Blue reaction showed metachromatic granulations in vacuole, and Periodic Acid Schiff stain showed a decrease in the number of floridean starch grains. UVBR also caused changes in the ultrastructure of cortical cells, which included increased thickness of the cell wall, reduced intracellular spaces, changes in the cell contour, destruction of chloroplast internal organization, and rough endoplasmic reticula increase. The algae cultivated under PAR-only showed growth rates of 9.7%day -1, while algae exposed to PAR+UVBR grew only 3.2%day -1. Furthermore, compared with control algae, phycobiliprotein contents (phycoerythrin, phycocyanin, and allophycocyanin) were observed to decrease after PAR+UVBR. However, chlorophyll a levels were not significantly different (ANOVA, P=0.52) after exposure to PAR+UVBR. As a photoprotective adaptation strategy against UVB damage, an increase of 58.9% phenolic compounds and 3.6% of carotenoids was observed. Overall, these results lead to the conclusion that both ultrastructural damage and observable changes in metabolism occurred in H. musciformis after only 3h of daily UVB exposure over a 7-d experimental period.
KW - Carotenoids
KW - Carrageenan yield
KW - Hypnea musciformis
KW - Mitochondrial activity
KW - Phenolic compounds
KW - Photosynthetic performance
KW - Ultrastructure
KW - Ultraviolet radiation-B
UR - http://www.scopus.com/inward/record.url?scp=84860631699&partnerID=8YFLogxK
U2 - 10.1016/j.aquabot.2012.03.004
DO - 10.1016/j.aquabot.2012.03.004
M3 - Article
VL - 100
SP - 8
EP - 17
JO - Aquatic Botany
JF - Aquatic Botany
SN - 0304-3770
ER -