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Patarra R.F.,University of The Azores | Patarra R.F.,CIIMAR - Interdisciplinary Center of Marine and Environmental | Leite J.,Institute Inovacao Tecnologica Dos Acores INOVA | Pereira R.,CIIMAR - Interdisciplinary Center of Marine and Environmental | And 3 more authors.
Natural Product Research | Year: 2013

The content of total lipids and the fatty acid (FA) profile were determined for eight macroalgae (Cystoseira abies-marina, Fucus spiralis, Chaetomorpha pachynema, Codium elisabethae, Porphyra sp., Osmundea pinnatifida, Pterocladiella capillacea and Sphaeroccoccus coronopifolius). Total lipids were extracted using a solvent mixture of methanol/chloroform (2/1, v/v) and further derivatised to FA methyl esters (FAME). The analyses of FAME samples were performed by gas chromatography coupled to a flame ionisation detector. The total lipid content ranged from 0.06 to 3.54 g (per 100 g). The most abundant saturated FA were palmitic (C16:0) and myristic (C14:0), while oleic (C18:1 n-9) was the dominant monounsaturated acid. All seaweeds contained linoleic FA (C18:2 n-6). The α-linolenic (C18:3 n-3) and eicosapentaenoic (20:5 n-3) acids were present only in Porphyra sp. (3.34% ± 0.13) and C. pachynema (0.47% ± 0.12), respectively. The n-6/n-3 and h/H ratios were low, suggesting a high nutritional value of the algae studied. © 2013 Copyright Taylor and Francis Group, LLC.

Rainha N.,Institute Inovacao Tecnologica Dos Acores INOVA | Rainha N.,University of Lisbon | Medeiros V.P.,Institute Inovacao Tecnologica Dos Acores INOVA | Medeiros V.P.,University of The Azores | And 9 more authors.
Physiologia Plantarum | Year: 2016

Plants with the crassulacean acid metabolism (CAM) express high-metabolic plasticity, to adjust to environmental stresses. This article hypothesizes that irradiance and nocturnal temperatures are the major limitations for CAM at higher latitudes such as the Azores (37°45'N). Circadian CAM expression in Ananas comosus L. Merr. (pineapple) was assessed by the diurnal pattern of leaf carbon fixation into l-malate at the solstices and equinoxes, and confirmed by determining maximal phosphoenolpyruvate carboxylase (PEPC) activity in plant material. Metabolic adjustments to environmental conditions were confirmed by gas exchange measurements, and integrated with environmental data to determine CAM's limiting factors: light and temperature. CAM plasticity was observed at the equinoxes, under similar photoperiods, but different environmental conditions. In spring, CAM expression was similar between vegetative and flowering plants, while in autumn, flowering (before anthesis) and fructifying (with fully developed fruit before ripening) plants accumulated more l-malate. Below 100 μmol m-2 s-1, CAM phase I was extended, reducing CAM phase III during the day. Carbon fixation inhibition may occur by two major pathways: nocturnal temperature (<15°C) inhibiting PEPC activity and l-malate accumulation; and low irradiance influencing the interplay between CAM phase I and III, affecting carboxylation and decarboxylation. Both have important consequences for plant development in autumn and winter. Observations were confirmed by flowering time prediction using environmental data, emphasizing that CAM expression had a strong seasonal regulation due to a complex network response to light and temperature, allowing pineapple to survive in environments not suitable for high productivity. © 2015 Scandinavian Plant Physiology Society.

Rainha N.,Institute Inovacao Tecnologica Dos Acores INOVA | Rainha N.,University of Lisbon | Medeiros V.P.,Institute Inovacao Tecnologica Dos Acores INOVA | Ferreira C.,Institute Inovacao Tecnologica Dos Acores INOVA | And 6 more authors.
Plant Physiology and Biochemistry | Year: 2016

In plants with Crassulacean Acid Metabolism (CAM), organic acids, mainly malate are crucial intermediates for carbon fixation. In this research we studied the circadian oscillations of three organic anions (malate, citrate, and succinate) in Ananas comosus, assessing the effect of season and plant development stage. Seasonal and plant development dependencies were observed. The circadian oscillations of malate and citrate were typical of CAM pathways reported in the literature. Citrate content was quite stable (25-30 μmol g-1 FW) along the day, with a seasonal effect. Succinate was shown to have both diurnal and seasonal oscillations and also a correlation with malate, since it accumulated during the afternoon when malate content was normally at a minimum, suggesting a possible mechanistic effect between both anions in CAM and/or respiratory metabolisms. © 2016 Elsevier Masson SAS.

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