Recruitment of crustose coralline algae on tiles material for monitoring coral larvae settlement's consolidators at Nature Reserve Pulau Sempu, East Java, Indonesia / Recrutamento de algas coralinas crustosas em azulejos para monitorar consolidadores de assentamentos de larvas de coral na Reserva Natural Pulau Sempu, Java Oriental, Indonésia

Crustose coralline algae (Corallinophycideae) are red algae that produced calcium carbonate and are well recognized as foundation species in the epipelagic zone of the marine ecosystem. These algae induced settlement juvenile of coral by released chemical cues from bacterial communities on the surface of their colonies. Their extracellular calcium carbonate also can stabilize reef structure that influencing many invertebrate attaches and growth in the seabed. Crustose coralline algae (CCA) have obtained attention because of their distribution and health compromise to increasing seawater temperature, ocean acidification, and pollutant. As a cryptic species in the ecosystem, the presence of CCA recruit sometimes doesn’t have attention, especially on their capability to occupy the empty space. This study aimed to document coverage and number of CCA recruit in two different recruitment tile’s material. The highest CCA percentage of the cover was showed inside surface than others surface in all stations. Light intensity and low sedimentation were suggested as a key factor of success of high coverage. Overall, station higher CCA recruits have shown from Tiga Warna. Low sedimentation and protection from aerial exposure became the main reason for it. No significant difference number of CCA recruits between marble and sandstone in this study. Successful CCA recruitment in this study can give a wide picture that natural recruitment of coral and other reef biodiversity in Southern Malang might be will succeed because of the abundance of coralline algae that support their life history stage.

As algas coralinas crustosas (Corallinophycideae) são algas vermelhas que produzem carbonato de cálcio e são bem reconhecidas como espécies de base na zona epipelágica do ecossistema marinho. Essas algas induziram o assentamento juvenil de coral por meio de estímulos químicos liberados por comunidades bacterianas na superfície de suas colônias. Seu carbonato de cálcio extracelular também pode estabilizar a estrutura do recife que influencia muitos invertebrados anexados e crescimento no fundo do mar. As algas coralinas crustosas (CCA) têm obtido atenção devido à sua distribuição e comprometimento da saúde com o aumento da temperatura da água do mar, acidificação dos oceanos e poluentes. Como uma espécie enigmática no ecossistema, a presença de recrutamento CCA às vezes não recebe atenção, especialmente em sua capacidade de ocupar o espaço vazio. Este estudo teve como objetivo documentar a cobertura e o número de recrutamento de CCA em dois materiais de recrutamento diferentes. A maior porcentagem de CCA da cobertura foi mostrada na superfície interna do que nas outras superfícies em todas as estações. A intensidade da luz e a baixa sedimentação foram sugeridas como um fator-chave para o sucesso da alta cobertura. De modo geral, recrutas de CCA mais graduados mostraram-se em Tiga Warna. A baixa sedimentação e a proteção contra a exposição aérea se tornaram a principal razão para isso. Não houve diferença significativa no número de recrutas CCA entre mármore e arenito neste estudo. O recrutamento bem-sucedido de CCA neste estudo pode dar uma imagem ampla de que o recrutamento natural de corais e outros recifes da biodiversidade no sul de Malang será bem-sucedido por causa da abundância de algas coralinas que sustentam seu estágio de história de vida.

Physiological and biochemical responses driven by different UV-visible radiation in Osmundea pinnatifida (Hudson) Stackhouse (Rhodophyta).

Light, or visible radiation, serves as a source of energy for photosynthesis of plants and most algae. In addition, light and ultraviolet radiation (UV-A and UV-B) act as a biological signal, triggering several cellular processes that are mediated by photoreceptors. The aim of this study was to evaluate the physiological and biochemical responses of Osmundea pinnatifida driven by different radiations through putative photoreceptors. For this, O. pinnatifida was grown under different radiation treatments composed by high intensity of light emitted by a low pressure sodium lamp (SOX), aiming to saturate photosynthesis, which was supplemented by low intensities of visible (red, green and blue) and ultraviolet radiation (UV-A and UV-B), in order to activate photoreceptors. Growth rates, photosynthesis, antioxidant activity, polyphenols, soluble proteins, phycobiliproteins, mycosporine-like amino acids (MAAs) and carotenoids were evaluated during the experiment. Complementary UV-A radiation positively influenced growth rates after 15 days of experiment, although the presence of a peak of blue light in this treatment can also have contributed. UV-B radiation increased the concentration of zeaxanthin and chlorophyll a. The blue light caused the accumulation of chlorophyll a, violaxanthin, phycoerythrin and polyphenols on different days of the experiment. Phycoerythrin also increased under green and red light conditions. Our results showed that some compounds can be modulated by different radiation, and the involvement of photoreceptors is suggested. In red algae, photoreceptors sensitive to red, green and blue light have been identified, however little is known about UV photoreceptors. The presence of photoreceptors sensitive to UV radiation in O. pinnatifida is discussed.

Expression of Genes Related to Carrageenan Synthesis during Carposporogenesis of the Red Seaweed Grateloupia imbricata.

Carrageenan, the foremost constituent of extracellular matrix of some rhodophyta, is a galactan backbone with a different number of sulphate groups attached. Variations of degree of sulphation are associated with different types of carrageenans, which vary according to seaweed life cycles, and have consequences for the exploitation of this raw material. In this work, we used three well-recognised stages of development thalli and two stages of cystocarp maturation to analyse genes that encode addition and elimination of sulphate groups to cell-wall galactan of the red seaweed Grateloupia imbricata. Expressions of carbohydrate sulfotransferase and galactose-6 sulfurylase and genes encoding stress proteins such as cytochrome P450 and WD40, were examined. Results showed that transcript expression of carbohydrate sulfotransferase occurs at all stage of thalli development. Meanwhile galactose-6 sulfurylase expressions displayed different roles, which could be related to a temporal regulation of cystocarp maturation. Cytochrome P450 and WD40 are related to the disclosure and maturation of cystocarps of G. imbricata. Our conclusion is that differential expression of genes encoding proteins involved in the sulphation and desulphation of galactan backbone is associated with alterations in thalli development and cystocarp maturation in the red seaweed Grateloupia imbricata. Exploitation of industry-valued carrageenan will depend on insight into gene mechanisms of red seaweeds.

Autotrophic and Heterotrophic Growth Conditions Modify Biomolecole Production in the Microalga Galdieria sulphuraria (Cyanidiophyceae, Rhodophyta).

Algae have multiple similarities with fungi, with both belonging to the Thallophyte, a polyphyletic group of non-mobile organisms grouped together on the basis of similar characteristics, but not sharing a common ancestor. The main difference between algae and fungi is noted in their metabolism. In fact, although algae have chlorophyll-bearing thalloids and are autotrophic organisms, fungi lack chlorophyll and are heterotrophic, not able to synthesize their own nutrients. However, our studies have shown that the extremophilic microalga Galderia sulphuraria (GS) can also grow very well in heterotrophic conditions like fungi. This study was carried out using several approaches such as scanning electron microscope (SEM), gas chromatography/mass spectrometry (GC/MS), and infrared spectrophotometry (ATR-FTIR). Results showed that the GS, strain ACUF 064, cultured in autotrophic (AGS) and heterotrophic (HGS) conditions, produced different biomolecules. In particular, when grown in HGS, the algae (i) was 30% larger, with an increase in carbon mass that was 20% greater than AGS; (ii) produced higher quantities of stearic acid, oleic acid, monounsaturated fatty acids (MUFAs), and ergosterol; (iii) produced lower quantities of fatty acid methyl esters (FAMEs) such as methyl palmytate, and methyl linoleate, saturated fatty acids (SFAs), and poyliunsaturated fatty acids (PUFAs). ATR-FTIR and principal component analysis (PCA) statistical analysis confirmed that the macromolecular content of HGS was significantly different from AGS. The ability to produce different macromolecules by changing the trophic conditions may represent an interesting strategy to induce microalgae to produce different biomolecules that can find applications in several fields such as food, feed, nutraceutical, or energy production.

Day/Night Separation of Oxygenic Energy Metabolism and Nuclear DNA Replication in the Unicellular Red Alga Cyanidioschyzon merolae.

The transition from G1 to S phase and subsequent nuclear DNA replication in the cells of many species of eukaryotic algae occur predominantly during the evening and night in the absence of photosynthesis; however, little is known about how day/night changes in energy metabolism and cell cycle progression are coordinated and about the advantage conferred by the restriction of S phase to the night. Using a synchronous culture of the unicellular red alga Cyanidioschyzon merolae, we found that the levels of photosynthetic and respiratory activities peak during the morning and then decrease toward the evening and night, whereas the pathways for anaerobic consumption of pyruvate, produced by glycolysis, are upregulated during the evening and night as reported recently in the green alga Chlamydomonas reinhardtii Inhibition of photosynthesis by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) largely reduced respiratory activity and the amplitude of the day/night rhythm of respiration, suggesting that the respiratory rhythm depends largely on photosynthetic activity. Even when the timing of G1/S-phase transition was uncoupled from the day/night rhythm by depletion of retinoblastoma-related (RBR) protein, the same patterns of photosynthesis and respiration were observed, suggesting that cell cycle progression and energy metabolism are regulated independently. Progression of the S phase under conditions of photosynthesis elevated the frequency of nuclear DNA double-strand breaks (DSB). These results suggest that the temporal separation of oxygenic energy metabolism, which causes oxidative stress, from nuclear DNA replication reduces the risk of DSB during cell proliferation in C. merolaeIMPORTANCE Eukaryotes acquired chloroplasts through an endosymbiotic event in which a cyanobacterium or a unicellular eukaryotic alga was integrated into a previously nonphotosynthetic eukaryotic cell. Photosynthesis by chloroplasts enabled algae to expand their habitats and led to further evolution of land plants. However, photosynthesis causes greater oxidative stress than mitochondrion-based respiration. In seed plants, cell division is restricted to nonphotosynthetic meristematic tissues and populations of photosynthetic cells expand without cell division. Thus, seemingly, photosynthesis is spatially sequestrated from cell proliferation. In contrast, eukaryotic algae possess photosynthetic chloroplasts throughout their life cycle. Here we show that oxygenic energy conversion (daytime) and nuclear DNA replication (night time) are temporally sequestrated in C. merolae This sequestration enables "safe" proliferation of cells and allows coexistence of chloroplasts and the eukaryotic host cell, as shown in yeast, where mitochondrial respiration and nuclear DNA replication are temporally sequestrated to reduce the mutation rate.

Biochemical composition and in vitro digestibility of Galdieria sulphuraria grown on spent cherry-brine liquid.

The aim of this work was to valorise an industrial food by-product and to produce a microalgal biomass rich in phytochemicals at high added value for food and nutraceutical applications. The biochemical composition, in vitro digestibility and antioxidant activity of Galdieria sulphuraria biomass grown heterotrophically on standard medium (SM) and on spent Cherry-Brine Liquid (sCBL) were assessed and compared. The biomass produced in sCBL was characterized by a lower content of proteins and lipids, while showing an increase in carbohydrates and polyphenols (5.3 vs 1.6 mg g-1). The sCBL biomass lipid moiety had a lower palmitic and linoleic acid content and a higher oleic acid concentration than SM. The total protein digestibility of Galdieria grown in SM and sCBL was 79% and 63% respectively. The antioxidant activity (AA) of G. sulphuraria biomass grown in sCBL was significantly higher than that grown in SM. Studying the AA release for sCBL biomass during the digestion, the highest value was found in the intestinal phase. In conclusion, G. sulphuraria has a valuable nutritional profile and could become a valuable source of phytochemicals, depending on the cultivation media. Cultivation on sCBL would allow an environmentally and economically sustainable process, valorising the food by-product and producing a microalgal biomass rich in cherry anthocyanins with high AA released at the intestinal level.

Climate change induced range shifts in seaweeds distributions in Europe.

There are evidences of how climate change is affecting seaweeds distribution and the ecosystems services they provide. Therefore, it is necessary to consider these impacts when managing marine areas. One of the most applied tools in recent years to deal with this are species distribution models, however there are still some challenges to solve, such as the inclusion of hydrodynamic predictors and the application of effective, transferable and user-oriented methodologies. Five species (Saccorhiza polyschides, Gelidium spinosum, Sargassum muticum, Pelvetia canaliculata and Cystoseira baccata) in Europe and 15 variables were considered. Nine of them were projected to the RCPs 4.5 and 8.5 for the mid-term (2040-2069) and the long term (2070-2099). Algorithms for each species were applied to generate models that were assessed by comparison of probabilities and observations (area under the curve, true skill statistics, Boyce index, sensitivity, correct classification rate), niches overlap (Schoener's D, Hellinger's I), geographical similarity (interquartile range) and ecological realism. Models built demonstrated very good predictive accuracy and sensitivity, without overfitting risk. A medium overlap in the historical and RCPs environmental conditions were obtained, therefore the models can be considered transferable and results accurate because only some isolated points were detected as outliers, corresponding to low probabilities. The areas of S. polyschides and G. spinosum have been identified to be dramatically reduced, meanwhile S. muticum and C. baccata were predicted to expand their range. P. canaliculata was expected to keep its sites of presence but with a decrease in its probability of occurrence. For all species it was remarkable the importance of hydrodynamic variables and parameters representing extreme conditions. Spatially predictions of the potential species and areas at risk are decisive for defining management strategies and resource allocation. The performance and usefulness of the approach applied in this study have been demonstrated for algae with different ecological requirements (from upper littoral to subtidal) and distributional patterns (native and invasive), therefore results can be used by marine planners with different goals: marine protected areas designation, monitoring efforts guiding, invasions risk assessment or aquaculture facilities zonation.

Participation of actin filaments, myosin and phosphatidylinositol 3-kinase in the formation and polarisation of tetraspore germ tube of Gelidium floridanum (Rhodophyta, Florideophyceae).

This study aimed to examine the evidence of direct interaction among actin, myosin and phosphatidylinositol 3-kinase (PI3K) in the polarisation and formation of the tetraspore germ tube of Gelidium floridanum. After release, tetraspores were exposed to cytochalasin B, latrunculin B, LY294002 and BDM for a period of 6 h. In control samples, formation of the germ tube occurred after the experimental period, with cellulose formation and elongated chloroplasts moving through the tube region in the presence of F-actin. In the presence of cytochalasin B, an inhibitor of F-actin, latrunculin B, an inhibitor of G-actin, and BDM, a myosin inhibitor, tetraspores showed no formation of the germ tube or cellulose. Spherical-shaped chloroplasts were observed in the central region with a few F-actin filaments in the periphery of the cytoplasm. Tetraspores treated with LY294002, a PI3K inhibitor, showed no formation of the tube at the highest concentrations. Polarisation of cytoplasmic contents did not occur, only cellulose formation. It was concluded that F-actin directs the cell wall components and contributes to the maintenance of chloroplast shape and elongation during germ tube formation. PI3K plays a fundamental role in signalling for the asymmetric polarisation of F-actin. Thus, F-actin regulates the polarisation and germination processes of tetraspores of G. floridanum.

Effects of Ultraviolet Radiation (UVA + UVB) on Germination of Carpospores of the Red Macroalga Pyropia acanthophora var. brasiliensis (Rhodophyta, Bangiales): Morphological Changes.

Carpospores of Pyropia acanthophora var. brasiliensis are dispersion and reproduction units responsible for giving rise to the diploid filamentous structure of this alga's life cycle. The present study assesses the anthropogenic impact of ultraviolet radiation (UVR) on morphology and ultrastructure, spore viability, autofluorescence of chloroplasts and the amount of intensity of ROS during the germination of carpospores. Carpospores were cultivated at 24 ± 1°C, 40 ± 10 µmol photons m-2  s-1 with photoperiod of 12 h and exposed to UVAR + UVBR for 3 h a day for 2 days with a daily dose of 5.05 J cm-2 for UVAR and 0.095 J cm-2 for UVBR. Samples were cultured for another five days exposed only to PAR in order to confirm their viability after the initial 2-day exposure. Carpospores showed significant sensitivity to UVR exposure after only 48 h, including changes in developmental rate, overall morphology, cell organization and chloroplast autofluorescence. UVR exposure inhibited germ tube formation in carpospores, which were mostly nonviable and/or altered, showing retracted cytoplasm and disorganized cytoplasmic content. Even in the absence of UVR exposure, carpospores remained collapsed, indicating irreversible damage. It can be concluded that UVR is a limiting factor for the development of P. acanthophora.

The impact of elevated atmospheric CO2 on cadmium toxicity in Pyropia haitanensis (Rhodophyta).

Cadmium is one of the major heavy metal pollutions in coastal waters, and it is well known that cadmium at trace concentration is toxic to macroalgae. Change in marine carbonate system and ocean acidification caused by elevated atmospheric CO2 also alter physiological characteristics of macroalgae. However, less research is focused on the combined impacts of elevated CO2 and cadmium pollution on the growth and physiology in macroalgae. In this study, the maricultivated macroalga Pyropia haitanensis (Rhodophyta) was cultured at three levels of Cd2+ (control, 4 and 12 mg L-1) and two concentrations of CO2, the ambient CO2 (AC, 410 ppm) and elevated CO2 (HC, 1100 ppm). The results showed that 12 mg L-1 Cd2+ significantly suppressed the relative growth rate and superoxide dismutase activity in AC-grown P. haitanensis, while such inhibition extents by Cd2+ were alleviated in HC-grown algae. Cd2+ had no effects on efficiency of electron transport (α) and maximum electron transport rate (ETRmax), but α was increased by elevated CO2. Cd2+ dramatically suppressed the maximum net photosynthesis oxygen evolution rate (NPRm) and the minimum saturation irradiance (Ik) when the algal thalli were grown at AC, while such suppression of NPRm by Cd2+ was much decreased when the thalli were grown at HC. Collectively, our results suggested that elevated CO2 would alleviate Cd2+ toxicity on P. haitanensis.

Molecular mechanisms underlying Grateloupia imbricata (Rhodophyta) carposporogenesis induced by methyl jasmonate.

When applied in vitro, methyl jasmonate is sensed by the red seaweed Grateloupia imbricate, substantially and visually affecting its carposporogenesis. However, although there is some understanding of the morphological changes induced by methyl jasmonate in vitro, little is known about the genes that are involved in red seaweed carposporogenesis and how their protein products act. For the work reported herein, the expression of genes in red seaweed that encode enzymes involved in the synthesis of methyl jasmonate (jasmonic acid carboxyl methyl transferase and a putative methyl transferase) was monitored. Additionally the genes involved in oxidation (cytochrome P450 and WD40), jasmonate synthesis, signal transduction, and regulation of reactive oxygen species (MYB), and reproduction (ornithine decarboxylase) were monitored. To determine when or if the aforementioned genes were expressed during cystocarp development, fertilized and fertile thalli were exposed to methyl jasmonate and gene expression was measured after 24 and 48 h. The results showed that methyl jasmonate promoted differential gene expression in fertilized thalli by 24 h and upregulated expression of the ornithine decarboxylase gene only by 48 h in fertile thalli (0.75 ± 003 copies · µL-1 at 24 h vs. 1.11 ± 0.04 copies · µL-1 at 48 h). We conclude that Ornithine decarboxylase expression involves methyl jasmonate signaling as well as development and maturation of cystocarps.

Lipid metabolism and potentials of biofuel and high added-value oil production in red algae.

Biomass production is currently explored in microalgae, macroalgae and land plants. Microalgal biofuel development has been performed mostly in green algae. In the Japanese tradition, macrophytic red algae such as Pyropia yezoensis and Gelidium crinale have been utilized as food and industrial materials. Researches on the utilization of unicellular red microalgae such as Cyanidioschyzon merolae and Porphyridium purpureum started only quite recently. Red algae have relatively large plastid genomes harboring more than 200 protein-coding genes that support the biosynthetic capacity of the plastid. Engineering the plastid genome is a unique potential of red microalgae. In addition, large-scale growth facilities of P. purpureum have been developed for industrial production of biofuels. C. merolae has been studied as a model alga for cell and molecular biological analyses with its completely determined genomes and transformation techniques. Its acidic and warm habitat makes it easy to grow this alga axenically in large scales. Its potential as a biofuel producer is recently documented under nitrogen-limited conditions. Metabolic pathways of the accumulation of starch and triacylglycerol and the enzymes involved therein are being elucidated. Engineering these regulatory mechanisms will open a possibility of exploiting the full capability of production of biofuel and high added-value oil. In the present review, we will describe the characteristics and potential of these algae as biotechnological seeds.

Potential anti-inflammatory natural products from marine algae.

Inflammatory diseases have become one of the leading causes of health issue throughout the world, having a considerable influence on healthcare costs. With the emerging developments in natural product, synthetic and combinatorial chemistry, a notable success has been achieved in discovering natural products and their synthetic structural analogs with anti-inflammatory activity. However, many of these therapeutics have indicated detrimental side effects upon prolonged usage. Marine algae have been identified as an underexplored reservoir of unique anti-inflammatory compounds. These include polyphenols, sulfated polysaccharides, terpenes, fatty acids, proteins and several other bioactives. Consumption of these marine algae could provide defense against the pathophysiology of many chronic inflammatory diseases. With further investigation, algal anti-inflammatory phytochemicals have the potential to be used as therapeutics or in the synthesis of structural analogs with profound anti-inflammatory activity with reduced side effects. The current review summarizes the latest knowledge about the potential anti-inflammatory compounds discovered from marine algae.

Occurrence of jasmonates during cystocarp development in the red alga Grateloupia imbricata.

In this study, we highlight the effects of methyl jasmonate (MeJa) on cystocarp development in the red macroscopic alga Grateloupia imbricata. In G. imbricata, jasmonate release is related to the reproductive state, as fertile thalli (i.e., those that have cystocarps) released significant amounts of this volatile compound (1.27 ± 0.20 mM · mg fw-1  · h-1 ) compared with infertile thalli (0.95 ± 0.12 mM · mg fw-1  · h-1 ). Treating G. imbricata thalli with MeJa revealed a significant increase in cystocarp number (1.5 ± 0.27 cystocarps · mm-2 ), which was ~7.5-fold greater than in untreated thalli (0.2 ± 0.07 cystocarps · mm-2 ). Maturation was completed within 48 h with MeJa treatment, a shortening of the typical >3-week maturation period, and included the opening of cystocarps and the presence of dehiscent cavities. Release rates of jasmonates after exogenous MeJa treatment were also modified based on the cystocarp maturation level. All of these effects were reduced in the presence of phenidone, which blocks MeJa production, indicating that the MeJa action is genuine. The effects of MeJa during cystocarp maturation were not replicated by derivatives of reactive oxygen species from the same jasmonic acid biosynthetic pathway, as the activities of scavenger enzymes and lipid peroxidation were unchanged between infertile and fertile thalli. Therefore, a reactive oxygen species-based mechanism is not involved during cystocarp development. We conclude that MeJa has an independent function as a growth regulator during G. imbricata reproduction.

Impact of Sulfur Starvation in Autotrophic and Heterotrophic Cultures of the Extremophilic Microalga Galdieria phlegrea (Cyanidiophyceae).

In plants and algae, sulfate assimilation and cysteine synthesis are regulated by sulfur (S) accessibility from the environment. This study reports the effects of S deprivation in autotrophic and heterotrophic cultures of Galdieria phlegrea (Cyanidiophyceae), a unicellular red alga isolated in the Solfatara crater located in Campi Flegrei (Naples, Italy), where H2S is the prevalent form of gaseous S in the fumarolic fluids and S is widespread in the soils near the fumaroles. This is the first report on the effects of S deprivation on a sulfurous microalga that is also able to grow heterotrophically in the dark. The removal of S from the culture medium of illuminated cells caused a decrease in the soluble protein content and a significant decrease in the intracellular levels of glutathione. Cells from heterotrophic cultures of G. phlegrea exhibited high levels of internal proteins and high glutathione content, which did not diminish during S starvation, but rather glutathione significantly increased. The activity of O-acetylserine(thiol)lyase (OASTL), the enzyme synthesizing cysteine, was enhanced under S deprivation in a time-dependent manner in autotrophic but not in heterotrophic cells. Analysis of the transcript abundance of the OASTL gene supports the OASTL activity increase in autotrophic cultures under S deprivation.

In silico characterization of DNA motifs associated with the differential expression of the ornithine decarboxylase gene during in vitro cystocarp development in the red seaweed Grateloupia imbricata.

To gain a better understanding of the regulatory mechanism(s) modulating expression of the ornithine decarboxylase gene ODC during cystocarp development in the red seaweed Grateloupia imbricata, DNA motifs found in the 5'-upstream region of the gene were identified by in silico analysis. In addition, when infertile G. imbricata thalli were treated with ethylene, methyl jasmonate, or light as an elicitor of cystocarp development, different ODC expression patterns were observed. ODC expression correlated with (i) the elicitation (treatment) period and the period post-treatment just prior to observation of the first visible developing cystocarps (disclosure period), and (ii) the type of elicitor. Ethylene and light activated ODC expression during the elicitation period, and methyl jasmonate activated its expression during the disclosure period, suggesting that initiation and cystocarp development may involve more than one signaling pathway. In addition, expression of ODC was 450-fold greater when thalli were stimulated by ethylene compared with untreated control thalli, suggesting that G. imbricata mounts an efficient response to sense and activate ethylene-responsive signaling pathways. The patterns of differential ODC expression induced by the different elicitors during cystocarp development might provide an useful tool for characterizing the precise transcriptional regulation of ODC in G. imbricata.

Differential responses of tetrasporophytes and gametophytes of Mazzaella laminarioides (Gigartinales, Rhodophyta) under solar UV radiation.

The effects of solar UV radiation on mycosporine-like amino acids (MAAs), growth, photosynthetic pigments (Chl a, phycobiliproteins), soluble proteins (SP), and C and N content of Mazzaella laminarioides tetrasporophytes and gametophytes were investigated. Apical segments of tetrasporophytes and gametophytes were exposed to solar radiation under three treatments (PAR [P], PAR+UVA [PA], and PAR+UVA+UVB [PAB]) during 18 d in spring 2009, Punta Arenas, Chile. Samples were taken after 2, 6, 12, and 18 d of solar radiation exposure. Most of the parameters assessed on M. laminarioides were significantly influenced by the radiation treatment, and both gametophytes and tetrasporophytes seemed to respond differently when exposed to high UV radiation. The two main effects promoted by UV radiation were: (i) higher synthesis of MAAs in gametophytes than tetrasporophytes at 2 d, and (ii) a decrease in phycoerythrin, phycocyanin, and SPs, but an increase in MAA content in tetrasporophytes at 6 and 12 d of culture. Despite some changes that were observed in biochemical parameters in both tetrasporophytes and gametophytes of M. laminarioides when exposed to UVB radiation, these changes did not promote deleterious effects that might interfere with the growth in the long term (18 d). The tolerance and resistance of M. laminarioides to higher UV irradiance were expected, as this intertidal species is exposed to variation in solar radiation, especially during low tide.

Functional recombinants designed from a fetuin/asialofetuin-specific marine algal lectin, rhodobindin.

Plant lectins have attracted much attention for biomedical applications including targeted drug delivery system and therapy against tumors and microbial infections. The main problem of using lectins as a biomedical tool is a batch-to-batch variation in isoforms content. The production of lectins using recombination tools has the advantage of obtaining high amounts of proteins with more precise properties, but there are only a handful of functional recombinant lectins presently available. A fetuin/asialo-fetuin specific lectin, Rhodobindin, has unique tandem repeats structure which makes it useful in exploiting for recombinant lectin. We developed three functional recombinant lectins using E. coli expression system: one from full cDNA sequence and two from fragmentary sequences of Rhodobindin. Hemagglutinating activity and solubility of the recombinant lectins were highest at OD 0.7 cell concentration at 20 °C. The optimized process developed in this study was suitable for the quality-controlled production of high amounts of soluble recombinant lectins.

The effect of cadmium under different salinity conditions on the cellular architecture and metabolism in the red alga Pterocladiella capillacea (Rhodophyta, Gelidiales).

The in vitro effect of cadmium (Cd) on apical segments of Pterocladiella capillacea was examined. Over a period of 7 days, the segments were cultivated with the combination of different salinities (25, 35, and 45 practical salinity units) and Cd concentrations, ranging from 0.17 to 0.70 ppm. The effects of Cd on growth rates and content of photosynthetic pigments were analyzed. In addition, metabolic profiling was performed, and samples were processed for microscopy. Serious damage to physiological performance and ultrastructure was observed under different combinations of Cd concentrations and salinity values. Elementary infrared spectroscopy revealed toxic effects registered on growth rate, photosynthetic pigments, chloroplast, and mitochondria organization, as well as changes in lipids and carbohydrates. These alterations in physiology and ultrastructure were, however, coupled to activation of such defense mechanisms as cell wall thickness, reduction of photosynthetic harvesting complex, and flavonoid. In conclusion, P. capillacea is especially sensitive to Cd stress when intermediate concentrations of this pollutant are associated with low salinity values. Such conditions resulted in metabolic compromise, reduction of primary productivity, i.e., photosynthesis, and carbohydrate accumulation in the form of starch granules. Taken together, these findings improve our understanding of the potential impact of this metal in the natural environment.

Effects of ultraviolet radiation (UVA+UVB) on young gametophytes of Gelidium floridanum: growth rate, photosynthetic pigments, carotenoids, photosynthetic performance, and ultrastructure.

This study investigated the effects of radiation (PAR+UVA+UVB) on the development and growth rates (GRs) of young gametophytes of Gelidium floridanum. In addition, photosynthetic pigments were quantified, carotenoids identified, and photosynthetic performance assessed. Over a period of 3 days, young gametophytes were cultivated under laboratory conditions and exposed to photosynthetically active radiation (PAR) at 80 µmol photons m(-2) s(-1) and PAR+UVA (0.70 W m(-2))+UVB (0.35 W m(-2)) for 3 h per day. The samples were processed for light and electron microscopy to analyze the ultrastructure features, as well as carry out metabolic studies of GRs, quantify the content of photosynthetic pigments, identify carotenoids and assess photosynthetic performance. PAR+UVA+UVB promoted increase in cell wall thickness, accumulation of floridean starch grains in the cytoplasm and disruption of chloroplast internal organization. Algae exposed to PAR+UVA+UVB also showed a reduction in GR of 97%. Photosynthetic pigments, in particular, phycoerythrin and allophycocyanin contents, decreased significantly from UV radiation exposure. This result agrees with the decrease in photosynthetic performance observed after exposure to ultraviolet radiation, as measured by a decrease in the electron transport rate (ETR), where values of ETRmax declined approximately 44.71%. It can be concluded that radiation is a factor that affects the young gametophytes of G. floridanum at this stage of development.