Ingestion of contaminated kelps by the herbivore Tetrapygus niger: Negative effects on food intake, growth, fertility, and early development

Indexación ScopusMacrocystis pyrifera reaches distant areas after detachment, accumulate heavy metals, and serve as trophic subsidy. In this context, effects on both adults and larvae of Tetrapygus niger fed with polluted kelps were determined by assessing growth, fertility, and early larval development. Results revealed that sea urchins fed with polluted kelps from highly impacted zone (HIZ) showed a lower growth (3.6% gained weight) and gamete release (358 cells mL−1) than those fed with non-impacted kelps (NIZ) (19.3% and 945 cells mL−1). The HIZ treatment showed a developmental delay in comparison to NIZ, accounted mainly by the abundance of malformed 2-arm pluteus larvae (10–15%) during most of the culture. Malformed 4-arm pluteus larvae showed a constant increase, reaching 37% at the end of the culture. Thus, the pollutants ingested by sea urchins can be transferred to their offspring and cause negative effects in their early development, categorizing M. pyrifera as a pollutant carrier. © 2021 The Authorshttps://www-sciencedirect-com.recursosbiblioteca.unab.cl/science/article/pii/S0025326X21003994?via%3Dihu

Proteome analysis reveals extensive light stress-response reprogramming in the seagrass Zostera muelleri (alismatales, zosteraceae) metabolism

© 2017, Kumar, Padula, Davey, Pernice, Jiang, Sablok, Contreras-Porcia and Ralph. Seagrasses are marine ecosystem engineers that are currently declining in abundance at an alarming rate due to both natural and anthropogenic disturbances in ecological niches. Despite reports on the morphological and physiological adaptations of seagrasses to extreme environments, little is known of the molecular mechanisms underlying photo-acclimation, and/or tolerance in these marine plants. This study applies the two-dimensional isoelectric focusing (2D-IEF) proteomics approach to identify photo-acclimation/tolerance proteins in the marine seagrass Zostera muelleri. For this, Z. muelleri was exposed for 10 days in laboratory mesocosms to saturating (control, 200 µmol photons m−2 s−1), super-saturating (SSL, 600 µmol photons m−2 s−1), and limited light (LL, 20 µmol photons m−2 s−1) irradiance conditions. Using LC-MS/MS analysis, 93 and 40 protein spots were differentially regulated under SSL and LL conditions, respectively, when compared to the control. In contrast to the LL condition, Z. muelleri robustly tolerated super-saturation light than control conditions, evidenced by their higher relative maximum electron transport rate and minimum saturating irradiance values. Proteomic analyses revealed up-regulation and/or appearances of proteins belonging to the Calvin-Benson and Krebs cycle, glycolysis, the glycine cleavage system of photorespiration, and the antioxidant system. These proteins, together with those from the inter-connected glutamate-proline-GABA pathway, shaped Z. muelleri photosynthesis andgrowth under SSL conditions. In contrast, the LL condition negatively impacted the metabolic activities of Z. muelleri by down-regulating key metabolic enzymes for photosynthesis and the metabolism of carbohydrates and amino acids, which is consistent with the observation with lower photosynthetic performance under LL condition. This study provides novel insights into the underlying molecular photo-acclimation mechanisms in Z. muelleri, in addition to identifying protein-based biomarkers that could be used as early indicators to detect acute/chronic light stress in seagrasses to monitor seagrass health

Desarrollo y caracterización de seis marcadores microsatélites para el alga roja chilena pyropia orbicularis

Indexación: Scopus.Mariculture of edible Porphyra/Pyropia species, which are cosmopolitan red foliose algae, represent an important source of income for the pharmaceutical and food industries. In Chile, the most common alga of this complex is Pyropia orbicularis (Bangiales, Rhodophyta). Here we report 6 microsatellite markers obtained from P. orbicularis through a genomic library from 10 individuals of the gametophytic phase by next generation (Illumina) sequencing. Polymorphism analyses were done from 10 individuals of the conchocelis phase, revealing an allelic diversity ranging from three to six alleles per locus, and observed heterozygosity (HO) and expected heterozygosity (HE) ranging from 0.200 to 0.995, and 0.250 to 0.610, respectively. A large proportion of genetic variance (61%) in P. orbicularis was among individuals within population, and 39% genetic variance was among populations. Nonetheless, these results should be interpreted with caution; further research using larger sample sizes is required. These polymorphic markers could be useful in future studies on population genetic structure, for conservation and applied purposes.https://revistas.uv.cl/index.php/rbmo/article/view/235

Spatio-temporal variation in the composition of the macroalgae assemblage of the intertidal rocky zone from maitencillo, valparaíso, central coast of Chile

Indexación: Scopus.Records on the diversity of algae serve as a foundation for establishing management and environmental protection programs, as well as for determining new commercial uses of algae. With this context in mind, the goal of the present study was to determine the richness, coverage, and composition of the macroalgae assemblage in the intertidal zone of Maitencillo, Valparaíso, Chile over the course of 3 years (2013-2015). A total of 29 species were recorded from 3 phyla - 23 Rhodophyta; 3 Ochrophyta, of the Phaeophyceae class; and 3 Chlorophyta. Species richness presented high spatial and temporal variations, with these variations most significantly explained by intertidal zone (61%) and the seasons (31%). The highest levels of specific richness were recorded in the mid and lower intertidal zones (14 species) in spring, as well as in the lower intertidal zone (14 species) during summer. The lowest values of specific richness were recorded for the mid intertidal zone (2 species) during fall. The distinct levels of the intertidal zone also notably impacted algae assemblage, explaining 53% of variation while the seasons explained 18% of variation. The greatest coverage was recorded in the mid intertidal zone during spring, with a predominance of Mazzaella laminarioides and Ulva spp. complex. In turn, the lowest coverage was found in fall, linked with processes of sand accretion. In rocky walls, the Pyropia complex dominated. Results indicate a marked pattern of vertical and seasonal distribution in the macroalgae assemblage, as well as notably high presence of Rhodophyta species. This benthic flora description serves to update information on the diversity of representative algal species from Valparaíso Region of Chile. © 2018, Universidad de Valparaiso. All rights reserved

ß-glucans, production and properties in microalgae with emphasis on Nannochloropsis genus (Ochrophyta, Eustigmatales)

Indexación: Scopus; Scielo.Las microalgas son microorganismos eucariontes fotosintéticos capaces de producir una amplia gama de compuestos de interés comercial, tales como vitaminas, antioxidantes, ácidos grasos omega-3 e inmunoestimulantes como los ß-glucanos. Los ß-glucanos son polímeros de D-glucosa unidos por enlaces ß-1,3 o ß-1,4 los cuales pueden presentar ramificaciones de enlaces ß-1,6. Los más conocidos en microalgas son el paramilón (presente en euglenoides) y la crisolaminarina (presente en diatomeas). En el género Nannochloropsis, (Ochrophyta), la secuenciación de los genomas y los transcriptomas de algunas de sus especies ha evidenciado que también serían capaces de sintetizar ß-glucanos de enlaces ß-1,3 con ramificaciones ß-1,6. Si bien, existen pocos estudios con respecto a dichos compuestos en estas especies, se sugiere que corresponderían a moléculas de reserva energética de carbono, que reemplazan el almidón y que presentan un comportamiento similar al de los lípidos de reserva como el triacilglicerol (TAG). Por lo que, puden competir por las mismas moléculas precursoras derivadas de la fijación de carbono. La presencia de los ß-glucanos junto con su caracterización y la validación de sus propiedades beneficiosas para la salud humana, pueden otorgar un potencial interés económico al cultivo de Nannochloropsis. Estos cultivos, han adquirido un enorme interés debido a su alto contenido de TAG para la producción de biodiesel o ácido eicosapentanoico (EPA) para la alimentación de rotíferos, peces y humanos con fines nutracéuticos. Esta revisión tiene como finalidad evidenciar las propiedades de los ß-glucanos en microalgas y el uso potencial de Nannochloropsis en la producción de esas moléculas.Microalgae are photosynthetic eukariotic microorganisms capable of producing a wide range of compounds of commercial interest, such as vitamins, antioxidants, omega-3 fatty acids, and immunostimulants like ß-glucans. ß-glucans are D-glucose polymers linked by ß-1,3 and/or ß-1,4 bonds, which can present branches of ß-1,6 bonds. The most well known in microalgae are the paramylon (in euglenoids) and the chrysolaminarin (in diatoms). In the genus Nannochloropsis, (Ochrophyta), the genome and transcriptome sequencing of species has shown that they are also likely to be able to synthesize ß-glucans with ß-1,3 bonds with ß-1,6 side branches. There are few studies about these ß-glucans in those species but it is suggested that they are carbon/energy-storage molecules that replace starch and perform similarly to storage lipids such as triacylglycerol (TAG), competing for the same precursor molecules produced by the carbon fixation. The presence of ß-glucans, along with characterizing them and confirming their beneficial properties for human health, could grant a high potential to the culture of Nannochloropsis with commercial purposes. These cultures have already gained great interest because of their high contents of TAG used to produce biodiesel or eicosapentanoic acid (EPA) to feed rotifers, fish or for nutraceutical purposes in humans. The objective of this review is to describe the properties of b-glucans in microalgae and the potential use of Nannochloropsis in the production of these molecules.http://ref.scielo.org/57mjn

Polyamines: Stress Metabolite in Marine Macrophytes

© 2017 Elsevier B.V. All rights reserved. Marine macrophytes including seaweeds and sea grasses are the ecosystem engineers and experience constant threats from a wide range of anthropogenic stressors and climate fluctuations in their ecological niche. Marine macrophytes acclimate and/or tolerate these external perturbations by reprogramming their metabolite networks. Among the various metabolites that contribute to alleviate the stress, polyamines (PAs) are the nitrogenous metabolites that play a key role in plant growth, development, and biotic/abiotic stress protection in land plants. Their mode of action, signaling, and cross talk with diverse metabolic networks have been well studied in land plants; however, their functionality in marine macrophytes has merely scratched the window. In this brief chapter we attempt to summarize PA research in marine macrophytes in response to abiotic stress conditions. We emphasize to undertake futuristic efforts to explore PA involvement in stress response and to identify novel stress tolerance mechanism in marine macrophytes

Marine metal pollution and effects on seaweed species

© Springer International Publishing AG 2017. Heavy metals are significant pollutants continuously released into the biosphere, both naturally and anthropogenically. Conceptually, metal speciation, bioavailability, and associated toxicity in marine organisms depend on a wide array of abiotic and biotic factors. Among these, pH variation is one of the most important environmental factors influencing metal speciation and toxicity. Due to this, ocean acidification is expected to modify metal speciation, altering the effects these nondegradable contaminants have on marine organisms, such as seaweeds. One clear effect of heavy metals on seaweeds is the rapid formation of reactive oxygen species (ROS). The production of ROS beyond the physiological tolerance threshold causes an oxidative stress condition that, if not attenuated, can irreversibly damage cellular constituents such as DNA/RNA, proteins, and lipids. To cope with heavy metal excess, several mechanisms exist in tolerant seaweed species, including the activation of an efficient ROS-scavenging system constituted by metal-binding compounds, antioxidant enzymes, and oxygenated polyunsaturated fatty acids, among others. Another adaptive mechanism involves the participation of ATP-binding cassette (ABC) transporter proteins in translocating a wide variety of compounds across cell membranes, including heavy metals. In contrast, an excessive heavy metal presence can inhibit photosynthesis, reduce pigment concentration and growth, induce cation losses, and disrupt gametophyte development in non-tolerant seaweed species. In a scenario of lowered ocean pH and increased heavy metal toxicity, the important roles played by non-tolerant seaweed species in structuring communities could be severely compromised, with unknown consequences for associated organisms. Therefore, in the upcoming decades, marine pollution could majorly shift and rearrange community compositions and the distributional ranges of species

Seaweeds early development: detrimental effects of desiccation and attenuation by algal extracts

The effects of desiccation on the early development stages of Mazzaella laminarioides, Scytosiphon lomentaria and Lessonia nigrescens, algal species with different patterns of distribution across the intertidal zone, were examined in the laboratory. In addition, the protective effect against desiccation was evaluated using algal extracts, including those from Porphyra columbina, a macroalga tolerant to desiccation that lives in the uppermost part of the intertidal zone. Our results showed that M. laminarioides displayed the highest resistance to daily desiccation, followed by S. lomentaria, whereas L. nigrescens was the most susceptible. Spores from L. nigrescens exposed to desiccation, although being able to germinate, ceased further post-germination development. In addition, our results showed that all species exposed to extracts from desiccated P. columbina successfully completed their development and strongly suggest the occurrence of compounds with protective properties that help in attenuating the stress caused by desiccation. Finally, our results indicate that the magnitude of the effects generated by desiccation on the early algal development is related to the position of the species in the intertidal zone, and that the protective effects of P. columbina extracts reveal an exceptional metabolism of this species under desiccation stress

Non-Random Distribution and Ecophysiological Differentiation of Pyropia Species (Bangiales, Rhodophyta) Through Environmental Gradients.

Recently 18 Bangiales seaweed species were reported for the Chilean coast, including Pyropia orbicularis and Pyropia variabilis (large [LM] and green [GM] morphotypes). Porphyra/Pyropia spp. occur mainly in the upper intertidal where desiccation stress is triggered by tidal fluctuations. However, the influence of environmental and ecophysiological variables and seasonal differences on Porphyra/Pyropia (microhabitats) intertidal distributions is unknown. Accordingly, we determined (i) the effect of environmental variables (temperature [T], relative humidity [RH], and photosynthetically active radiation [PAR]) and season on distribution, and (ii) physiological (cellular activity and lipid peroxidation [LPX]) and molecular responses (antioxidant enzymes expression at biochemical and transcript level) to desiccation stress in both Pyropia species and morphotypes (common garden experiment, on flat rocky platforms). Multivariate analyses of coverage and abundance in relation to environmental variables revealed a significant effect of temperature on P. variabilis GM distribution, GM dominating almost exclusively on rocky walls (where lowest PAR and T values but maximum RH were registered). Conversely, Pyropia orbicularis and Pyropia variabilis LM were found in high abundance on flat rocky platforms in summer, LM and GM also dominating flat rocky platforms in winter and spring. LPX and catalase activity did not differed among species in summer, while in winter activity and transcription of cat were higher in P. orbicularis than P. variabilis. Results suggest that tolerance to environmental stresses such as temperature could regulate the occurrence of P. variabilis GM on rocky walls; conversely, abundances of P. variabilis and P. orbicularis on flat rocky platforms would be also regulated by other abiotic and/or biotic factors