Publications by authors named "Renato C Pereira"

Submerged or partially floating seagrasses in marine or brackish waters form productive seagrass beds, feeding grounds for a rich and varied associated biota, play key ecological roles in mitigating climate change and provide ecosystem services for humanity. The objective of this study was to perform a temporal quali- and quantitative analysis on the scientific production on seagrasses in the Atlantic Ocean during last 64 years (1960 to 2024) through defined workflow by scientometric analysis on Scopus database. Publications in this database date back to 1969, comprising a total of 3.

View Article and Find Full Text PDF
Article Synopsis
  • - Seaweed species produce a variety of secondary metabolites, particularly terpenes like elatol, which help protect them from fouling and herbivores.
  • - Recent studies identified a complex system in seaweeds for synthesizing, storing, and releasing these terpenes, with a focus on the unknown proteins that transport these compounds across cell membranes.
  • - Experiments showed that specific ABC transport proteins in seaweed are crucial for maintaining terpene concentrations and enhancing defense mechanisms against biofouling and marine pathogens.
View Article and Find Full Text PDF

Brown marine macroalga (Phaeophyceae, Ochrophyta) produces both secondary metabolites (phlorotannins) and precipitate calcium carbonate (CaCO-aragonite) on its surface as potential defensive strategies against herbivory. Here, we have evaluated the effect of natural concentrations of organic extracts (dichloromethane-DI; ethyl acetate-EA and methanol-ME, and three isolated fractions) and mineralized tissues of as chemical and physical resistance, respectively, against the sea urchin through experimental laboratory feeding bioassays. Fatty acids (FA), glycolipids (GLY), phlorotannins (PH) and hydrocarbons (HC) were also characterized and/or quantified in extracts and fractions from using nuclear magnetic resonance (NMR) and gas chromatography (GC) coupled to mass spectrometry (CG/MS) or GC coupled to flame ionization detector (FID) and chemical analysis.

View Article and Find Full Text PDF

Coralline algae constitute one of the main groups of highly vulnerable calcified benthic organisms to ocean acidification. Although damaging effects of seawater acidification on the coralline algae skeleton have been widely demonstrated, the susceptibility to dissolution varies according to the Mg in the calcite lattice. Even though the Southwest Atlantic Ocean exhibits the world's largest rhodolith beds, which occupies 20,902 km, there is no information regarding the coralline algae species mineralogy in this area.

View Article and Find Full Text PDF

Premise: The optimal defense theory (ODT) predicts that the allocation of chemical defenses in plants will be concentrated in parts or tissues that are of higher fitness value for the individuals that produce them. Chemicals are known to be allocated to certain parts of aquatic plants, and the morphological architecture of Nymphoides humboldtiana, a species that exposes its parts to different environmental factors and consumers, may be an excellent model to evaluate within-plant susceptibility to consumers according to the ODT.

Methods: Under laboratory experimental conditions, we evaluated the defensive properties of extracts from vegetative (leaves, rhizomes, roots) and reproductive (long stem internodes, flowers, fruits) parts of N.

View Article and Find Full Text PDF

Several experimental studies on aquatic plants have reported the prevalence of chemical defense mechanism against herbivory, as opposed to structural, life-forms or other traits. Here, our laboratory feeding experiments and integrative analysis explored the relationship among palatability (fresh or reconstituted plants used as artificial diet) and various chemical/nutritional traits ( contents of dry mass, ash, nitrogen, protein, and phenols) of diverse aquatic plants and their susceptibility to consumption by the generalist gastropod . consumed all of the assayed aquatic plants in a hierarchical yet generalized way, with the consumption of fresh plants, their reconstituted forms and defensive properties of lipophilic extracts not being significantly correlated with plant physical or chemical traits to determine the feeding preference of the gastropod.

View Article and Find Full Text PDF

To date, evidence regarding the performance of secondary metabolites from larval stages of sea stars as an anti-predation defense relates only to a few species/specimens from a few geographic ranges. Unfortunately, this hinders a comprehensive global understanding of this inter-specific predator-prey interaction. Here, we present laboratory experimental evidence of chemical defense action in the early developmental stages and adults of the sea star () from Brazil against sympatric and allopatric invertebrate consumers.

View Article and Find Full Text PDF

Infectious diseases affecting habitat-forming species can have significant impacts on population dynamics and alter the structure and functioning of marine ecosystems. Recently, a fungal infection was described as the causative agent of necrotic lesions on the stipe of the forest-forming macroalga Phyllospora comosa, a disease named "stipe rot" (SR). Here, we developed a quantitative PCR (qPCR) method for rapid detection and quantification of this pathogen, which was applied to evaluate the level of SR infection in eight P.

View Article and Find Full Text PDF

Ultraviolet B-light (UV-B) can exert indirect effects on plant-herbivore interactions by inducing changes in constitutive and induced chemical defenses, since it modulates physiological aspects of plants. This study evaluated the action of UV-B radiation on photosynthesis and production of secondary metabolites in Nymphoides humboldtiana and the cascade effects on the relationship of this macrophyte with a generalist herbivore, the gastropod mollusk Biomphalaria glabrata. After 13 days of UV-B exposition under laboratory conditions, the floating macrophyte N.

View Article and Find Full Text PDF

Inducible chemical defenses are more common in temperate seaweeds than tropical ones, and are directly detected by increase of chemical contents, or indirectly by differential consumption of live seaweed tissues or artificial food with algal extracts by herbivores. In general, seaweed-induced chemical defense occur between 11 and 20 days after both simulated/artificial or direct herbivory. Here, we used experimental procedures to assess induced chemical defense in the tropical red seaweed Laurencia dendroidea as response to direct grazing, chemical cues from grazed conspecific neighbors and only presence of herbivores.

View Article and Find Full Text PDF
Article Synopsis
  • Autotoxicity and allelopathy, known processes in land plants, are largely unexplored in seaweeds, specifically in this study of red seaweed populations from Azeda and Forno beaches.
  • The research utilized chlorophyll fluorescence imaging to measure photosynthesis inhibition, discovering that the Azeda population was significantly affected by extracts and the compound elatol, while the Forno population showed no inhibitory effects from its own extracts or compounds.
  • This study highlights the significance of secondary metabolites in shaping interactions and population dynamics within and between seaweed species.
View Article and Find Full Text PDF

Phlorotannins are primary and/or secondary metabolites found exclusively in brown seaweeds, but their geographic distribution and abundance dynamic are not very well understood. In this study we evaluated the phlorotannin concentrations among and within-species of brown seaweeds in a broad latitudinal context (range of 21°) along the Brazilian coast (Southwestern Atlantic), using the Folin-Ciocalteau colorimetric method. In almost all species (16 out of 17) very low phlorotannin concentrations were found (<2.

View Article and Find Full Text PDF

The new pyrrole-imidazole and pyrrole-guanidine alkaloids 4-debromooroidin (1), 4-debromougibohlin (2), 5-debromougibohlin (3), and 5-bromopalau'amine (4), along with the known hymenidin (5) and (+)-monobromoisophakellin (6), have been isolated from a Dictyonella sp. marine sponge, collected at the Amazon River mouth. The bromine-substitution pattern observed for compounds 1, 2 and 4 is unusual among bromopyrrole alkaloids isolated from marine sponges.

View Article and Find Full Text PDF

Most coral reefs have recently experienced acute changes in benthic community structure, generally involving dominance shifts from slow-growing hard corals to fast-growing benthic invertebrates and fleshy photosynthesizers. Besides overfishing, increased nutrification and sedimentation are important drivers of this process, which is well documented at landscape scales in the Caribbean and in the Indo-Pacific. However, small-scale processes that occur at the level of individual organisms remain poorly explored.

View Article and Find Full Text PDF

In order to evaluate the chemical diversity of Syzygiella rubricaulis (Nees) Stephani, a species with a disjunct distribution in the neotropical high mountains, a phytochemical study was carried out with samples from 12 different populations of different altitudes from four South American countries. The chemical profiles of lipophilic extracts were analyzed by GC/MS for each population and 50 different compounds were found with the predominance and richness of sesquiterpenes. The majority of the compounds were found only in one population and the total number of substances ranged from 1 to 15 among the populations, but these numbers were not correlated with altitude, and characterize each population as distinct, based on similarity analysis.

View Article and Find Full Text PDF

The ability to recognize and respond to the presence of microbes is an essential strategy for seaweeds to survive in the marine environment, but understanding of molecular seaweed-microbe interactions is limited. clones were inoculated with the marine bacterium . The seaweed RNA was sequenced, providing an unprecedentedly high coverage of the transcriptome of , and the gene expression levels were compared between control and inoculated samples after 24, 48, and 72 h.

View Article and Find Full Text PDF

Despite advances in understanding the ecological functions of secondary metabolites from marine organisms, there has been little focus on the influence of chemically-defended species at the community level. Several compounds have been isolated from the gorgonian octocoral , a conspicuous species that forms dense canopies on rocky reefs of northern Rio de Janeiro State, Brazil. Manipulative experiments were performed to study: (1) the effects of live colonies of (physical presence and chemistry) on recruitment of sympatric benthic organisms; (2) the allelopathic effects of its chemicals on competitors; and (3) chemotactic responses of the non-indigenous brittle star, .

View Article and Find Full Text PDF

The red seaweed Laurencia dendroidea belongs to the Rhodophyta, a phylum of eukaryotic algae that is widely distributed across the oceans and that constitute an important source of bioactive specialized metabolites. Laurencia species have been studied since 1950 and were found to contain a plethora of specialized metabolites, mainly halogenated sesquiterpenes, diterpenes and triterpenes that possess a broad spectrum of pharmacological and ecological activities. The first committed step in the biosynthesis of triterpenes is the cyclization of 2,3-oxidosqualene, an enzymatic reaction carried out by oxidosqualene cyclases (OSCs), giving rise to a broad range of different compounds, such as the sterol precursors cycloartenol and lanosterol, or triterpene precursors such as cucurbitadienol and β-amyrin.

View Article and Find Full Text PDF
Article Synopsis
  • Large rivers, like the Amazon, significantly disrupt reef distributions on tropical shelves by affecting salinity, pH, light penetration, and sedimentation over a large area of the North Atlantic.
  • Despite these harsh conditions, a complex carbonate system thrives off the Amazon's mouth, characterized by unique hard-bottom structures, originating from sedimentation during low sea levels and continuing in certain areas.
  • These carbonate structures support diverse marine life, including sponges and filter feeders, and act as a connectivity corridor for reef-associated species, offering insights into how tropical reefs can adapt to challenging conditions, which are becoming more common globally.
View Article and Find Full Text PDF

This paper has identified, for the first time in a member of the Rhodophyta, a vacuolar organelle containing enzymes that are involved in the mevalonate pathway-an important step in red algal isoprenoid biosynthesis. These organelles were named mevalonosomes (Mev) and were found in the cortical cells (CC) of Plocamium brasiliense, a marine macroalgae that synthesizes several halogenated monoterpenes. P.

View Article and Find Full Text PDF

We investigated the organelles involved in the biosynthesis of fatty acid (FA) derivatives in the cortical cells of Laurencia translucida (Rhodophyta) and the effect of these compounds as antifouling (AF) agents. A bluish autofluorescence (with emission at 500 nm) within L. translucida cortical cells was observed above the thallus surface via laser scanning confocal microscopy (LSCM).

View Article and Find Full Text PDF

Guanabara Bay is the second largest bay in the coast of Brazil, with an area of 384 km(2). In its surroundings live circa 16 million inhabitants, out of which 6 million live in Rio de Janeiro city, one of the largest cities of the country, and the host of the 2016 Olympic Games. Anthropogenic interference in Guanabara Bay area started early in the XVI century, but environmental impacts escalated from 1930, when this region underwent an industrialization process.

View Article and Find Full Text PDF

A new open access database, Brazilian Marine Biodiversity (BaMBa) (https://marinebiodiversity.lncc.br), was developed in order to maintain large datasets from the Brazilian marine environment.

View Article and Find Full Text PDF

The red seaweeds belonging to the genus Laurencia are well known as halogenated secondary metabolites producers, mainly terpenoids and acetogennins. Several of these chemicals exhibit important ecological roles and biotechnological applications. However, knowledge regarding the genes involved in the biosynthesis of these compounds is still very limited.

View Article and Find Full Text PDF

Marine macroalgae, or seaweeds, are a formidable source of natural compounds with diverse biological activities. In the last five decades it has been estimated that more than 3000 natural compounds were discovered from these organisms. The great majority of the published works have focused on terpenoids.

View Article and Find Full Text PDF