Fernanda Rodríguez-Rojas

Playa Ancha University · HUB-AMBIENTAL

Desalination brines from direct seawater intake that get discharged to coastal areas may produce stress responses on benthic marine communities, mostly due to its excess salinity, and especially on sessile organisms; in this context, macroalgae have been understudied in desalination ecotoxicological investigations. In this study, we assessed the sh...

Desalination residual brines are mostly discharged to marine environments, which can produce osmotic stress on sensitive benthic organisms. In this investigation, we performed transplantation experiments nearby desalination plants using two brown macroalgae species from a cosmopolitan genus: Dictyota kunthii (Chile) and Dictyota dichotoma (Spain)....

Marine ecosystems in the Arctic and Antarctica were once thought pristine and away from important human influence. Today, it is known that global processes as atmospheric transport, local activities related with scientific research bases, military and touristic maritime traffic, among others, are a potential source of pollutants. Macroalgae have be...

In order to analyze the mechanisms involved in copper accumulation in Ulva compressa, algae were collected at control sites of central and northern Chile, and at two copper-polluted sites of northern Chile. The level of intracellular copper, reduced glutathione (GSH), phytochelatins (PCs), PC2 and PC4, and transcripts encoding metallothioneins (MTs...

Fluctuations in solar radiation are one of the key factors affecting productivity and survival in habitat forming coastal macroalgae, in this regard, photoacclimation has a direct impact on the vulnerability and the capacity of seaweed to withstand, for instance, radiation excess. Here, we study ecophysiological responses through photosynthetic act...

Physiological and metabolic responses to hypersalinity reveal interpopulation tolerance in the green macroalga Ulva compressa with different pollution histories, Aquatic Toxicology (2020), Highlights  Ulva compressa from a polluted environment suffers reduced photosynthetic performance  A population from a polluted environment shows more oxidativ...

The Antarctic Peninsula is one of the regions to be most affected by increase in sea surface temperatures (SSTs) mediated by Global Climate Change; indeed, most negative predictions imply an up to 6 °C increment by the end of the XXI century. Temperature is one of the most important factors mediating diversity and distribution of macroalgae, althou...

There is currently no information regarding the role that whole mitogen activated protein kinase (MAPK) pathways play in counteracting environmental stress in photosynthetic organisms. To address this gap, we exposed Ulva compressa to chronic levels of copper (10 µM) specific inhibitors of Extracellular Signal Regulated Kinases (ERK), c-Jun N-termi...

Following the physiological complementary/parallel Celis-Plá et al., by inhibiting extracellular signal regulated kinases (ERK), c-Jun N-terminal kinases (JNK), and cytokinin specific binding protein (p38), we assessed the role of the mitogen-activated protein kinases (MAPK) pathway in detoxification responses mediated by chronic copper (10 µM) in...

In this investigation, we assessed the effects of Cu and/or Cd excess on physiological and metabolic processes of the widespread seagrass Zostera marina. Adult were exposed to low Cd and Cu (0.89 and 0.8 µM, respectively) and high Cd and Cu (8.9 and 2.4 µM, respectively) for 6 d at: Control conditions; low Cu; high Cu; low Cd; high Cd; low Cd and l...

Antibiotic resistance determinants found in the P. putida ATH-43 genome.

ANI and pangenome analysis of P. putida ATH-43. (A) Heatmap representing the comparison of the average nucleotide identity among ten P. putida genomes. (B) Pangenome comparison bar chart showing the number of shared genes clustered in cloud (genes in 0–20% of genomes), shell (genes in 20–90% of genomes), soft core (90–99% of genomes), and core geno...

Metal resistance determinants found in the P. putida ATH-43 genome.

At low concentrations, heavy metals and metalloids are highly toxic for most microorganisms (Lemire et al., 2013). Over evolution, bacteria have developed several molecular mechanisms in order to cope with heavy metal/metalloid toxicity (Lemire et al., 2013; Nies, 2000). Pseudomonas putida belongs to a group of versatile microorganisms capable to t...

The tellurium oxyanion tellurite (TeO32-) is extremely harmful for most organisms. It has been suggested that a potential bacterial tellurite resistance mechanism would consist of an enzymatic, NAD(P)H-dependent, reduction to the less toxic form elemental tellurium (Te0). To date, a number of enzymes such as catalase, type II NADH dehydrogenase and...

SDS-PAGE of purified putative tellurite reductases. (A) Purified E. coli flavoproteins E3 (∼56 kDa), YkgC (∼48 kDa), GorA (∼49 kDa), AhpF (∼56 kDa), TrxB (∼35 kDa), SthA (∼52 kDa), and NorW (∼41 kDa) were visualized by PAGE-SDS. Each lane contained 15 μg of protein. (B) Mercuric reductase (MerA, ∼56 kDa, 10 μg) from the environmental plasmid pTP6....

Amino acid sequence alignment of the indicated E. coli flavoproteins. Secondary structure elements of E3 (PDB_ID: 4JDR), GorA (PDB_ID: 1GER), AhpF (PDB_ID: 1FL2), and TrxB (PDB_ID: 1CL0) are indicated at the top (hairsprings: α-helix; arrows, β-sheets). Cys residues are indicated by black dots.

Transmission electron microscopy of in vivo synthesized electron-dense assemblies. The structures resulting from the in vivo tellurite reduction by E. coli strains overproducing AhpF (A), E3 (B), GorA (C), YkgC (D), TrxB (E), and NorW (F) were visualized by TEM as described in Section “Materials and Methods.”

Mercury salts and tellurite are among the most toxic compounds for microorganisms on Earth. Bacterial mercury resistance is established mainly via mercury reduction by the mer operon system. However, specific mechanisms underlying tellurite resistance are unknown to date. To identify new mechanisms for tellurite detoxification we demonstrate that m...

Through the diversity of cytokinin regulated processes, this phytohormone has a profound impact on plant growth and development. Cytokinin signaling is involved in the control of apical and lateral meristem activity, branching pattern of the shoot, and leaf senescence. These processes influence several traits, including the stem diameter, shoot arc...

The phytohormone cytokinin has been shown to play a major role in plant development. To better understand the cytokinin response pathway in Prunus persica at specific stages of fruit development, we have identified two putative orthologs of the Arabidopsis cytokinin signaling pathway (Arr1 and Arr6) and a cytokinin/auxin crosstalk factor (Shy2). Th...