Climate change has been associated with a higher incidence of combined adverse environmental conditions that can promote a significant decrease in crop productivity. However, knowledge on how a combination of stresses might affect plant... more
Climate change has been associated with a higher incidence of combined adverse environmental conditions that can promote a significant decrease in crop productivity. However, knowledge on how a combination of stresses might affect plant development is still scarce. MicroRNAs (miRNAs) have been proposed as potential targets for improving crop-productivity. Here, we have combined deep-sequencing, computational characterization of responsive miRNAs and validation of their regulatory role in a comprehensive analysis of melon’s response to several combinations of four stresses (cold, salinity, short day, and infection with a fungus). Twenty-two miRNA families responding to double and/or triple stresses were identified. The regulatory role of the differentially expressed miRNAs was validated by quantitative measurements of the expression of the corresponding target genes. A high proportion (ca. 60%) of these families (mainly highly conserved miRNAs targeting transcription factors) showed ...
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Research Interests: Genetics, Plant Biology, Biology, RNA silencing, Gene Silencing, and 4 moreRNA interference, Plant, Genome, and Gene
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Gene silencing for functional studies in plants has been largely facilitated by manipulating viral genomes with inserts from host genes to trigger virus induced gene silencing (VIGS) against the corresponding mRNAs. However, viral genomes... more
Gene silencing for functional studies in plants has been largely facilitated by manipulating viral genomes with inserts from host genes to trigger virus induced gene silencing (VIGS) against the corresponding mRNAs. However, viral genomes encode multiple proteins and disrupt plant homeostasis by interfering with endogenous cell mechanisms. To circumvent this issue, we have developed a silencing method based on the minimal autonomously-infectious nucleic acids currently known: viroids. In particular, Eggplant latent viroid (ELVd), an asymptomatic viroid, was manipulated with insertions between 21 to 42 nucleotides and our results show that larger insertions are tolerated but secondary structure is critical for their stability. Additionally, these ELVd constructs are able of local and systemic spread and can silence a target gene in eggplant. Inspired by the design of artificial microRNAs, we have developed a standardized procedure to generate stable insertions into the ELVd genome ca...
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Infectious viroid clones consist of dimeric cDNAs used to generate transcripts which mimic the longer-than-unit replication intermediates. These transcripts can be either generated in vitro or produced in vivo by agro-inoculation. We have... more
Infectious viroid clones consist of dimeric cDNAs used to generate transcripts which mimic the longer-than-unit replication intermediates. These transcripts can be either generated in vitro or produced in vivo by agro-inoculation. We have designed a new plasmid, which allows both inoculation methods, and we have compared them by infecting Solanum lycopersicum and Solanum melongena with clones of Citrus exocortis virod (CEVd), Tomato chlorotic dwarf viroid (TCDVd), and Potato spindle tuber viroid (PSTVd). Our results showed more uniform and severe symptoms in agro-inoculated plants. Viroid accumulation and the proportion of circular and linear forms were different depending on the host and the inoculation method and did not correlate with the symptoms, which correlated with an increase in PR1 induction, accumulation of the defensive signal molecules salicylic (SA) and gentisic (GA) acids, and ribosomal stress in tomato plants. The alteration in ribosome biogenesis was evidenced by bo...
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ABSTRACTViroids are circular RNAs of minimal complexity compelled to subvert plant-regulatory networks to accomplish their infectious process. Studies focused on the response to viroid infection have mostly addressed specific regulatory... more
ABSTRACTViroids are circular RNAs of minimal complexity compelled to subvert plant-regulatory networks to accomplish their infectious process. Studies focused on the response to viroid infection have mostly addressed specific regulatory levels and considered a unique infection time. Thus, much remains to be done to understand the temporal evolution and complex nature of viroid-host interactions. Here we present an integrative analysis of the temporal evolution and intensity of the genome-wide alterations in cucumber plants infected with hop stunt viroid (HSVd) by integrating differential host transcriptome, sRNAnome and methylome. Our results support that HSVd promotes the redesign of the cucumber regulatory-pathways predominantly affecting specific regulatory layers at different infection-phases. The initial response was characterized by a reconfiguration of the host-transcriptome by differential exon usage, followed by a progressive transcriptional down-regulation modulated by epi...
Research Interests: Biology and Transcriptome
Climate change has been associated with a higher incidence of combined adverse environmental conditions that can promote a significant decrease in crop productivity. However, knowledge on how a combination of stresses might affect plant... more
Climate change has been associated with a higher incidence of combined adverse environmental conditions that can promote a significant decrease in crop productivity. However, knowledge on how a combination of stresses might affect plant development is still scarce. MicroRNAs (miRNAs) have been proposed as potential targets for improving crop productivity. Here, we have combined deep-sequencing, computational characterization of responsive miRNAs and validation of their regulatory role in a comprehensive analysis of response of melon to several combinations of four stresses (cold, salinity, short day, and infection with a fungus). Twenty-two miRNA families responding to double and/or triple stresses were identified. The regulatory role of the differentially expressed miRNAs was validated by quantitative measurements of the expression of the corresponding target genes. A high proportion (ca. 60%) of these families (mainly highly conserved miRNAs targeting transcription factors) showed...
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miRNAs are small RNAs that regulate mRNAs at both transcriptional and posttranscriptional level. In plants, miRNAs are involved in the regulation of different processes including development and stress-response. Elucidating how... more
miRNAs are small RNAs that regulate mRNAs at both transcriptional and posttranscriptional level. In plants, miRNAs are involved in the regulation of different processes including development and stress-response. Elucidating how stress-responsive miRNAs are regulated is key to understand the global response to stress but also to develop efficient biotechnological tools that could help to cope with stress. Here, we describe a computational approach based on sRNA sequencing, transcript quantification and degradome data to analyze the accumulation, function and structural organization of melon miRNAs reactivated under seven biotic and abiotic stress conditions at two and four days post-treatment. Our pipeline allowed us to identify fourteen stress-responsive miRNAs (including evolutionary conserved such as miR156, miR166, miR172, miR319, miR398, miR399, miR894 and miR408) at both analyzed times. According to our analysis miRNAs were categorized in three groups showing a broad-, intermed...
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miRNAs are fundamental endogenous regulators of gene expression in higher organisms. miRNAs modulate multiple biological processes in plants. Consequently, miRNA accumulation is strictly controlled through miRNA precursor accumulation and... more
miRNAs are fundamental endogenous regulators of gene expression in higher organisms. miRNAs modulate multiple biological processes in plants. Consequently, miRNA accumulation is strictly controlled through miRNA precursor accumulation and processing. Members of the miRNA319 family are ancient ribo-regulators that are essential for plant development and stress responses and exhibit an unusual biogenesis that is characterized by multiple processing of their precursors. The significance of the high conservation of these non-canonical biogenesis pathways remains unknown. Here, we analyze data obtained by massive sRNA sequencing and 5' - RACE to explore the accumulation and infer the processing of members of the miR319 family in melon plants exposed to adverse environmental conditions. Sequence data showed that miR319c was down regulated in response to low temperature. However, the level of its precursor was increased by cold, indicating that miR319c accumulation is not related to th...
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Impairments in sleep and cognitive function have been observed in patients with substance abuse disorders and may be potential factors contributing to drug relapse. In addition, sleep disruption may itself contribute to cognitive... more
Impairments in sleep and cognitive function have been observed in patients with substance abuse disorders and may be potential factors contributing to drug relapse. In addition, sleep disruption may itself contribute to cognitive deficits. In the present study we examined the impact of prolonged cocaine self-administration and abstinence on actigraphy-based measures of night-time activity in rhesus macaques as an inferential measure of sleep, and determined whether sleep-efficiency correlated with cognitive impairments in the same subjects on drug free days. Actigraphy data was obtained from a group of rhesus macaques intravenously self-administering cocaine (n=6) and a control group (n=5). Periods were evaluated during which the mean cumulative doses of cocaine were 3.0+0.0 and 4.5+0.2mg/kg/day for 4days (Tuesday-Thursday) each week. Actigraphy-based sleep efficiency decreased during days of cocaine self-administration in a dose-dependent manner. Consistent with this observation, s...
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ABSTRACT
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ABSTRACT This paper presents the results of a comparative study of digital segmentation methods and analog methods - digital segmentation. The spectral images were acquired with an acousto-optic system, which allows the acquisition of... more
ABSTRACT This paper presents the results of a comparative study of digital segmentation methods and analog methods - digital segmentation. The spectral images were acquired with an acousto-optic system, which allows the acquisition of grayscale pictures in a narrow range of wavelengths. The series of images acquired for the entire visible spectrum, allows simple digital operations, perform segmentation processes. The segmentation is based on the analysis of spectral components over regions of the image. This type of processing is compared with traditional digital processing. The experimental results demonstrate that the segmentation processes developed with the acousto-optical system in conjunction with digital techniques of image processing, reduce the computational cost without compromise the quality of the segmentation.
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ABSTRACTA rapid, specific and reliable isocratic high‐performance liquid chromatography combined with quadrupole time‐of‐flight electrospray ionization tandem mass spectrometry (LC/Q‐TOF‐ESI‐MS/MS) method has been developed and validated... more
ABSTRACTA rapid, specific and reliable isocratic high‐performance liquid chromatography combined with quadrupole time‐of‐flight electrospray ionization tandem mass spectrometry (LC/Q‐TOF‐ESI‐MS/MS) method has been developed and validated for the identification and characterization of stressed degradation products of metoprolol. Metoprolol, an anti‐hypertensive drug, was subjected to hydrolysis (acidic, alkaline and neutral), oxidation, photolysis and thermal stress, as per ICH‐specified conditions. The drug showed extensive degradation under oxidative and hydrolysis (acid and base) stress conditions. However, it was stable to thermal, neutral and photolysis stress conditions. A total of 14 degradation products were observed and the chromatographic separation of the drug and its degradation products was achieved on a C18 column (4.6 × 250 mm, 5 µm). To characterize degradation products, initially the mass spectral fragmentation pathway of the drug was established with the help of MS/...
Research Interests: Chemistry, Analytical Chemistry, Chromatography, Mass Spectrometry, Medicine, and 14 moreBiomedical, Biological Sciences, Tandem Mass Spectrometry, High Performance Liquid Chromatography, High Pressure Liquid Chromatography, Reproducibility of Results, Photolysis, Hydrolysis, Drug Stability, Oxidation-Reduction, Ions, Metoprolol, Electrospray Ionization, and Pharmacology and pharmaceutical sciences
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The conceptual design of a bio‐based process for 2‐butanol production is presented for the first time. Considering a hypothetical efficient producing strain, a vacuum fermentation is proposed to alleviate product toxicity, but the main... more
The conceptual design of a bio‐based process for 2‐butanol production is presented for the first time. Considering a hypothetical efficient producing strain, a vacuum fermentation is proposed to alleviate product toxicity, but the main challenge is the energy‐efficient product recovery from the vapor. Three downstream scenarios were examined for this purpose: 1) multi‐stage vapor recompression; 2) temperature swing adsorption; and 3) vapor absorption. The processes were simulated using Aspen Plus, considering a production capacity of 101 kton/yr. Process optimization was performed targeting the minimum selling price of 2‐butanol. The feasibility of the different configurations was analyzed based on the global energy requirements and capital expenditure. The use of integrated adsorption and absorption minimized the energy duty required for azeotrope purification, which represents 11% of the total operational expenditure in Scenario 1. The minimum selling price of 2‐butanol as commodi...