André Caeiro

Dr. André Caeiro

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 September 2018 in Molecules
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AUAdriana Cristina Urcan
Adriana Cristina Urcan
ACAdriana Dalila Criste
Adriana Dalila Criste
Daniel S. DezmireanDaniel S. Dezmirean
Daniel S. Dezmirean
Rodica MargaoanRodica Margaoan
Rodica Margaoan
ACAndré Caeiro
André Caeiro
Maria Graça CamposMaria Graça Campos
Maria Graça Campos
Bee Bread samples from Romania and India were analysed by microscopy and High Performance Liquid Chromatography with Diode Array Detection (HPLC/DAD) and compared with pollen from the correspondent taxa. The quantification of sugars, fructose/glucose ratio, total phenolics and flavonoids was also carried out. From the results was possible to identify Brassica and Eucalyptus samples that present similar HPLC/DAD profiles with the respective ultraviolet (UV) identification of the main compounds as Kaempferol-3-O-glycosides and Hydrocinnamic acid derivatives. The Fructose/Glucose (F/G) ratio and the total amounts of phenolics and flavonoids was in line with the prevalence of the specie identified. These coincident fingerprints gave the identification of the samples, as was previously proposed for bee pollens. This paper relates for the first time the achievement on the taxon carried out previously only for bee pollens. It was reported for the first time that this phenolic profile remains unchanged in the case of floral pollen (hand collected), bee pollen and bee bread. Despite the biochemical transformation that occurs during the fermentation of bee bread, it seems that these phenolic compounds are not affected and remain unchanged. Also, variables such as soil and climate do not seem to influence these compounds for the kind of samples under study.

19 May 2022 in Plants
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ACAndré Caeiro
André Caeiro
Sandra CaeiroSandra Caeiro
Sandra Caeiro
SCSandra Correia
Sandra Correia
Jorge CanhotoJorge Canhoto
Jorge Canhoto
Somatic embryogenesis (SE) is a complex biological process regulated by several factors, such as the action of plant growth regulators, namely auxins, of which the most physiologically relevant is indole-3-acetic acid (IAA). In tamarillo, an optimized system for induction of SE creates, after an induction process, embryogenic (EC) and non-embryogenic callus (NEC). In this work the endogenous levels of auxin along the induction phase and in the calli samples were investigated using chemical quantifications by colorimetric reactions and HPLC as well as immunohistochemistry approaches. Differential gene expression (IAA 11, IAA 14, IAA 17, TIR 1, and AFB3) analysis during the induction phase was also carried out. The results showed that the endogenous IAA content is considerably higher in embryogenic than in non-embryogenic calli, with a tendency to increase as the dedifferentiation of the original explant (leaf segments) evolves. Furthermore, the degradation rates of IAA seem to be related to these levels, as non-embryogenic tissue presents a higher degradation rate. The immunohistochemical results support the quantifications made, with higher observable labeling on embryogenic tissue that tends to increase along the induction phase. Differential gene expression also suggests a distinct molecular response between EC and NEC.

4 August 2023 in Plants
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Journal Article
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ACAndré Caeiro
André Caeiro
Ivana JarakIvana Jarak
Ivana Jarak
SCSandra Correia
Sandra Correia
Jorge CanhotoJorge Canhoto
Jorge Canhoto
Rui Albuquerque CarvalhoRui Albuquerque Carvalho
Rui Albuquerque Carvalho
Tamarillo is a solanaceous tree that has been extensively studied in terms of in vitro clonal propagation, namely somatic embryogenesis. In this work, a protocol of indirect somatic embryogenesis was applied to obtain embryogenic and non-embryogenic callus from leaf segments. Nuclear magnetic resonance spectroscopy was used to analyze the primary metabolome of these distinct calli to elucidate possible differentiation mechanisms from the common genetic background callus. Standard multivariate analysis methods were then applied, and were complemented by univariate statistical methods to identify differentially expressed primary metabolites and related metabolic pathways. The results showed carbohydrate and lipid metabolism to be the most relevant in all the calli assayed, with most discriminant metabolites being fructose, glucose and to a lesser extent choline. The glycolytic rate was higher in embryogenic calli, which shows, overall, a higher rate of sugar catabolism and a different profile of phospholipids with a choline/ethanolamine analysis. In general, our results show that a distinct primary metabolome between embryogenic and non-embryogenic calli occurs and that intracellular levels of fructose and sucrose and the glucose to sucrose ratio seem to be good candidates as biochemical biomarkers of embryogenic competence.

10 April 2024 in Biomolecules
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SSSara Sofio
Sara Sofio
ACAndré Caeiro
André Caeiro
Ana RibeiroAna Ribeiro
Ana Ribeiro
Ana Maria Telmo Dias Pereira Vicente CabralAna Maria Telmo Dias Pereira Vicente Cabral
Ana Maria Telmo Dias Pereira Vicente Cabral
Artur ValenteArtur Valente
Artur Valente
Miguel A EstesoMiguel A Esteso
Miguel A Esteso
This scientific study employs the Taylor dispersion technique for diffusion measurements to investigate the interaction between sulfamerazine (NaSMR) and macromolecular cyclodextrins (β-CD and HP-β-CD). The results reveal that the presence of β-CD influences the diffusion of the solution component, NaSMR, indicating a counterflow of this drug due to solute interaction. However, diffusion data indicate no inclusion of NaSMR within the sterically hindered HP-β-CD cavity. Additionally, toxicity tests were conducted, including pollen germination (Actinidia deliciosa) and growth curve assays in BY-2 cells. The pollen germination tests demonstrate a reduction in sulfamerazine toxicity, suggesting potential applications for this antimicrobial agent with diminished adverse effects. This comprehensive investigation contributes to a deeper understanding of sulfamerazine–cyclodextrin interactions and their implications for pharmaceutical and biological systems.

29 November 2021 in Biology and Life Sciences Forum
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Sandra CaeiroSandra Caeiro
Sandra Caeiro
TLTércia Lopes
Tércia Lopes
APAna Pedrosa
Ana Pedrosa
ACAndré Caeiro
André Caeiro
RPRita Costa Pires
Rita Costa Pires
SCSandra Correia
Sandra Correia
Almond (Prunus dulcis (Mill.) D. A. Webb) is a traditional culture in Portugal, which gained a renewed interest due to the installation of new orchards. Grafting remains the main method used for almond propagation. The successful establishment of a graft union between two parts (scion and rootstock) requires auxins, which are involved in wound response and vascular regeneration. This work aimed at the quantification and immunolocalization of indole-3-acetic acid (IAA) in almond micrografts before micrografting (T0) and 21 days after micrografting (T2). The results are a step forward to understand of how auxin is involved in graft compatibility in almond.

7 December 2021 in Biology and Life Sciences Forum
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Conference Paper
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ACAndré Caeiro
André Caeiro
FVFilipa Ventura
Filipa Ventura
SCSandra Correia
Sandra Correia
Jorge CanhotoJorge Canhoto
Jorge Canhoto
Tamarillo (Solanum betaceum Cav.) is a Solanaceae tree cultivated for its edible fruits. Under specific stimuli, indirect somatic embryogenesis (SE) originates distinct calli: embryogenic (EC) and non-embryogenic (NEC). Both types proliferate, but only EC originates somatic embryos. The presence of secondary metabolites is known to influence induction and embryogenic competence. The objective of this work is to study some of these compounds on SE. Results showed highest dedifferentiation rates (>90%) in the control and when rutin and caffeic acid were tested, whereas lower concentrations inhibit dedifferentiation. In contrast, the compounds seem to inhibit growth of established calli without affecting protein, phenolic acids and flavonoid levels, measured by spectrophotometric methods. Anthranilic acid completely inhibited both induction and calli growth. The results seem to present a correlation of some secondary metabolites with dedifferentiation rates during induction and a tendency to inhibit growth of established calli, probably related to metabolic effects. Further studies are underway to further characterize the dose–response relation of these compounds and molecular mechanism underlying this phenotypic effect.