Cristina Ortega Villasante

Cristina Ortega Villasante
Universidad Autónoma de Madrid | UAM · Department of Biology

PhD in Science (Biology)

About

34
Publications
7,671
Reads
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1,236
Citations
Citations since 2016
11 Research Items
732 Citations
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2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
Introduction
Cristina Ortega Villasante currently works at the Department of Biology, Universidad Autónoma de Madrid. Cristina does research in Agricultural Plant Science and Plant Physiology, focused on the mecanisms that control plant tolerance to toxic metals and protein trafficking within the plant cell. Their current project is Biothiol metabolism regulation, critical factor in the dynamics of toxic metal(loid)s in crop plant, as bases for a safer agriculture'(METALSAFE).'
Additional affiliations
March 2009 - September 2009
Umeå Plant Science Centre
Position
  • EMBO Short Term Fellowship "Characterization of the elements involved in N-glycoprotein trafficking to the chloroplast through the endomembrane system"
November 2008 - present
Universidad Autónoma de Madrid
Position
  • Professor (Assistant)
March 2007 - November 2008
Universidad Autónoma de Madrid
Position
  • A novel route through the endomembrane system for N-glycoproteins targeted to the chloroplast in plants. Its application in the design of strategies for production of recombinant glycoproteins in plants

Publications

Publications (34)
Article
Full-text available
Reactive oxygen species (ROS) of varied types can be yielded in plants at several primary sites (such as the chloroplast, mitochondria, and peroxisomes) under normal aerobic metabolism via processes including photosynthetic and respiratory electron transport chains. However, impaired oxidant-antioxidant balance and extreme growth conditions in plan...
Preprint
Full-text available
Background and aims Mercury (Hg) is one of the most dangerous pollutant heavy metals to the environment, which causes several toxic effects in plants upon accumulation, such as induction of oxidative stress. Nitrogen (N) is one of the most limiting macronutrient for plants, being mostly assimilated as NO3─ which is reduced to NO2─ by the enzyme nit...
Article
Toxic metals such as cadmium (Cd) and mercury (Hg) represent a threat to photosynthetic organisms of polluted aquatic ecosystems, and knowledge about mechanisms of toxicity is essential for appropriate assessment of environmental risks. We used Synchrotron Radiation-Fourier Transformed Infrared microspectroscopy (μSR-FTIR) to characterise major cha...
Article
Mercury (Hg) is one of the most hazardous pollutants released by humans and is of global environmental concern. Mercury causes oxidative stress and strong cellular damages in plants, which can be attenuated by the biosynthesis of thiol-rich peptides (biothiols), including glutathione (GSH) and phytochelatins (PCs). We analysed Hg tolerance and spec...
Chapter
Autophagy constitutes an essential process triggered by oxidative stress that enables cells to recycle damaged biomolecules and organelles, which is eventually traced by immunodetection with anti-ATG8. In parallel with autophagy induction, carbon metabolism in Chlamydomonas reinhardtii under abiotic stress is diverged toward lipid biosynthesis and...
Article
Reactive oxygen species (ROS) are by-products of aerobic metabolism, and excessive production can result in oxidative stress and cell damage. In addition, ROS function as cellular messengers, working as redox regulators in a multitude of biological processes. Understanding ROS signalling and stress responses requires methods for precise imaging and...
Chapter
Efficient phytoremediation of soils polluted with toxic elements greatly depends on the ability of selected plants to withstand the damages induced by these contaminants. Among other metabolites, glutathione (GSH) plays a fundamental dual role in tolerance as an antioxidant required for the attenuation of reactive oxygen species (ROS), such as supe...
Article
Reactive oxygen species (ROS) are metabolic by-products in aerobic organisms including plants. Endogenously produced ROS act as cellular messengers and redox regulators involved in several plant biological processes, but excessive accumulation of ROS cause oxidative stress and cell damage. Understanding ROS signalling and stress responses requires...
Article
Full-text available
The accumulation of toxic metals and metalloids, such as cadmium (Cd), mercury (Hg), or arsenic (As), as a consequence of various anthropogenic activities, poses a serious threat to the environment and human health. The ability of plants to take up mineral nutrients from the soil can be exploited to develop phytoremediation technologies able to all...
Article
Full-text available
The induction of oxidative stress is one of the quickest symptoms appearing in plants subjected to metal stress. A transcriptional analysis of the early responses of alfalfa (Medicago sativa) seedlings to mercury (Hg; 3 μM for 3, 6 and 24 h) showed that up-regulation of genes responding to ethylene were up-regulated, a phytohormone known to mediate...
Article
Full-text available
A tool for stoichiometric co-expression of effector and target proteins to study intracellular protein trafficking processes has been provided by the so called 2A peptide technology. In this system, the 16-20 amino acid 2A peptide from RNA viruses allows synthesis of multiple gene products from single transcripts. However, so far the use of the 2A...
Data
Sorting of 2A polyprotein transfected protoplasts using FACS. (A) Scheme of fluorescent-activated cell sorting (FACS) of protoplasts transfected with 2A polyprotein in order to obtain a homogenous mutant population. Protoplasts were transfected with GS-CFP-2A-RABD2a vector (v), resulting in a heterogeneous mixture of transfected (v, about 10% of to...
Data
Accumulation of GS-CFP-2A in vacuole like structures when co-expressed with ARF1 (T31N). Bright field (A) and confocal (B) images of Arabidopsis protoplast transiently expressing GS-CFP-2A-ARF1 (T31N). In addition to the phenotype shown in Figure 5G–H, some protoplasts showed CFP fluorescence in vacuole like structures as shown here. Bars = 5 µm. (...
Data
Endo H is a valid marker for protein trafficking. (A) Immunoblot analysis of ultracentrifuged protein extracts from Nicotiana benthamiana transiently expressing HACAH1-2A-RABD2a (wt) using anti-HA, anti-Rubisco and anti-BiP antibodies. Soluble stroma-containing and pelleted ER-containing microsome fractions are indicated. Samples were subjected (+)...
Chapter
Full-text available
The characterization of the mechanisms of heavy metal detoxification has been undertaken through several experimental approaches, where high metal concentrations have been frequently used. A microscale hydroponic system was used to discriminate between the direct and indirect phytotoxic effects that may occur under heavy metal stress at short expos...
Data
Localization of HA-tagged CAH1 by immunogold labelling and electron microscopy. (A and B) Transmission Electron Microscopy (TEM) images of wt Arabidopsis suspension culture cells. (A) Detailed image of a chloroplast. (B) General view of the cell with ER, Golgi (G), cell wall (CW), vacuole (V), and chloroplast (C). The immunogold (IG) labelling over...
Data
CAH1 contains an intramolecular disulphide bridge. (A) ClustalW2 [47] protein sequence analysis of Arabidopsis α-CA homologues. Cysteine residues at positions 27 and 191 (red) in CAH1 sequence are conserved (*) in seven of the eight homologues described by Fabre et al. [4]. CA8 is substantially larger than CA1-7, possibly indicating that this gene...
Data
TargetP analysis of Arabidopsis α-type CAs. TargetP [8] analysis of Arabidopsis α-type CAs protein sequences described by Fabre et al. [4]. Seven of the eight homologues have an N-terminal signal sequence (SP) for the ER. (TIF)
Data
Cycloheximide treatment results in a higher proportion of Endo H resistant HC. (A) Protoplasts from Arabidopsis cell suspension culture were transiently transfected with HA-tagged wt CAH1 (HC). Prior to protein extraction, protoplasts were either incubated in presence or absence of the protein biosynthesis inhibitor cycloheximide (CHX) for 8 h. Ext...
Data
HA-tagged CAH1 is glycosylated in plant cells, harbouring four or five N-glycans. Migration patterns of HA-tagged CAH1 forms in protoplasts of Arabidopsis suspension culture cells (A) and Arabidopsis mesophyll cells (B) expressing wt (HC) or mutant CAH1. Antibody specificity was verified using water-transfected protoplasts (−). (A) Protoplasts from...
Data
Enrichment of ER marker in microsome fraction. Western blot using antibodies against the ER localized protein BiP to verify that microsome fractions in Figure 4a and b were intact. S and I, soluble supernatant and insoluble microsome pellet, respectively. (TIF)
Data
Nomenclature of constructs used to transfect plant cells and protoplasts. (DOC)
Article
Full-text available
The Arabidopsis CAH1 alpha-type carbonic anhydrase is one of the few plant proteins known to be targeted to the chloroplast through the secretory pathway. CAH1 is post-translationally modified at several residues by the attachment of N-glycans, resulting in a mature protein harbouring complex-type glycans. The reason of why trafficking through this...
Article
Full-text available
Nicotiana tabacum transgenic plants overexpressing manganese (Mn) superoxide dismutase (SOD) targeted to plastids were studied upon 12.5 PM cadmium (Cd) application. No differences in tolerance were observed in comparison to wild type plants. Seed germination inhibition, seedling growth, and plant biomass were measured at different developmental st...
Article
Full-text available
Several physiological parameters related to oxidative stress, which is a characteristic of plants exposed to toxic metals, were studied in 3-week-old alfalfa plants treated with cadmium (Cd) or mercury (Hg) at doses of 0, 3, 10 and 30 microM for 7d. The concentrations of biothiols, glutathione (GSH), homoglutathione (hGSH) and phytochelatins (PCs)...
Conference Paper
Full-text available
Appearance of oxidative stress is one of the characteristic symptoms of plant exposure to toxic metals. The accumulation of reactive oxygen species, and the corresponding cell damages, can be used as an index to determine plant responses to toxic metals. Several physiological parameters related to oxidative stress were studied in alfalfa plants exp...
Article
Here, the kinetics of oxidative stress responses of alfalfa (Medicago sativa) seedlings to cadmium (Cd) and mercury (Hg) (0, 3, 10 and 30 microm) exposure, expanding from a few minutes to 24 h, were studied. Intracellular oxidative stress was analysed using 2',7'-dichlorofluorescin diacetate and extracellular hydrogen peroxide (H(2)O(2)) production...
Article
Full-text available
A hydroponic experiment was carried out to characterize the oxidative stress responses of maize seedlings (Zea mays L. cv. Dekalb DK604) to cadmium (Cd) and mercury (Hg). Plants were grown hydroponically for 7days in a nutrient solution supplemented with several concentrations of Cd and Hg: 0.0 (control), 6 or 30μM. Growth was inhibited by both met...
Article
Full-text available
Alfalfa (Medicago sativa) plantlets were exposed to Cd or Hg to study the kinetics of diverse stress indexes. In the so-called beaker-size hydroponic system, plantlets were grown in 30 microM of Cd or Hg for 7 d. Oxidative stress took place and increased over time, a linear response being observed with Cd but not with Hg. To improve the sensitivity...
Article
Full-text available
In this study we describe photodamaging and photokilling effects of palladium(II)-tetraphenylporphycene (PdTPPo) (previously incorporated into dipalmitoylphosphatidylcholine liposomes) on the human lung adenocarcinoma A-549 cell line. No dark cytotoxicity was found when the drug was applied at 10(-6) M or 5 x 10(-7) M for 1 or 18 h, respectively. A...

Questions

Questions (2)
Question
Has anyone here tried this method for Arabidopsis?
How easy is it to find and handle the tape?
Has anyone done protoplast electroporation instead of using PEG, in which conditions? Is it really worth it?
Thanks!
Question
I found a paper suggesting Tween-20, but transformation efficiently is lowered by 30%... Thank you!

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Projects

Projects (3)
Archived project
Se analizarán los diferentes niveles de respuesta de las plantas a distintos tiempos de exposición y dosis de metal
Project
There has been an important research effort to unravel the mechanism of plant resistance to toxic metals and metalloids, as a contribution to use them in the fitoremediation of polluted soils. However, the information available is still fragmented, so the kinetic parameters of the processes involved in tolerance should be established, and their regulation characterised in detail. Previous data of our laboratory point out that cadmium (Cd), mercury (Hg) and arsenic (As) cause different phytotoxicity, triggering a differentiated homeostatic responses. Sulphur metabolism, more precisely the synthesis of phytochelatins (PCs), seems a tolerance mechanism to those toxic elements, in particular in plants treated with Cd and As. Moreover, these pollutants lead to the accumulation of reactive oxygen species (ROS), causing an oxidative burst, which might be the first step of a signal transduction mechanism in metal stress. It should be highlighted the dual role played by glutathione, either as an antioxidant metabolite together with ascorbic acid (AA); and also as a precursor of PCs. Among the antioxidant enzymes studied in our laboratory, glutathione reductase activity was differentially affected by Hg, Cd y As; propriety that could be exploited to develop a specific bioindicator of metal toxicity. In the proposed project, we will study the physiological responses of alfalfa (Medicago sativa), forage leguminous species with strong capability to improve the fertility of degraded soils, treated with Hg, Cd and As grown in two different culture systems: micro-scale and macro-scale. In the first, small seedlings will be kept in a pure hydroponic system with very reduce medium volume. This growth setting allows the visualization in vivo of the stress induced at the cellular level in extremely short exposure times (from few minutes to 24 h), by using the fluorescent tracers 2’,7’-dichlorofluorescin (oxidative stress) and propidium iodide (cell death). We have also identified several PCs-Hg complexes with high performance liquid chromatography coupled to mass spectrometry (HPLC-ESI/MS TOF), thanks to the isotopic fingerprint of Hg. With our experience, we want to develop new chromatographic procedures to detect and characterise complexes with Cd or As, and to quantify their role in the tolerance to these pollutants. To this respect, the analysis of metal localization and ligand association in vivo using X-ray Absorption Spectroscopy might provide key information. early responding genes of metal toxicity, which might be involved in cellular homeostasis and signalling. The differential transcription profile of selected genes will be validated by RT-PCR techniques, and functional analysis will comprise the use of Arabidopsis thaliana mutants (from insertion mutant collections). Finally, all data obtained from micro-scale experiments will be assessed with plants kept under macro-scale growth conditions, were plants development would resemble more closely that of future pilot phytoremediation experiments. Thus, plants with a more mature phenological status will be grown in a semi-hydroponic system using perlite as inert substrate.