Person: Vicente Córdoba, Carlos
Universidad Complutense de Madrid
Faculty / Institute
Now showing 1 - 10 of 33
PublicationBioactive Compounds from Brazilian Lichens and Their Biotechnological Applications(Springer, 2020-05-12) Pereira, Eugênia C.; Silva, Nicaçio H. da; Buril, M. L. L.; Martins, Mônica C.B.; Silva, Hianna A. M. F.; Falcão, Emerson Peter S.; Oliveira, Helinando P. de; Costa, Mateus Matiuzzi da; Legaz González, María Estrella; Santiago, Rocío; Vicente Córdoba, Carlos; Swamy, Mallappa KumaraLichens are the symbiotic organisms formed by one species of fungus associated to one or more species of green algae and/or cyanobacteria. The relationship between these organisms results in a metabolism that culminates in a production of exclusive compounds, named lichen substances, also known as lichen compounds or lichen acids. These products are known to exhibit several biological properties, and can be effective against several diseases. Several species of lichens found in Brazil have been identified and characterized for their bioactives during the last few decades. Studies have shown that these species possess antimicrobial, antineoplastic, anti-inflammatory, anti-leishmanial, and many more such bioactivities. In most cases, the articles mention different mechanisms of action. In complement, biotechnological studies have been carried out to achieve a continuous production of bioactive compounds, for example, the use of small amounts of thallus, collected directly from the environment, bioconservation processes, nanotechnological assays, nano and microencapsulations for a controlled drug liberation, incorporation in polymer matrix for pharmacological uses, etc. The possibility of extensive use of lichen substances encourages for further studies in this field, including the Brazilian species. PublicationA cyanobacterial b-actin-like protein, responsible for lichenized Nostoc sp. motility towards a fungal lectin(Springer, 2015-11) Díaz Peña, Eva María; Vicente-Manzanares, Miguel; Legaz González, María Estrella; Vicente Córdoba, CarlosLichenized Nostoc cells isolated from the lichen Peltigera canina develop chemotactic movement towards a lectin purified from the lichen thallus. Inhibitors of cytoskeleton dynamics, such as phalloidin, latrunculin A and blebbistatin, impede cell displacement. The inhibition of chemotaxis produced by the combined action of phalloidin and blebbistatin is largely reversed by GTP and its analogs, GTP(c)S and GDP(b)S, as well as by cyclic AMP. Movement implies a rearrangement of the cytoskeleton causing cell polarity, which is, in turn, inhibited by phalloidin and latrunculin A, as revealed by confocal microscopy. F-actin fibers composing Nostoc cytoskeleton have been visualized by immunocytochemical techniques associated with transmission electron microscopy. PublicationPhysiological basis of smut infectivity in the early stages of sugar cane colonization(MDPI, 2021-01-12) Vicente Córdoba, Carlos; Legaz González, María Estrella; Sánchez Elordi, ElenaSugar cane smut (Sporisorium scitamineum) interactions have been traditionally considered from the plant’s point of view: How can resistant sugar cane plants defend themselves against smut disease? Resistant plants induce several defensive mechanisms that oppose fungal attacks. Herein, an overall view of Sporisorium scitamineum’s mechanisms of infection and the defense mechanisms of plants are presented. Quorum sensing effects and a continuous reorganization of cytoskeletal components, where actin, myosin, and microtubules are required to work together, seem to be some of the keys to a successful attack. PublicationPotential phenolic bioherbicides from Cladonia verticillaris produce ultrastructural changes in Lactuca sativa seedlings(Elsevier, 2015-05) Tigre, R. C.; Pereira, Eugênia C.; Da Silva, Nicácio H.; Vicente Córdoba, Carlos; Legaz González, María EstrellaThe possibilities for using phenolics, extracted from the lichen Cladonia verticillaris with different organic solvents, as bioherbicides have herein been studied through observation of the ultrastructural changes produced in Lactuca sativa seedlings. The different extracts mainly contain protocetraric and fumarprotocetraric acids and very small amounts of atranorin. It has been observed that the roots of lettuce seedlings grow more rapidly in the presence of the phenols than in their absence. This fact is supported by a minor number of lobes and less indentation of the parenchymatous cells as well as a major appearance of active dictyosomes in their cytoplasm. Nevertheless, seedling leaves developed in the presence of these extracts show drastic degenerative changes. Intergranal lamellae of chloroplasts disappear whereas thylakoids are melted in amorphous masses. In some cases, the number of dictyosomes increases in parenchymatous cells and mitochondria disorganize their internal membranes, though in a minor degree of that observed for chloroplasts. PublicationThe role of lichenized algae in the production of Cladonia verticillaris depsidones, revealed by using alginate-immobilized cells(Trade Science Inc., 2015) Díaz, Eva María; Davó, Nuria; Vicente Córdoba, Carlos; Legaz González, María EstrellaThe mycobiont of the lichen Cladonia verticillaris produces two depsidones, protocetraric and fumarprotocetraric acids, in the nature. This last compound is produced from the former depsidone. To study the role of the algal partner in the production of these depsidones in the lichen thallus, fungal and algal partners were separated and immobilized in calcium alginate. The fungal immobilizates, as lichenized or isolated mycobiont, produced both depsidones, preferently fumarporotocetraric acid from acetate as a precursor. However, when algal immobilizates were co-incubated on acetate with the fungal ones, protocetraric acid was over-produced during the first 11 days of incubation to be later converted into fumarprotocetraric acid. We hypothesized about the algal production of a diffusible metabolite that inhibits the transformation of a depsidone into the other one. PublicationDefence sugarcane glycoproteins disorganize microtubules andprevent nuclear polarization and germination of Sporisoriumscitamineum teliospores(Elsevier, 2016) Sánchez Elordi, Elena; Baluska, Frantisek; Echevarría, Clara; Vicente Córdoba, Carlos; Legaz González, María EstrellaMicrotubules (MTs) are involved in the germination of Sporisorium scitamineum teliospores. Resistant varieties of sugar cane plants produce defence glycoproteins that prevent the infection of the plants by the ﬁlamentous fungi Sporisorium scitamineum. Here, we show that a fraction of these glycoproteins pre-vents the correct arrangement of MTs and causes nuclear fragmentation defects. As a result, nuclei cannotcorrectly migrate through the growing hyphae, causing germinative failure. Arginase activity contained in defence glycoproteins is already described for preventing fungal germination. Now, its enzymatically active form is presented as a link between the defensive capacity of glycoproteins and the MT disor-ganization in fungal cells. Active arginase is produced in healthy and resistant plants; conversely, it is not detected in the juice from susceptible varieties, which explains why MT depolarization, nuclear dis-organization as well as germination of teliospores are not signiﬁcantly affected by glycoproteins from non-resistant plants. Our results also suggest that susceptible plants try to increase their levels of arginase after detecting the presence of the pathogen. However, this signal comes “too late” and such defensive mechanism fails. PublicationDefensive glycoproteins from sugarcane plants induce hemotaxis, cytoaglutination and death of smut teliospores(Italian Phytopathological Society, 2016) Sánchez Elordi, Elena; Morales de los Ríos, L.; Díaz, E. M.; Ávila, A.; Legaz González, María Estrella; Vicente Córdoba, CarlosSugarcane produces and secretes high molecular mass glycoproteins (HMMG) in response to pathogenic infections, wounds or several types of stress. The teliospores of the pathogenic filamentous fungus Sporisorium scitamineum produces smut disease in non-resistant varieties of sugarcane. Two HMMG from smut-resistant varieties of sugarcane promote teliospore chemotaxis and agglutination, respectively. However, HMMG from by non-resistant varieties do not promote teliospore aggregation. Agglutination is a lectin-dependent response from the HMMG endowed with arginase activity that also inhibits teliospore germination. Conversely, dispersal of teliospore aggregates and loss of chemotaxis are induced by other glycoproteins from resistant cultivars after prolonged contact with the chemoattractant. This is accompanied by disassembly of the cell wall protoplast leakage, which is caused by hydrolytic enzymes, such as chitinase and β-1,4- and β-1,3-glucanases. In this report, we describe agglutination as a “bait and kill” mechanism that congregates as many pathogenic organisms in a specific region to be killed by the action of a second, concerted hydrolytic switch. PublicationInhibition by substrates of a coniferyl alcohol dehydrogenase purifiedfrom sugarcane stalks(Bentham Science Publishers, 2019) Alarcón, Borja; Armas, Roberto de; Vicente Córdoba, Carlos; Legaz González, María EstrellaAims and Objectives: This study aimed to characterize a coniferyl alcohol dehydrogenase from sugarcane stalks. Also, the purification of CAD from sugarcane stalks was also carried out to study kinetic properties and substrate specificity. Background : Sugarcane plants contain an alcohol dehydrogenase able to reduce both coniferyl and sinapyl aldehydes to their correspondent alcohols, although there are reasonable grounds for suspecting that these are two distinct enzymes. Methods : The enzyme, coniferyl alcohol dehydrogenase was 125-fold purified from sugarcane stalks. Its activity was estimated by HPLC by calculating the amount of product formed. Results : The enzyme showed an optimum pH value of 7.9, at an optimum temperature of 20-22 °C and a molecular mass of 48 kDa. The K m value for coniferyl alcohol was 3.03 μM and the enzyme was shown to be inhibited by an excess of the substrate from 17 μM. This dehydrogenase showed a similar affinity to sinapyl alcohol (K m 1.78 μM). Conclusion : This paper provides circumstantial evidence about the existence of two different alcohol dehydrogenases, specific to each of the substrates. PublicationSugarcane glycoproteins control dynamics of cytoskeleton during teliospore germination of Sporisorium scitamineum(Springer, 2019-09-14) Sánchez Elordi, Elena; Baluška, František; Vicente Córdoba, Carlos; Legaz González, María EstrellaSporisorium scitamineum teliospores possess an organized cytoskeleton involved in important developmental and physiological processes. It has been described that microtubules appear to be fundamental for nucleus translocation during germination and hyphal growth, whereas actin polymerization is necessary for the formation of invaginations during teliospore displacement. Here, a global vision of the actin cytoskeleton organization throughout the life cycle of S. scitamineum cells is shown, providing evidence that a perfectly structured F-actin network is necessary to trigger smut pathogenicity. Moreover, although myosin presence in teliospores had been previously described, herein actin and myosin co-locations are demonstrated by confocal microscopy during both invaginations formation and germination. In turn, F-actin and microtubules (MTs) interact, jointly participating in the establishment of cell polarity. The resistant sugarcane cultivar Mayari 55-14 produces high molecular mass glycoproteins (HMMG) that differently affect F-actin organization at different stages of fungal development. HMMG first supported F-actin to induce the movement of teliospores towards the cytoagglutination points. At later stages of fungal development, HMMG disorganized F-actin which prevented the protrusion of germinative tube. A continuous exposure to HMMG provoked apoptosis in pathogenic, diploid cells and a delay in sporidia conjugation that could be crucial for plant resistance. PublicationPolyamines levels increase in smut teliospores after contact with sugarcane glycoproteins as a plant defensive mechanism(Springer, 2019-03-12) Sánchez Elordi, Elena; Morales de los Ríos, Laura; Vicente Córdoba, Carlos; Legaz González, María EstrellaPrevious studies have already highlighted the correlation between Sporisorium scitamineum pathogenicity and sugarcane polyamine accumulation. It was shown that high infectivity correlates with an increase in the amount of spermidine, spermine and cadaverine conjugated to phenols in the sensitive cultivars whereas resistant plants mainly produce free putrescine. However, these previous studies did not clarify the role of these polyamides in the disorders caused to the plant. Therefore, the purpose of this research is to clarify the effect of polyamines on the development of smut disease. In this paper, commercial polyamines were firstly assayed on smut teliospores germination. Secondly, effects were correlated to changes in endogenous polyamines after contact with defense sugarcane glycoproteins. Low concentrations of spermidine significantly activated teliospore germination, while putrescine had no activating effect on germination. Interestingly, it was observed that the diamine caused nuclear decondensation and breakage of the teliospore cell wall whereas the treatment of teliospores with spermidine did not induce nuclear decondensation or cell wall breakdown. Moreover, the number of polymerized microtubules increased in the presence of 7.5 mM spermidine but it decreased with putrescine which indicates that polyamines effects on Sporisorium scitamineum teliospore germination could be mediated through microtubules interaction. An increased production of polyamines in smut teliospores has been related to sugarcane resistance to the disease. Teliospores incubation with high molecular mass glycoproteins (HMMG) from the uninoculated resistant variety of sugarcane, Mayari 55-14, caused an increase of the insoluble fraction of putrescine, spermidine and spermine inside the teliospore cells. Moreover, the level of the soluble fraction of spermidine (S fraction) increased inside teliospores and the excess was released to the medium. The HMMG glycoproteins purified from Mayarí 55-14 plants previously inoculated with the pathogen significantly increased the levels of both retained and secreted soluble putrescine and spermidine. Polyamines levels did not increase in teliospores after incubation with HMMG produced by non resistant variety Barbados 42231 which could be related to the incapacity of these plants to defend themselves against smut disease. Thus, a hypothesis about the role of polyamines in sugarcane-smut interaction is explained.