Current overview of S-nitrosoglutathione (GSNO) in higher plants

S-nitrosoglutathione is a nitric oxide-derived molecule, generated by the interaction of nitric oxide (NO) with reduced glutathione (GSH) in a process called S-nitrosylation (Figure 1). The reaction appears to take place either through the formation of N2O3 or the addition of NO to a glutathionyl radical formed during this reaction (Broniowska et al., 2013). GSNO is regarded as an intracellular NO reservoir as well as a vehicle of NO throughout the cell, which enables NO biological activity to expand. GSNO is also considered to be the most abundant low-molecular-mass (LMM) S-nitrosothiol (SNO). This family includes other molecules such as S-nitrosocysteine (CySNO) and S-nitrosocysteinylglycine (GlyCySNO), which have been the subject of less study in the field of plant research. There is another group of SNOs called high-molecular mass (HMM) SNOs which are produced by NO binding to sulfhydryl (-SH) groups present in specific cysteine residues of proteins. Figure 1 shows a simple model of GSNO metabolism and its interactions with other molecules in cells where different reactions including S-nitrosylation, S-transnitrosation, and S-glutathionylation are involved (Hogg, 2002; Martínez-Ruiz and Lamas, 2007). In plants, research has focused on the importance of total SNOs in specific stress situations (Feechan et al., 2005; Chaki et al., 2011a) and on the identification of the potential protein targets of S-nitrosylation as this kind of post-translational modification can alter the function of the affected proteins (Astier et al., 2012). Initial studies in this area exogenously applied GSNO in order to identify the pool of potential protein candidates (Lindermayr et al., 2005). However, less attention has been paid to the abundance, distribution, and modulation of endogenous GSNO under natural and stress conditions. In this article, we will provide a current overview of GSNO in higher plants. [EN]Work in our laboratories is supported by ERDF-cofinanced grants from the Ministry of Science and Innovation (BIO2012-33904 and BFU2011-22779)Peer reviewe

Editorial:Subcellular compartmentalization of plant antioxidants and ROS generating systems, volume II

JP, MR-R and FC were financed by ERDF-co-financed grants from the Junta de Andalucía (P18-FR-1359) and the Ministry of Science and Innovation (PID2019-103924GB-I00), Spain. CF was financed by BBSRC/GCRF Grant (BB/T008865/1), UK

NADP-Dependent Isocitrate Dehydrogenase from Arabidopsis Roots Contributes in the Mechanism of Defence against the Nitro-Oxidative Stress Induced by Salinity

NADPH regeneration appears to be essential in the mechanism of plant defence against oxidative stress. Plants contain several NADPH-generating dehydrogenases including isocitrate dehydrogenase (NADP-ICDH), glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), and malic enzyme (ME). In Arabidopsis seedlings grown under salinity conditions (100 mM NaCl) the analysis of physiological parameters, antioxidant enzymes (catalase and superoxide dismutase) and content of superoxide radical (O2  ∙−), nitric oxide (NO), and peroxynitrite (ONOO−) indicates a process of nitro-oxidative stress induced by NaCl. Among the analysed NADPH-generating dehydrogenases under salinity conditions, the NADP-ICDH showed the maximum activity mainly attributable to the root NADP-ICDH. Thus, these data provide new insights on the relevance of the NADP-ICDH which could be considered as a second barrier in the mechanism of response against the nitro-oxidative stress generated by salinity

Antioxidant Profile of Pepper (Capsicum annuum L.) Fruits Containing Diverse Levels of Capsaicinoids

Capsicum is the genus where a number of species and varieties have pungent features due to the exclusive content of capsaicinoids such as capsaicin and dihydrocapsaicin. In this work, the main enzymatic and non-enzymatic systems in pepper fruits from four varieties with different pungent capacity have been investigated at two ripening stages. Thus, a sweet pepper variety (Melchor) from California-type fruits and three autochthonous Spanish varieties which have different pungency levels were used, including Piquillo, Padrón and Alegría riojana. The capsaicinoids contents were determined in the pericarp and placenta from fruits, showing that these phenyl-propanoids were mainly localized in placenta. The activity profiles of catalase, total and isoenzymatic superoxide dismutase (SOD), the enzymes of the ascorbate–glutathione cycle (AGC) and four NADP-dehydrogenases indicate that some interaction with capsaicinoid metabolism seems to occur. Among the results obtained on enzymatic antioxidants, the role of Fe-SOD and the glutathione reductase from the AGC is highlighted. Additionally, it was found that ascorbate and glutathione contents were higher in those pepper fruits which displayed the greater contents of capsaicinoids. Taken together, all these data indicate that antioxidants may contribute to preserve capsaicinoids metabolism to maintain their functionality in a framework where NADPH is perhaps playing an essential role

Differential molecular response of monodehydroascorbate reductase and glutathione reductase by nitration and S-nitrosylation

The ascorbate–glutathione cycle is a metabolic pathway that detoxifies hydrogen peroxide and involves enzymatic and non-enzymatic antioxidants. Proteomic studies have shown that some enzymes in this cycle such as ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), and glutathione reductase (GR) are potential targets for post-translational modifications (PMTs) mediated by nitric oxide-derived molecules. Using purified recombinant pea peroxisomal MDAR and cytosolic and chloroplastic GR enzymes produced in Escherichia coli, the effects of peroxynitrite (ONOO–) and S-nitrosoglutathione (GSNO) which are known to mediate protein nitration and S-nitrosylation processes, respectively, were analysed. Although ONOO– and GSNO inhibit peroxisomal MDAR activity, chloroplastic and cytosolic GR were not affected by these molecules. Mass spectrometric analysis of the nitrated MDAR revealed that Tyr213, Try292, and Tyr345 were exclusively nitrated to 3-nitrotyrosine by ONOO–. The location of these residues in the structure of pea peroxisomal MDAR reveals that Tyr345 is found at 3.3 Å of His313 which is involved in the NADPbinding site. Site-directed mutagenesis confirmed Tyr345 as the primary site of nitration responsible for the inhibition of MDAR activity by ONOO–. These results provide new insights into the molecular regulation of MDAR which is deactivated by nitration and S-nitrosylation. However, GR was not affected by ONOO– or GSNO, suggesting the existence of a mechanism to conserve redox status by maintaining the level of reduced GSH. Under a nitro-oxidative stress induced by salinity (150 mM NaCl), MDAR expression (mRNA, protein, and enzyme activity levels) was increased, probably to compensate the inhibitory effects of S-nitrosylation and nitration on the enzyme. The present data show the modulation of the antioxidative response of key enzymes in the ascorbate–glutathione cycle by nitric oxide (NO)- PTMs, thus indicating the close involvement of NO and reactive oxygen species metabolism in antioxidant defence against nitro-oxidative stress situations in plants.Spanish GovernmentERDF - Ministry of Economy and Competitiveness BIO2012-33904Junta de Andalucía BIO286 BIO19

Autoaprendizaje a través de Trabajos de Investigación Tutorizados en la enseñanza de Ingeniería de los Nuevos Materiales

El presente trabajo pretende abordar las posibilidades de la innovación docente, haciendo que los estudiantes de segundo y tercer curso de I.T. Industrial se inicien en métodos y técnicas de investigación que le ayuden en su propio aprendizaje así como en el diseño y planificación de sus trabajos. Los nuevos estudios de grado diversifican los instrumentos pedagógicos al servicio del docente para transmisión del conocimiento al alumnado

Validation of the no presential teaching evaluation instrument in Vocational Training

La pandemia de COVID-19 está amenazando gravemente la salud de la humanidad provocando consecuencias de toda índole. Un sector bastante afectado, es el educativo. El aprendizaje del alumnado se ha visto reducido en el último cuatrimestre del curso escolar 2019-20, y probablemente los métodos de enseñanza que han tenido que forzarse en este tiempo tengan que repetirse para el curso próximo, si la ciencia no encuentra un remedio rápido para combatir el virus. En este contexto las administraciones públicas en el marco de sus competencias constitucionales están desarrollando distintos modelos educativos para que cada centro educativo gracias a su autonomía elija la mejor opción de acuerdo con el tipo de enseñanzas que ofertan y los distintos niveles educativos que desarrollan. El objetivo del presente estudio ha sido desarrollar un instrumento válido y fiable para evaluar la práctica docente no presencial en Formación Profesional. El enfoque metodológico corresponde a una investigación por encuesta transversal de carácter cuantitativo. Se ofrecen los diferentes resultados de los valores de alfa de Cronbach, así como una serie de estadísticos descriptivos. La estructura factorial de esta escala es analizada mediante análisis factorial exploratorio, análisis confirmatorio utilizando una muestra de 329 profesores. Los análisis realizados muestran que la escala se compone de seis factores: índice de actitud del alumnado-profesorado, atención a la diversidad, índice de coordinación docente, índice de eficacia virtual, índice de orientación y tutoría, índice de práctica docente virtual.The COVID-19 pandemic seriously threatens the health of humanity, causing all types of consequences. The education sector is one of the most affected. Student learning has been reduced in the last quarter of the 2019-20 school year, and if science doesn't find a quick solution to fight the virus, the teaching methods that have had to be forced during this time will likely have to be repeated over the next year. In this context, public administrations within the framework of their constitutional powers are developing different educational models so that each teaching center, thanks to its autonomy, chooses the best option according to the type of education they offer and the different educational levels they develop. The objective of this study has been to develop a valid and reliable instrument to evaluate teaching practice in times of pandemic. The methodological approach corresponds to a cross-sectional research survey of a quantitative nature. The different results of Cronbach's alpha values are offered, as well as a series of descriptive statistics. The factorial structure of this scale is analyzed by exploratory factor analysis, confirmatory analysis using a sample of 329 teachers. The studies carried out show that the scale is made up of six factors: student-teacher attitude index, attention to diversity, teacher coordination index, virtual efficiency index, orientation and tutoring index, virtual teaching practice index.Universidad Pablo de Olavid

Nitroproteínas implicadas en la maduración de frutos y en el estrés por baja temperatura en plantas de pimiento (Capsicum annuum L)

Comunicaciones a congreso

Análisis de la nitración fisiológica de proteínas en órganos de plantas de guisante (Pisum sativum L) durante su desarrollo y senescencia

Comunicaciones a congreso

Chemical priming enhances plant tolerance to salt stress

Salt stress severely limits the productivity of crop plants worldwide and its detrimental effects are aggravated by climate change. Due to a significant world population growth, agriculture has expanded to marginal and salinized regions, which usually render low crop yield. In this context, finding methods and strategies to improve plant tolerance against salt stress is of utmost importance to fulfill food security challenges under the scenario of the ever-increasing human population. Plant priming, at different stages of plant development, such as seed or seedling, has gained significant attention for its marked implication in crop salt-stress management. It is a promising field relying on the applications of specific chemical agents which could effectively improve plant salt-stress tolerance. Currently, a variety of chemicals, both inorganic and organic, which can efficiently promote plant growth and crop yield are available in the market. This review summarizes our current knowledge of the promising roles of diverse molecules/compounds, such as hydrogen sulfide (HS), molecular hydrogen, nitric oxide (NO), hydrogen peroxide (HO), melatonin, chitosan, silicon, ascorbic acid (AsA), tocopherols, and trehalose (Tre) as potential primers that enhance the salinity tolerance of crop plants