Is ABA involved in tolerance responses to salinity by affecting cytoplasm ion homeostasis in rice cell lines?

Abstract The ability of plant cells to maintain cytoplasm ion homeostasis under saline stress is among the main mechanisms involved in salt tolerance. To cope with excess Na + , cells extrude it from the cytoplasm, which requires expenditure of metabolic energy, provided by H + gradients generated by membrane-bound H + -pumps. ABA is well-known to be involved in physiological processes elicited or enhanced by stresses causing cell dehydration. In this work we studied the possible implication of this plant hormone in the control of salt-induced cellular mechanisms conducting to Na + extrusion from the cytoplasm. We used rice ( Oryza sativa L.) cell lines selected for their different toleranc…

El uso de materiales didácticos de exposiciones por parte del profesorado y su adecuación a la visita al museo universitario

El presente trabajo describe el proceso desarrollado en la asignatura Expresión Plástica de Educación Primaria, a partir de una práctica  que llevaron a cabo nuestros estudiantes de segundo curso de Magisterio de la Universidad de Alicante a través del Aprendizaje Basado en Proyectos. El mencionado proyecto de cuatro semanas de duración englobaba: la visita al Museo MUA; la investigación sobre una de las obras percibidas, su autores y las técnicas empleadas; la elaboración de un material didáctico adaptado a niños como medio de trabajo con alumnos que acudirían a la misma visita; la exposición pública de todo ello a los compañeros de clase; y finalmente la recopilación en un portafolio digi…

Uptake of Acidic and Basic Sugar Derivatives in Lemna gibba G1

The uptake of acidic and basic sugar derivatives in Lemna gibba L. was studied. Uronic acids applied to the experimental solution (50 millimolar) induced a small decrease of the membrane potential (10 +/- 1 millivolt galacturonic acid, and 20 +/- 4 millivolt glucuronic acid). After incubation of the plants in a 0.1 millimolar solution of these substrates, no decrease in the concentration of reducing groups in the external solution was detected. Respiration increased by 31% with 50 millimolar galacturonic acid, whereas no effect was found with the same concentration of glucuronic acid. Glucosamine caused a considerable concentration-dependent membrane depolarization. ((14)C)glucosamine uptak…

Mathematical literacy in Plant Physiology undergraduates: results of interventions aimed at improving students' performance

The importance of mathematical literacy in any scientific career is widely recognized. However, various studies report lack of numeracy and mathematical literacy in students from various countries. In the present work we present a detailed study of the mathematical literacy of Spanish undergraduate students of Biology enrolled in a Plant Physiology course. We have performed individual analyses of results obtained during the period 2000-2011, for questions in the examinations requiring and not requiring mathematical skills. Additionally, we present the outcome of two interventions introduced with the aim of helping students improve their prospects for success in the course. Our results confi…

Daily rhythmicity of high affinity copper transport

A differential demand for copper (Cu) of essential cupro-proteins that act within the mitochondrial and chloroplastal electronic transport chains occurs along the daily light/dark cycles. This requires a fine-tuned spatiotemporal regulation of Cu delivery, becoming especially relevant under non-optimal growth conditions. When scarce, Cu is imported through plasma membrane-bound high affinity Cu transporters (COPTs) whose coding genes are transcriptionally induced by the SPL7 transcription factor. Temporal homeostatic mechanisms are evidenced by the presence of multiple light- and clock-responsive regulatory cis elements in the promoters of both SPL7 and its COPT targets. A model is presente…

Effect of Hormones on Sucrose Uptake and on ATPase Activity of Citrus sinensis L. Osbeck Leaves

Carbohydrate accumulation in young, fully expanded leaves of Citrus sinensis L. Osbeck is affected by the presence of the fruitlet on the shoot. Previous work gave evidence that gibberellins may be involved in this 'fruit effect'. In the present work we have studied the effect of gibberellic acid (GA3) on 14C-sucrose uptake by leaf discs and whether its action could be due to a modulation of the plasma membrane ATPase, which maintains the H+ gradient that drives H+/sucrose co-transport. The effect of GA3 on 14C-sucrose uptake depended on the osmolarity of the assay medium. At 300 mOsm a reduction in the uptake rate was observed. The inhibitory effect of the hormone disappeared after preincu…

Hormone Effects on the Membrane Potential and on Sucrose-Induced Depolarization of Young <italic>Citrus</italic> Leaves

Schools: wrong spaces face the ones desired by the students

ResumenEste trabajo estudia las ideas que algunos estudiantes tienen sobre la mejora de su espacio, es decir, las proyecciones de los deseos de escolares hacia su propio centro educativo. Este estudio sobre la calidad estética se desarrolla gracias a la participación de tres colegios de Educación Infantil y Educación Primaria de Alicante, en España. La metodología es mixta pues combina la investigación educativa basada en las Artes Visuales y la investigación basada en imágenes para obtener mediante métodos gráficos la voz visual infantil. Los productos son diversos dibujos y collages que expresan información y contenido comunicativo analizado de manera cualitativa y cuantitativa. Con base …

Aesthetic factors determining quality and comfort in childhood classroom

This study analyses how school age children experience their educational environment. The objective is to collect the determining factors of aesthetic quality and comfort at school. A pluralistic methodology allows: gather both quantitative and qualitative data using photographic elicitation, and show the responses on an artistic way. Eighty-six children participate on this research; they are from 3 until 5 years old, and belong to rural and urban schools of Alicante. The results determine which places of school are more comfortable, pleasant and enjoyable in Early Childhood Education. Pupils are able to examine in a critically form their everyday educational activities and express their op…

Differential salinity-induced variations in the activity of H+-pumps and Na+/H+ antiporters that are involved in cytoplasm ion homeostasis as a function of genotype and tolerance level in rice cell lines

The characterisation of cellular responses to salinity in staple crops is necessary for the reliable identification of physiological markers of salinity tolerance. Under saline conditions, variations in proton gradients that are generated by membrane-bound H⁺ pumps are crucial for maintaining cytoplasm homeostasis. We examined short (15 h) and longer term effects (4 days) of NaCl stress on the H⁺ pumping activities that are associated with the plasma membrane (P-ATPase) and the tonoplast (V-ATPase and V-PPase) in rice (Oryza sativa L.) callus lines that displayed different levels of NaCl tolerance and were established from two japonica rice cultivars. The applied stress conditions were base…

Educació artística per a mestres de primària

A través dels capítols que formen aquest document anem desgranant aspectes que considerem més evocadors a fi d’animar el professorat a aprofitar les arts com a argument educatiu. Introduïm en el text conceptes i metodologies recents, reivindiquem autors clàssics i destaquem estudis actuals. Recorrem a experiències viscudes des de la proximitat i, també, parlem d’aportacions que arriben de tot arreu, perquè l’educació artística evoluciona de manera diversa en les diverses realitats que es viuen a cada país. Tal com ha evolucionat els darrers anys el riquíssim àmbit de les arts, considerem que ara toca satisfer les exigències del domini del territori de l’educació en arts, dins del qual inclo…