UPTAKE OF NITROGEN FORMS IN ZEA MAYS A molecular and physiological study of urea transport

In questa tesi \ue8 stata svolta la caratterizzazione fisiologica e molecolare del sistema di trasporto dell\u2019urea ad alta affinit\ue0 in radici di Zea mays. I risultati hanno mostrato che l\u2019esposizione delle radici a urea e/o ad altre fonti azotate (quali nitrato) moduli la capacit\ue0 di assorbimento della fonte organica. Inoltre, mediante analisi microarray e di real time RT-PCR, si \ue8 valutato l\u2019effetto di urea e nitrato sulla modulazione trascrizionale. Infine, da radici di mais \ue8 stato isolato e caratterizzato in sistemi eterologhi il trasportatore di urea, ZmDUR3

The urease inhibitor NBPT negatively affects DUR3-mediated uptake and assimilation of urea in maize roots

Despite the widespread use of urease inhibitors in agriculture, little information is available on their effect on nitrogen (N) uptake and assimilation. Aim of this work was to study, at physiological and transcriptional level, the effects of N-(n-butyl) thiophosphoric triamide (NBPT) on urea nutrition in hydroponically grown maize plants. Presence of NBPT in the nutrient solution limited the capacity of plants to utilize urea as a N-source; this was shown by a decrease in urea uptake rate and 15N accumulation. Noteworthy, these negative effects were evident only when plants were fed with urea, as NBPT did not alter 15N accumulation in nitrate-fed plants. NBPT also impaired the growth of Arabidopsis plants when urea was used as N-source, while having no effect on plants grown with nitrate or ammonium. This response was related, at least in part, to a direct effect of NBPT on the high affinity urea transport system. Impact of NBPT on urea uptake was further evaluated using lines of Arabidopsis overexpressing ZmDUR3 and dur3-knockout; results suggest that not only transport but also urea assimilation could be compromised by the inhibitor. This hypothesis was reinforced by an over-accumulation of urea and a decrease in ammonium concentration in NBPT-treated plants. Furthermore, transcriptional analyses showed that in maize roots NBPT treatment severely impaired the expression of genes involved in the cytosolic pathway of ureic-N assimilation and ammonium transport. NBPT also limited the expression of a gene coding for a transcription factor highly induced by urea and possibly playing a crucial role in the regulation of its acquisition. This work provides evidence that NBPT can heavily interfere with urea nutrition in maize plants, limiting influx as well as the following assimilation pathway. \ua9 2015 Zanin, Tomasi, Zamboni, Varanini and Pinton

Aplicación del programa de Reducción del Estrés Basado en la Atención Plena (REBAP) en pacientes con enfermedad orgánica atendidos en el Programa de Enlace e Interconsultas de Salud Mental. Un estudio piloto

El Programa de Enlace e Interconsultas de Salud Mental del Hospital Universitario “Virgen del Rocío” de Sevilla atiende a pacientes hospitalizados que presentan alteraciones emocionales que repercuten negativamente en su enfermedad (cáncer, dolor crónico, trasplante de órganos, enfermedades crónicas, etc.) e interfieren en su proceso de recuperación. Algunos/as de estos/as pacientes precisan atención psicoterapéutica tras el alta hospitalaria y una posible alternativa eficaz sería la aplicación del programa REBAP (Reducción del estrés basado en la Atención Plena). El principal objetivo del uso de este programa de tratamiento sería que los/as pacientes tomasen una respuesta emocional adaptativa ante la enfermedad orgánica que padecen, de modo que las alteraciones emocionales disminuyeran y dejaran de interferir en el curso de la enfermedad. El presente trabajo recoge los datos de un estudio piloto realizado con un grupo de pacientes a quienes se les aplicó el programa a lo largo de ocho sesiones usando un formato grupal. Los resultados obtenidos apuntan a que el programa REBAP es un instrumento útil para lograr que la sintomatología afectiva de los/as pacientes disminuya, puesto que consiguen preservar su autoestima y aceptar de forma más adaptativa las limitaciones derivadas de su enfermedad física.The Consultation-Liaison Mental Health program of the University Hospital “Virgen del Rocío”, in Seville, assists to patients with emotional disturbances that negatively impact their illness (cancer, chronic pain, organ transplantation, chronic diseases, etc.) and interfere with their recovery process. Some patients require psychotherapeutic care after hospital discharge and a possible effective alternative would be the implementation of the MBSR (Mindfulness Based Stress Reduction) program. The main purpose of this treatment program would be that patients took an adaptive emotional response to the organic disease causing the reduction of the emotional disturbance and stopping the interference in the course of the disease. This paper provides data from a pilot study of a group of patients who were administered the program over eight group sessions. The results indicate that the program is useful to make affective symptomatology decrease, since patients get to preserve their self-esteem and accept in a more adaptively way the limitations imposed by his physical illness

Transgenerational Response to Nitrogen Deprivation in Arabidopsis thaliana

Nitrogen (N) deficiency is one of the major stresses that crops are exposed to. It is plausible to suppose that a stress condition can induce a memory in plants that might prime the following generations. Here, an experimental setup that considered four successive generations of N-sufficient and N-limited Arabidopsis was used to evaluate the existence of a transgenerational memory. The results demonstrated that the ability to take up high amounts of nitrate is induced more quickly as a result of multigenerational stress exposure. This behavior was paralleled by changes in the expression of nitrate responsive genes. RNAseq analyses revealed the enduring modulation of genes in downstream generations, despite the lack of stress stimulus in these plants. The modulation of signaling and transcription factors, such as NIGTs, NFYA and CIPK23 might indicate that there is a complex network operating to maintain the expression of N-responsive genes, such as NRT2.1, NIA1 and NIR. This behavior indicates a rapid acclimation of plants to changes in N availability. Indeed, when fourth generation plants were exposed to N limitation, they showed a rapid induction of N-deficiency responses. This suggests the possible involvement of a transgenerational memory in Arabidopsis that allows plants to adapt efficiently to the environment and this gives an edge to the next generation that presumably will grow in similar stressful conditions

Genome-wide microarray analysis of tomato roots showed defined responses to iron deficiency

<p>Abstract</p> <p>Background</p> <p>Plants react to iron deficiency stress adopting different kind of adaptive responses. Tomato, a <it>Strategy I </it>plant, improves iron uptake through acidification of rhizosphere, reduction of Fe³⁺to Fe²⁺and transport of Fe²⁺into the cells. Large-scale transcriptional analyses of roots under iron deficiency are only available for a very limited number of plant species with particular emphasis for <it>Arabidopsis thaliana</it>. Regarding tomato, an interesting model species for <it>Strategy I </it>plants and an economically important crop, physiological responses to Fe-deficiency have been thoroughly described and molecular analyses have provided evidence for genes involved in iron uptake mechanisms and their regulation. However, no detailed transcriptome analysis has been described so far.</p> <p>Results</p> <p>A genome-wide transcriptional analysis, performed with a chip that allows to monitor the expression of more than 25,000 tomato transcripts, identified 97 differentially expressed transcripts by comparing roots of Fe-deficient and Fe-sufficient tomato plants. These transcripts are related to the physiological responses of tomato roots to the nutrient stress resulting in an improved iron uptake, including regulatory aspects, translocation, root morphological modification and adaptation in primary metabolic pathways, such as glycolysis and TCA cycle. Other genes play a role in flavonoid biosynthesis and hormonal metabolism.</p> <p>Conclusions</p> <p>The transcriptional characterization confirmed the presence of the previously described mechanisms to adapt to iron starvation in tomato, but also allowed to identify other genes potentially playing a role in this process, thus opening new research perspectives to improve the knowledge on the tomato root response to the nutrient deficiency.</p

Physiological and RNA sequencing data of white lupin plants grown under Fe and P deficiency

This DIB article provides details about transcriptional and physiological response of Fe- and P-deficient white lupin roots, an extensive and complete description of plant response is shown in the research article \u201cPhysiological and transcriptomic data highlight common features between iron and phosphorus acquisition mechanisms in white lupin roots\u201d Venuti et al. [1]. White lupin plants were grown under hydroponic system and three different nutritional regimes: Fe deficiency (-Fe), P deficiency (-P), or Fe and P sufficiency (+P + Fe). Depending on nutritional treatment, white lupin plants showed changes in the fresh weights, in root external acidification and FeIII-reductase activity. Moreover, the transcriptomic changes occurring in apices and clusters of Fe-deficient lupin roots were investigated and compared with differences of gene expression occurring in P-deficient plants (-P) and in Fe- and P-sufficient plants (+P + Fe). Transcriptomic data are available in the public repository Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo) under the series entry (GSE112220). The annotation, mapping and enrichment analyses of differentially modulated transcripts were assessed

Responses of hydroponically grown maize to various urea to ammonium ratios: physiological and molecular data

To date urea and ammonium are two nitrogen (N) forms widely used in agriculture. Due to a low production cost, urea is the N form most applied in agriculture. However, its stability in the soil depends on the activity of microbial ureases, that operate the hydrolysis of urea into ammonium. In the soil ammonium is subjected to fast volatilization in form of ammonia, an environmental N loss that contributes to the atmospheric pollution and impacts on farm economies. Based on these considerations, the optimization of N fertilization is useful in order to maximize N acquired by crops and at the same time limit N losses in the environment. The use of mixed nitrogen forms in cultivated soils allows to have urea and ammonium simultaneously available for the root acquisition after a fertilization event. A combination of different N-sources is known to lead to positive effects on the nutritional status of crops. It is plausible suppose that N acquisition mechanisms in plants might be responsive to N forms available in the root external solution, and therefore indicate a cross connection among different N forms, such as urea and ammonium

Isolation and functional characterization of a high affinity urea transporter from roots of Zea mays

Background Despite its extensive use as a nitrogen fertilizer, the role of urea as a directly accessible nitrogen source for crop plants is still poorly understood. So far, the physiological and molecular aspects of urea acquisition have been investigated only in few plant species highlighting the importance of a high-affinity transport system. With respect to maize, a worldwide-cultivated crop requiring high amounts of nitrogen fertilizer, the mechanisms involved in the transport of urea have not yet been identified. The aim of the present work was to characterize the high-affinity urea transport system in maize roots and to identify the high affinity urea transporter. Results Kinetic characterization of urea uptake (<300 \u3bcM) demonstrated the presence in maize roots of a high-affinity and saturable transport system; this system is inducible by urea itself showing higher Vmax and Km upon induction. At molecular level, the ORF sequence coding for the urea transporter, ZmDUR3, was isolated and functionally characterized using different heterologous systems: a dur3 yeast mutant strain, tobacco protoplasts and a dur3 Arabidopsis mutant. The expression of the isolated sequence, ZmDUR3-ORF, in dur3 yeast mutant demonstrated the ability of the encoded protein to mediate urea uptake into cells. The subcellular targeting of DUR3/GFP fusion proteins in tobacco protoplasts gave results comparable to the localization of the orthologous transporters of Arabidopsis and rice, suggesting a partial localization at the plasma membrane. Moreover, the overexpression of ZmDUR3 in the atdur3-3 Arabidopsis mutant showed to complement the phenotype, since different ZmDUR3-overexpressing lines showed either comparable or enhanced 15[N]-urea influx than wild-type plants. These data provide a clear evidence in planta for a role of ZmDUR3 in urea acquisition from an extra-radical solution. Conclusions This work highlights the capability of maize plants to take up urea via an inducible and high-affinity transport system. ZmDUR3 is a high-affinity urea transporter mediating the uptake of this molecule into roots. Data may provide a key to better understand the mechanisms involved in urea acquisition and contribute to deepen the knowledge on the overall nitrogen-use efficiency in crop plants

Consumo de sustancias lícitas e ilícitas en estudiantes de nivel medio

El objetivo del presente trabajo fue investigar la existencia y severidad del consumo de sustancias lícitas e ilícitas en estudiantes de nivel medio de ambos sexos, identificar factores psicosociales de riesgo asociados y determinar si hay diferencias según el género en los distintos dominios de severidad evaluados.Sección Pósters.Facultad de Psicologí