1,720,964 research outputs found
Nitrogen Starvation Differentially Influences Transcriptional and Uptake Rate Profiles in Roots of Two Maize Inbred Lines with Different NUE
Full text linkNitrogen use efficiency (NUE) of crops is estimated to be less than 50%, with a strong impact on environment and economy. Genotype-dependent ability to cope with N shortage has been only partially explored in maize and, in this context, the comparison of molecular responses of lines with different NUE is of particular interest in order to dissect the key elements underlying NUE. Changes in root transcriptome and NH4+/NO3- uptake rates during growth (after 1 and 4 days) without N were studied in high (Lo5) and low (T250) NUE maize inbred lines. Results suggests that only a small set of transcripts were commonly modulated in both lines in response to N starvation. However, in both lines, transcripts linked to anthocyanin biosynthesis and lateral root formation were positively affected. On the contrary, those involved in root elongation were downregulated. The main differences between the two lines reside in the ability to modulate the transcripts involved in the transport, distribution and assimilation of mineral nutrients. With regard to N mineral forms, only the Lo5 line responded to N starvation by increasing the NH4+ fluxes as supported by the upregulation of a transcript putatively involved in its transport
Changes in physiological activities and root exudation profile of two grapevine rootstocks reveal common and specific strategies for Fe acquisition
Full text linkIn several cultivation areas, grapevine can suffer from Fe chlorosis due to the calcareous and alkaline nature of soils. This plant species has been described to cope with Fe deficiency by activating Strategy I mechanisms, hence increasing root H+ extrusion and ferric-chelate reductase activity. The degree of tolerance exhibited by the rootstocks has been reported to depend on both reactions, but to date, little emphasis has been given to the role played by root exudate extrusion. We studied the behaviour of two hydroponically-grown, tolerant grapevine rootstocks (Ramsey and 140R) in response to Fe deficiency. Under these experimental conditions, the two varieties displayed differences in their ability to modulate morpho-physiological parameters, root acidification and ferric chelate reductase activity. The metabolic profiling of root exudates revealed common strategies for Fe acquisition, including ones targeted at reducing microbial competition for this micronutrient by limiting the exudation of amino acids and sugars and increasing instead that of Fe(III)-reducing compounds. Other modifications in exudate composition hint that the two rootstocks cope with Fe shortage via specific adjustments of their exudation patterns. Furthermore, the presence of 3-hydroxymugenic acid in these compounds suggests that the responses of grapevine to Fe availability are rather diverse and much more complex than those usually described for Strategy I plants
Technological, nutritional, and sensory properties of durum wheat fresh pasta fortified with Moringa oleifera L. leaf powder.
No full textBACKGROUND: Pasta is a staple food that is consumed worldwide and is an excellent product for the addition of ingredients rich in bioactive compounds. The fortication of pasta with such compounds could represent a healthy choice for consumers. RESULTS: In this study, fresh pasta was formulated by replacing durum wheat semolina with 0, 5, 10, and 15 g 100 g −1 of dried Moringa oleifera leaf powder (MOLP), rich in bers, minerals, and antioxidant compounds. Increasing levels of MOLP inuenced the technological and nutritional properties of wheat-based fresh pasta. Moringa oleifera reduced the optimum cooking time, the swelling index and rmness, while increasing the cooking loss and adhesiveness. From a nutritional viewpoint, the inclu- sion of MOLP enhanced the phenol content, the antioxidant activity, and the mineral content of fresh pasta. The products obtained had good sensorial acceptability and can make several nutritional claims due to MOLP richness minerals. CONCLUSIONS: The fortication of fresh pasta with MOLP could represent a valuable strategy to increase the nutritional value of the product, preserving pasta technological properties without affecting sensory acceptability
Caratterizzazione molecolare del trasporto del Mg in radici di vite: prime evidenze
No full textCaratterizzazioni fisiologico-molecolari delle risposte di vite alla carenza di magnesio (Mg) non sono attualmente disponibili. Gli effetti di questa carenza sono stati approfonditi esclusivamente in piante erbacee quali Arabidopsis thaliana, barbabietola, peperone e spinacio.
Gli studi condotti in Arabidopsis thaliana hanno dimostrato come la carenza di Mg influisca sulla traslocazione dei fotosintati all’interno della pianta, causando un accumulo di questi nella parte epigea e il conseguente minor sviluppo della parte ipogea. La gran parte delle informazioni riguardanti la carenza di Mg in vite si basano principalmente su osservazioni empiriche in campo, che si limitano a descrivere gli effetti visivi senza essere supportati da approfondimenti fisiologici.
Gli effetti della carenza del nutriente sono stati precedententemente analizzati dal punto di vista fisiologico utilizzando microtalee allevate in soluzione idroponica di due portinnesti di vite, SO4 e 1103 P, descritti rispettivamente come suscettibile e tollerante alla carenza stessa. La caratterizzazione fisiologica si è basata sulla valutazione dei parametri di crescita, sul contenuto di Mg e dei fotosintetati nei diversi tessuti della pianta.
In questo lavoro, l’attenzione è rivolta alla determinazione delle entità molecolari responsabili delle risposte differenziali dei due genotipi di vite alla carenza del nutriente. Il sequenziamento del genoma di vite ha permesso di identificare, attraverso analisi di omologia di sequenza, 7 putativi geni codificanti le proteine di membrana MRS2/MGT che sulla base di risultati ottenuti in Arabidopsis thaliana sembrano giocare un ruolo nel trasporto del Mg attraverso la membrana plasmatica. Sulla base delle informazioni ottenute dal genoma sarà possibile caratterizzare le variazioni di espressione dei diversi membri della famiglia genica in risposta alle variabili condizioni nutrizionali sia nelle radici che nella parte aerea. Al contempo gli stessi geni saranno clonati in entrambi i genotipi per identificare innanzitutto possibili differenze nella sequenza (SNP e/o INDEL) e per effettuare analisi funzionali attraverso la complementazione di mutanti di lievito
Evaluation of the Potential Use of a Collagen-Based Protein Hydrolysate as a Plant Multi-Stress Protectant
Full text linkProtein hydrolysates (PHs) are a class of plant biostimulants used in the agricultural practice to improve crop performance. In this study, we have assessed the capacity of a commercial PH derived from bovine collagen to mitigate drought, hypoxic, and Fe deficiency stress in Zea mays. As for the drought and hypoxic stresses, hydroponically grown plants treated with the PH exhibited an increased growth and absorption area of the roots compared with those treated with inorganic nitrogen. In the case of Fe deficiency, plants supplied with the PH mixed with FeCl3 showed a faster recovery from deficiency compared to plants supplied with FeCl3 alone or with FeEDTA, resulting in higher SPAD values, a greater concentration of Fe in the leaves and modulation in the expression of genes related to Fe. Moreover, through the analysis of circular dichroism spectra, we assessed that the PH interacts with Fe in a dose-dependent manner. Various hypothesis about the mechanisms of action of the collagen-based PH as stress protectant particularly in Fe-deficiency, are discussed
A novel FePO4 nanosized fertilizer is as effective as triple superphosphate in sustaining the growth of cucumber plants
No full textThe behaviour of nanofertilizers (NFs) in plant-soil systems can differ from that of conventional chemical fertilizers due to their peculiar chemical-physical properties. Their effectiveness is still poorly understood. In this study, we evaluated the P fertilization potential of a novel nanosized FePO4 NF (FePNF) in a plant-soil microcosm in a pot experiment. The efficacies of FePNF and a conventional P fertilizer (triple superphosphate, TSP) in sustaining the growth of cucumber plants were evaluated. Plants were grown for 28 d on a P-deficient soil and determinations were made, including plant growth parameters, mineral nutrient concentrations in plant tissues, P availability in soil, activities of enzymes involved in C, N, P, and S mineralization, and soil microbial community structure. No significant differences were found in plant dry weight, leaf area, chlorophyll content, or root growth between the FePNF and TSP treatments. Conversely, P availability in soil and P concentration in plant tissues at the end of the plant growth period were significantly higher after TSP fertilization compared to FePNF fertilization, whereas no significant differences were observed for other nutrients. Among the measured soil enzyme activities, there were no significant differences in the activities of soil acid phosphatase, β-glucosidase, and arylsulfatase between the FePNF and TSP treatments, while soil alkaline phosphatase activity was higher in the TSP treatment than in the FePNF treatment, and the protease activity was higher in the FePNF treatment than in the TSP treatment. The FePNF and TSP treatments showed significant differences in soil archaeal, bacterial, and fungal community structures, although the microbial community profiles generally clustered closer to each other in two treatments. We concluded that FePNF can be an efficient alternative to the conventional P fertilizer TSP
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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