Μελέτη της φωσφολιπάσης Α1 (AT2G30550) στο φυτό Arabidopsis thaliana

Η φωσφολιπάση Α1, PLA1-Iγ2 (AT2G30550, DAD1-like lipase 3 ή DALL3) είναι μια χλωροπλαστιδιακή πρωτεΐνη και ανήκει στην οικογένεια λιπασών DAD1-like lipase λόγω ομοιοτήτων στην αμινοξική αλληλουχία της καταλυτικής περιοχής με την πρωτεΐνη DAD1. Η φωσφολιπάση PLA1-Iγ2 (DALL3) συμμετέχει στο μονοπάτι βιοσύνθεσης του ιασμονικού και επιπλέον σχετίζεται με αποκρίσεις σε βιοτικές και αβιοτικές καταπονήσεις. Επίσης, πιθανόν αλληλεπιδρά με τις πρωτεΐνες που δεσμεύουν σελήνιο (SBP, Selenium-Binding Proteins). Για να διερευνηθεί η πιθανή κοινή ιστοειδική παρουσία, της PLA1-Iγ2 και των SBP, έγινε μελέτη της πρωτεΐνης PLA1-Iγ2, μέσω της ιστοειδικής μελέτης της έκφρασης του γονιδίου PLA1-Iγ2. Για το σκοπό αυτό επιλέχθηκε μια αλληλουχία, μεγέθους 2.430bp, ανοδικά του σημείου έναρξης της αντιγραφής του γονιδίου και μια απαλοιφή του 5’-άκρου του, μεγέθους 1.571bp, και ακολούθησε η δημιουργία διαγονιδιακών GUS φυτών, με τη δημιουργία κατασκευών που περιέχουν αυτές τις αλληλουχίες σε μεταγραφική σύντηξη με το γονίδιο αναφοράς GUS. Παρατηρήθηκε αλλαγή στο πρότυπο έκφρασης μεταξύ των δύο κατασκευών, λόγω της παρουσίας ρυθμιστικών στοιχείων που σχετίζονται με το φως. Επίσης, μελετήθηκε το επίπεδο έκφρασης του γονιδίου PLA1-Iγ2, μέσω ημιποσοτικής αλυσιδωτής αντίδρασης αντίστροφης μεταγραφής σε διάφορα αναπτυξιακά στάδια και ιστούς, όπου παρατηρήθηκε η συνεχής έκφρασή του με μέγιστο στις κοτυληδόνες αρτιβλάστων 10 ημερών. Τέλος, μέσω της μελέτης των επιπέδων έκφρασης του γονιδίου υπό αβιοτικές συνθήκες καταπόνησης, παρατηρήθηκε αύξηση της έκφρασης κατά την παρουσία τετρασθενούς σεληνίου (SeIV) και μείωση της έκφρασης με την παρουσία εξασθενούς σεληνίου (SeVI). Τα στοιχεία αυτά ενισχύουν την πιθανή κοινή ιστοειδική παρουσία των δύο πρωτεϊνών.Phospholipase A1, PLA1-Iγ2 (AT2G30550, DAD1-like lipase 3 or DALL3) is a chloroplastic protein, which shares similarities in the aminoacid sequence of the catalytic region of DAD1. Hence, phospholipase A1 belongs to a major protein family called DAD1-like lipase. PLA1-Ιγ2 (DALL3) is involved in the biosynthesis pathway of jasmonic acid and is also related to responses to biotic and abiotic stress. In the present study we investigated the tissue specific expression of PLA1-Iγ2. An upstream sequence of 2430bp and its 5' end deletion (1571bp) were selected for the engineering of transgenic GUS plants. This has been accomplished through transcriptional fusion of the aforementioned sequences with the GUS reporter gene. A change in the pattern of expression was between the two transgenic constructs, which is attributed to regulatory elements related to light. Additionally, the level of expression of PLA1-Iγ2 gene was measured by semi-quantitive RT-PCR in various tissues and developmental stages. Ubiquitous expression was observed with a maximum occurring in cotyledon leaves of 10 day old seedlings. While studying the PLA1-Iγ2 level of expression under abiotic stress, we observed upregulation of PLA1-Iγ2 in the presence of Selenite (SeIV), whereas downregulation was recorded in the presence of Selenate (SeVI). Our results present further evidence in support of the proposed interaction and common tissue specific expression of PLA1-Iγ2 and SBPs

Colour and rheological properties of non-conventional grapefruit jams: instrumental and sensory measurement

Alternative methods with which to obtain grapefruit jams have been applied. These include the use of osmotic dehydration (OD) and/or microwave energy (MW), as an alternative to conventional heating, and the incorporation of bamboo fibre together with pectin in order to increase the jam's consistency. Colour, consistency and rheological behaviour were measured and sensory evaluation was carried out to compare product quality. When compared to the fresh fruit, the greatest colour changes took place in those jams processed by MW and conventional heating, both of them showing lower L*, a*, b* and chrome values than the rest of the samples obtained by applying osmotic dehydration. By adding bamboo fibre, the colour of OD samples approaches that of fresh fruit. The higher yield stress, greater consistency and more viscoelastic behaviour was displayed by jams obtained by combining OD and MW processes. In the sensory analysis, the judges awarded this sample a better score. The sensory attribute product coverage in mouth was closely related to viscosity at a shear rate of 120 s(-1) and consistency. (C) 2013 Elsevier Ltd. All rights reserved.Igual Ramo, M.; Contreras Monzón, CI.; Martínez Navarrete, N. (2014). Colour and rheological properties of non-conventional grapefruit jams: instrumental and sensory measurement. Food Science and Technology. 56(1):200-206. doi:10.1016/j.lwt.2013.10.038S20020656

An energy efficient modulation scheme for body-centric nano-communications in the THz band

In body-centric communications, energy efficiency is the most critical parameter, while the maximum achievable data rate is not of primary concern. In this paper we present a novel modulation scheme, which can be efficiently used in body-centric terahertz (THz) nanonetworks. This scheme is a combination of the time-spread On-Off keying (TS-OOK) and the pulse position modulation (PPM). The new modulation scheme presents lower energy consumption levels at a small cost to the achievable data rate. Furthermore, another important aspect is that, due to the nature of noise in THz communications, the proposed modulation is affected in a much smaller way by the noise. Finally, we present analytical and simulation results in order to compare the new scheme with TS-OOK

Novel interactions of Selenium Binding Protein family with the PICOT containing proteins AtGRXS14 and AtGRXS16 in Arabidopsis thaliana

During abiotic stress the primary symptom of phytotoxicity can be ROS production which is strictly regulated by ROS scavenging pathways involving enzymatic and non-enzymatic antioxidants. Furthermore, ROS are well described secondary messengers of cellular processes, while during the course of evolution, plants have accomplished high degree of control over ROS and used them as signalling molecules. Glutaredoxins (GRXs) are small and ubiquitous glutathione (GSH) -or thioredoxin reductase (TR)-dependent oxidoreductases belonging to the thioredoxin (TRX) superfamily which are conserved in most eukaryotes and prokaryotes. In Arabidopsis thaliana GRXs are subdivided into four classes playing a central role in oxidative stress responses and physiological functions. In this work, we describe a novel interaction of AtGRXS14 with the Selenium Binding Protein 1 (AtSBP1), a protein proposed to be integrated in a regulatory network that senses alterations in cellular redox state and acts towards its restoration. We further show that SBP protein family interacts with AtGRXS16 that also contains a PICOT domain, like AtGRXS14.Microbial Biotechnolog

An energy efficient modulation scheme for body-centric terahertz (THz) nanonetworks

In body-centric communications, energy efficiency is a critical performance metric, while the achievable data rate is not of primary concern. In this paper we present a novel modulation scheme, which can be efficiently used in body-centric terahertz (THz) nanonetworks. The proposed scheme is a combination of the time-spread On-Off keying (TS–OOK) and the pulse position modulation (PPM) and presents lower energy consumption, compared to other existing methods as TS–OOK, at a minor cost to the data rate. Furthermore, another important aspect is that the proposed modulation scheme can be effectively used to mitigate the impact of the specific kind of noise in THz body-centric communications, thus leading to better error performance. Finally, we present analytical and simulation results in order to compare the new scheme with the existing TS–OOK

Influence of healthy sweeteners (tagatose and oligofructose) on the physicochemical characteristics of orange marmalade

This is the peer reviewed version of the following article: Rubio‐Arraez, S., Sahuquillo, S., Capella, J. V., Ortolá, M. D., & Castelló, M. L. (2015). Influence of healthy sweeteners (tagatose and oligofructose) on the physicochemical characteristics of orange marmalade. Journal of Texture Studies, 46(4), 272-280, which has been published in final form at http://dx.doi.org/10.1111/jtxs.12127. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Today's society shows a growing interest in healthy, safe and high nutritional quality food. Thus, in this paper sweet orange marmalades have been developed using healthy sweeteners (tagatose and oligofructose) in different proportions. Analyses of Brix, pH, moisture, water activity, antioxidant capacity, optical and rheological properties have been carried out, initially and after 45 days of storage. Microbiological analyses have also been performed to determine their stability. Furthermore, a sensorial assessment has been conducted to find out acceptance of these new orange marmalades by consumers. The results showed that the highest proportion of oligofructose contributed to improve the initial antioxidant capacity of marmalades. The marmalade with the same proportions of oligofructose and tagatose was more consistent and showed a further increase in the elastic component over time. All marmalades had a similar appearance, but oligofructose reduced L*. Finally, orange marmalades made with healthy sweeteners were better scored.The authors would like to thank the Serigo family for donating the raw material and the project GV/2013/029 by the GVA, Valencia, Spain.Rubio Arraez, S.; Sahuquillo Ceruelos, S.; Capella Hernández, JV.; Ortolá Ortolá, MD.; Castelló Gómez, ML. (2015). Influence of healthy sweeteners (tagatose and oligofructose) on the physicochemical characteristics of orange marmalade. Journal of Texture Studies. 46(4):272-280. https://doi.org/10.1111/jtxs.12127S27228046

Use of isomaltulose to formulate healthy spreadable strawberry products. Application of response surface methodology

Response surface methodology (RSM) was applied to optimize the formulation of a 50 Brix spreadable strawberry product with healthier sugars and a high percentage of fruit. A central composite design was applied to analyse the influence of four independent variables on the quality parameters. Each of the variables was analysed at five different levels (X1: % of isomaltulose (0, 12.5, 25, 37.5 and 50%), X2: % of pectin (0.5, 1, 1.5, 2 and 2.5%), X3: % of citric acid (0, 0.25, 0.5, 0.75 and 1%) and X4: time of thermal treatment (0, 5 10, 15 and 20 min). Physicochemical properties, microbiological stability, antioxidant properties (anthocyanin content and antioxidant activity) as well as optical and mechanical properties were considered for the optimization. The influence of storage time on the above parameters was also evaluated. Percentages of pectin and citric acid were the variables that most influenced the measured parameters. In general terms, high levels of these two variables (2% pectin; 0.75% citric acid) resulted in greater antioxidant activity, consistency and adhesiveness values. The optimal formulation to obtain a spreadable strawberry product was fresh strawberry, 50% fructose, 50% isomaltulose, 1% citric acid and 1.5% pectin; the ingredients were mixed, and heated to 85 1C, and the product was stable after 90 days stored at room temperature.Authors would like to thank Direccion General de Investigacion del Ministerio de Ciencia y Tecnologia (AGL2008-01745/ALI) as well as the Universitat Politecnica de Valencia for the financial support given to this investigation.Peinado Pardo, I.; Rosa Barbosa, EM.; Heredia Gutiérrez, AB.; Andrés Grau, AM. (2015). Use of isomaltulose to formulate healthy spreadable strawberry products. Application of response surface methodology. Food Bioscience. 9:47-59. https://doi.org/10.1016/j.fbio.2014.08.002S4759

Physicochemical and sensorial properties of grapefruit jams as affected by processing

Jam is an effective and tasty way of preserving fruit. Jam processing procedures as well as storage conditions and duration are important factors for jam quality. Traditional jam processing involves the application of severe thermal treatments that imply undesirable changes in the product quality characteristics such as colour, texture, flavour and nutritional and functional value. In this work, osmotic dehydration (OD) and/or microwave energy (MW) was proven as adequate to obtain jam with the typical characteristics of water content, degree Brix, pH and water activity of jam obtained by conventional thermal heating. The sensory evaluation carried out to compare the product showed that samples submitted to more intense heating treatments (conventional or MW) had significantly higher scores in colour saturation, brightness, grapefruit taste and extensibility than OD or OD+MW ones. As deduced from the obtained results, OD treatment prevents grapefruit colour changes, and mild MW heating contributes to increase the consistency and decrease the extensibility of the obtained jam. In this way, OD+MW jam was preferred by assessors mainly due to its higher consistency. The sample obtained by this procedure was stable during storage.The authors would like to thank the Ministerio de Educacion y Ciencia for the financial support given throughout the Project AGL 2005-05994. The language revision of this paper was funded by the Universidad Politecnica de Valencia, Spain.Igual Ramo, M.; García Martínez, EM.; Camacho Vidal, MM.; Martínez Navarrete, N. (2013). Physicochemical and sensorial properties of grapefruit jams as affected by processing. Food and Bioprocess Technology. 6(1):177-185. https://doi.org/10.1007/s11947-011-0696-2S17718561AENOR (2009). Sensory analysis. Methodology. Paired comparison test. UNE-EN-ISO 5495.AOAC. (2000). Official methods of analysis of AOAC International (17th ed.). Gaithersburg: AOAC International.Baker, R.-A., Berry, N., Hui, Y.-H., & Barrett, D.-M. (2005). Fruit preserves and jams. In Processing fruits: science and technology (2nd ed., pp. 113–125). Boca Ratón: CRC Press.Bodart, M., de Peñaranda, R., Deneyer, A., & Flamant, G. (2008). Photometry and colorimetry characterisation of materials in daylighting evaluation tools. Building and Environment, 43, 2046–2058.BOE (1990). Real Decreto 670/1990, de 25 de mayo, por el que se aprueba la norma de calidad para confituras, jaleas y marmalade de frutas, crema de castañas y mermelada de frutas. BOE Nº 130 (31/5/1990), 15140–15144.Bourne, M. (1982). Food texture and viscosity—concept and measurement. New York: Academic.Cañumir, J.-A., Celis, J.-E., Brujin, J., & Vidal, L. (2002). Pasteurisation of apple juice by using microwaves. Lebensmittel-Wissenschaft und Technologie, 35, 389–392.Contreras, C., Martín-Esparza, M.-E., Martínez-Navarrete, N., & Chiralt, A. (2008). Influence of microwave application on convective drying: effects on drying kinetics, and optical and mechanical properties of apple and strawberry. Journal of Food Engineering, 88, 55–64.Dervisi, P., Lamb, J., & Zabetakis, I. (2001). High pressure processing in jam manufacture: effects on textural and color properties. Food Chemistry, 73, 85–91.Deyhim, F., Garica, K., Lopez, E., Gonzalez, J., Ino, S., Garcia, M., et al. (2006). Citrus juice modulates bone strength in male senescent rat model of osteoporosis. Nutrition, 22(5), 559–563.García-Martínez, E., Ruiz-Diaz, G., Martínez-Monzó, J., Camacho, M.-M., Martínez-Navarrete, N., & Chiralt, A. (2002). Jam manufacture with osmodehydrated fruit. Food Research International, 35, 301–306.Igual, M., García-Martínez, E., Camacho, M.-M., & Martínez-Navarrete, N. (2010a). Effect of thermal treatment and storage on the stability of organic acids and the functional value of grapefruit juice. Food Chemistry, 118, 291–299.Igual, M., Contreras, C., & Martínez-Navarrete, N. (2010b). Non-conventional techniques to obtain grapefruit jam. Innovative Food Science and Emerging Technologies, 11(2), 335–341.Meilgaard, M., Civille, G.-V., & Carr, B.-T. (1999). Attribute differences test. Pairwise ranking test: Friedman analysis. Sensory evaluation techniques (pp. 103–106). Boca Ratón: CRC Press.Moraga, M.-J., Moraga, G., Fito, P. J., & Martínez-Navarrete, N. (2009). Effect of vacuum impregnation with calcium lactate on the osmotic dehydration kinetics and quality of osmodehydrated grapefruit. Journal of Food Engineering, 90, 372–379.Nikdel, S., Chen, C., Parish, M., MacKellar, D., & Friedrich, L. (1993). Pasteurization of citrus juice with microwaves energy in a continuous-flow unit. Journal of Agricultural and Food Chemistry, 41, 2116–2119.Poulose, S.-M., Harris, E.-D., & Patil, B.-S. (2005). Citrus limonoids induce apoptosis in human neuroblastoma cells and have radical scavenging activity. Journal of Nutrition, 135, 870–877.Sanchez-Moreno, C., Plaza, L., De Ancos, B., & Cano, M.-P. (2003). Quantitative bioactive compounds assessment and their relative contribution to the antioxidant capacity of commercial orange juices. Journal of the Science of Food and Agriculture, 83, 430–439.Shi, X.-Q., Chiralt, A., Fito, P., Serra, J., Escoin, C., & Gasque, L. (1996). Application of osmotic dehydration technology on jam processing. Drying Technology, 14(3&4), 841–857.Tárrega, A., & Costell, E. (2007). Colour and consistency of semi-solid dairy desserts: instrumental and sensory measurements. Journal of Food Engineering, 78, 655–661.Vanamala, J., Reddivari, L., Yoo, K.-S., Pike, L.-M., & Patil, B.-S. (2006). Variation in the content of bioactive flavonoid in different brands of orange and grapefruit juices. Journal of Food Composition and Analysis, 19(2–3), 157–166.Wicklund, T., Rosenfeld, H.-J., Martinsen, B.-K., Sundførb, M.-W., Lea, P., Bruun, T., et al. (2005). Antioxidant capacity and colour of strawberry jam as influenced by cultivar and storage conditions. LWT-Food Science and Technology, 38(4), 387–391.Yu, L.-L., Zhou, K.-K., & Parry, J. (2005). Antioxidant properties of cold-pressed black caraway, carrot, cranberry, and hemp seed oils. Food Chemistry, 91, 723–729

Structural preferences in phosphanylthiolato platinum(II) complexes

Invited for this month's cover picture are the groups of Prof. Alfonso Polo and Dr. Albert Poater at the Universitat de Girona, as well as their collaborators from the Universitat Autònoma de Barcelona and the Institute of Chemical Research of Catalonia. The cover picture shows phosphanylthiolate ligand coordination on a platinum(II) center to give only the bischelate cis -P,P isomer when the ligand/Pt ratio is 2, whereas a trinuclear unexpected complex is achieved with a ligand/Pt ratio of 1. Here, the synthesis and structural determination is combined with density functional theory (DFT) calculations to rationalize the reaction mechanistically and through conceptual DFT. The exciting point of this study is that it opens the door to test new experimental pathways to monitor the preferred cis or trans arrangement of bidentate ligands to platinum. (Legend: H-white, C-black, P-purple, S-yellow, Cl-green, Pt-blue.