Composition chimique de sèves xylémiques du genre Lycopersicon (Solanaceae) en relation avec l'environnement. I. Effet de la température

1990 ◽  
Vol 68 (9) ◽  
pp. 1942-1947 ◽  
Author(s):  
Philippe Brunet ◽  
Bruno Sarrobert ◽  
Nicole Paris-Pireyre ◽  
Ange-Marie Risterucci

Two species of tomato, Lycopersicon esculentum Mill. var. EGE12P1 and Lycopersicon hirsutum Humb. & Bonpl. ecotype LA 1777, were submitted to two temperature treatments, 20 or 10 °C. After a short study of plant growth, we analysed the chemical composition (cations, anions, and amino acids) of xylem sap by high performance liquid chromatography. A comparison of fresh weight increase at 20 and 10 °C of both plant species showed that L. hirsutum was the least affected by low temperature. The volumes of secreted sap and the quantities of ions transported showed great disturbances in the sensitive species (L. esculentum), especially in the case of potassium. In xylem sap of both species studied, but only at 10 °C, we noticed the appearance of ammonium. The possibility of contamination during analytical processing was eliminated. Moreover, determinations of amino acids levels showed that ammonium did not arise from degradation of amides present in xylem sap. In any event, the proportion of nitrate absorbed and reduced in roots increased at low temperature; it is much more important in L. hirsutum and could constitute a tolerance factor to low temperatures. Key words: ammonium, low temperature, Lycopersicon, xylem sap.

1990 ◽  
Vol 68 (9) ◽  
pp. 1948-1952 ◽  
Author(s):  
Bruno Sarrobert ◽  
Philippe Brunet ◽  
Nicole Paris-Pireyre ◽  
Ange-Marie Risterucci

Two tomato species, Lycopersicon esculentum Mill. var. Edkawy and Lycopersicon cheesmanii (Hook) C. H. Mull, ecotype LA 1138, were grown in saline (100 mM NaCl) conditions. The study of weight increase of these two species showed that L. cheesmanii was the least affected by salinity. The chemical composition of xylem sap (cations, anions, amino acids) was analysed by high performance liquid chromatography. This study demonstrated a control of NaCl transport in L. esculentum, but not in L. cheesmanii. Moreover, ammonium appeared in xylem sap of L. cheesmanii in saline culture. Different hypotheses about its origin are discussed. Key words: ammonium, salinity, xylem sap, Lycopersicon.


Proceedings ◽  
2020 ◽  
Vol 65 (1) ◽  
pp. 25
Author(s):  
Antonio Garrido Marijuan ◽  
Roberto Garay ◽  
Mikel Lumbreras ◽  
Víctor Sánchez ◽  
Olga Macias ◽  
...  

District heating networks deliver around 13% of the heating energy in the EU, being considered as a key element of the progressive decarbonization of Europe. The H2020 REnewable Low TEmperature District project (RELaTED) seeks to contribute to the energy decarbonization of these infrastructures through the development and demonstration of the following concepts: reduction in network temperature down to 50 °C, integration of renewable energies and waste heat sources with a novel substation concept, and improvement on building-integrated solar thermal systems. The coupling of renewable thermal sources with ultra-low temperature district heating (DH) allows for a bidirectional energy flow, using the DH as both thermal storage in periods of production surplus and a back-up heating source during consumption peaks. The ultra-low temperature enables the integration of a wide range of energy sources such as waste heat from industry. Furthermore, RELaTED also develops concepts concerning district heating-connected reversible heat pump systems that allow to reach adequate thermal levels for domestic hot water as well as the use of the network for district cooling with high performance. These developments will be demonstrated in four locations: Estonia, Serbia, Denmark, and Spain.


Solar RRL ◽  
2021 ◽  
pp. 2100108
Author(s):  
Shih-Chi Yang ◽  
Jordi Sastre ◽  
Maximilian Krause ◽  
Xiaoxiao Sun ◽  
Ramis Hertwig ◽  
...  

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 321
Author(s):  
Maria Orfanoudaki ◽  
Anja Hartmann ◽  
Julia Mayr ◽  
Félix L. Figueroa ◽  
Julia Vega ◽  
...  

This study presents the validation of a high-performance liquid chromatography diode array detector (HPLC-DAD) method for the determination of different mycosporine-like amino acids (MAAs) in the red alga Bostrychia scorpioides. The investigated MAAs, named bostrychines, have only been found in this specific species so far. The developed HPLC-DAD method was successfully applied for the quantification of the major MAAs in Bostrychia scorpioides extracts, collected from four different countries in Europe showing only minor differences between the investigated samples. In the past, several Bostrychia spp. have been reported to include cryptic species, and in some cases such as B. calliptera, B. simpliciuscula, and B. moritziana, the polyphyly was supported by differences in their MAA composition. The uniformity in the MAA composition of the investigated B. scorpioides samples is in agreement with the reported monophyly of this Bostrychia sp.


2020 ◽  
Vol 61 (1) ◽  
Author(s):  
Ming-Hsiu Chung ◽  
Tzu-Shing Deng

Abstract Background Melatonin acts as a signaling hormone and entraining agent in many organisms. We studied the spatiotemporal regulation and influence of light (photoperiods, intensities, and spectral qualities) on melatonin concentration in the medicinal herb Hypericum perforatum L. Furthermore, melatonin concentrations in the leaves of eight species of the Hypericum genus were compared and analyzed using high-performance liquid chromatography. Results Melatonin concentration was found to be the highest in its flowers and leaves. The leaves exhibited a rhythmic variation in melatonin concentration of approximately 24 h under both light–dark entrained (Zeitgeber time) and constant light [circadian time (CT)] conditions, with melatonin concentration peaking at approximately CT6 in the middle of the subjective day. Melatonin concentration was influenced significantly by not only photoperiods but also applied light’s wavelength and intensity. It was approximately six times higher under long-day conditions (18-h light:6-h dark) than under short-day photoperiods (10-h light:14-h dark) and was the highest (131 μg/g fresh weight [FW]) under treatment with blue light at an intensity of 45 µmol·m2/s of photons. The melatonin concentration of the two examined Hypericum spp., namely H. kouytchense Lev. and H. coris L., were approximately twice that of H. perforatum L. Conclusion Our findings provide first insights on melatonin-related functions and mechanisms in the circadian system of H. perforatum and useful resources for further melatonin-oriented research and possible applications in agriculture and pharmaceutical industries.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Muhammad Naqi ◽  
Kyung Hwan Choi ◽  
Hocheon Yoo ◽  
Sudong Chae ◽  
Bum Jun Kim ◽  
...  

AbstractLow-temperature-processed semiconductors are an emerging need for next-generation scalable electronics, and these semiconductors need to feature large-area fabrication, solution processability, high electrical performance, and wide spectral optical absorption properties. Although various strategies of low-temperature-processed n-type semiconductors have been achieved, the development of high-performance p-type semiconductors at low temperature is still limited. Here, we report a unique low-temperature-processed method to synthesize tellurium nanowire networks (Te-nanonets) over a scalable area for the fabrication of high-performance large-area p-type field-effect transistors (FETs) with uniform and stable electrical and optical properties. Maximum mobility of 4.7 cm2/Vs, an on/off current ratio of 1 × 104, and a maximum transconductance of 2.18 µS are achieved. To further demonstrate the applicability of the proposed semiconductor, the electrical performance of a Te-nanonet-based transistor array of 42 devices is also measured, revealing stable and uniform results. Finally, to broaden the applicability of p-type Te-nanonet-based FETs, optical measurements are demonstrated over a wide spectral range, revealing an exceptionally uniform optical performance.


2021 ◽  
Vol 412 ◽  
pp. 127034
Author(s):  
Yang Yu ◽  
Zhuoya Ren ◽  
Qianqian Shang ◽  
Jiangang Han ◽  
Lei Li ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1738
Author(s):  
Saeid Vafaei ◽  
Alexander Wolosz ◽  
Catlin Ethridge ◽  
Udo Schnupf ◽  
Nagisa Hattori ◽  
...  

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.


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