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101.
Strahil Berkov Atanas Pavlov Vasil Georgiev Jost Weber Thomas Bley Francesc Viladomat Jaume Bastida Carles Codina 《Plant Physiology and Biochemistry》2010,48(10-11):827-835
Calli, shoot-clumps and regenerated plants were initiated from young fruits of Pancratium maritimum L. Their genetic stability was monitored by flow cytometry before chemical studies. Apolar metabolites (alkaloids extracted at pH > 7, free fatty acids and fatty alcohols, sterols etc.) were qualitatively and quantitatively analyzed by GC–MS. The results clearly demonstrated that alkaloid synthesis in P. maritimum is closely related with tissue differentiation. The highest amounts of alkaloids and presence of homolycorine and tazettine type compounds (end products of the biosynthetic pathway of the Amaryllidaceae alkaloids) were found in highly differentiated tissues. Galanthamine accumulated in the leaves of plantlets. The amount of hordenine, a protoalkaloid, is related with the ability of tissues to synthesize alkaloids. Saturated fatty acids were found in considerably higher levels in undifferentiated callus cultures and partially differentiated shoot-clumps than in regenerated plants. Mono- and dienoic fatty acids were found at higher levels in non-photosynthesizing tissues – calli, and in vitro and intact bulbs, while α-linolenic acid (trienoic acid) was found in higher amounts in the photosynthesizing leaves of shoot-clumps and regenerated plants than in bulbs and calli. Fatty alcohols were found mainly in leaves, while sterols tended to accumulate in photosynthesizing and undifferentiated tissues. 相似文献
102.
103.
M. Helena Garcia Andreia Valente Tânia S. Morais M. Teresa Duarte Francesc X. Avilés 《Inorganica chimica acta》2010,363(14):3765-3775
A new family of Ru(II) mixed metallocene complexes of the type [Ru(η5-C5H5)(η6-arene)][PF6] has been synthesized and fully characterized by NMR and UV-Vis spectroscopy. X-ray analysis of single crystal was achieved for all the complexes and revealed the presence of two enantiomers expected for planar chirality originated by the η6 coordination of the arene prochiral ligands. Studies of interaction of the new complexes with pBR322 DNA by atomic force microscopy showed very strong and different types of interaction. Antiproliferative tests were examined on human leukemia cancer cells (HL-60) using the MTT assay, and the IC50 values revealed low antiproliferative activity compared to cisplatin. 相似文献
104.
Tanit Guitart Teresa Leon Bernardo Jessica Sagalés Thomas Stratmann Jordi Bernués Lluís Ribas de Pouplana 《The Journal of biological chemistry》2010,285(49):38157-38166
Aminoacyl-tRNA synthetases (ARS) are modular enzymes that aminoacylate transfer RNAs (tRNA) for their use by the ribosome during protein synthesis. ARS are essential and universal components of the genetic code that were almost completely established before the appearance of the last common ancestor of all living species. This long evolutionary history explains the growing number of functions being discovered for ARS, and for ARS homologues, beyond their canonical role in gene translation. Here we present a previously uncharacterized paralogue of seryl-tRNA synthetase named SLIMP (seryl-tRNA synthetase-like insect mitochondrial protein). SLIMP is the result of a duplication of a mitochondrial seryl-tRNA synthetase (SRS) gene that took place in early metazoans and was fixed in Insecta. Here we show that SLIMP is localized in the mitochondria, where it carries out an essential function that is unrelated to the aminoacylation of tRNA. The knockdown of SLIMP by RNA interference (RNAi) causes a decrease in respiration capacity and an increase in mitochondrial mass in the form of aberrant mitochondria. 相似文献
105.
Turró S Ingelmo-Torres M Estanyol JM Tebar F Fernández MA Albor CV Gaus K Grewal T Enrich C Pol A 《Traffic (Copenhagen, Denmark)》2006,7(9):1254-1269
Alcoholic and nonalcoholic liver steatosis and steatohepatitis are characterized by the massive accumulation of lipid droplets (LDs) in the cytosol of hepatocytes. Although LDs are ubiquitous and dynamic organelles found in the cells of a wide range of organisms, little is known about the mechanisms and sites of LD biogenesis. To examine the participation of these organelles in the pathophysiological disorders of steatotic livers, we used a combination of mass spectrometry (matrix-assisted laser desorption ionization-time of flight and LC-MS electrospray) and Western blot analysis to study the composition of LDs purified from rat liver after a partial hepatectomy. Fifty proteins were identified. Adipose differentiation-related protein was the most abundant, but other proteins such as calreticulin, TIP47, Sar1, Rab GTPases, Rho and actin were also found. In addition, we identified protein associated with lipid droplets I ALDI (tentatively named Associated with LD protein 1), a novel protein widely expressed in liver and kidney corresponding to the product of 0610006F02Rik (GI:27229118). Our results show that, upon lipid loading of the cells, ALDI translocates from the endoplasmic reticulum into nascent LDs and indicate that ALDI may be targeted to the initial lipid deposits that eventually form these droplets. Moreover, we used ALDI expression studies to view other processes related to these droplets, such as LD biogenesis, and to analyze LD dynamics. In conclusion, here we report the composition of hepatic LDs and describe a novel bona fide LD-associated protein that may provide new insights into the mechanisms and sites of LD biogenesis. 相似文献
106.
107.
Leaf litter is a major basal resource to stream ecosystems, but few studies addressed their role in karst systems, mainly
in intermittent springs and lakes. Patterns of resource use in perennial rivers are poorly known, although the input of leaf
litter strongly influences macroinvertebrate assemblage structure. In this study, we evaluated the structure of macroinvertebrate
assemblages along the decomposition of leaf litter in a tropical karst river, using leaf litter cages made of coarse nylon
mesh (25 mm) to allow colonization by macroinvertebrates. The experiment was followed weekly for 10 weeks. The assemblages
were dominated by snails (90.5% of total fauna), hyalellid amphipods, and larval chironomid midges, with highest abundances
in the intermediate stages of the experiment, resulting in a gradient in assemblage structure. The large abundance of snails,
which are common in other karst systems, suggest that this group may have an important role in decomposer food webs, facilitating
or directly contributing to leaf breakdown.
Electronic supplementary material Electronic supplementary material is available for this article at
and accessible for authorised users. 相似文献
108.
Neoli Lucyszyn Marguerite Quoirin Luciana L. F. Ribas Henrique S. Koehler Maria Rita Sierakowski 《In vitro cellular & developmental biology. Plant》2006,42(3):287-290
Summary The influence of partial substitution of agar by galactomannans (GMs) in culture media was studied in pear (Pyrus communis L. cv. ‘Durondeau’) micropropagation. GMs. extracted from seeds of Cassia fastuosa (cassia) or Cyamopsis tetragonolobus (guar gum, a commercial GM), were mixed in equal proportions with agar to a final concentration of 0.3% (w/v) for each type
of gelling agent. The production of multiple shoots and the formation of roots from shoots were compared with the control
solidified with agar alone at a concentration of 0.6% (w/v). In the media solidified with the mixtures of agar/guar and agar/cassia
GMs, an, increase of 32 and 17%, respectively, was obtained in the number of regenerated shoots. The modified media promoted
a higher number of roots and increased the rooting percentage. A maximum of 91% rooting was obtained in the medium solidified
with the agar/cassia GM and containing 9.80 μM indole-3-butyric acid. Less callus formation at the base of the shoot was also observed on this medium. The improved in vitro performance of shoot formation and rooting, combined with a significantly lower cost, suggests a potential use of agar/GM
gels in plant tissue culture. 相似文献
109.
110.
A new member of the PBAN family in Spodoptera littoralis: molecular cloning and immunovisualisation in scotophase hemolymph 总被引:2,自引:0,他引:2
Iglesias F Marco P François MC Camps F Fabriàs G Jacquin-Joly E 《Insect biochemistry and molecular biology》2002,32(8):901-908
In this article, we report evidence suggesting that the immunoreactive factor previously detected in Spodoptera littoralis scotophase hemolymph is PBAN, which supports a humoral route of the hormone to the pheromone gland. Western blot after native-PAGE of prepurified scotophase hemolymph extracts yielded an immunoreactive band with the same mobility as S. littoralis Br-SOG factor and the expected mobility for a noctuid PBAN. This band was not detected in photophase hemolymph extract. The identity of S. littoralis Br-SOG factor as PBAN was obtained from cDNA cloning using RT-PCR strategy. This allowed us to deduce the amino acid sequence of Spl-PBAN, which is highly homologous to other known PBANs. Moreover, we found that the PBAN encoding cDNA also encoded four other putative amidated peptides (Spl-DH homologue, Spl-alpha-NP, Spl-beta-NP and Spl-gamma-NP) that are identical or highly conserved among noctuids, and two non amidated peptides of unknown function. This cDNA organization is common to all known cDNAs encoding PBANs, leading to the release of different peptides after putative enzymatic cleavage of the preprohormone. 相似文献