排序方式: 共有112条查询结果,搜索用时 17 毫秒
31.
Forty-eight species of Astragalus L. sections Onobrychoidei DC., Uliginosi Gray and Ornithopodium Bunge (Fabaceae) in Turkey were studied in order to describe and investigate their seed morphologies and to evaluate the diagnostic value of this character using a stereoscopic microscope and a scanning electron microscope (SEM). SEM pictures of seeds were taken as a whole and in detail. The systematic implications of the findings are discussed. Six main seed types were observed. A key to identifying the different seed types is provided. 相似文献
32.
Oksuzoglu E Tekiner-Gulbas B Alper S Temiz-Arpaci O Ertan T Yildiz I Diril N Sener-Aki E Yalcin I 《Journal of enzyme inhibition and medicinal chemistry》2008,23(1):37-42
Some novel fused heterocyclic compounds of 2, 5-disubstituted-benzoxazole and benzimidazole derivatives, which were previously synthesized by our group, were investigated for their inhibitory activity on both eukaryotic DNA topoisomerase I and II in a cell free system. 2-Phenoxymethylbenzimidazole (17), 5-amino-2-(p-fluorophenyl)benzoxazole (3), 5-amino-2-(p-bromophenyl)benzoxazole (5), 5-nitro-2-phenoxymethyl-benzimidazole (18), 2-(p-chlorobenzyl)benzoxazole (10) and 5-amino-2-phenylbenzoxazole (2) were found to be more potent as eukaryotic DNA topoisomerase I poisons than the reference drug camptothecin having IC(50) values of 14.1, 132.3, 134.1, 248, 443.5, and 495 microM, respectively. 5-Chloro-2-(p-methylphenyl)benzoxazole (4), 2-(p-nitrobenzyl)benzoxazole (6) and 5-nitro-2-(p-nitrobenzyl)benzoxazole (8) exhibited significant activity as eukaryotic DNA topoisomerase II inhibitors, having IC(50) values of 22.3, 17.4, 91.41 microM, respectively, showing higher potency than the reference drug etoposide. 相似文献
33.
Hüsnü Çakırlar Nuran Çiçek Ivanka Fedina Katya Georgieva Ali Doğru Maya Velitchkova 《Acta Physiologiae Plantarum》2008,30(4):561-567
The effect of pre-treatment with 200 mM NaCl on the response of four barley cultivars (Hordeum vulgare L. cv. Bülbül-89, Kalaycı-97, Tarm-92 and Tokak-157/37) to UV-B radiation was investigated. Salt stress as well as UV-B irradiation
led to a decrease of the total chlorophyll (chl) content in all cultivars, except in Kalaycı-97. While carotenoids are almost
not affected by NaCl treatment, UV-B irradiation caused an increase by 5–20% of carotenoid content of all cultivars. UV-B
induced damages of photosynthetic apparatus were estimated by the rate of photosynthetic electron transport measured by chl
fluorescence and the rate of oxygen evolution, the latter being more affected. Pre-treatment with NaCl alleviated harmful
effect of UV-B irradiation on F
v/F
m and ETR, but not on oxygen evolution. UV-B-induced and UV-B-absorbing compounds with absorption at 300 and 438 nm increased
as a result of UV-B treatment. The level of stress marker proline increased considerably as a result of NaCl treatment, while
UV-B irradiation resulted in a pronounced increase of the level of H2O2. MDA enhanced in the seedlings subjected to salt and UV-B stress. Established cross-acclimation to UV-B as a result of salt
treatment could be due to the increased free proline and the level of UV-B absorbing compounds in barley seedlings subjected
to NaCl. 相似文献
34.
Choline transporter‐like1 (CHER1) is crucial for plasmodesmata maturation in Arabidopsis thaliana
下载免费PDF全文
![点击此处可从《The Plant journal : for cell and molecular biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Max E. Kraner Katrin Link Michael Melzer Arif B. Ekici Steffen Uebe Pablo Tarazona Ivo Feussner Jörg Hofmann Uwe Sonnewald 《The Plant journal : for cell and molecular biology》2017,89(2):394-406
Plasmodesmata (PD) are microscopic pores connecting plant cells and enable cell‐to‐cell transport. Currently, little information is known about the molecular mechanisms regulating PD formation and development. To uncover components of PD development we made use of the 17 kDa movement protein (MP17) encoded by the Potato leafroll virus (PLRV). The protein is required for cell‐to‐cell movement of the virus and localises to complex PD. Forward genetic screening for Arabidopsis mutants with altered PD binding of MP17 revealed several mutant lines, while molecular genetics, biochemical and microscopic studies allowed further characterisation. Map‐based cloning of one mutant revealed a point mutation in the choline transporter‐like 1 (CHER1) protein, changing glycine247 into glutamate. Mutation in CHER1 resulted in a starch excess phenotype and stunted growth. Ultrastructure analysis of shoot apical meristems, developing and fully developed leaves showed reduced PD numbers and the absence of complex PD in fully developed leaves. This indicates that cher1 mutants are impaired in PD formation and development. Global lipid profiling revealed only slight modifications in the overall lipid composition, however, altered composition of PD‐associated lipids cannot be ruled out. Thus, cher1 is devoid of complex PD in developed leaves and provides insights into the formation of complex PD at the molecular level. 相似文献
35.
We investigated the protective and therapeutic effects of molsidomine (MOL) in a rat model of whole brain radiotherapy (RT). Forty female rats were divided into five groups of eight: group 1, control; group 2, 15 Gy single dose RT (RT); group 3, 4 mg/kg MOL treated for 5 days (MOL); group 4, 4 mg/kg MOL for 5 days, 10 days after RT treatment (RT + MOL); group 5, 4 mg/kg MOL treatment for 5 days before RT treatment and for 5 days after RT treatment (MOL + RT). All rats were sacrificed on day 16. Neurodegenerative changes in the brain and tissue levels of oxidants and antioxidants were evaluated. The oxidative parameters were increased and antioxidant status was decreased in group RT compared to groups MOL + RT and RT + MOL. Histopathological examination showed that treatment with MOL after RT application and treatment with MOL before RT treatment decreased neuronal degeneration. No difference in neuronal appearance was found between groups RT + MOL and MOL + RT. MOL treatment protected the nervous system of rats and may be a treatment option for preventing RT induced neural injury. 相似文献
36.
In this study, polysaccharide and RNA contents of anthers were investigated on different phases of sporogenesis by using light microscopy techniques from histological and cytological point of view in Leucojum aestivum. Paraffin and semi-thin sections of anthers were stained with toluidine blue and PAS. Anthers were tetrasporangiate. The wall of the anther consists of an epidermis, endothecium, middle layer and glandular tapetum. During one nucleated microspore and mature pollen phase microspores and tapetum cells began to degenerate and they were become very rich of RNA in L. aestivum. And also RNA content was increased in endothecium and middle layer cells except the epidermis cells of anther wall. An increase in RNA content indicates cell activation. Polysaccharides were not seen in young anther wall but they were seen in older ones. They were generally condensed in the cell walls and especially in the cell walls of vascular bundles of connective tissue. This could be thought that insoluble polysaccharides were used in metabolic events in early developmental stages. Appearance of polysaccharides in late phases was indicated that polysaccharides were used in the formation of cuticule and differentiation of endothelium cell walls. 相似文献
37.
38.
Thiel C Kessler K Giessl A Dimmler A Shalev SA von der Haar S Zenker M Zahnleiter D Stöss H Beinder E Abou Jamra R Ekici AB Schröder-Kress N Aigner T Kirchner T Reis A Brandstätter JH Rauch A 《American journal of human genetics》2011,(1):634-114
Defects of ciliogenesis have been implicated in a wide range of human phenotypes and play a crucial role in signal transduction and cell-cycle coordination. We used homozygosity mapping in two families with autosomal-recessive short-rib polydactyly syndrome Majewski type to identify mutations in NEK1 as an underlying cause of this lethal osteochondrodysplasia. NEK1 encodes a serine/threonine kinase with proposed function in DNA double-strand repair, neuronal development, and coordination of cell-cycle-associated ciliogenesis. We found that absence of functional full-length NEK1 severely reduces cilia number and alters ciliar morphology in vivo. We further substantiate a proposed digenic diallelic inheritance of ciliopathies by the identification of heterozygous mutations in NEK1 and DYNC2H1 in an additional family. Notably, these findings not only increase the broad spectrum of ciliar disorders, but suggest a correlation between the degree of defective microtubule or centriole elongation and organization and the severity of the resulting phenotype. 相似文献
39.
40.
Oxidative stress is seen in various metabolic disorders for unknown reasons. Oxidative stress is defined as an imbalance between pro-oxidant and antioxidant status in favor of the former. This study investigated whether oxidative stress exists in phenylketonuria (PKU) using the BTBR-Pah(enu2) animal model for PKU. Animals (14-24 weeks old) were sacrificed and brain and red blood cells (RBCs) were obtained aseptically. The lipid peroxidation by-product, evaluated as malondialdehyde (MDA), was significantly higher in the brains and RBCs of PKU animals (n = 6) than in controls (n = 6). Glutathione/glutathione disulfide, a good indicator for tissue thiol status, was significantly decreased both in the brains and RBCs. Some antioxidant enzymes were also analyzed in RBCs, including glucose-6-phosphate dehydrogenase (G6PD), which provides the RBC's main reducing power, reduced nicotinamide adenine dinucleotide phosphate (NADPH), and catalase detoxifies H2O2 by catalyzing its reduction to O2 and H2O. Both catalase and G6PD were significantly increased in the RBCs of PKU animals. 相似文献