Genetic and geographic polymorphism of cultivated tobaccos (Nicotiana tabacum) in Turkey

Nicotiana tabacum (2n = 48) is a natural amphidiploid and shows a distribution over a geographical area in eastern Anatolia. Random amplified polymorphic DNA (RAPD) technique was used to evaluate both genetic diversity among 21 primitive tobacco accessions comparing flue cure virginia genotype (FCV) and their geographical polymorphism as a source of genetic variations for breeding programs. Only 13 of all the 60 random primers used in RAPD showed polymorphism acceptable for characterization of these accessions. Totally 118 RAPD fragments were generated from 13 decamer primer and 64 of them were found polymorphic (54.2%). Mus and FCV showed the smallest genetic distance among accessions cultivated in the eastern Anatolia. These results shows that the RAPD assay is a powerful approach for identifying genetic and geographic polymorphism. This article was submitted by the authors in English.     

A theoretical study of substituent effects on tautomerism of 2-hydroxybenzimidazoles

The geometries, relative stabilities of some 4(7) and 5(6) substituted 2-hydroxybenzimidazole derivatives were calculated with full geometry optimization using AM1 and PM3 in aqueous phase. With the exception of molecules 4, 6 and 7 for all the 4(7) and 5(6) substituted 2-hydroxybenzimidazole derivatives the 3H and keto forms were found to be favored.     

Rainfed vetch-barley mixed cropping in the Syrian semi-arid conditions

A field experiment on vetch and barley grown in monoculture and in mixed culture was conducted under rain-fed conditions throughout two growing seasons. Plants were either subjected to three sequential harvests, or were harvested only once, at physiological maturity. Our results showed the advantage of a mixed cropping system of vetch and barley over sole cropping under rainfed conditions in terms of dry matter production, total nitrogen content, and land use efficiency expressed as land equivalent ratio (LER). This advantage was more pronounced in the plants harvested once at the end of the season than those subjected to the three successive harvests. Based on this result, a single seasonal rather than several harvests would be recommended under similar rainfed conditions. Nitrogen fixation in vetch measured by the¹⁵N-isotope dilution method, varied with the number of harvests and with cropping system. The percentage of N derived from the atmosphere (%Ndfa) of vetch in mixed culture was in most cases higher than in monoculture. The poor competitiveness of vetch for soil N uptake was responsible for the higher soil N uptake by barley and therefore, a higher %Ndfa in vetch. Positive and high final nitrogen balance was observed in the mixture. We excluded, under the current experimental conditions, the possibility of N-transfer from vetch to barley.     

Chemical Constituents of Some<Emphasis Type="Italic">Hypericum</Emphasis> Species Growing in Turkey

The present study was conducted to determine the content of pharmacologically important constituents hypericin, pseudohypericin, chlorogenic acid, rutin, hyperoside, apigenin-7-O-glucoside, quercitrin, quercetin and vitexin in eightHypericum species namely,H. aviculariifolium Jaup. and Spach subsp.depilatum (Freyn and Bornm.) Robson var.depilatum (endemic),H. lydium Boiss.,H. montbretii Spach,H. orientale L,H. origanifolium Willd,H. perfoliatum L,H. perforatum L. andH. pruinatum Boiss. and Bal. growing in different locations of Turkey. Wild growing plants were harvested at flowering and after dried subsequently assayed for the constituents by HPLC method. Hyperoside, quercitrin and pseudohypericin were found in all species. Hypericin, quercetin and chlorogenic acid were also detected in all species with the exceptions ofH. orientale for hypericin,H. montbretii for quercetin andH. lydium for chlorogenic acid. Apigenin-7-O-glucoside accumulation was observed in all examined species at various levels, except forH. orientale andH. origanifolium. Rutin was detected inH. aviculariifolium,H. lydium, H. orientale, H. perfoliatum andH. perforatum. On the contrary of the other species, vitexin was found in onlyH. motbretii. The presence of flavonoid vitexin in the genusHypericum was reported for the first time.     

PCI proteins eIF3e and eIF3m define distinct translation initiation factor 3 complexes

Background  

PCI/MPN domain protein complexes comprise the 19S proteasome lid, the COP9 signalosome (CSN), and eukaryotic translation initiation factor 3 (eIF3). The eIF3 complex is thought to be composed of essential core subunits required for global protein synthesis and non-essential subunits that may modulate mRNA specificity. Interactions of unclear significance were reported between eIF3 subunits and PCI proteins contained in the CSN.     

Effect of testosterone on epididymal proteins in castrated rhesus monkeys

The effect of testosterone on regulation of epididymal protein synthesis has been investigated in castrated rhesus monkeys (Macaca mulatta). The proteins in the treated monkeys were characterized using polyacrylamide gel electrophoresis (under nondenaturing and denaturing conditions) and electrofocusing. At least four distinct proteins have been shown to be synthesized by the monkey epididymis under testosterone influence. Two of these proteins were detected following two days of testosterone treatment while the other two proteins were detected after a six-day treatment period. None of these proteins was detectable in monkeys treated with estradiol for six days. Electrofocusing of epididymal cytosol proteins from untreated and testosterone-treated and castrated monkeys also confirmed the presence of four androgen-dependent proteins in this species. The isoelectric points of these proteins were shown to range between 5.8 and 6.4. The molecular weights of these proteins were found to vary between 47,500 and 66,000. The in vitro incorporation of ³H-labeled amino acids was markedly greater in the androgen-primed epididymis as compared with the control tissue.