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排序方式: 共有360条查询结果,搜索用时 31 毫秒
11.
Kyoji Hagiwara Takahiko Higashi Kazunari Takahashi Naho Hara Hideyuki Aoki Naoyuki Miyazaki Qing-Yu Wang Yafeng Zhu Osamu Yatou Hiroshi Tanaka Toshihiro Omura 《Journal of General Plant Pathology》2006,72(3):186-189
Transencapsidation of the Rice gall dwarf virus (RGDV) inner core by the Rice dwarf virus (RDV) outer capsid P8 protein was examined in vitro and in planta. When RGDV core particles were incubated with an extract
from RDV P8-transgenic rice leaf tissue, RDV P8 encapsidated the RGDV core particles to form double-shelled virus-like particles
in vitro. In contrast, when RDV P8-transgenic rice plants were inoculated with RGDV, progeny RGDV particles contained RGDV
P8 but RDV P8 was not detectable in the virions. No significant differences were found in acquisition by the vector insects
and subsequent transmission rates between RGDV infecting nontransgenic rice plants and those infecting RDV P8-transgenic rice
plants. These results indicate that mechanisms of and/or requirements for interactions between P8 and the inner core particles
of phytoreoviruses differ between in vitro and in planta. 相似文献
12.
Tomoko Takeda 《Pesticide biochemistry and physiology》2006,86(1):15-22
Insecticidal tests using diazinon showed that the mortality of Plutella xylostella larvae parasitized by Cotesia plutellae was reduced by 4.6-fold compared to that of the nonparasitized hosts. The use of chemicals with synergistic effect to insecticides in toxicity assay helps to elucidate the kind of enzyme involved in lowering insect mortality. Synergism of diethyl maleate and piperonyl butoxide with diazinon resulted to 2.4- and 1.9-fold increase, respectively, in susceptibility of parasitized larvae compared to those of nonparasitized larvae. These results indicated the possibility that the decrease in susceptibility to diazinon was due to the elevated activities of glutathione-S-transferase (GST) and cytochrome P450 monooxygenase (CYP), respectively. The GST activities in parasitized larvae were significantly higher than those of nonparasitized ones starting from three days post-parasitization until emergence of parasitoid larva. High GST activities during late parasitism could be attributed to both enzyme activities toward diazinon of parasitized P. xylostella larva itself and C. plutellae larva inside larval host. High GST activity one day after parasitization, although statistical significance was not detected, was caused by polydnavirus (PDV) and the venom of C. plutellae not by parasitoid larvae. Artificial injection of PDV plus venom demonstrated that the resulting increase in GST activity is similar to the increase brought by parasitization. High CYP activity after 3 days post-parasitization in parasitized larva was attributed mainly to the activity of parasitoid larva. Carboxylesterase activity in the parasitized host remained at a high level, while that in the nonparasitized host decreased slightly as pupation approaches. On the other hand, acetylcholinesterase activity also remained constant after parasitization until larval emergence, while that of the nonparasitized hosts decreased gradually as the host larvae approach pupation. These results were supported by inhibition tests using diazoxon in vitro. 相似文献
13.
14.
Kodama S Yamamoto A Sato A Suzuki K Yamashita T Kemmei T Taga A Hayakawa K 《Journal of agricultural and food chemistry》2007,55(16):6547-6552
Chiral resolution of isoxanthohumol (IX) in beer samples was performed by hydroxypropyl-gamma-cyclodextrin-modified micellar electrokinetic chromatography. The optimum running conditions were found to be 20 mM phosphate buffer (pH 7.0) containing 45 mM hydroxypropyl-gamma-cyclodextrin and 100 mM sodium dodecyl sulfate with an effective voltage of +20 kV at 20 degrees C using direct detection at 210, 295, and 370 nm. IX was detected in 12 beer samples and the total levels of (+)- and (-)-IX ranged from 0.15 to 1.4 mg/L. But the amount of xanthohumol (XN) was below the detection limit (0.017 mg/L). Each level of (-)-IX was almost the same as that of (+)-IX, suggesting that IX was a racemic mixture in these beer samples. The racemization of IX in beer could be attributed to the production of a racemic mixture from XN during boiling and to the fact that IX enantiomers were easily interconverted. 相似文献
15.
Study on the glass transition for several processed fish muscles and its protein fractions using differential scanning calorimetry 总被引:1,自引:0,他引:1
ABSTRACT: The glass transition behavior of processed fish muscles (bonito, tuna, mackerel, sea bream, cod) and its muscle protein fractions (sarcoplasmic and myofibrillar proteins) were studied using differential scanning calorimetry. Each dried processed fish muscle and the extracted protein fractions showed clear glass transition phenomenon. The T g values of muscles and myofibrillar proteins from red muscle fishes tended to be lower than those from white muscle fishes though there was no difference on T g of sarcoplasmic proteins. The T g value of whole muscle was considerably lower than that of extracted protein fractions because of the plasticizing effects of low molecular weight materials contained in the muscle. 相似文献
16.
Satoru TANAKA Tomoko UTOH Yoshiaki YAMADA Noriyuki HORIE Akihiro OKAMURA Atsushi AKAZAWA Naomi MIKAWA Hideo P OKA Hisashi KUROKURA 《Fisheries Science》2004,70(5):780-787
ABSTRACT: In order to find out the role of sodium bicarbonate (NaHCO3 ) on the initiation of sperm motility in the Japanese eel Anguilla japonica , interactions were investigated between NaHCO3 and various reagents (K+ channel blocker 4-aminopyridine [4-AP], ammonium chloride [NH4 Cl], sodium acetate and calcium chloride [CaCl2 ]) that could regulate internal factors (intracellular K+ , intracellular pH [[pH]i ] and intracellular Ca2+ ) in sperm motility. Contradictory effects of NaHCO3 were observed (i.e. an inhibitory effect when 4-AP was absent and a promoting effect when 4-AP was present). Sodium bicarbonate inhibited the initiation of sperm motility in the Japanese eel. However, NaHCO3 restored the motility of immotile sperm that 4-AP inhibited. The inhibitory effect of NaHCO3 disappeared with the addition of NH4 Cl, which raised [pH]i , but the promoting effect was not affected by [pH]i . Although NaHCO3 recovered motility in the presence of 4-AP, this recovery was also observed with the addition of CaCl2 instead of NaHCO3 . In the initiation of sperm motility in the Japanese eel, two roles for NaHCO3 are suggested: an inhibitory role relating to the regulation of [pH]i and a promoting role relating to the uptake of another initiation factor, which could be Ca2+ . 相似文献
17.
18.
In the present study, the effect of passage of nuclear donor cells on the in vitro development of nuclear transfer (NT) embryos was investigated using colostrum‐derived mammary gland epithelial (MGE) cells at different passages (3–30 passages) to find reliable passages for the efficiency of cloning. Development of NT embryos to the blastocyst stage was affected by the number of passages of MGE cells (P < 0.05). Nuclear transfer embryos reconstructed with MGE cells at 3–7 passages showed a significantly higher blastocyst development (31.3–48.5%) than those with the cells at 10–30 passages (2.5–12.5%, P < 0.05). No difference in the proportion of the MGE cells with normal diploid was observed among passage of 3, 15 and 30 (P > 0.05). The use of MGE cells at early passages for nuclear donor cells may be advantageous for the production of NT embryos. 相似文献
19.
Kenji Ohse Kenji Tamura Haruo Tanaka Teruo Higashi 《Soil Science and Plant Nutrition》2005,51(1):37-42
At Mt. Hirugatake in the Tanzawa Mountains, Kanto district, Japan, the deciduous broadleaved forests have rapidly declined. In our previous studies, we reported that the amount of soil organic matter had significantly decreased at the early and final stages of forest decline, and that the soil microbial biomass also showed a large decrease at these stages, suggesting that the composition of soil organic matter might have also changed with forest decline. To clarify the influences of forest decline on the composition of soil organic matter, the amount of humic substances, optical properties of humic acid, and the amount of soil carbohydrates in surface soils at different stages of forest decline were investigated. The amounts of humic acid and fulvic acid decreased to a lesser extent at the early and middle stages of forest decline, and showed a significant decrease at the final stage. As the amount of humin significantly decreased at the early stage, it was plausible that the distinct decrease in the total carbon content of the soil surface horizons at the early stage of forest decline was induced by the decrease in the amount of humin, and at the final stage, by the decrease in the amounts of humic acid and fulvic acid. The amount of soil carbohydrates did not change appreciably with forest decline although the soil organic matter content markedly decreased. It was suggested that most of the carbohydrates in the soil surface horizons were in a stabilized form consisting of complexes with humic substances, metals, and minerals, and would not be affected by the environmental changes associated with forest decline. 相似文献
20.
Digestion of carp myofibrils at 30 degrees C in 0.5 M KCl medium with calcium ion generated unique 135 kDa heavy meromyosin (HMM). The HMM was not produced when digested at 10 degrees C. A further digestion of the 135 kD HMM isolated in the absence of calcium ion generated uniquely short subfragment-2 (S-2) with a size of 40 kDa (40 kDa S-2) together with subfragment-1 (S-1). The 40 kDa S-2 was identified by N- and C-end sequencing, and demonstrated to locate the amino end of the rod portion. The unfolding temperature for the 40 kDa S-2 was around 52 degrees C as studied by circular dichroism measurement. The same unfolding peak was also detected with the intact rod together with a large unfolding peak at around 36 degrees C coming from the rest of the rod portion, light meromyosin. The unfolding peak for the 40 kDa S-2 in myosin was a little lower (48 degrees C) than that in free form, suggesting the involvement of the head portion in the stability of the 40 kDa S-2 in the structure. 相似文献