排序方式: 共有66条查询结果,搜索用时 15 毫秒
31.
It has been reported that the use of dimethylsulfoxide (DMSO) as a solvent for fixatives enhances preservation of cellular ultrastructure. By contrast, we have shown that DMSO alters the ultrastructural integrity of glutaraldehyde fixed cells. The cell membrane, nuclear envelope, endoplasmic reticulum, ribosomes, microtubules and intracytoplasmic organelles are most susceptible to the action of DMSO. We hypothesize that DMSO exerts intracellular alterations via its interaction with remnant interfacial water in fixed cells. DMSO-induced alterations of these and related cellular components may result in the formation of artefactual structures and networks. Thus, it appears that DMSO containing glutaraldehyde neither accelerates fixation nor enhances stabilization of cellular ultrastructure. For these reasons, addition of DMSO to fixatives is not recommended. 相似文献
32.
A. V. Il’ina S. N. Kulikov G. I. Chalenko N. G. Gerasimova V. P. Varlamov 《Applied Biochemistry and Microbiology》2008,44(5):551-558
The possibility of obtaining monosaccharide derivatives of low-molecular-weight chitosan with the use of the Maillard reaction was studied. Chitosan derivatives (molecular weight, 24 and 5 kDa) obtained with glucosamine, N-acetyl galactosamine, galactose, and mannose with a substitution degree of 4–14% and a yield of 60–80% were obtained. Some physicochemical and biological properties of these derivatives were studied. We showed that monosaccharide derivatives of low-molecular-weight chitosan exhibited antibacterial activity. Chitosan at a concentration of 0.01% caused 100% death of bacteria B. subtilis and E. coli. The strongest antibacterial effect was exhibited by 24-kDa derivatives: only 0.02–0.08% of cells survived. These derivatives were two orders of magnitude more effective than the 5-kDa chitosan modified with galactose. 相似文献
33.
Vasyukova N. I. Chalenko G. I. Valueva T. A. Gerasimova N. G. Panina Ya. S. Ozeretskovskaya O. L. 《Applied Biochemistry and Microbiology》2003,39(6):613-617
Laminarin blocks potato immune responses by inhibiting the reaction of oversensitivity, formation of phytoalexins, wound repair, and the activity of proteinase inhibitors. It was found that laminarin exhibits antielicitor activity. Addition of salicylic acid to laminarin enhances its immunosuppressing effect, which becomes systemic. 相似文献
34.
35.
An Atlantic salmon (Salmo salar L.) expressed sequence tag (EST) database consisting of 58 146 ESTs was screened for microsatellite sequences. Subsequent development of 75 polymorphic EST‐associated microsatellite markers in this species is described together with cross‐species amplification results of 133 gene‐associated tandem repeat markers in five salmonid species (Salmo trutta, Oncorhynchus mykiss, Salvelinus aplinus, Thymallus thymallus, Coregonus lavaretus). The number of alleles among EST‐linked microsatellites in Atlantic salmon ranged from two to 41 with an average of 12 alleles per locus. Cross‐species amplification resulted in detection of a total of 111 polymorphic locus‐species combinations (12–32 loci per species). 相似文献
36.
Ozeretskovskaia OL Vasiukova NI Chalenko GI Gerasimova NG Grishanina AN Khromova LIa Iakovleva GA Varlamov VP Skriabin KG 《Prikladnaia biokhimiia i mikrobiologiia》2002,38(5):552-555
Resistance of transgenic cultivars based on the expression of one or more resistance genes is sooner or later broken by pathogens whose race-producing rates are high. Thus, combining transgenesis with elicitor-induced resistance is a promising approach. The elicitor-induced resistance is based on the expression of multiple resistance genes, which can prevent the adaptation of pathogens to transgenic races, maintain the stability of cultivars, and increase their lifespan. In this work, we used transgenic potato cultivars Temp and Superior transformed with Bacillus thuringiensis delta-endotoxin gene and Lukyanovskii transformed with leukocyte alpha-interferon gene. Arachidonic acid (10(-8) M) and soluble chitosan (5 kDa, 100 micrograms/ml) were used as elicitors for tuber treatment. Our data showed that pretreatment with elicitors causes a 15-25% increase in both the systemic prolonged resistance of potato tubers to Phytophthora infestans and their ability to repair mechanical damage. 相似文献
37.
MI YOON CHUNG CHONG-WOOK PARK ERIC R. MYERS MYONG GI CHUNG 《Botanical journal of the Linnean Society. Linnean Society of London》2007,153(1):41-48
Levels of allozyme variation and intrapopulation spatial genetic structure of the two terrestrial clonal orchids Liparis kumokiri , a self-compatible relatively common species, and L. makinoana , a self-incompatible rare species, were examined for 17 ( N = 1875) and four ( N = 425) populations, respectively, in South Korea. Populations of L. makinoana harboured high levels of genetic variation ( H e = 0.319) across 15 loci. In contrast, L. kumokiri exhibited a complete lack of allozyme variation ( H e = 0.000). Considering the lack of genetic variability, it is suggested that current populations of L. kumokiri in South Korea originated from a genetically depauperate ancestral population. For L. makinoana , a significant deficit of heterozygosity (mean F IS = 0.198) was found in population samples excluding clonal ramets, suggesting that pollen dispersal is localized, generating biparental inbreeding. The significant fine-scale genetic structuring (≤ 2 m) found in a previous study, in addition to the moderate levels of population differentiation ( F ST = 0.107) and the significant relationship between genetic and geographical distances ( r = 0.680) found here, suggests a leptokurtic distribution of seed dispersal for L. makinoana . Although populations of L. makinoana harbour high levels of genetic variation, they are affected by a recent genetic bottleneck. This information suggests that genetic drift and limited gene flow could be the main evolutionary forces for speciation of a species-rich genus such as Liparis . © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 41–48. 相似文献
38.
Ozeretskovskaia OL Varlamov VP Vasiukova NI Chalenko GI Gerasimova NG Panina IaS 《Prikladnaia biokhimiia i mikrobiologiia》2004,40(2):252-256
Mobile systemic signaling molecules (salicylic and jasmonic acids) enhance and accelerate the spread of systemic immunizing effect of elicitors (arachidonic acid and chitosan) over potato tuber tissues (Solanum tuberosum L.). 相似文献
39.
L. I. Il’inskaya G. I. Chalenko E. A. Perekhod N. G. Gerasimova O. L. Ozeretskovskaya 《Applied Biochemistry and Microbiology》2000,36(2):181-186
Methyl ester of jasmonic acid (Me-JA) influences the induced resistance of potato tubers to late blight caused byPhytophthora infestans. Treatment of potato tuber disk surfaces with Me-JA solution or exposure to an atmosphere containing Me-JA vapors (10−6–10−5 M) increased the rate of rishitin biosynthesis induced by arachidonic acid orP. infestans. Methyl jasmonate increased the sensitivity of potato tissue to arachidonic acid. As a result, in the presence of Me-JA,
the protective properties of arachidonic acid were observed at lower concentrations than in the absence of Me-JA. In addition,
Me-JA reduced the adverse effects of lipoxygenase inhibitors (salicylhydroxamic acid and esculetin) on the induced resistance
of potato tubers to late blight. Therefore, the synergistic interaction of Me-JA and biogenic elicitors can be regarded as
part of a mechanism of potato defense against diseases. 相似文献
40.
N. I. Vasyukova O. L. Ozeretskovskaya G. I. Chalenko N. G. Gerasimova A. A. L’vova A. V. Il’ina A. N. Levov V. P. Varlamov I. A. Tarchevsky 《Applied Biochemistry and Microbiology》2010,46(3):346-351
A study of biological activity of the derivatives of the chitin-chitosan oligomer with salicylic acid and its fragments showed
that chitosan salicylate actively protected potato tubers against Phytophthora infestans but sharply inhibited reparation of potato tissues. N-(2-hydroxybenzyl)chitosan exhibited good protective properties but
did not influence wound reparation. N-(2-hydroxy-3-methoxybenzyl)-N-pyridoxchitosan, which contained the pyridoxal and 2-hydroxy-3-methoxy
fragments, was the most efficient, stimulating both defense against late blight and wound reparation in potato tissues. 相似文献