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991.
992.
A series of 2-arylamino-5-aryl-1,3,4-thiadiazoles 1a-j were synthesized and screened for their anticancer activity against various human cancer cell lines. The novel one-pot synthesis of 1,3,4-thiadiazoles was achieved by refluxing aryl aldehydes, hydrazine hydrate, and aryl isothiocyanates in methanol followed by oxidative cyclization with ferric ammonium sulfate. The compounds 1g-j with trimethoxyphenyl at the C-5 position displayed extremely potent anticancer activity with at least twofold selectivity (IC50: 4.3-9.2 μM). The nature of substituent on the C-2 arylamino ring may be critical in opting for the selectivity towards a particular cancer cell. 相似文献
993.
Maize leaf temperature responses to drought: Thermal imaging and quantitative trait loci (QTL) mapping 总被引:2,自引:0,他引:2
Ya Liu Chander SubhashJianbin Yan Chunpeng SongJiuran Zhao Jiansheng Li 《Environmental and Experimental Botany》2011,71(2):158-165
Leaf temperature has been shown to vary when plants are subjected to water stress conditions. Recent advances in infrared thermography have increased the probability of recording drought tolerant responses more accurately. The aims of this study were to identify the effects of drought on leaf temperature using infrared thermography. Furthermore, the genomic regions responsible for the expression of leaf temperature variation in maize seedlings (Zea mays L.) were explored. The maize inbred lines Zong3 and 87-1 were evaluated using infrared thermography and exhibited notable differences in leaf temperature response to water stress. Correlation analysis indicated that leaf temperature response to water stress played an integral role in maize biomass accumulation. Additionally, a mapping population of 187 recombinant inbred lines (RILs) derived from a cross between Zong3 and 87-1 was constructed to identify quantitative trait loci (QTL) responsible for physiological traits associated with seedling water stress. Leaf temperature differences (LTD) and the drought tolerance index (DTI) of shoot fresh weight (SFW) and shoot dry weight (SDW) were the traits evaluated for QTL analysis in maize seedlings. A total of nine QTL were detected by composite interval mapping (CIM) for the three traits (LTD, RSFW and RSDW). Two co-locations responsible for both RSFW and RSDW were detected on chromosomes 1 and 2, respectively, which showed common signs with their trait correlations. Another co-location was detected on chromosome 9 between LTD and shoot biomass, which provided genetic evidence that leaf temperature affects biomass accumulation. Additionally, the utility of a thermography system for drought tolerance breeding in maize was discussed. 相似文献
994.
Recent reports have shown that natural killer (NK) cells may be long-lived, possess memory-like features and may need microbial priming to become fully reactive. Thus, the notion that these cells are typically innate, nonadaptive lymphocytes has been challenged. If microbial priming is essential for functional maturity, it is necessary to raise the question whether NK cells of laboratory mice, kept under strict hygienic conditions, represent these cells adequately. In their natural habitat, mice will encounter microbes to a greater extent, and we here investigated whether NK cells of feral mice showed signs of being primed. In comparison with C57BL/6 mice raised under specific pathogen-free conditions, NK cells from feral mice had high expression of CD69, KLRG1, granzyme B and NKp46 and a higher proportion of CD27+ cells, mostly CD11b-, as well as a higher presence in peripheral lymph nodes. Following cytokine stimulation, feral mouse NK cells had quickly inducible CD25 expression and a stronger interferon-gamma response. These findings indicate a high degree of pre-activation of NK cells of free-living mice, indicating a strong environmental impact on NK cells, which may be highly relevant for interpretation of studies in the mouse model. 相似文献
995.
Marta A. Polti Mariana C. AtjiánMaría J. Amoroso Carlos M. Abate 《International biodeterioration & biodegradation》2011,65(8):1175-1181
The aim of this work was to evaluate a strategy to reduce the bioavailable chromium fraction in soil, using a Cr(VI) resistant microorganism, Streptomyces sp. MC1, under non sterile conditions, with maize plants as bioindicator and/or bioremediator.Soil samples were contaminated with 100, 200 and 400 mg kg−1 of Cr(VI) or Cr(III). Bioavailable chromium (35%) was only detected in samples with Cr(VI). Soil samples with Cr(VI) 200 mg kg−1 were inoculated with Streptomyces sp. MC1, and bioavailable chromium decreased up to 73%.Zea mays seedlings were planted in soil samples contaminated with chromium. Plantlets accumulated chromium mainly as Cr(III), and biomass decreased up to 88%. Streptomyces sp. MC1 was inoculated in soil samples contaminated with 200 mg kg−1 of Cr(VI) and Z.mays seedlings were planted.Streptomyces sp. MC1 caused Z.mays biomass increase (57%), chromium accumulation and bioavailable chromium decreased up to 46% and 96%, respectively.This work constitutes the first contribution of cooperative action between actinobacteria and Z.mays in the bioremediation of Cr(VI) contaminated soil. The large removal capacity of bioavailable chromium by Streptomyces sp. MC1 and Z.mays infers that they could be successfully applied together in bioremediation of soils contaminated with Cr(VI). 相似文献
996.
The mediation of tentoxin-induced chlorosis through inhibition of chloroplast coupling factor 1 (CF1 ) ATPase activity was investigated through an examination of the effects of tentoxin on electrophoretically-separated CF1 ATPases from sensitive and insensitive Nicotiana species. Sensitive species exhibited three major ATPases, only one of which was inhibited at some concentrations of tentoxin. Insensitive Nicotiana species showed the same three "isozymes"upon electrophoresis but none of the isozymes were tentoxin sensitive. CF1 isolated from Zea mays L. cv. Pioneer 3541, which is insensitive to tentoxin in vivo based on lack of chlorosis, exhibited two ATPases, one of which was sensitive to tentoxin. The concentration/activity relationships between tentoxin and ATPase inhibition of the sensitive isozyme did not correlate well with the chlorosis induced at similar levels of tentoxin in vivo. Both Oenothera hookeri Torr. & Gray and the CF1 -deficient I iota mutant derived from it are sensitive to tentoxin as determined by loss of chlorophyll and ultrastructural changes typical of the tentoxin syndrome. These results support a mechanism of action different from inhibition of CF1 for tentoxin-induced chlorosis. 相似文献
997.
Searching for genetic factors of fatty liver in SMXA-5 mice by quantitative trait loci analysis under a high-fat diet 总被引:1,自引:0,他引:1
Kumazawa M Kobayashi M Io F Kawai T Nishimura M Ohno T Horio F 《Journal of lipid research》2007,48(9):2039-2046
Fatty liver is strongly associated with the metabolic syndrome characterized by obesity, insulin resistance, and type 2 diabetes, but the genetic basis and functional mechanisms linking fatty liver with the metabolic syndrome are largely unknown. The SMXA-5 mouse is one of the SMXA recombinant inbred substrains established from SM/J and A/J strains and is a model for polygenic type 2 diabetes, characterized by moderately impaired glucose tolerance, hyperinsulinemia, and mild obesity. SMXA-5 mice also developed fatty liver, and a high-fat diet markedly worsened this trait, although SM/J and A/J mice are resistant to fatty liver development under a high-fat diet. To dissect loci for fatty liver in the A/J regions of the SMXA-5 genome, we attempted quantitative trait loci (QTLs) analysis in (SM/JxSMXA-5)F2 intercross mice fed a high-fat diet. We mapped a major QTL for relative liver weight and liver lipid content near D12Mit270 on chromosome 12 and designated this QTL Fl1sa. The A/J allele at this locus contributes to the increase in these traits. We confirmed the effect of Fl1sa on lipid accumulation in liver using the A/J-Chr12(SM) consomic strain, which showed significantly less accumulation than A/J mice. This suggests that the SM/J and A/J strains, neither of which develops fatty liver, possess loci causing fatty liver and that the coexistence of these loci causes fatty liver in SMXA-5 mice. 相似文献
998.
Two types of gene encoding small subunits (SSU) of ADP-glucose pyrophosphorylase, a starch-biosynthetic enzyme, have been
found in cereals and other grasses. One of these genes encodes two SSU proteins. These are targeted to different subcellular
compartments and expressed in different organs of the plant: the endosperm cytosol and the leaf plastids. The SSU gene encoding
two proteins evolved from an ancestral gene encoding a single protein by the acquisition of an alternative first exon. Prior
to the work reported here, this type of SSU gene had been found in all grasses examined except maize. In maize, two separate
genes, Bt2 and L2, were known to have the same roles as the alternatively spliced gene found in other grasses. The evolutionary origin of these
maize genes and their relationship to the SSU genes in other grasses were unclear. Here we show that Bt2 and L2 are paralogous genes that arose as a result of the tetraploidization of the maize genome. Both genes derive from an ancestral
alternatively spliced SSU gene orthologous to that found in other grasses. Following duplication, the Bt2 and L2 genes diverged in function. Each took a different one of the two functions of the ancestral gene. Now Bt2 encodes the endosperm cytosolic SSU but does not contribute significantly to leaf AGPase activity. Similarly, L2 has lost
the use of one of its two alternative first exons. It can no longer contribute to the endosperm cytosolic SSU but is probably
responsible for the bulk of the leaf AGPase SSU.
Reviewing Editor: Dr. Patrick Keeling
Sequences have been deposited in GenBank under accession numbers AY727927, DQ118037, and DQ118038. 相似文献
999.
In order to examine the possible involvement of the 20S proteasome in degradation of oxidized proteins, the effects of different cadmium concentrations on its activities, protein abundance and oxidation level were studied using maize (Zea mays L.) leaf segments. The accumulation of carbonylated and ubiquitinated proteins was also investigated. Treatment with 50 microM CdCl(2) increased both trypsin- and PGPH-like activities of the 20S proteasome. The incremental changes in 20S proteasome activities were probably caused by an increased level of 20S proteasome oxidation, with this being responsible for degradation of the oxidized proteins. When leaf segments were treated with 100 microM CdCl(2), the chymotrysin- and trypsin-like activities of the 20S proteasome also decreased, with a concomitant increase in accumulation of carbonylated and ubiquitinated proteins. With both Cd(2+) concentrations, the abundance of the 20S proteasome protein remained similar to the control experiments. These results provide evidence for the involvement of this proteolytic system in cadmium-stressed plants. 相似文献
1000.
Zhao ZG Jiang L Zhang WW Yu CY Zhu SS Xie K Tian H Liu LL Ikehashi H Wan JM 《Planta》2007,226(5):1087-1096
Partial abortion of female gametes and the resulting semi-sterility of indica × japonica inter-subspecific rice hybrids have been ascribed to an allelic interaction, which can be avoided by the use of wide compatibility
varieties. To further understand the genetic mechanism of hybrid sterility, we have constructed two sets of hybrids, using
as male parent either the typical japonica variety Asominori, or the wide compatibility variety 02428; and as female, a set of 66 chromosome segment substitution lines
in which various chromosomal segments from the indica variety IR24 have been introduced into a common genetic background of Asominori. Spikelet semi-sterility was observed in
hybrid between CSSL34 and Asominori, which is known to carry the sterility gene S31 (Zhao et al. in Euphytica 151:331–337, 2006). Cytological analysis revealed that the semi-sterility of the CSSL34 × Asominori hybrid was caused primarily by partial
abortion of the embryo sac at the stage of the mitosis of the functional megaspore. A population of 1,630 progeny of the three-way
cross (CSSL34 × 02428) × Asominori was developed to map S31. Based on the physical location of linked molecular markers, S31 was thereby delimited to a 54-kb region on rice chromsome 5. This fragment contains eight predicted open reading frames,
four of which encode known proteins and four putative proteins. These results are relevant to the map-based cloning of S31, and the development of marker-assisted transfer of non-sterility allele inducing alleles to breeding germplasm, to allow
for a more efficient exploitation of heterosis in hybrid rice. 相似文献