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61.
3′,5′-cyclic guanosine monophosphate (cGMP) is an important second messenger in plants. In the present study, roles of cGMP
in salt resistance in Arabidopsis roots were investigated. Arabidopsis roots were sensitive to 100 mM NaCl treatment, displaying a great increase in electrolyte leakage and Na+/K+ ratio and a decrease in gene expression of the plasma membrane (PM) H+-ATPase. However, application of exogenous 8Br-cGMP (an analog of cGMP), H2O2 or CaCl2 alleviated the NaCl-induced injury by maintaining a lower Na+/K+ ratio and increasing the PM H+-ATPase gene expression. In addition, the inhibition of root elongation and seed germination under salt stress was removed
by 8Br-cGMP. Further study indicated that 8Br-cGMP-induced higher NADPH levels for PM NADPH oxidase to generate H2O2 by regulating glucose-6-phosphate dehydrogenase (G6PDH) activity. The effect of 8Br-cGMP and H2O2 on ionic homeostasis was abolished when Ca2+ was eliminated by glycol-bis-(2-amino ethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA, a Ca2+ chelator) in Arabidopsis roots under salt stress. Taken together, cGMP could regulate H2O2 accumulation in salt stress, and Ca2+ was necessary in the cGMP-mediated signaling pathway. H2O2, as the downstream component of cGMP signaling pathway, stimulated PM H+-ATPase gene expression. Thus, ion homeostasis was modulated for salt tolerance. 相似文献
62.
RP-HPLC法测定不同产地蓬子菜中二个黄酮类成分的含量 总被引:1,自引:0,他引:1
目的:测定10个产地蓬子菜中喇叭茶苷和香叶木苷的含量,建立蓬子菜中黄酮类成分含量测定的方法;方法:HPLC法,色谱柱:Hypersil ODS2 5μm(200mm×4.6mm i.d);流动相:甲醇-水-冰醋酸(体积比30:70:0.20);检测波长:340nm.结果:香叶木苷在0.601 0~1.510 μg(r=0.999 9),喇叭茶苷在0.098~0.249 8μg(r=0.996 2)与峰面积线性关系良好.结论:这两个黄酮类成分在10个产地中含量比较稳定,本法简单可行,准确性好,重现性高,是蓬子莱中黄酮类成分含量测定的有效方法. 相似文献
63.
64.
L Wen K He Y Ni X Zhang B Li X Wang RL Guo Z Yu A Mao J Zhou L Lv J Jiang 《Journal of virology》2012,86(16):8911
We report here for the first time the genome sequence of a rearranged porcine circovirus type 2 (PCV2) strain, CH-IVT1, isolated from PCV2-infected PK-15 cells. The complete circular genome of the CH-IVT1 is 605 nucleotides (nt) in length. The finding will help us to understand the molecular evolution of PCV2 and the relationship between PCV2 and PCV-associated diseases. 相似文献
65.
Mitochondrial reactive oxygen species signal hepatocyte steatosis by regulating the phosphatidylinositol 3-kinase cell survival pathway 总被引:2,自引:0,他引:2
Kohli R Pan X Malladi P Wainwright MS Whitington PF 《The Journal of biological chemistry》2007,282(29):21327-21336
Abnormal dietary intake of macronutrients is implicated in the development of obesity and fatty liver disease. Steatosis develops in cultured hepatocytes exposed to medium containing either a high concentration of long chain free fatty acids (HFFA) or medium deficient in methionine and choline (MCD). This study examined the mitochondrial reactive oxygen species (ROS)-dependent regulation of the phosphoinositol (PI) 3-kinase pathway in steatosis induced by exposure of AML-12 mouse hepatocytes to MCD or HFFA medium. Exposure to either MCD or HFFA medium resulted in increased production of superoxide anions and H(2)O(2), transduction of the PI 3-kinase pathway and steatosis. Inhibition of PI 3-kinase with LY294002 prevented steatosis. Pharmacologically inhibiting electron transport chain complex III production of ROS prevented activation of PI 3-kinase during macronutrient perturbation, whereas pharmacologically promoting electron transport chain complex III ROS production activated PI 3-kinase independent of nutrient input. The data suggest that H(2)O(2) is the ROS species involved in signal transduction; promoting the rapid conversion of superoxide to H(2)O(2) does not inhibit PI 3-kinase pathway activation during nutrient perturbation, and exogenous H(2)O(2) activates it independent of nutrient input. In addition to transducing PI 3-kinase, the ROS-dependent signal cascade amplifies the PI 3-kinase signal by maintaining phosphatase and tensin homolog in its inactive phosphorylated state. Knockdown of phosphatase and tensin homolog by small interfering RNA independently activated the PI 3-kinase pathway. Our findings suggest a common path for response to altered nutrition involving mitochondrial ROS-dependent PI 3-kinase pathway regulation, leading to steatosis. 相似文献
66.
Fu Y Xu B Zou X Ma C Yang X Mou K Fu G Lü Y Xu P 《Bioorganic & medicinal chemistry letters》2007,17(4):1102-1106
A novel class of furan-based compounds as potential 20S proteasome inhibitors have been designed and synthesized, among which nine compounds are peptide derivatives and six molecules are statine peptidomimetics. The C-terminal furanyl moiety was introduced to target molecules as furan-based amino acids. All the compounds were obtained steadily with moderate to high yield. Compound 12 was a selective moderate potent proteasome peptidomimetic inhibitor. It inhibited HepG2 and HL-60 proliferation effectively. 相似文献
67.
Zhao X Oh SH Jajko R Diekema DJ Pfaller MA Pujol C Soll DR Hoyer LL 《Fungal genetics and biology : FG & B》2007,44(12):1298-1309
The Candida albicans ALS (agglutinin-like sequence) gene family encodes eight cell-surface glycoproteins, some of which function in adhesion to host surfaces. ALS genes have a central tandem repeat-encoding domain comprised entirely of head-to-tail copies of a conserved 108-bp sequence. The number of copies of the tandemly repeated sequence varies between C. albicans strains and often between alleles within the same strain. Because ALS alleles can encode different-sized proteins that may have different functional characteristics, defining the range of allelic variability is important. Genomic DNA from C. albicans strains representing the major genetic clades was PCR amplified to determine the number of tandemly repeated sequence copies within the ALS5 and ALS6 central domain. ALS5 alleles had 2-10 tandem repeat sequence copies (mean=4.82 copies) while ALS6 alleles had 2-8 copies (mean=4.00 copies). Despite this variability, tandem repeat copy number was stable in C. albicans strains passaged for 3000 generations. Prevalent alleles and allelic distributions varied among the clades for ALS5 and ALS6. Overall, ALS6 exhibited less variability than ALS5. ALS5 deletions can occur naturally in C. albicans via direct repeats flanking the ALS5 locus. Deletion of both ALS5 alleles was associated particularly with clades III and SA. ALS5 exhibited allelic polymorphisms in the coding region 5' of the tandem repeats; some alleles resembled ALS1, suggesting recombination between these contiguous loci. Natural deletion of ALS5 and the sequence variation within its coding region suggest relaxed selective pressure on this locus, and that Als5p function may be dispensable in C. albicans or redundant within the Als family. 相似文献
68.
69.
Xiaoxuan Guo Ning Liu Xiaomin Li Yun Ding Fei Shang Yongsheng Gao Jisheng Ruan Ying Huang 《Applied and environmental microbiology》2015,81(9):3086-3103
Red soils, which are widely distributed in tropical and subtropical regions of southern China, are characterized by low organic carbon, high content of iron oxides, and acidity and, hence, are likely to be ideal habitats for acidophilic actinomycetes. However, the diversity and biosynthetic potential of actinomycetes in such habitats are underexplored. Here, a total of 600 actinomycete strains were isolated from red soils collected in Jiangxi Province in southeast China. 16S rRNA gene sequence analysis revealed a high diversity of the isolates, which were distributed into 26 genera, 10 families, and 7 orders within the class Actinobacteria; these taxa contained at least 49 phylotypes that are likely to represent new species within 15 genera. The isolates showed good physiological potentials for biosynthesis and biocontrol. Chemical screening of 107 semirandomly selected isolates spanning 20 genera revealed the presence of at least 193 secondary metabolites from 52 isolates, of which 125 compounds from 39 isolates of 12 genera were putatively novel. Macrolides, polyethers, diketopiperazines, and siderophores accounted for most of the known compounds. The structures of six novel compounds were elucidated, two of which had a unique skeleton and represented characteristic secondary metabolites of a putative novel Streptomyces phylotype. These results demonstrate that red soils are rich reservoirs for diverse culturable actinomycetes, notably members of the families Streptomycetaceae, Pseudonocardiaceae, and Streptosporangiaceae, with the capacity to synthesize novel bioactive compounds. 相似文献
70.
Xu Han Lixuan Gui Bing Liu Jing Wang Yaru Li Xiayun Dai Jun Li Binyao Yang Gaokun Qiu Jing Feng Xiaomin Zhang Tangchun Wu Meian He 《BMC genetics》2015,16(1)