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171.
Cadmium (Cd) is a widespread heavy metal pollutant and environmental and human health hazard, which may be partially resolved using green and cost-effective phytoremediation techniques. However, the efficiency of phytoremediation is often limited by the small biomass of Cd-hyperaccumulator plants. Although cattail (Typha angustifolia L.) is tolerant of heavy metals and has a high biomass, there is little information available on its detoxification mechanisms for heavy metals, especially Cd. In the present study we investigated the tolerance of cattail to Cd and mechanisms involved in its Cd detoxification. Our results show that: (a) cattail is tolerant of Cd; (b) the root Casparian band, cell wall, vacuole, glutathione (GSH), and glutathione peroxidase (GPX) play important roles in Cd detoxification; and (c) mechanisms of Cd detoxification differ in leaf cell cytoplasm (mainly a GSH-related antioxidant defense system) and root cell cytoplasm (mainly a GSH-related chelation system). In summary, cattail possesses multiple detoxification mechanisms for Cd and is a promising species for phytoremediation of Cd-polluted environments. 相似文献
172.
Shibin Gao Carlos Martinez Debra J. Skinner Alan F. Krivanek Jonathan H. Crouch Yunbi Xu 《Molecular breeding : new strategies in plant improvement》2008,22(3):477-494
Leaf collection from the field, labeling and tracking back to the source plants after genotyping are rate limiting steps in
leaf DNA-based genotyping. In this study, an optimized genotyping method using endosperm DNA sampled from single maize seeds
was developed, which can be used to replace leaf DNA-based genotyping for both genetic studies and breeding applications.
A similar approach is likely to be suitable for all plants with relatively large seeds. Part of the endosperm was excised
from imbibed maize seeds and DNA extracted in 96-tube plates using individuals from eight F2 populations and seven inbreds. The quality of the resultant DNA was functionally comparable to DNA extracted from leaf tissue.
Extraction from 30 mg of endosperm yields 3–10 μg DNA, which is sufficient for analysis of 200–400 agarose-gel PCR-based markers,
with the potential for several million chip-based SNP marker analyses. By comparing endosperm DNA and leaf DNA for individuals
from an F2 population, genotyping errors caused by pericarp contamination and hetero-fertilization were found to average 3.8 and 0.6%,
respectively. Endosperm sampling did not affect germination rates under controlled conditions, although under normal field
conditions the germination rate, seedling establishment, and growth vigor were significantly lower than that of non-sampled
controls for some genotypes. However, careful field management can compensate for these effects. Seed DNA-based genotyping
lowered costs by 24.6% compared to leaf DNA-based genotyping due to reduced field plantings and labor costs. A substantial
advantage of this approach is that it can be used to select desirable genotypes before planting. As such it provides an opportunity
for dramatic improvements in the efficiency and selective gain of breeding systems based on optimum combinations of marker-assisted
selection and phenotypic selection within and between generations. 相似文献
173.
Samit Kumar Dutta Pedro Serrano Michael Geralt Herbert L. Axelrod Qingping Xu Scott A. Lesley Adam Godzik Ashley M. Deacon Marc‐André Elsliger Ian A. Wilson Kurt Wüthrich 《Protein science : a publication of the Protein Society》2015,24(10):1600-1608
Flavodoxins in combination with the flavin mononucleotide (FMN) cofactor play important roles for electron transport in prokaryotes. Here, novel insights into the FMN‐binding mechanism to flavodoxins‐4 were obtained from the NMR structures of the apo‐protein from Lactobacillus acidophilus (YP_193882.1) and comparison of its complex with FMN. Extensive reversible conformational changes were observed upon FMN binding and release. The NMR structure of the FMN complex is in agreement with the crystal structure (PDB ID: 3EDO ) and exhibits the characteristic flavodoxin fold, with a central five‐stranded parallel β–sheet and five α‐helices forming an α/β‐sandwich architecture. The structure differs from other flavoproteins in that helix α2 is oriented perpendicular to the β‐sheet and covers the FMN‐binding site. This helix reversibly unfolds upon removal of the FMN ligand, which represents a unique structural rearrangement among flavodoxins. 相似文献
174.
175.
1992年3月至11月,我们在海南和长沙两地,先后使用38种化学调控剂,对水稻两用不育系,三系不育系及普通核不育系进行了喷施和注射试验,筛选出7种较为有效的调控剂,代号为CR1—CR7,其中CR5和CR7表现较为突出。这些调控剂对两用不育系和三系不育系均表现出一定程度的恢复效应,且CR1和CR2还能在可育条件下提高培矮64S的结实率,但所有调控剂对普通核不育系均无恢复作用。 相似文献
176.
Du F Shen PC Xu J Sung LY Jeong BS Lucky Nedambale T Riesen J Cindy Tian X Cheng WT Lee SN Yang X 《Theriogenology》2006,65(3):642-657
One of the several factors that contribute to the low efficiency of mammalian somatic cloning is poor fusion between the small somatic donor cell and the large recipient oocyte. This study was designed to test phytohemagglutinin (PHA) agglutination activity on fusion rate, and subsequent developmental potential of cloned bovine embryos. The toxicity of PHA was established by examining its effects on the development of parthenogenetic bovine oocytes treated with different doses (Experiment 1), and for different durations (Experiment 2). The effective dose and duration of PHA treatment (150 microg/mL, 20 min incubation) was selected and used to compare membrane fusion efficiency and embryo development following somatic cell nuclear transfer (Experiment 3). Cloning with somatic donor fibroblasts versus cumulus cells was also compared, both with and without PHA treatment (150 microg/mL, 20 min). Fusion rate of nuclear donor fibroblasts, after phytohemagglutinin treatment, was increased from 33 to 61% (P < 0.05), and from 59 to 88% (P < 0.05) with cumulus cell nuclear donors. The nuclear transfer (NT) efficiency per oocyte used was improved following PHA treatment, for both fibroblast (13% versus 22%) as well as cumulus cells (17% versus 34%; P < 0.05). The cloned embryos, both with and without PHA treatment, were subjected to vitrification and embryo transfer testing, and resulted in similar survival (approximately 90% hatching) and pregnancy rates (17-25%). Three calves were born following vitrification and embryo transfer of these embryos; two from the PHA-treated group, and one from non-PHA control group. We concluded that PHA treatment significantly improved the fusion efficiency of somatic NT in cattle, and therefore, increased the development of cloned blastocysts. Furthermore, within a determined range of dose and duration, PHA had no detrimental effect on embryo survival post-vitrification, nor on pregnancy or calving rates following embryo transfer. 相似文献
177.
To investigate the regulatory mechanisms of sex expression in cucumber, morphological observations and biochemical analyses were carried out on inappropriate stamen development of female flowers of cucumber. It was found that developmental arrest of the inappropriate stamen mainly occurs at the anther primordium. This arrest is closely correlated with DNA damage, as detected by TUNEL assay, and might result from anther-specific DNase activation. It was also found that the DNA damage does not lead to cell degeneration, although chromatin condensation is observed in the anther primordia.Abbreviations DAPI 4,6-diamidine-2-phenylindole dihydrochloride - MTT 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide - PCD programmed cell death - TUNEL TdT-mediated dUTP nick-end labeling 相似文献
178.
Yanming Sun Ruofeng Yan Charles I. Muleke Guangwei Zhao lixin Xu Xiangrui Li 《International journal of peptide research and therapeutics》2007,13(3):387-392
The effect of Haemonchus contortus galectin peptides rHco-gal-m/f to induce apoptosis in the peripheral blood lymphocytes (PBLCs) of goats was investigated. Analysis of apoptosis was
carried out with agarose gel electrophoresis, flow cytometry and transmission electron microscopy. The results indicated that
there were visible apoptosis bodies and typical DNA ladders by genomic DNA fragmentation. The quantitative analysis of apoptosis
by flow cytometry indicated that rHco-gal-m/f peptides induced apoptosis was time and dose dependent. Ultrastructural studies of the PBLCs revealed that a large
number of apoptotic cells were present in galectin-treated cells, which had the typical morphologic changes of apoptosis such
as reduction of the cytoplasmic volume, loss of cell surface microvilli, chromatin condensation and fragmentation of the apoptotic
cells into small apoptotic bodies. 相似文献
179.
Lingling Xu Marie-Laurence Tremblay Kathleen E. Orrell Jérémie Leclerc Qing Meng Xiang-Qin Liu Jan K. Rainey 《FEBS letters》2013
Artificial spider silk proteins may form fibers with exceptional strength and elasticity. Wrapping silk, or aciniform silk, is the toughest of the spider silks, and has a very different protein composition than other spider silks. Here, we present the characterization of an aciniform protein (AcSp1) subunit named W1, consisting of one AcSp1 199 residue repeat unit from Argiope trifasciata. The structural integrity of recombinant W1 is demonstrated in a variety of buffer conditions and time points. Furthermore, we show that W1 has a high thermal stability with reversible denaturation at ∼71 °C and forms self-assembled nanoparticle in near-physiological conditions. W1 therefore represents a highly stable and structurally robust module for protein-based nanoparticle formation. 相似文献
180.
瘦素对高脂血症小鼠血胆固醇含量的影响 总被引:4,自引:0,他引:4
目的:观察瘦素对高脂膳食所致的高血胆固醇的调节作用。方法:喂饲高脂饲料建立高脂血症模型,瘦素干预后测定血浆中总胆固醇和低密度脂蛋白胆固醇的水平。结果:干预组血浆总胆固醇和低密度脂蛋白胆固醇的水平显著低于高脂对照纽。结论:瘦素可降低高脂血症小鼠血浆总胆固醇和低密度脂蛋白胆固醇水平。 相似文献