异丙酚对全脑缺血/再灌注大鼠海马谷氨酸、抗坏血酸释放的影响

目的：观察异丙酚对全脑缺血／再灌注大鼠海马细胞外谷氨酸（Glu）和抗坏血酸（AA）的影响,探讨异丙酚脑保护作用机制。方法：采用Pulsinelli-Brlerley四血管阻断法制备全脑缺血模型,应用脑微透析技术结合高效液相色谱（HPLc）检测大鼠海马细胞外Glu、AA含量的变化。结果：与缺血／再灌注组各对应时点相比较,异丙酚处理组大鼠海马细胞外Glu、AA含量明显降低,统计结果差异均有显著性（P〈0．05,或〈0．01）。结论：缺血／再灌注早期应用异丙酚不仅减少兴奋性氨基酸释放,还能清除自由基、抑制脂质过氧化反应而产生脑保护作用。     

Rapid analysis of Jatropha curcas gene functions by virus-induced gene silencing

Jatropha curcas L. is a small, woody tree of the Euphorbiaceae family. This plant can grow on marginal land in the tropical and subtropical regions and produces seeds containing up to 30% oil. Several Asian countries have selected Jatropha for large scale planting as a biodiesel feedstock. Nevertheless, Jatropha also possesses several undesirable traits that may limit its wide adoption. An improved understanding of plant development and the regulation of fatty acid (FA) and triacylglyceride biosynthesis in Jatropha is particularly facilitative for the development of elite crops. Here, we show that a tobacco rattle virus (TRV) vector can trigger virus-induced gene silencing (VIGS) in Jatropha. Our optimized method produced robust and reliable gene silencing in plants agroinoculated with recombinant TRV harbouring Jatropha gene sequences. We used VIGS to investigate possible functions of 13 Jatropha genes of several functional categories, including FA biosynthesis, developmental regulation and toxin biosynthesis, etc. Based on the effects of VIGS on the FA composition of newly emerged leaves, we determined the function of several genes implicated in FA biosynthesis. Moreover, VIGS was able to discriminate independent functions of related gene family members. Our results show that VIGS can be used for high-throughput screening of Jatropha genes whose functions can be assayed in leaves.     

4-Hydroxy hexenal derived from dietary n-3 polyunsaturated fatty acids induces anti-oxidative enzyme heme oxygenase-1 in multiple organs

It has recently been reported that expression of heme oxygenase-1 (HO-1) plays a protective role against many diseases. Furthermore, n-3 polyunsaturated fatty acids (PUFAs) were shown to induce HO-1 expression in several cells in vitro, and in a few cases also in vivo. However, very few reports have demonstrated that n-3 PUFAs induce HO-1 in vivo.     

硫稳定同位素技术在生态学研究中的应用

随着人为SO₂释放的增加, 硫稳定同位素的动态已成为生物地球化学循环过程中研究的热点。该文对天然硫稳定同位素在大气自然过程中的硫来源分析及其在森林生态系统、农田生态系统和水域生态系统中的硫动态研究, 人为添加的硫稳定同位素在生态环境中的应用及硫稳定同位素技术在我国酸雨研究中的潜在贡献等进行了综述, 并从硫稳定同位素技术应用研究的范围、分析手段及源解析模型方面介绍了可能的发展方向。     

Extracellular superoxide production, viability and redox poise in response to desiccation in recalcitrant Castanea sativa seeds

Reactive oxygen species (ROS) are implicated in seed death following dehydration in desiccation-intolerant 'recalcitrant' seeds. However, it is unknown if and how ROS are produced in the apoplast and if they play a role in stress signalling during desiccation. We studied intracellular damage and extracellular superoxide (O₂^·−) production upon desiccation in Castanea sativa seeds, mechanisms of O₂^·− production and the effect of exogenously supplied ROS. A transient increase in extracellular O₂^·− production by the embryonic axes preceded significant desiccation-induced viability loss. Thereafter, progressively more oxidizing intracellular conditions, as indicated by a significant shift in glutathione half-cell reduction potential, accompanied cell and axis death, coinciding with the disruption of nuclear membranes. Most hydrogen peroxide (H₂O₂)-dependent O₂^·− production was found in a cell wall fraction that contained extracellular peroxidases (ECPOX) with molecular masses of ∼50 kDa. Cinnamic acid was identified as a potential reductant required for ECPOX-mediated O₂^·− production. H₂O₂, applied exogenously to mimic the transient ROS burst at the onset of desiccation, counteracted viability loss of sub-lethally desiccation-stressed seeds and of excised embryonic axes grown in tissue culture. Hence, extracellular ROS produced by embryonic axes appear to be important signalling components involved in wound response, regeneration and growth.     

植物绿原酸的研究动态

阐述了近些年来国内外关于植物绿原酸所做的研究工作.植物绿原酸的提取、纯化、鉴定和药理活性及其应用开发所取得成果.揭示了绿原酸具有潜在的、广阔的应用前景.