乌蕨的研究进展

概述了民间药用植物乌蕨的形态特征和资源分布情况,综述了国内外对乌蕨的药理药效作用、化学成分的研究进展。乌蕨对小鼠砷中毒、乐果中毒具有解毒作用,对小鼠CCl4肝损伤具防治作用,可治疗家畜肝炎,临床上治疗腹泻、下肢顽固性溃疡、慢性肾衰等疾病取得了显著疗效,乌蕨具有抗菌活性,对酪氨酸酶活性有一定抑制作用。乌蕨对小鼠基本无毒。乌蕨含有黄酮类化合物,已从叶分离得到牡荆素(Vitexin)、丁香酸(Syringic acid)、原儿茶醛(Protocatechualdehyde)和原儿茶酸(Protocatechuic acid)。提出应当对乌蕨药效的物质基础进行深入研究,另一方面还应研究其引种栽培技术,为开发利用这一植物资物资源建立基础。     

SP500263, a novel SERM,blocks osteoclastogenesis in a human bone cell model: role of IL-6 and GM-CSF

Bone metabolism requires tightly coupled activities exhibited by two unique cell populations, the bone-resorbing osteoclasts and the bone-forming osteoblasts. Imbalance in the function of these two cell types can result in osteoporosis, a condition characterized by loss in bone integrity and of bone mass. We developed a human bone cell culture model that allows the in vitro study of bone formation and osteoclastogenesis and employed this bone model for the screening and pharmacological analyses of protein and small molecule therapeutics. The cytokines, interleukin-6 (IL-6) and granulocyte macrophage colony stimulating factor (GM-CSF), play an intricate role in osteoclastogenesis in this system. Neutralizing antibodies to IL-6 and GM-CSF decreased the formation of osteoclast-like cells. SP500263, an early lead compound from a novel class of selective estrogen receptor modulators (SERMs), was more efficacious than estrogen and comparable to raloxifene in blocking cytokine production and formation of osteoclast-like cells. Our research demonstrates the usefulness of the in vitro co-culture model in the dissection of molecular events relevant to bone metabolism and provides greater insight into a potential novel role for cytokines in bone resorption. Furthermore, representatives of the SP500263 family of SERMs may be effective as therapeutics for the treatment of osteoporosis.     

Use of an immunoaffinity column for tetrachlorodibenzo-p-dioxin serum sample cleanup

Covalently linking 1-amino-3,7,8-trichlorodibenzo-p-dioxin with either keyhole limpet hemocyanin (KLH) or bovine serum albumin (BSA) provided antigens that generated antibodies in chickens. Competitive ELISA analysis demonstrated that the antibodies isolated from egg yolk (IgY) bound with 1,3,7,8-tetrachlorodibenzo-p-dioxin (1,3,7,8-TCDD). The antibodies were linked to CNBr-Sepharose to generate an immunoaffinity column. Radiolabeled 1,3,7,8-TCDD in a 0.05% Tween 20 solution was retained by the column and could be eluted by increasing the Tween 20 concentration. The binding efficiency for 10.7 ng per ml gel matrix ranged from 85 to 97%. Immunoaffinity columns generated by this method did not effectively bind ¹⁴C-1,3,7,8-TCDD from serum samples. Diluting the serum 1:20 with 0.05% Tween 20 increased the binding efficiency. Alternately, ethanol–hexane extraction followed by solid phase extraction on a carbon column using a fat removal protocol also provided an appropriate preaffinity column cleanup for serum samples. After this preaffinity column cleanup, spiked serum samples applied to the immunoaffinity column showed binding efficiencies of over 90%.     

A new film for the fabrication of an unmediated H2O2 biosensor

A novel and stable film made from polyethylene glycol (PEG) on pyrolytic graphite (PG) electrode was presented in this paper for incorporating horseradish peroxidase (HRP) to study the direct electrochemistry of the enzyme. In PEG film, HRP showed a thin-layer electrochemistry behavior. The apparent standard potential (E degrees ') was -0.379 V versus SCE at pH 7.2. Moreover, the PEG-HRP modified electrode exhibited excellent electrocatalytical response to the reduction of H2O2 with a calibration range between 2.0 x 10(-6) and 6.0 x 10(-4) M and a good linear relation from 2.0 x 10(-6) to 1.0 x 10(-4) M, on which an unmediated H2O2 biosensor was based. The detection limit of 6.7 x 10(-7) M was estimated when the signal-to-noise ratio was 3. The relative standard deviation (R.S.D.) was 4.7% for six successive determinations at a concentration of 4.0 x 10(-5) M. The apparent Michaelis-Menten constant (Km app) of the sensor was found to be 1.38 mM. Epinephrine, dopamine, and ascorbic acid did not interfere with the sensitive determination of H2O2.     

Synthesis and characterization of thermo-sensitive semi-IPN hydrogels based on poly(ethylene glycol)-co-poly(ε-caprolactone) macromer, N-isopropylacrylamide, and sodium alginate

Thermo-sensitive semi-IPN hydrogels were prepared via in situ copolymerization of N-isopropylacrylamide (NIPAAm) with poly(ethylene glycol)-co-poly(ε-caprolactone) (PEG-co-PCL) macromer in the presence of sodium alginate by UV irradiation technology. The effects of the sodium alginate content, temperature, and salt on the swelling behavior of the as-obtained hydrogels were studied. The results showed that the swelling ratio of the hydrogels increased with the increasing sodium alginate content at the same temperature, and decreased with the increase in temperature. The salt sensitivity of the semi-IPN hydrogels was dependent on the content of sodium alginate introduced in the hydrogels. The mechanical rheology of the hydrogels and in vitro release behavior of bovine serum albumin (BSA) in situ encapsulated within the hydrogels were also investigated. It was found that the introduction of sodium alginate with semi-IPN structure improved mechanical strength of the hydrogels and the cumulative release percentage of BSA from the hydrogels. Such double-sensitive semi-IPN hydrogel materials could be exploited as potential candidates for drug delivery carriers.     

A nonspecific lipid transfer protein,StLTP10, mediates resistance to Phytophthora infestans in potato

Nonspecific lipidtransfer proteins (nsLTPs), which are small, cysteine-rich proteins, belong to the pathogenesis-related protein family, and several of them act as positive regulators during plant disease resistance. However, the underlying molecular mechanisms of these proteins in plant immune responses are unclear. In this study, a typical nsLTP gene, StLTP10, was identified and functionally analysed in potato. StLTP10 expression was significantly induced by Phytophthora infestans, which causes late blight in potato, and defence-related phytohormones, including abscisic acid (ABA), salicylic acid, and jasmonic acid. Characterization of StLTP10-overexpressing and knockdown lines indicated that StLTP10 positively regulates plant resistance to P. infestans. This resistance was coupled with enhanced expression of reactive oxygen species scavenging- and defence-related genes. Furthermore, we identified that StLTP10 physically interacts with ABA receptor PYL4 and affects its subcellular localization. These two proteins work together to regulate stomatal closure during pathogen infection. Interestingly, we also found that wound-induced protein kinase interacts with StLTP10 and positively regulates its protein abundance. Taken together, our results provide insight into the role of StLTP10 in resistance to P. infestans and suggest candidates to enhance broad-spectrum resistance to pathogens in potato.     

NaCl胁迫对滨梅扦插苗生物量和水分积累的影响

以1年生滨梅(Prunus maritima Marshall)扦插苗为实验材料,在盆栽条件下用质量浓度为0.15%、0.29%、0.58%、0.88%、1.17%、1.46%的NaCl溶液进行盐胁迫处理,测定胁迫后根、茎、叶Na+、K+含量以及全叶、一年生茎、二年生茎和根系生物量、含水率、根系活力变化,探讨滨梅的抗盐胁迫机制。结果显示:(1)盐胁迫80d后,随着盐胁迫强度提高,滨梅植株根、茎、叶Na+含量显著提高,而其根、茎K+含量显著降低,根、茎、叶K+/Na+值显著降低;根Na+含量在低于0.58%NaCl胁迫下显著高于茎、叶,而在高于0.58%NaCl胁迫下却表现为叶Na+含量显著高于根、茎。(2)滨梅根、茎、叶生物量均随盐胁迫强度的提高呈先增加后减少的趋势;随着盐胁迫时间的延长,茎、叶生物量在低于0.58%NaCl胁迫下均呈积累趋势,且茎生物量在0.58%NaCl胁迫下显著提高,而根、一年生茎、叶生物量在高于0.58%NaCl胁迫下均显著下降。(3)滨梅茎、叶含水率均随盐胁迫强度的增加呈先增加后减少的趋势,而随着胁迫时间的延长呈逐渐减少趋势;根系活力及根含水率均随盐胁迫强度的提高而增加,但根含水率随着胁迫时间的延长变化不明显。由此可见,滨梅能通过根系稀释并蓄积Na+,保护地上部分正常生长,当进入根系的Na+量超过吸收阈值时,Na+迅速在叶中积累储存,且叶中较高含量的K+对Na+形成了有效的缓冲。     

Small brown planthopper resistance loci in wild rice (Oryza officinalis)

Host-plant resistance is the most practical and economical approach to control the rice planthoppers. However, up to date, few rice germplasm accessions that are resistant to the all three kinds of planthoppers (1) brown planthopper (BPH; Nilaparvata lugens Stål), (2) the small brown planthopper (SBPH; Laodelphax striatellus Fallen), and (3) the whitebacked planthopper (WBPH, Sogatella furcifera Horvath) have been identified; consequently, the genetic basis for host-plant broad spectrum resistance to rice planthoppers in a single variety has been seldom studied. Here, one wild species, Oryza officinalis (Acc. HY018, 2n = 24, CC), was detected showing resistance to the all three kinds of planthoppers. Because resistance to WBPH and BPH in O. officinalis has previously been reported, the study mainly focused on its SBPH resistance. The SBPH resistance gene(s) was (were) introduced into cultivated rice via asymmetric somatic hybridization. Three QTLs for SBPH resistance detected by the SSST method were mapped and confirmed on chromosomes 3, 7, and 12, respectively. The allelic/non-allelic relationship and relative map positions of the three kinds of planthopper resistance genes in O. officinalis show that the SBPH, WBPH, and BPH resistance genes in O. officinalis were governed by multiple genes, but not by any major gene. The data on the genetics of host-plant broad spectrum resistance to planthoppers in a single accession suggested that the most ideally practical and economical approach for rice breeders is to screen the sources of broad spectrum resistance to planthoppers, but not to employ broad spectrum resistance gene for the management of planthoppers. Pyramiding these genes in a variety can be an effective way for the management of planthoppers.     

利用简并引物克隆黑莓、树莓肌动蛋白基因片段及表达分析

采用同源克隆法,利用设计的一对肌动蛋白(actin)基因简并引物,从黑莓、树莓和悬钩子杂种3个悬钩子植物品种均得到一条743 bp的actin cDNA片段,推测编码247个氨基酸.序列比对发现,克隆的actin基因推导的氨基酸序列和其他植物的肌动蛋白氨基酸序列具有高度保守性,经数据库搜索后将来自黑莓和树莓品种的actin cDNA片段在GenBank中登录,登录号分别为HQ439558和HQ439559.不同来源的植物actin蛋白系统进化树的聚类结果表明,树莓和悬钩子杂种亲缘关系较为密切.actin基因在3个悬钩子植物品种不同组织中的RT-PCR分析结果表明,其在检测的不同组织中均有一定程度的表达量,可能都属于组成型表达的肌动蛋白基因.研究结果为利用actin基因作为内参进一步研究黑莓和树莓其他基因的丰度奠定基础.