Detection of <Emphasis Type="Italic">Xanthomonas oryzae</Emphasis> pv. <Emphasis Type="Italic">oryzae</Emphasis> in seeds using a specific TaqMan probe

Xanthomonas oryzae pv. oryzae is the pathogen that causes bacterial leaf blight in rice. Bacterial leaf blight is the main cause for severe rice underproduction in many countries. However, with conventional methods it is difficult to quickly and reliably distinguish this pathogen from other closely related pathogenic bacteria, especially X. oryzae pv. oryzicola, the causal organism of bacterial leaf streak in rice. We have developed a novel and highly sensitive real-time method for the identification of this specific bacteria based on a TaqMan probe. This probe is designed to recognize the sequence of a putative siderophore receptor gene cds specific to X. oryzae pv. oryzae, and can be identified from either a bacterial culture or naturally infected rice seeds and leaves in only 2 h. The sensitivity of the method is 100 times higher than that of the current polymerase chain reaction (PCR) gel electrophoresis method for diagnosis.     

绿盲蝽腹神经节的解剖结构

【目的】揭示绿盲蝽Apolygus lucorum腹神经节的组成结构。【方法】采用免疫组织化学染色方法,利用突触蛋白抗体对绿盲蝽成虫的腹神经节进行免疫标记,激光共聚焦扫描显微镜扫描照相获得原始数据,用图像分析软件进行标记,构建三维结构模型。【结果】绿盲蝽成虫腹神经节位于腹神经索的末端,与其前方的后胸神经节和中胸神经节紧密融合,形成后部神经节。与脑和胸神经节类似,腹神经节由周围的细胞体和内部的神经髓构成。腹神经节的神经纤维束主要包括位于腹侧的两条纵向神经连索和向两侧发出的9束神经纤维。9束神经纤维连接着9个神经原节,即富含突触联系的神经髓。这些神经原节紧密融合,无明显的边界,最后两节形成膨大的末端腹神经节。两侧的神经原节由横向的神经连锁连接起来。腹神经节外周的细胞体数量较多,排列紧密,大小一致,仅在前端背侧中间和后端腹侧中间位置分别有2个和5个体积较大的细胞体。【结论】本研究结果明确了绿盲蝽腹神经节的结构,为进一步研究昆虫的行为调控及神经系统发育和演化奠定一定的形态学基础。     

Role of the prostaglandin E2/E-prostanoid 2 receptor signalling pathway in TGFβ-induced mice mesangial cell damage

The prostaglandin E2 receptor, EP2 (E-prostanoid 2), plays an important role in mice glomerular MCs (mesangial cells) damage induced by TGFβ1 (transforming growth factor-β1); however, the molecular mechanisms for this remain unknown. The present study examined the role of the EP2 signalling pathway in TGFβ1-induced MCs proliferation, ECM (extracellular matrix) accumulation and expression of PGES (prostaglandin E₂ synthase). We generated primary mice MCs. Results showed MCs proliferation promoted by TGFβ1 were increased; however, the production of cAMP and PGE₂ (prostaglandin E₂) was decreased. EP2 deficiency in these MCs augmented FN (fibronectin), Col I (collagen type I), COX2 (cyclooxygenase-2), mPGES-1 (membrane-associated prostaglandin E1), CTGF (connective tissue growth factor) and CyclinD1 expression stimulated by TGFβ1. Silencing of EP2 also strengthened TGFβ1-induced p38MAPK (mitogen-activated protein kinase), ERK1/2 (extracellular-signal-regulated kinase 1/2) and CREB1 (cAMP responsive element-binding protein 1) phosphorylation. In contrast, Adenovirus-mediated EP2 overexpression reversed the effects of EP2-siRNA (small interfering RNA). Collectively, the investigation indicates that EP2 may block p38MAPK, ERK1/2 and CREB1 phosphorylation via activation of cAMP production and stimulation of PGE₂ through EP2 receptors which prevent TGFβ1-induced MCs damage. Our findings also suggest that pharmacological targeting of EP2 receptors may provide new inroads to antagonize the damage induced by TGFβ1.     

中国和美国红火蚁毒腺生物碱组分的比较分析

【目的】比较两个入侵地红火蚁Solenopsis invicta毒腺生物碱成分及相对含量的地区间差异。【方法】以在中国广东省惠州、 广州、 深圳、 东莞、 珠海和美国阿拉巴马州采集的红火蚁工蚁为材料, 用正己烷溶剂浸提48 h获得浸提液, 将浸提液进行硅胶柱层析分离, 用气相色谱-质谱联用仪（GC-MS）分析其所含的生物碱成分及其相对含量。【结果】红火蚁毒腺生物碱含顺式生物碱组分和反式生物碱组分。通过总离子图对比, 得到了7种顺式生物碱、 8种四氢吡啶和7种反式生物碱, 并计算得到这些组分的相对百分含量。【结论】中国广东省5个地区红火蚁生物碱组成无差别, 相对含量略有差异, 惠州种群和深圳种群差别最大, 其他地区间没有差别。中美两国入侵地的红火蚁种群生物碱成分种类无差别, 其各个组分之间相对含量略有差异, 美国阿拉巴马州种群与中国深圳种群各组分相对含量差别最大, 与中国广州种群差别最小。另外, 在检测的中国广东样品中, 只确认了红火蚁的存在, 提示杂合蚁与黑火蚁还未传入中国。     

Inhibiting gene expression of alpha3 nicotinic receptor in SH-SY5Y cells with the effects on APP metabolism and antioxidation in Alzheimer's disease

In order to examine the effects of alpha3 nicotinic acetylcholine receptor (nAChR) in connection with the pathogenesis of Alzheimer's disease (AD), neuroblastoma (SH-SY5Y) cells were transfected with small interference RNAs (siRNAs) that target specifically towards alpha3 nAChR. The expressions of alpha3 nAChR mRNA and protein were measured by real-time PCR and Western blotting, respectively. The levels of the alpha-form of secreted amyloid precursor protein (alphaAPPs) and total-APP were determined by Western blotting. SH-SY5Y cells transfected with siRNA were then treated with 1muM beta-amyloid peptide (Abeta)(1-42), following which the levels of lipid peroxidation, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the reduction rate of MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] were characterized by utilizing spectrophotometric procedures. As compared to controls, SH-SY5Y cells transfected with siRNA expressed the decreases in the levels of alpha3 nAChR mRNA and protein by 98% and 66% lower levels, respectively; exhibited reduced level of the alphaAPPs; and demonstrated enhanced lipid peroxidation, decreased rate of MTT reduction, and declined activities of SOD and GSH-Px. Inhibited gene expression of the alpha3 nAChR enhanced the toxicity exerted by Abeta. These results indicate that alpha3 nAChR may improve cleavage of APP by alpha-secretase, enhance antioxidation and inhibit the toxicity of Abeta, suggesting that the receptor might play an important role in AD.     

牛疱疹病毒Ⅰ型VP22和猪繁殖与呼吸综合征病毒GP5融合基因DNA疫苗的免疫效应

为了提高表达GP5的猪繁殖与呼吸综合征病毒（PRRSV）DNA疫苗的免疫效应,将具有蛋白转导功能的牛疱疹病毒1型（BHV-1）VP22基因插入到经过修饰具有更好免疫原性的PRRSV修饰型ORF5基因（ORF5M）上游,构建VP22和ORF5M融合表达的真核表达质粒pCI-VP22-ORF5M。经间接免疫荧光试验（IFA）和Westernblot检测证实体外表达后,免疫BALB/c小鼠,检测小鼠免疫后的GP5特异性ELISA抗体、抗PRRSV中和抗体和脾淋巴细胞增殖反应,并与非融合的真核表达质粒pCI-ORF5M进行比较。结果显示,融合表达VP22-GP5的DNA疫苗 pCI-VP22ORF5M诱导的体液免疫和细胞免疫反应均明显高于非融合表达的DNA疫苗pCI-ORF5M,表明蛋白转导相关蛋白BHV-1 VP22能显著增强表达GP5的PRRSV DNA 疫苗的免疫效应,有效发挥了基因免疫佐剂效应;这为研制PRRSV高效DNA疫苗奠定了基础,同时也为其它疾病的高效新型疫苗研究提供了思路。     

两种种植体系下地下水硝态氮含量变化

寿光作为全国闻名的保护地蔬菜产区,过量施肥的现象非常普遍。为了解集约化大棚蔬菜种植区地下水中硝酸盐的含量变化状况,于2003～2005年对寿光市大田（小麦-玉米）、大棚（一年两茬番茄）两种不同的种植体系下农田灌溉水和农村饮用水水井进行了定点跟踪监测。结果表明：大田区地下水中硝态氮的含量随着时间的变化波动很小,农村饮用水中硝态氮含量没有超标现象;随着时间推移,大棚区灌溉水井中硝态氮含量年内（从年初到年末）呈明显的上升趋势,年际间则存在有规律的波动并逐年升高;灌溉水中硝态氮平均含量普遍高于饮用水,浅层地下水明显高于深层地下水;无论大棚区还是大田区,井深不同对地下水的硝态氮含量影响差异很大,浅井中硝态氮的含量明显高于深井。大棚区农村饮用水硝态氮含量超标现象非常普遍,对国家饮用水标准（20mg&#183;L^-1）超标率最高达37.50%,平均为14.06%;对WHO推荐饮用水上限（10mg&#183;L^-1）超标率最高达56.25%,平均为42.19%,硝态氮最高含量45.60mg&#183;L^-1。集约化大棚蔬菜栽培模式已经对农村地下水造成了很大的硝态氮污染,饮用水中较高的硝酸盐含量已经对当地居民的健康构成了潜在的威胁。     

The Roles of Auxin in Regulating “Shoot Branching” of Cremastra appendiculata

Cremastra appendiculata (D. Don) Makino is a mainly vegetative propagation terrestrial orchid that is a typical representative of the warm-temperate vegetation in China. In this experiment, we investigated the growth and development process of C. appendiculata leaf buds and examined their biochemical components (proteins, auxin, and cytokinin) to gain insight into the “shoot branching” of C. appendiculata pseudobulb string. The results showed that the metabolic activity of C. appendiculata pseudobulbs became lower with the increase of pseudobulb age. However, biennial and triennial pseudobulbs have higher auxin levels than annual pseudobulbs in the intact plant (P < 0.05). After decapitation, the auxin rapidly reduces in biennials. The reduction of auxin level promotes cytokinin biosynthesis, which makes the biennial dormant buds start to germinate 18 days after decapitation. These data and phenomena suggested that auxin plays important roles in regulating shoot branching of C. appendiculata, although further studies are needed to consolidate this viewpoint. Our data indirectly support the classical apical dominance theory whereby biennial pseudobulbs are strongly dependent on reduced auxin to initiate leaf bud outgrowth.

     

甘草属种间杂交种叶绿体DNA父系遗传的发现及分析

通过对甘草属乌拉尔甘草(Glycyrrhiza uralensis)、光果甘草(G.glabra)、胀果甘草(G.inflata)及其人工杂交种组合G.uralensis♀×G.glabra♂、G.glabra♀×G.uralensis♂、G.uralensis♀×G.inflata♂、G.inflata♀×G.uralensis♂共68份材料的核基因ITS序列、叶绿体rbc L、mat K、trn H-psb A基因的序列分析,探讨了甘草属叶绿体DNA遗传方式。结果表明:(1)亲本种和人工杂交种ITS序列长度均为614 bp,其中34份人工杂交种ITS序列存在4处变异位点,且人工杂交种均检测出来自父本、母本ITS序列相同位点碱基的叠加,检测率为100%。(2)亲本种与人工杂交种的叶绿体基因rbc L、mat K、trn H-psb A序列长度相同,共有4处变异位点,人工杂交种在变异位点处的碱基与其相对应的父本碱基一致率高达97.1%。以上结果说明,该研究获得34份人工杂交种为100%杂交成功的F_1子代,核基因ITS序列可用于甘草属杂交种的遗传鉴定;甘草属叶绿体rbcL、mat K、trn H-psb A基因具有父系遗传特性,推测甘草属质体的遗传方式主要表现为父系遗传,这种质体遗传方式的发现为甘草属杂交种和遗传多样性研究提供了新的认识,也为杂交种的亲本鉴定提供分子依据。     

干旱胁迫对不同基质网袋桢楠幼苗生长及生物量的影响

探讨不同育苗基质下桢楠（Phoebe zhennan）苗木对周期性干旱胁迫的适应能力及生存对策,为筛选抗旱育苗基质提供参考。以耕作土、森林腐殖土、泥炭土、蛭石为原料,按体积比配制成5种育苗基质,T1：耕作土=10（传统桢楠育苗）、T2：森林腐殖土=10、T3：耕作土：森林腐殖土：泥炭土：蛭石=4：3：2：1、T4：耕作土：森林腐殖土：泥炭土：蛭石=3：2：4：1、T5：耕作土：森林腐殖土：泥炭土：蛭石=2：1：6：1,采用随机区组设置干旱胁迫梯度,分析不同胁迫水平对桢楠幼苗生长的影响。结果表明：（1）配比基质的理化性质与苗木生长密切相关,正常浇水时,基质处理苗生长质量均优于传统育苗,但重度胁迫下,仅T3、T4处理苗木生长较好;（2）随着干旱胁迫程度的增加,各基质配比桢楠苗木株高、基径、叶面积、叶面积指数、地上生物量、地下生物量等生长指标均受到抑制,但受影响程度存在差异;（3）各基质处理苗木质量隶属函数值T3 > T4=T1 > T2 > T5,T3基质配比最优,所育苗木生长优良,耐旱抗旱性强,显著提高造林成效。表明适宜的基质配比能够协调植物生长所需的水、肥、气、热,有利于植物在逆境中生存。