Antimicrobial effects of black rice extract on Helicobacter pylori infection in Mongolian gerbil

It has been reported that cyanidin 3-O-glucoside (C3G) is an inhibitor of Helicobacter pylori toxin secretion. C3G is classified as an anthocyanin and is a major component of black rice extract (BRE). The present study aimed to identify a new functional food material to prevent H. pylori infection in Mongolian gerbil model. Toxicity in the liver and kidney were not detected after BRE administration (10 or 50 mg/kg). BRE treatment reduced bacterial colonization in animal gastric tissue, as well as infection signs as observed on the analysis of the hematological data. It was also found that the relative mRNA levels of the inflammatory cytokines were reduced in BRE-treated groups. These findings suggest that BRE acts as a potent inhibitor of H. pylori infection and pathogenesis in Mongolian gerbils. We propose that BRE may be used to manage gastroduodenal diseases caused by H. pylori infection.     

不同性别湖羊生长激素分泌特点的比较

6 头装有颈静脉插管的成年湖羊,雌雄各半,按性别分组,间隔 15 min 连续采取 3 h 的血样,用放射免疫分析法研究了不同性别湖羊生长激素的分泌特点。结果显示成年湖羊的生长激素呈脉冲式分泌;与雌性相比,雄性湖羊生长激素的总体水平高 179．60％(P＜0．01),基线水平高 124．84％(P＜0．01),峰强度高 272．80％(P＜0．01),3 h 峰频率则高一倍(P＜0．01)、而峰持续时间基本不变。以上结果表明湖羊生长激素的分泌有性别的差异,雄性湖羊生长激素分泌的量比雌性湖羊生长激素分泌的量高。     

水稻根系泌氧对水稻土磷素化学行为的影响

通过模拟试验研究了水稻根系泌氧作用对水稻土磷素化学行为以及水稻吸磷的影响。淹水极显著地增加土壤对磷的吸附,降低磷的解吸。而模拟的水稻泌氧作用则可明显降低土壤对磷的吸附,增加根际土壤的磷解吸和离子交换树脂对磷的吸收量。因此,水稻根系的泌氧作用应该是水稻在淹水明显降低土壤磷有效性情况下能正常从土壤获取磷的重要机制之一。淹水导致土壤磷有效性降低与淹水引起土壤磷组分转化有关。淹水2周,经富磷预处理而增加的Al-P组分,几乎全被转化为Fe-P。     

Nectar secretion of RN-type cytoplasmic male sterility three lines in soybean [Glycine max (L.) Merr.]

Significant progress has been achieved in the use of heterosis in soybean and several soybean hybrids have been released in China. However, broad use of hybrid soybean seed is limited due to low seed setting of female parents. Breeding cytoplasmic male sterile(CMS) lines with high out-crossing rate is necessary to solve the problem. The objective of this study was to determine the relationship between out-crossing rate of CMS lines and their nectar secretion. The daily nectar secretion rhythm, meteorological effect on nectar secretion, and differences in nectar secretion among genotypes and years were investigated in 27 soybean CMS lines(A-lines) with their maintainers(B-lines) and restorers(R-lines). The correlation between out-crossing rate of CMS lines and nectar production was also evaluated. Nectar secretion had diurnal variation. Secretion initiated at about 06:00 for most materials and reached a peak at 07:00–08:30 after flower opened, then the nectar secretion decreased gradually. A sub-peak appeared at about 13:00, while the nectar could not be detected at 17:00. Nectar secretion was greatly influenced by the weather conditions. The amount of nectar secretion increased gradually over time during periods of high temperature and no rainfall for several days. Rainy weather and low temperatures inhibited nectar secretion. There were obvious variations of nectar amount among different genotypes tested. Significant nectar variation within a genotype among years was also observed, and the highest nectar secretion was 3-fold higher than the lowest. The amount of nectar secretion from R-lines was significantly higher than that of A-and B-lines. There was no significant difference in nectar secretion between A-and B-lines. A-and B-lines with higher out-crossing rates secreted more nectar. The amount of nectar secretion of A-and B-lines were significantly positively correlated with the out-crossing rate of A-lines.     

小麦条锈菌果胶酶基因PsPL1的克隆与功能分析

【目的】研究小麦条锈菌果胶酶基因PsPL1的功能,确定其在小麦条锈菌侵染过程中的作用,为揭示小麦与病原菌互作的分子机理奠定理论基础。【方法】利用RACE技术扩增PsPL1基因全长,通过qRT-PCR对PsPL1的表达特征进行分析,并在酵母系统中验证其编码蛋白信号肽的分泌功能,最后通过HIGS技术沉默PsPL1基因,确定其在条锈菌侵染小麦过程中的作用。【结果】克隆得到PsPL1基因全长,其ORF长471bp,编码157个氨基酸;经预测PsPL1蛋白包含一个果胶酶保守结构域,N端含有一段由21个氨基酸组成的信号肽序列;经酵母系统验证,确定PsPL1蛋白信号肽具有分泌功能;qRT-PCR分析发现,PsPL1在条锈菌侵染早期表达上调;利用HIGS技术沉默PsPL1基因后,条锈菌的产孢量没有发生明显变化。【结论】成功克隆了小麦条锈菌果胶酶基因PsPL1,明确了其分泌特性及表达特征。     

猪胸膜肺炎放线杆菌Ⅱ型分泌蛋白结构与功能的研究

猪胸膜肺炎放线杆菌(APP)引起猪传染性胸膜肺炎,是猪的最重要呼吸道传染病之一。通过筛选APP 3～8 kb随机基因组文库,获得1株阳性克隆。测序拯救质粒得到序列,通过BLAST分析确定此片段为APP Ⅱ型分泌蛋白基因,预计成熟蛋白分子量为45.716 KD。根据序列设计特异性引物PCR扩增该基因,分子克隆表达该Ⅱ型分泌蛋白。Western blot结果表明,该蛋白与APP康复期血清发生反应;研究还发现,纯化的Ⅱ型分泌蛋白能结合C3。     

侧孢芽孢杆菌2-Q-9外泌抑菌物质性质

侧孢芽孢杆菌(Bacillus laterosporus)菌株2-Q-9分泌的抑菌物质能强烈抑制青枯病菌的3个生理小种的正常生长.为了进一步在生产上利用该抑菌物质,就该抑菌物质的性质进行了初步研究.结果表明,该抑菌物质经高温处理后性质稳定;在碱性条件下比酸性条件下稳定;对胰蛋白酶和蛋白酶K不敏感,对胃蛋白酶部分敏感;该抑菌物质可能为蛋白或多肽类物质.     

半胱胺对湖羊生长激素分泌特点的影响半胱胺对湖羊生长激素分泌特点的影响

对4只装有颈静脉导管的成年湖羊(自身对照)按60mg／kg     

不同作物根系分泌物对黄瓜的化感作用

就不同作物根系分泌物溶液对黄瓜种子和黄瓜幼苗的化感作用进行了研究。结果表明,油菜、玉米、小麦和小白菜对黄瓜种子发芽势和发芽率的抑制作用均较低;除玉米根系分泌物溶液外,其余作物根系分泌物溶液均抑制黄瓜种子胚根和胚芽生长,且胚芽的受抑制强度大于胚根;玉米、油菜、小白菜和黄瓜根系分泌物溶液对黄瓜幼苗苗高和茎粗有促进作用,且对黄瓜幼苗根长和根数的抑制作用较小。说明玉米是黄瓜种植最适宜的前茬作物,其次是油菜和小白菜,而豇豆、豆角和黑豆等豆科作物不宜作为黄瓜种植的前茬作物。     

无乳链球菌研究进展

VII型分泌系统存在于无乳链球菌 (Streptococcus agalactiae) 中,其组成膜蛋白对底物蛋白的分泌转运至关重要。为此利用热敏型自杀质粒,构建了含氯霉素筛选标签的膜蛋白重组敲除载体pSET4s-ΔessA、pSET4s-ΔessB、pSET4s-ΔessC,经同源重组后,利用PCR技术筛选到了其缺失突变株-无乳链球菌ΔessA、ΔessB、ΔessC。通过菌株生长曲线分析,ΔessA、ΔessB、ΔessC敲除株均较野生株 (WT) 生长过程变慢,其中ΔessA、ΔessB敲除株在生长早期有显著性差异 (P<0.01)。对ESAT6蛋白分泌影响分析显示,与WT株相比,ΔessA、ΔessB、ΔessC敲除株ESAT6的表达量均显著下调 (P<0.01)。结果显示,ΔessA、ΔessB、ΔessC敲除株均较WT株毒力显著降低 (P<0.01)。研究表明,essA、essB、essC为无乳链球菌VII型分泌系统重要的膜蛋白,其基因缺失造成了分泌蛋白ESAT6 mRNA表达水平下降,影响了菌株毒力。