Changes in phosphatidylinositol metabolism in response to hyperosmotic stress in Daucus carota L. cells grown in suspension culture.

Carrot (Daucus carota L.) cells plasmolyzed within 30 s after adding sorbitol to increase the osmotic strength of the medium from 0.2 to 0.4 or 0.6 osmolal. However, there was no significant change in the polyphosphorylated inositol phospholipids or inositol phosphates or in inositol phospholipid metabolism within 30 s of imposing the hyperosmotic stress. Maximum changes in phosphatidylinositol 4-monophosphate (PIP) metabolism were detected at 5 min, at which time the cells appeared to adjust to the change in osmoticum. There was a 30% decrease in [3H]inositol-labeled PIP. The specific activity of enzymes involved in the metabolism of the inositol phospholipids also changed. The plasma membrane phosphatidylinositol (PI) kinase decreased 50% and PIP-phospholipase C (PIP-PLC) increased 60% compared with the control values after 5 min of hyperosmotic stress. The PIP-PLC activity recovered to control levels by 10 min; however, the PI kinase activity remained below the control value, suggesting that the cells had reached a new steady state with regard to PIP biosynthesis. If cells were pretreated with okadaic acid, the protein phosphatase 1 and 2A inhibitor, the differences in enzyme activity resulting from the hyperosmotic stress were no longer evident, suggesting that an okadaic acid-sensitive phosphatase was activated in response to hyperosmotic stress. Our work suggests that, in this system, PIP is not involved in the initial response to hyperosmotic stress but may be involved in the recovery phase.     

肝胆显像螯合物—氮基三乙酸单酰苯胺及其类似物的合成

本课题合成四个氮基三乙酸单酰苯胺(IDA)类及其类似物肝胆显像螯合物。(1)用家兔做了肝胆显像扫描实验,其显像效果较好。(2)～(3)为未见报道的化合物。     

Localization of the Functional p34cdc2 Homolog of Maize in Root Tip and Stomatal Complex Cells: Association with Predicted Division Sites

We have used an antibody against the functional homolog of the cdc2 kinase of maize to localize the p34cdc2 protein within dividing cells of the root apex and the stomatal complex of leaf epidermis. The microtubule cytoskeletal structure of plant cells was visualized concomitantly with a monoclonal antibody specific for [alpha]-tubulin. We found that the cdc2 protein is localized mainly to the nucleus in plant cells at interphase and early prophase. This finding contrasts markedly with the predominantly cytoplasmic staining obtained using antibody to the PSTAIRE motif, which is common to cdc2 and numerous cdc2-like proteins. In a subpopulation of root cells at early prophase, the p34cdc2 protein is also distributed in a band bisecting the nucleus. Double labeling with the maize p34cdc2Zm antibody and tubulin antibody revealed that this band colocalizes with the preprophase band (PPB) of microtubules, which predicts the future division site. Root cells in which microtubules had been disrupted with oryzalin did not contain this band of p34cdc2 protein, suggesting that formation of the microtubule PPB is necessary for localization of the p34cdc2 kinase to the plane of the PPB. The p34cdc2 protein is also localized to the nucleus and PPB in cells that give rise to the stomatal complex, including those cells preparing for the highly asymmetrical divisions that produce subsidiary cells. Association of the p34cdc2 protein with the PPB suggests that the cdc2 kinase has a role in establishing the division site of plant cells and, therefore, a role in plant morphogenesis.     

高砷含水层参与腐殖酸-铁矿物转化的关键微生物群落及其对砷迁移转化的影响

【目的】探究不同腐殖酸浓度下参与含砷水铁矿转化的微生物类群组成和丰度变化及对砷释放的影响,预测原位高砷含水层中功能微生物群参与有机质—含砷铁矿物转化过程对砷转化释放的作用。【方法】对河套平原高砷地下水和同深度高砷沉积物中的铁还原功能群落进行富集培养,构建室内厌氧微宇宙体系,将富集菌群分别加入到实验室条件下合成的不同浓度腐殖酸(0、1.5、7、14 mg C/L)-含砷水铁矿体系中,通过体系中砷、铁形态及浓度的变化分析,结合高通量测序技术、X-射线衍射(X-ray diffractometer, XRD),探究不同条件下砷的释放固定和群落的演替。【结果】高砷地下水组(G组)和沉积物组(S组)富集得到的铁还原功能群落具有明显差异,G组中以Aeromonadaceae为特殊优势菌群,而S组中以Shewanellaceae为特殊优势菌群。微宇宙实验结果显示,S组的铁还原量相对较高且速率较快;G组与S组中液相砷形态存在明显差异,整个培养期内G组均以As(Ⅴ)为主,而S组中前期以As(Ⅴ)为主,当反应到达20 d时液相As(Ⅲ)高达3.4μmol/L,推测此时具有砷还原功能的群落占优势地位。当反应...     

Fine-scale mapping of physicochemical and microbial landscapes of the coral skeleton

The coral skeleton harbours a diverse community of bacteria and microeukaryotes exposed to light, O₂ and pH gradients, but how such physicochemical gradients affect the coral skeleton microbiome remains unclear. In this study, we employed chemical imaging of O₂ and pH, hyperspectral reflectance imaging and spatially resolved taxonomic and inferred functional microbiome characterization to explore links between the skeleton microenvironment and microbiome in the reef-building corals Porites lutea and Paragoniastrea benhami. The physicochemical environment was more stable in the deep skeleton, and the diversity and evenness of the bacterial community increased with skeletal depth, suggesting that the microbiome was stratified along the physicochemical gradients. The bulk of the coral skeleton was in a low O₂ habitat, whereas pH varied from pH 6–9 with depth. Physicochemical gradients of O₂ and pH of the coral skeleton explained the β-diversity of the bacterial communities, and skeletal layers that showed O₂ peaks had a higher relative abundance of endolithic algae, reflecting a link between the abiotic environment and the microbiome composition. Our study links the physicochemical, microbial and functional landscapes of the coral skeleton and provides new insights into the involvement of skeletal microbes in the coral holobiont metabolism.     

Intracellular distribution of the hydrophobic triterpene,bryonolic acid,in cultured cells of Luffa cylindrica L.

Summary Intracellular localization of bryonolic acid, an antiallergic pentacyclic triterpene, in cultured cells of Luffa cylindrica was investigated with reference to the sites of its biosynthesis and accumulation. The results of cell fractionation showed that bryonolic acid was mostly located in the cell wall fraction. The addition of FC-43 emulsion to the culture medium was found to cause the release of bryonolic acid from the cell wall into the medium without affecting cell growth and bryonolic acid production. Under this culture condition, ¹⁴C-labeled sodium acetate administered to the cells was rapidly incorporated into bryonolic acid which was then excreted into the medium within 10 min after administration. Electron microscopic observations suggested that spherical vesicles (ca 0.1 m in diameter) derived from the rough endoplasmic reticulum may be associated with the biosynthesis and excretion of this compound into the cell wall. Furthermore, the activity of 2,3-oxidosqualene cyclase, a key enzyme involved in the biosynthesis of bryonolic acid, was detected in the microsomal fraction containing the endoplasmic reticulum.Abbreviations BA bryonolic acid - ER endoplasmic reticulum - LS Linsmaier-Skoog - NAA 1-naphthaleneacetic acid - MES 2-(N-morpholino)ethanesulfonic acid - PVPP polyvinyl polypyrrolidone     

New branched Porolithon species (Corallinales,Rhodophyta) from the Great Barrier Reef,Coral Sea,and Lord Howe Island

Porolithon is one of the most ecologically important genera of tropical and subtropical crustose (non-geniculate) coralline algae growing abundantly along the shallow margins of coral reefs and functioning to cement reef frameworks. Thalli of branched, fruticose Porolithon specimens from the Indo-Pacific Ocean traditionally have been called P. gardineri, while massive, columnar forms have been called P. craspedium. Sequence comparisons of the rbcL gene both from type specimens of P. gardineri and P. craspedium and from field-collected specimens demonstrate that neither species is present in east Australia and instead resolve into four unique genetic lineages. Porolithon howensis sp. nov. forms columnar protuberances and loosely attached margins and occurs predominantly at Lord Howe Island; P. lobulatum sp. nov. has fruticose to clavate forms and free margins that are lobed and occurs in the Coral Sea and on the Great Barrier Reef (GBR); P. parvulum sp. nov. has short (<2 cm), unbranched protuberances and attached margins and is restricted to the central and southern GBR; and P. pinnaculum sp. nov. has a mountain-like, columnar morphology and occurs on oceanic Coral Sea reefs. A rbcL gene sequence of the isotype of P. castellum demonstrates it is a different species from other columnar species. In addition to the diagnostic rbcL and psbA marker sequences, the four new species may be distinguished by a combination of features including thallus growth form, margin shape (attached or unattached), and medullary system (coaxial or plumose). Porolithon species, because of their ecological importance and sensitivity to ocean acidification, need urgent documentation of their taxonomic diversity.     

A Rapid Determination of 30 Prohibited Pesticide Residues in Lycii Fructus by UPLC-MS/MS

Prohibited pesticide residues have become one of the main factors affecting the quality and safety of Lycii Fructus, However, rarely studies focus on the rapid determination of these residues. Here, a total of 30 kinds of prohibited pesticide residues were determined by ultra-performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC-MS/MS) in five different process ways. Pretreatment methods, chromatographic separation and detection conditions in mass spectrometry were all optimized accordingly. Among the five different pretreatment methods, the first and third solid phase extraction failed to provide high recoveries of sulfosulfuron compounds (both lower than 60%). Recovery of chlorphenamidine by the Quick Easy Cheap Effective Rugged and Safe multiresidue method (QuEChERS) was lower than 60%, which did not meet the requirements of trace determination. The concentrations of 30 prohibited pesticides residues treated by straightforward and solid phase extraction showed good linearity in their corresponding ranges, with correlation coefficients over 0.99. The average recoveries of straightforward ranged from 78.13% to 110.9%, while RSD ranged from 1.3% to 16.9%, albeit poor purification was observed. The recovery yield from solid phase extraction was between 67.75% and 103.08% with RSD value from 0.8% to 14.0%, which met the requirements of trace determination, this method has good precision and stability. These results could be employed to other Traditional Chinese Medicines (TCMs) in detecting prohibited pesticide residues.     

泛素蛋白磷酸化修饰的功能与解析

泛素化是存在于真核生物中一种重要的翻译后修饰过程,参与调控包括蛋白质降解在内的多种生命活动。实现这一调控过程需要将一个由76个氨基酸组成的泛素蛋白共价连接到底物蛋白上。同时,泛素本身也存在多种翻译后修饰,包括泛素化、磷酸化、乙酰化等,进一步丰富了泛素的修饰类型,决定了底物蛋白不同的命运。近年来,伴随着第65位丝氨酸磷酸化泛素蛋白参与调控线粒体自噬这一突破性进展,泛素蛋白其余磷酸化位点的功能研究也获得越来越多的关注。本文根据目前已有的国内外研究和报道,总结了泛素蛋白已知的磷酸化修饰位点,梳理了泛素蛋白第12位和66位苏氨酸、第57位和65位丝氨酸等位点的磷酸化修饰对其生物物理特性带来的改变,并对相应修饰位点所涉及的生物学功能调控进行了综述。     

Research Progress on Anti-Inflammatory Mechanisms of Black Ginseng

In recent years, black ginseng, a new type of processed ginseng product, has attracted the attention of scholars globally. Ginsenoside and ginseng polysaccharide, the main active substances of black ginseng, have been shown to carry curative effects for many diseases. This article focuses on the mechanism of their action in anti-inflammatory response, which is mainly divided into three aspects: activation of immune cells to exert immune regulatory response; participation in inflammatory response-related pathways and regulation of the expression level of inflammatory factors; effect on the metabolic activity of intestinal flora. This study identifies active anti-inflammatory components and an action mechanism of black ginseng showing multi-component, multi-target, and multi-channel characteristics, providing ideas and a basis for a follow-up in-depth study of its specific mechanism.