Subspecies-specific intron length polymorphism markers reveal clear genetic differentiation in common wild rice （Oryza rufipogon L.） in relation to the domestication of cultivated rice （O. sativa L.）

It is generally accepted that Oryza rufipogon is the progenitor of Asian cultivated rice （O. sativa）. However, how the two subspecies of O. sativa （indica and japonica） were domesticated has long been debated. To investigate the genetic differentiation in O. rufipogon in relation to the domestication of O. sativa, we developed 57 subspecies-specific intron length polymorphism （SSILP） markers by comparison between 10 indica cultivars and 10 japonica cultivars and defined a standard indica rice and a standard japonica rice based on these SSILP markers. Using these SSILP markers to genotype 73 O. rufipogon accessions, we found that the indica alleles and japonica alleles of the SSILP markers were predominant in the O. rufipogon accessions, suggesting that SSILPs were highly conserved during the evolution of O. sativa. Cluster analysis based on these markers yielded a dendrogram consisting of two distinct groups： one group （Group I） comprises all the O. rufipogon accesions from tropical （South and Southeast） Asia as well as the standard indica rice; the other group （Group II） comprises all the O. rufipogon accessions from Southern China as well as the standard japonica rice. Further analysis showed that the two groups have significantly higher frequencies of indica alleles and japonica alleles, respectively. These results support the hypothesis that indica rice and japonica rice were domesticated from the O. rufipogon of tropical Asia and from that of Southern China, respectively, and suggest that the indica-japonica differentiation should have formed in O. rufipogon long before the beginning of domestication. Furthermore, with an O. glaberrima accession as an outgroup, it is suggested that the indica-japonica differentiation in O. ruffpogon might occur after its speciation from other AA-genome species.     

沙地樟子松人工林土壤理化性质与微生物生物量的动态变化

为揭示不同林龄沙地樟子松人工林土壤理化性质和微生物生物量的动态和相互关系,以毛乌素沙地、科尔沁沙地和呼伦贝尔沙地不同林龄樟子松人工林为对象,分析土壤理化性质、土壤微生物生物量碳和微生物生物量氮变化规律。结果表明:樟子松人工林土壤理化性质随林龄增加在不同沙地中表现不同,毛乌素沙地土壤容重和养分含量明显降低,科尔沁沙地土壤孔隙度和养分含量明显升高,呼伦贝尔沙地土壤养分则呈现先增加后降低趋势。与土壤理化性质变化趋势类似,毛乌素沙地樟子松人工林土壤微生物生物量氮随着林龄的增加而降低,科尔沁沙地土壤微生物生物量氮随着林龄的增加而升高,呼伦贝尔沙地土壤微生物生物量氮随着林龄的增加呈先增加而后降低趋势。影响毛乌素沙地、科尔沁沙地和呼伦贝尔沙地土壤微生物生物量碳、氮的主要因子分别是硝态氮、铵态氮和有机质含量。毛乌素与科尔沁沙地樟子松人工林主要限制因子为土壤氮,而呼伦贝尔沙地樟子松受土壤有机碳限制较强。     

Hispidulin Induces Apoptosis Through Mitochondrial Dysfunction and Inhibition of P13k/Akt Signalling Pathway in HepG2 Cancer Cells

Hispidulin is a flavonoid compound which is an active ingredient in a number of traditional Chinese medicinal herbs. However, it’s therapeutic activity remains poorly understood. The present study investigated the pro-apoptotic effects and mechanism by which Hispidulin induces apoptosis in human hepatoblastoma cancer (HepG2) cells. The results showed that Hispidulin induced cell death in a dose- and time-dependent manner in HepG2 cells whereas no toxic reaction was observed in normal human liver cells at indicated concentration. This study also demonstrated that Hispidulin induces apoptosis through mitochondrial dysfunction, which is characterized by decreased Bcl-2/Bax ratio, disrupted mitochondrial membrane potential and increased release of cytochrome C and activated capase-3. Our results also showed that mitochondrial dysfunction was triggered by Hispidulin-induced excessive ROS generation. Hispidulin also significantly inhibited Akt activation. ROS inhibitor NAC abrogated the inhibitory effect of Hispidulin on P13k/Akt signalling pathway and the proapoptotic effect in HepG2 cells. Our results demonstrate for the first time that Hispidulin induces apoptosis in HepG2 cells and suggested that the pro-apoptotic effect of Hispidulin was mediated through mitochondrial dysfunction and inhibition of P13k/Akt signalling pathway. Since no toxic effect was observed when normal liver cells were treated with Hispidulin, Hispidulin may have the potential to be used as therapeutic for liver cancer.     

An efficient,widely applicable cryopreservation of Lilium shoot tips by droplet vitrification

We report a straightforward and widely applicable cryopreservation method for Lilium shoot tips. This method uses adventitious shoots that were induced from leaf segments cultured for 4 weeks on a shoot regeneration medium containing 1 mg/l α-naphthaleneacetic acid and 0.5 mg/l thidiazuron. Shoot tips (1.5–2 mm in length) including 2–3 leaf primordia were precultured on Murashige and Skoog (MS; 1962) medium with 0.5 M sucrose for 1 day and then treated with a loading solution containing 0.4 M sucrose and 2 M glycerol for 20 min, followed by a Plant Vitrification Solution 2 (PVS2) treatment for 4 h at 0 °C. Dehydrated shoot tips were transferred onto 2.5 µl PVS2 droplets on aluminum foil strips, prior to a direct immersion into liquid nitrogen for 1 h. Frozen shoot tips were re-warmed in MS medium containing 1.2 M sucrose for 20 min at room temperature, followed by post-thaw culture for shoot regrowth. Shoot regrowth levels ranged from 42.5 % for L. longiflorum × Oriental ‘Triumphator’ to 87.5 % for L. Oriental hybrid ‘Siberia’, with a mean shoot regrowth level of 67.1 % across the six diverse Lilium genotypes tested. Histological observations found that the survival patterns were similar in cryopreserved shoot tips of ‘Triumphator’ and ‘Siberia’. Assessments using inter-simple sequence repeat markers found no differences in regenerants recovered from the control stock cultures and from cryopreserved shoot tips in ‘Triumphator’ and ‘Siberia’. This Lilium droplet-vitrification cryopreservation method is efficient, simple and widely applicable for the long-term conservation of lily genetic resources.     

Climate–ecosystem modelling made easy: The Land Sites Platform

Dynamic Global Vegetation Models (DGVMs) provide a state-of-the-art process-based approach to study the complex interplay between vegetation and its physical environment. For example, they help to predict how terrestrial plants interact with climate, soils, disturbance and competition for resources. We argue that there is untapped potential for the use of DGVMs in ecological and ecophysiological research. One fundamental barrier to realize this potential is that many researchers with relevant expertize (ecology, plant physiology, soil science, etc.) lack access to the technical resources or awareness of the research potential of DGVMs. Here we present the Land Sites Platform (LSP): new software that facilitates single-site simulations with the Functionally Assembled Terrestrial Ecosystem Simulator, an advanced DGVM coupled with the Community Land Model. The LSP includes a Graphical User Interface and an Application Programming Interface, which improve the user experience and lower the technical thresholds for installing these model architectures and setting up model experiments. The software is distributed via version-controlled containers; researchers and students can run simulations directly on their personal computers or servers, with relatively low hardware requirements, and on different operating systems. Version 1.0 of the LSP supports site-level simulations. We provide input data for 20 established geo-ecological observation sites in Norway and workflows to add generic sites from public global datasets. The LSP makes standard model experiments with default data easily achievable (e.g., for educational or introductory purposes) while retaining flexibility for more advanced scientific uses. We further provide tools to visualize the model input and output, including simple examples to relate predictions to local observations. The LSP improves access to land surface and DGVM modelling as a building block of community cyberinfrastructure that may inspire new avenues for mechanistic ecosystem research across disciplines.     

Role of bone marrow-derived mesenchymal stem cells in the prevention of hyperoxia-induced lung injury in newborn mice

BPD (bronchopulmonary dysplasia) is predominantly characterized by persistent abnormalities in lung structure and arrested lung development, but therapy can be palliative. While promising, the use of BMSC (bone marrow-derived mesenchymal stem cell) in the treatment of lung diseases remains controversial. We have assessed the therapeutic effects of BMSC in vitro and in vivo. In vitro co-culturing with injured lung tissue increased the migration-potential of BMSC; and SP-C (surfactant protein-C), a specific marker of AEC2 (type II alveolar epithelial cells), was expressed. Following intraperitoneal injection of BMSC into experimental BPD mice on post-natal day 7, it was found that BMSC can home to the injured lung, express SP-C, improve pulmonary architecture, attenuate pulmonary fibrosis and increase the survival rate of BPD mice. This work supports the notion that BMSC are of therapeutic benefit through the production of soluble factors at bioactive levels that regulate the pathogenesis of inflammation and fibrosis following hyperoxia.     

Drug discovery prospect from untapped species: indications from approved natural product drugs

Due to extensive bioprospecting efforts of the past and technology factors, there have been questions about drug discovery prospect from untapped species. We analyzed recent trends of approved drugs derived from previously untapped species, which show no sign of untapped drug-productive species being near extinction and suggest high probability of deriving new drugs from new species in existing drug-productive species families and clusters. Case histories of recently approved drugs reveal useful strategies for deriving new drugs from the scaffolds and pharmacophores of the natural product leads of these untapped species. New technologies such as cryptic gene-cluster exploration may generate novel natural products with highly anticipated potential impact on drug discovery.     

鸡视网膜母细胞瘤基因1(RB1)多态性与体重性状的相关性

为探讨鸡视网膜母细胞瘤基因1(Retinoblastoma1,RB1)多态性对体重性状的影响,文章以东北农业大学高、低脂双向选择品系肉鸡为实验材料,采用MALDI-TOF-MS、PCR-RFLP方法进行基因多态性检测和个体基因型分析,共获得27个SNP位点的基因型数据。采用滑动窗口法构建单倍型,进而利用单位点和单倍型分别与鸡体重性状进行关联分析。结合单位点和单倍型分析结果,确定了RB1基因上4个显著影响1周龄体重的SNP位点,2个显著影响1、3周龄体重的SNP位点。研究结果表明RB1基因是影响鸡早期体重性状的重要候选基因。