Comparative analysis of metabolome of rice seeds at three developmental stages using a recombinant inbred line population

Plants are considered an important food and nutrition source for humans. Despite advances in plant seed metabolomics, knowledge about the genetic and molecular bases of rice seed metabolomes at different developmental stages is still limited. Here, using Zhenshan 97 (ZS97) and Minghui 63 (MH63), we performed a widely targeted metabolic profiling in seeds during grain filling, mature seeds and germinating seeds. The diversity between MH63 and ZS97 was characterized in terms of the content of metabolites and the metabolic shifting across developmental stages. Taking advantage of the ultra‐high‐density genetic map of a population of 210 recombinant inbred lines (RILs) derived from a cross between ZS97 and MH63, we identified 4681 putative metabolic quantitative trait loci (mQTLs) in seeds across the three stages. Further analysis of the mQTLs for the codetected metabolites across the three stages revealed that the genetic regulation of metabolite accumulation was closely related to developmental stage. Using in silico analyses, we characterized 35 candidate genes responsible for 30 structurally identified or annotated compounds, among which LOC_Os07g04970 and LOC_Os06g03990 were identified to be responsible for feruloylserotonin and l ‐asparagine content variation across populations, respectively. Metabolite?agronomic trait association and colocation between mQTLs and phenotypic quantitative trait loci (pQTLs) revealed the complexity of the metabolite?agronomic trait relationship and the corresponding genetic basis.     

Defective Differentiation of Adipose Precursor Cells from Lipodystrophic Mice Lacking Perilipin 1

Perilipin 1 (Plin1) localizes at the surface of lipid droplets to regulate triglyceride storage and hydrolysis in adipocytes. Plin1 defect leads to low adiposity in mice and partial lipodystrophy in human. This study investigated the roles of Plin1 in adipocyte differentiation. Plin1 null (-/-) mice showed plenty of multilocular adipocytes and small unilocular adipocytes in adipose tissue, along with lack of a subpopulation of adipose progenitor cells capable of in vivo adipogenesis and along with downregulation of adipogenic pathway. Before initiation of differentiation, adipose stromal-vascular cells (SVCs) from Plin1-/- mice already accumulated numerous tiny lipid droplets, which increased in number and size during the first 12-h induction but thereafter became disappeared at day 1 of differentiation. The adipogenic signaling was dysregulated despite protein level of PPARγ was near normal in Plin1-/- SVCs like in Plin1-/- adipose tissue. Heterozygous Plin1+/- SVCs were able to develop lipid droplets, with both the number and size more than in Plin1-/- SVCs but less than in Plin1+/+ SVCs, indicating that Plin1 haploinsufficiency accounts for attenuated adipogenesis. Aberrant lipid droplet growth and differentiation of Plin1-/- SVCs were rescued by adenoviral Plin1 expression and were ameliorated by enhanced or prolonged adipogenic stimulation. Our finding suggests that Plin1 plays an important role in adipocyte differentiation and provides an insight into the pathology of partial lipodystrophy in patients with Plin1 mutation.     

Combining biocatalysis and chemoselective chemistries for glycopeptide antibiotics modification

Glycopeptide antibiotics are clinically important medicines to treat serious Gram-positive bacterial infections. The emergence of glycopeptide resistance among pathogens has motivated considerable interest in expanding structural diversity of glycopeptide to counteract resistance. The complex structure of glycopeptide poses substantial barriers to conventional chemical methods for structural modifications. By contrast, biochemical approaches have attracted great attention because ample biosynthetic information and sophisticated toolboxes have been made available to change reaction specificity through protein engineering, domain swapping, pathway engineering, addition of substrate analogs, and mutagenesis.     

The preventive effect of vaccine prophylaxis on severe respiratory syncytial virus infection:A meta-analysis

Respiratory syncytial virus(RSV) is the key underlying cause of acute lower respiratory tract infection in infants; however, no licensed vaccine against RSV infection is currently available. This study was undertaken to assess the preventive effect of vaccine on RSV infection. In this metaanalysis, 1,792 published randomized clinical trials of RSV vaccines from Jan 1973 to Sep 2015 were examined. Among thirteen studies that met the inclusion criteria, eleven studies estimated the impact of RSV vaccines and four studies estimated the effect of adjuvants. The odds ratios(ORs) were 0.31(95% CI, 0.15–0.67) and 0.62(95% CI, 0.29–1.34), respectively. We found that RSV subunit vaccines can significantly reduce the incidence of RSV infection and that whether vaccination with adjuvant therapy was an effective strategy still remained to be studied. This analysis of the preventive effect of vaccines on RSV infection has direct applications for the prevention of RSV infections.     

Biosynthesis and biotechnological production of salidroside from Rhodiola genus plants

Phytochemistry Reviews - Salidroside is a precious phenylethanoid glycoside derived from Rhodiola genus plants, which possesses a broad spectrum of biological properties for application in the...     

海南主要陆域自然保护地兰科植物多样性与生境的关联分析

为了掌握海南主要陆域自然保护地内野生兰科植物的物种多样性现状以及制约其发展的关键生境因子,对该地区进行兰科植物资源调查并分析兰科植物多样性的空间分布格局,进一步采用典范对应分析(CCA)探索生境因子对兰科植物组成的影响,最后运用广义线性模型(GLM)框架下的负二项回归拟合兰科植物丰富度和多度对生境变异的响应。结果表明:(1)共发现兰科植物67属193种,为海南兰科植物分布的绝对中心。(2)水平方向上,霸王岭兰科植物丰富度高但居群相对拥挤,而五指山最大的海拔落差带来了更加多样化的小生境类型和宽阔的生存空间,孕育了种类丰富且分布均匀的兰科植物资源。(3)垂直方向上,中海拔地区兰科植物种类最为丰富且种间竞争较为激烈,高海拔地区则存在明显的优势类群。(4)海拔变化对兰科植物物种组成变异有着非常高的解释率,而喀斯特和河谷地貌的显著影响也不容忽视。(5)多因子综合作用共同影响着兰科植物的多样性,其中坡度、河谷地貌、喀斯特地貌的显著正效应和枫香林的显著负效应受其他协变量的影响较小,是驱动兰科植物丰富度和多度变化的关键生境因子。综上所述,中高海拔地区以及特殊地貌(如河谷和喀斯特地貌)应作为兰科植物多样性的优先保护区域。     

Mistletoe lectin (Viscum album coloratum) modulates proliferation and cytokine expressions in murine splenocytes

It is well documented that an extract of European mistletoe has a variety of biological effects, such as the stimulation of cytokine production from immune cells, and additional immunoadjuvant activities. While the European mistletoe has been studied intensively, we know less about Korean mistletoe as a therapeutic plant, especially as a possible immunomodulating drug. This study will investigated the effects of Korean mistletoe lectin (Viscum album L. var. coloratum agglutinin, VCA) on murine splenocytes to investigate whether VCA acts as an immunomodulator, which could lead to improved immune responses in these cells. The results showed that VCA inhibited cell proliferation at higher concentrations (at 1-8 ng/ml) and enhanced cell proliferation at lower concentrations (at 4-32 pg/ml). Further studies were carried out to determine if the proproliferative or anti-proliferative activity exhibited by VCA was correlated with cytokine secretion. Consequently, interferon (IFN)-gamma secretion was decreased in concanavalin A (ConA)-stimulated murine splenocytes by VCA (4-64 ng/ml), but there was no change in IL-4 levels. This suggests that VCA has the ability to modulate murine splenocyte proliferation and can possibly act on the balance of Th1/Th2 cellular immune responses.     

大型海藻在珊瑚礁退化过程中的作用

随着全球范围珊瑚礁的退化,大型海藻在珊瑚礁区的覆盖度呈增多的趋势。大型海藻的大量生长,妨碍了珊瑚的生长、繁殖、恢复等过程。概括起来,大型海藻对珊瑚生长、繁殖及恢复过程所产生的不利影响主要包括:(1)大型海藻通过与珊瑚竞争空间和光照而影响珊瑚生长;(2)大型海藻与珊瑚直接接触时,通过摩擦作用及释放化感物质而影响珊瑚生长;(3)大型海藻的大量生长打破了珊瑚与海藻的竞争平衡,珊瑚为应对大型海藻的入侵而把用于生长和繁殖的能量转移到组织修复与防御上,进而造成珊瑚繁殖能量的减少;(4)大型海藻通过影响珊瑚幼虫的附着及附着后的存活率,而阻碍珊瑚群落的发展;(5)海藻还能通过富集沉积物、释放病原体及扰乱珊瑚共生微生物的生长等而间接影响珊瑚生长。明确的竞争机制有利于研究海藻与珊瑚的相互作用过程。在总结前人对海藻与珊瑚的竞争机制研究的基础上,把两者的竞争机制划分成物理机制、化学机制、微生物机制三大类,物理机制是研究得比较透彻的竞争机制,而化学机制与微生物机制则需要更深入的研究,是当前研究的热点。目前,我国对珊瑚礁中底栖海藻与珊瑚的相互作用研究甚少;鉴于此,对底栖海藻功能群的划分类型以及三大类型底栖海藻对珊瑚的作用特点做了简要介绍,并对珊瑚礁退化的现状和退化珊瑚礁区内海藻的表现做了概述。在此基础上,再综述国外关于大型海藻对珊瑚的影响研究进展,指出我国应该加强对南海珊瑚礁区大型海藻的种类分布及丰富度等的调查,评价大型海藻对南海珊瑚礁的影响现状;并结合生理学、分子生物学技术和生态学研究手段,在细胞与分子水平上探索海藻对珊瑚的影响机制,以期为珊瑚礁生态系统的保护提供参考。     

Young Seedling Stripe1 encodes a chloroplast nucleoid-associated protein required for chloroplast development in rice seedlings

Planta - Young Seedling Stripe1 (YSS1) was characterized as an important regulator of plastid-encoded plastid RNA polymerase (PEP) activity essential for chloroplast development at rice seedling...     

Decreases in Both the Seroprevalence of Serum Antibodies and Seroprotection against Japanese Encephalitis Virus among Vaccinated Children

The incidence of Japanese encephalitis(JE) has significantly decreased in China due to JE vaccines. In this study, we investigated the post-JE vaccination seroprevalence and protection provided by vaccinated sera against Japanese encephalitis virus(JEV) to elucidate the persistence and waning of antibodies to JEV among JE-SA14-14-2-vaccinated children. A total of 300 serum samples were collected from vaccinated children aged 3–10 years in Zhaotong, Yunnan,China. The seroprevalence of anti-JEV antibodies was determined by enzyme-linked immune sorbent assay and plaque reduction neutralization test. The highest seropositivity of 82% was observed in vaccinated children during the first0.5–1.5 years after booster vaccination. Then, the seropositivity began to decline and remained lower than the original level observed in the 0.5–1.5-year group. An association was found between the waning of seroprevalence and elapsed time of the post-booster vaccination. Similarly, the neutralizing antibody(nAb) titres gradually decreased over time, and the levels showed a positive correlation with the protective efficacy in mice. This finding suggests that nAbs play an important role in the antiviral process and that the nAb titre is an adequately credible parameter for evaluating the protective efficacy induced by the JE vaccine. Our results provide data that clarify the persistence and waning of antibodies to JEV, which may help elucidate the pathogenesis of JE.