我国植物食用色素资源开发利用评价

古代人们使用的着色剂都是天然产品,除少数矿物颜料外,主要是植物源色素。我国古代就有以红曲米作为着色剂利用的习惯;在高等植物方面,生产蓝色、黄色、绿色的颜料的高等植物种类不少,大多沿用至今。自19世纪中叶以后,人工合成色素以着色牢固、鲜艳、成本低廉等特点,迅速占领了印染、食品等许多行业,但20世纪60年代以后,许多研究表明,一般合成色素都有程度不等的毒性,特别是化学结构含偶氮型的色素有可能在人体内成为致癌物。同时,在色素合成的过程中,还有可能污染有重金属及其他有害物质。因此,合成色素越来越使人们感到不安全。从20世纪50年代的100多种人工合成色素用于食品着色,到20世纪末,已有60~70余种被禁用了,而植物食用色素在食品行业中成为主要着色剂。近年来又涌现出多种有价值的高等植物源色素,我们选择其主要一些植物种类做些介绍,供有关方面参考。     

表达鸡传染性法氏囊病毒VP2蛋白的干酪乳杆菌免疫保护效力

利用干酪乳杆菌作为传染性法氏囊病毒(IBDV)VP2抗原传递系统,探讨口服雏鸡的免疫次数、免疫剂量、免疫途径和攻毒保护效果。用pLA-VP2重组干酪乳杆菌对5日龄雏鸡进行二次和三次免疫,并设108、109、1010 CFU/mL的重组干酪乳杆菌组,间接ELISA检测血清IgG和小肠洗液sIgA,末免后7 d攻毒,计算保护效果。根据确定的2次免疫和109 CFU/mL免疫剂量免疫5日龄雏鸡,分别口服、滴鼻/点眼pLA-VP2/L.casei,口服、肌注商品活苗及口服pLA/L.casei和PBS为对照,监测IgG和sIgA抗体水平;末免后7 d检测脾淋巴细胞增殖情况并攻毒,7 d后剖检,观察法氏囊损伤程度并记录病变得分和保护率。结果表明各组的特异性sIgA、IgG抗体水平显著高于对照组(P0.01);口服pLA-VP2/L.casei组的淋巴细胞刺激指数显著高于其他组(P0.01),保护率高达83.3%,免疫保护效果优于滴鼻/点眼组。因此,构建的重组干酪乳杆菌的安全性优于商品活苗,可以作为IBDV候选疫苗。     

主编寄语：在不断改革中与时俱进——写在《生物化学与生物物理进展》创刊40周年

正《生物化学与生物物理进展》(以下简称《进展》)由中国科学院生物物理研究所创办于1974年(后与中国生物物理学会合办),迄今已届40周年.《进展》在"文革"尚未结束的特殊艰难时期诞生,随后与我国的社会变革和科学技术进步同行,在不断改革中发展,已经成为一份具备现代科技期刊的基本要素,被我国生物学界广为认知,并具有一定国际影响力的知名学术期刊.《进展》作为发表与记录科研成果的载体和传播科技知识的媒介,从创刊至今,刊物容量增加了近10倍,发表了来自全国近500多个单位的6381篇论     

Determination of lipid raft partitioning of fluorescently-tagged probes in living cells by Fluorescence Correlation Spectroscopy (FCS)

In the past fifteen years the notion that cell membranes are not homogenous and rely on microdomains to exert their functions has become widely accepted. Lipid rafts are membrane microdomains enriched in cholesterol and sphingolipids. They play a role in cellular physiological processes such as signalling, and trafficking but are also thought to be key players in several diseases including viral or bacterial infections and neurodegenerative diseases. Yet their existence is still a matter of controversy. Indeed, lipid raft size has been estimated to be around 20 nm, far under the resolution limit of conventional microscopy (around 200 nm), thus precluding their direct imaging. Up to now, the main techniques used to assess the partition of proteins of interest inside lipid rafts were Detergent Resistant Membranes (DRMs) isolation and co-patching with antibodies. Though widely used because of their rather easy implementation, these techniques were prone to artefacts and thus criticized. Technical improvements were therefore necessary to overcome these artefacts and to be able to probe lipid rafts partition in living cells. Here we present a method for the sensitive analysis of lipid rafts partition of fluorescently-tagged proteins or lipids in the plasma membrane of living cells. This method, termed Fluorescence Correlation Spectroscopy (FCS), relies on the disparity in diffusion times of fluorescent probes located inside or outside of lipid rafts. In fact, as evidenced in both artificial membranes and cell cultures, probes would diffuse much faster outside than inside dense lipid rafts. To determine diffusion times, minute fluorescence fluctuations are measured as a function of time in a focal volume (approximately 1 femtoliter), located at the plasma membrane of cells with a confocal microscope (Fig. 1). The auto-correlation curves can then be drawn from these fluctuations and fitted with appropriate mathematical diffusion models. FCS can be used to determine the lipid raft partitioning of various probes, as long as they are fluorescently tagged. Fluorescent tagging can be achieved by expression of fluorescent fusion proteins or by binding of fluorescent ligands. Moreover, FCS can be used not only in artificial membranes and cell lines but also in primary cultures, as described recently. It can also be used to follow the dynamics of lipid raft partitioning after drug addition or membrane lipid composition change.     

Intense harvesting of eastern wolves facilitated hybridization with coyotes

Despite ethical arguments against lethal control of wildlife populations, culling is routinely used for the management of predators, invasive or pest species, and infectious diseases. Here, we demonstrate that culling of wildlife can have unforeseen impacts that can be detrimental to future conservation efforts. Specifically, we analyzed genetic data from eastern wolves (Canis lycaon) sampled in Algonquin Provincial Park (APP), Ontario, Canada from 1964 to 2007. Research culls in 1964 and 1965 killed the majority of wolves within a study region of APP, accounting for approximately 36% of the park's wolf population at a time when coyotes were colonizing the region. The culls were followed by a significant decrease in an eastern wolf mitochondrial DNA (mtDNA) haplotype (C1) in the Park's wolf population, as well as an increase in coyote mitochondrial and nuclear DNA. The introgression of nuclear DNA from coyotes, however, appears to have been curtailed by legislation that extended wolf protection outside park boundaries in 2001, although eastern wolf mtDNA haplotype C1 continued to decline and is now rare within the park population. We conclude that the wolf culls transformed the genetic composition of this unique eastern wolf population by facilitating coyote introgression. These results demonstrate that intense localized harvest of a seemingly abundant species can lead to unexpected hybridization events that encumber future conservation efforts. Ultimately, researchers need to contemplate not only the ethics of research methods, but also that future implications may be obscured by gaps in our current scientific understanding.     

Is the originality of a species measurable?

In this paper, we introduce the concept of 'originality of a species within a set' in order to indicate the average rarity of all the features belonging to this species. Using a phylogenetic tree of 70 species of New World terrestrial Carnivora, we suggest measuring the originality by a probability distribution. This maximizes the expected number of features shared by two species randomly drawn from the set. By using this new index, we take account of branch lengths whereas current indices of originality focus on tree topology. As a supplement to Nee and May's optimizing algorithm, we find that originality must be one of the criteria used in conservation planning.     

The carbon fertilization effect over a century of anthropogenic CO2 emissions: higher intracellular CO2 and more drought resistance among invasive and native grass species contrasts with increased water use efficiency for woody plants in the US Southwest

From 1890 to 2015, anthropogenic carbon dioxide emissions have increased atmospheric CO₂ concentrations from 270 to 400 mol mol^?1. The effect of increased carbon emissions on plant growth and reproduction has been the subject of study of free‐air CO₂ enrichment (FACE) experiments. These experiments have found (i) an increase in internal CO₂ partial pressure (c_i) alongside acclimation of photosynthetic capacity, (ii) variable decreases in stomatal conductance, and (iii) that increases in yield do not increase commensurate with CO₂ concentrations. Our data set, which includes a 115‐year‐long selection of grasses collected in New Mexico since 1892, is consistent with an increased c_i as a response to historical CO₂ increase in the atmosphere, with invasive species showing the largest increase. Comparison with Palmer Drought Sensitivity Index (PDSI) for New Mexico indicates a moderate correlation with Δ¹³C (r² = 0.32, P < 0.01) before 1950, with no correlation (r² = 0.00, P = 0.91) after 1950. These results indicate that increased c_i may have conferred some drought resistance to these grasses through increased availability of CO₂ in the event of reduced stomatal conductance in response to short‐term water shortage. Comparison with C₃ trees from arid environments (Pinus longaeva and Pinus edulis in the US Southwest) as well as from wetter environments (Bromus and Poa grasses in New Mexico) suggests differing responses based on environment; arid environments in New Mexico see increased intrinsic water use efficiency (WUE) in response to historic elevated CO₂ while wetter environments see increased c_i. This study suggests that (i) the observed increases in c_i in FACE experiments are consistent with historical CO₂ increases and (ii) the CO₂ increase influences plant sensitivity to water shortage, through either increased WUE or c_i in arid and wet environments, respectively.     

Genotypic and environmental variations in root morphology in rice genotypes under upland field conditions

Improving the water capturing capacity of its large and deep root system is required to stabilize the yield of upland rice in drought-prone areas in the tropics. For the improvement of the root system through breeding and soil management, it is critical to understand the relative importance of genotypic and environmental effect and their interaction on the root development under various soil conditions and agronomic management. This study aimed to quantify and characterize the effect of genotype and environment, soils and N application levels (0 and 90 kg N ha^–1) in the variations of the traits related to the size and distribution of the root system at the flowering stage using 11 rice genotypes in upland fields in southern Luzon in the Philippines. The results indicated that, among the root traits, the genotypic factor accounted for the largest portion of variation for the number of nodal roots, specific root weight (SRW), and R/S ratio, whereas the environmental effect was relatively large for deep root length ratio (DRR) and total root dry weight (RDW). Especially, the DRR, the ratio of root length at deeper than 30 cm per unit area to the RDW, was strongly affected by the site. Nitrogen application increased RDW without a substantial change in the R/S ratio and DRR. On the other hand, significant genotypic variations of RDW and DRR were obtained, which may imply the opportunity for the genetic improvement. Japonica upland varieties showed a large RDW (90–111 g m^–2) associated with high R/S ratio (0.18–0.23) and a high SRW (0.26–0.27 mg cm^–1), whereas aus (Dular) and indica (Vandana) upland varieties had a large DRR (12.5–13.8 m g^–1) with a medium R/S ratio (0.14–0.17), suggesting an efficient formation of a deep root system with a limited biomass allocation to the roots. In addition, the analysis of G × E interaction term for RDW by an Additive Main Effects and Multiplicative Interaction (AMMI) model indicated that the response to soil conditions also differed between these groups. This indicated that proper deployment of genotype to the given soil conditions is also important to maximize the expression of genotypic potentials.     

Building large trees by combining phylogenetic information: a complete phylogeny of the extant Carnivora (Mammalia)

One way to build larger, more comprehensive phylogenies is to combine the vast amount of phylogenetic information already available. We review the two main strategies for accomplishing this (combining raw data versus combining trees), but employ a relatively new variant of the latter: supertree construction. The utility of one supertree technique, matrix representation using parsimony analysis (MRP), is demonstrated by deriving a complete phylogeny for all 271 extant species of the Carnivora from 177 literature sources. Beyond providing a 'consensus' estimate of carnivore phylogeny, the tree also indicates taxa for which the relationships remain controversial (e.g. the red panda; within canids, felids, and hyaenids) or have not been studied in any great detail (e.g. herpestids, viverrids, and intrageneric relationships in the procyonids). Times of divergence throughout the tree were also estimated from 74 literature sources based on both fossil and molecular data. We use the phylogeny to show that some lineages within the Mustelinae and Canidae contain significantly more species than expected for their age, illustrating the tree's utility for studies of macroevolution. It will also provide a useful foundation for comparative and conservational studies involving the carnivores.     

香菇中镉含量的检测与分析

为了解影响香菇镉富集的一些因素,对不同品种、不同地区、不同潮次的香菇以及香菇不同形态部分中的镉含量进行了比较研究。结果表明：不同品种香菇、不同地区以及不同潮次香菇中的镉含量具有一定的差异;此外,香菇的不同形态部分中镉的含量也不一样,其镉含量从高到低的顺序为：菌褶＞菌盖＞菌柄。