Engineering Natural and Synthetic Resistance for Nematode Management

Bioengineering strategies are being developed that will provide specific and durable resistance against plant-parasitic nematodes in crops. The strategies come under three categories: (i) transfer of natural resistance genes from plants that have them to plants that do not, to mobilize the defense mechanisms in susceptible crops; (ii) interference with the biochemical signals that nematodes exchange with plants during parasitic interactions, especially those resulting in the formation of specialized feeding sites for the sedentary endoparasites—many nematode genes and many plant genes are potential targets for manipulation; and (iii) expression in plant cells of proteins toxic to nematodes.     

不同EGF和胰岛素水平对体外培养的大熊猫皮肤成纤维细胞的影响

用DME∶Ham sF12(1∶1)培养液,添加3个水平的EGF和2个水平的胰岛素,组合成6种培养体系(CS)分别培养大熊猫皮肤成纤维细胞。通过对细胞生长速度和染色体数目变异率进行测定,测得在添加10μg/ml的胰岛素和40 ng/ml的表皮生长因子的培养体系中,以1.673±0.185×105/ml密度接种细胞,经3.5天,密度达到6.890×105/ml,其生长速度最快;染色体数目为二倍体的百分率为75.77%。综合衡量,CS-5在本研究中更适合大熊猫皮肤成纤维细胞的培养。     

Physicochemical properties of giant embryo rice Seonong 17 and Keunnunjami

This study was carried out to determine the physicochemical properties of giant embryo rice “Seonong 17” and “Keunnunjami” in comparison with the normal embryo rice. Scanning electron microscopy revealed that Seonong 17 and Keunnunjami have larger embryo and that starch granules from Keunnunjami were more tightly packed with smaller air spaces between granules. Seonong 17 exhibited the lowest amylose content. Keunnunjami showed the highest protein content, pasting temperature, peak and breakdown viscosities, and gelatinization temperature and enthalpy. Both giant embryo rice samples contained significantly higher amounts of essential amino acids and unsaturated fatty acids than the normal rice. Proteomic analysis using two-dimensional gel electrophoresis revealed differences in the protein profile of Seonong 17 and Keunnunjami. The results could serve as baseline information in evaluating the quality of these two giant embryo rice cultivars and provide a better understanding of their potential uses and food industry applications.     

Giant tortoises spread to western Indian Ocean islands by sea drift in pre‐Holocene times,not by later human agency – response to Wilmé et al. (2016a)

Evidence from DNA phylogeny, Plio‐Pleistocene ocean currents, giant tortoise dispersal, evolution of plant defences, radiocarbon dates and archaeology indicates that the endemic giant tortoises on the Mascarenes and Seychelles colonized naturally and were not translocated there by humans.     

Phytase production by Sporotrichum thermophile in a cost‐effective cane molasses medium in submerged fermentation and its application in bread

Aims: Phytase production by Sporotrichum thermophile in a cost‐effective cane molasses medium in submerged fermentation and its application in bread. Methods and Results: The production of phytase by a thermophilic mould S. thermophile was investigated using free and immobilized conidiospores in cane molasses medium in shake flasks, and stirred tank and air‐lift fermenters. Among surfactants tested, Tweens (Tween‐20, 40 and 80) and sodium oleate increased phytase accumulation, whereas SDS and Triton X‐100 inhibited the enzyme production. The mould produced phytase optimally at a_w 0·95, and it declined sharply below this a_w value. The enzyme production was comparable in air‐lift and stirred tank reactors with a marked reduction in fermentation time. Among the matrices tried, Ca‐alginate was the best for conidiospore immobilization, and fungus secreted sustained levels of enzyme titres over five cycles. The phytic acid in the dough was efficiently hydrolysed by the enzyme accompanied by the liberation of soluble phosphate in the bread. Conclusions: The phytase production by S. thermophile was enhanced in the presence of Tween‐80 in cane molasses medium. A peak in enzyme production was attained in 48 h in the fermenter when compared with that of 96 h in shake flasks. Ca‐alginate immobilized conidiospores germinated to produce fungal growth that secreted sustained levels of phytase over five cycles. The bread made with phytase contained reduced level of phytic acid and a high‐soluble phosphate. Significance and Impact of the Study: The phytase accumulation by S. thermophile was increased by the surfactants. The sustainability of enzyme production in stirred tank and air‐lift fermenters suggested the possibility for scaling up of phytase. The bread made with phytase contained low level of antinutrient, i.e. phytic acid.     

岷山地区大熊猫(Ailuropoda melanoleuca)生境影响因子连通性及主导因子

岷山地区是大熊猫保护的关键地区.运用图论分析法研究了岷山地区大熊猫生境影响因子,及其相互作用关系.结果表明:在岷山地区,12个影响因子66对组合中,47.0%的影响因子间存在直接的联系,其中89.2%的影响具有增大效应,这说明人类活动对大熊猫生境的影响具有协同增大效应,并占主导地位.研究发现,在影响因子关系集中,存在强连通性的子集K={(TD);(RB);(MI);(HPL);(AP);(AD);(SR);(TH);(FC)},这表明近期进行的旅游景点开发,公路建设,采矿,高压电线走廊建设,以及传统的农业开发,畜牧业,薪柴采集等影响因子之间存在着强烈相互作用关系,这些人类活动还会将其他人类活动对大熊猫生境的影响放大,加剧其对大熊猫生境的不利影响,是影响岷山地区大熊猫生境的主导因素.研究还表明如果不能对主导因子进行有效的控制,很难有效地保护岷山地区大熊猫生境.研究表明图论分析法是研究大熊猫生境影响因子的一个有效工具,有助于明确影响熊猫生境的主导和关键因子,为制定有效的大熊猫保护策略提供科学依据.     

Cutaneous and diphtheritic avian poxvirus infection in a nestling Southern Giant Petrel (Macronectes giganteus) from Antarctica

The Southern giant petrel (Macronectes giganteus) is declining over much of its range and currently is listed as vulnerable to extinction by the International Union for the Conservation of Nature (IUCN). Island-specific breeding colonies near Palmer Station, Antarctica, have been monitored for over 30 years, and because this population continues to increase, it is critically important to conservation. In austral summer 2004, six diseased giant petrel chicks were observed in four of these colonies. Diseased chicks were 6–9 weeks old and had multiple proliferative nodules on their bills and skin. One severely affected chick was found dead on the nest and was salvaged for necropsy. Histopathological examination of nodules from the dead chick revealed epithelial cell hyperplasia and hypertrophy with numerous eosinophilic intracytoplasmic inclusions (Böllinger bodies). A poxvirus was isolated from multiple nodules. Poxviral infection has not been reported in this species, and the reason for its emergence and its potential impact on the population are not yet known.     

秦岭大熊猫主食竹的分类学研究（I）

研究为秦岭大熊猫主食竹系列报道之一,主要报道产于陕西长青国家级自然保护区大熊猫主食竹。该保护区内共有野生禾本科竹亚科植物4属、5种,栽培逸为野生的1属、1种,其中巴山木竹（Bashania fargesii）和秦岭箭竹（Fargesia qinlingensis）为该区域大熊猫最主要的采食野生竹种,龙头竹（Fargesia dracocephala）次之,由栽培逸为野生的金竹（Phyllostachys sulpurea）为大熊猫喜爱的竹种。     

草履蚧一龄若虫的发育历期与防治

在郑州通过室外埋卵观察,草履蚧Drosicha corpulenta Kuwana从1月初开始孵化,孵化后在土里等到2月初开始出土,此时日最高气温在6～8℃之间。若虫出土期约30d,2月中下旬为出土高峰期。经设置14,18,22,26和30℃5个温度梯度观察,草履蚧1龄若虫发育起点温度为7.9℃,有效积温为203.8日.度。利用树干绑缚杀虫药带防治效果达到98%以上。     

Interaction of an artificial antimicrobial peptide with lipid membranes

Antimicrobial peptides constitute an important part of the innate immune defense and are promising new candidates for antibiotics. Naturally occurring antimicrobial peptides often possess hemolytic activity and are not suitable as drugs. Therefore, a range of new synthetic antimicrobial peptides have been developed in recent years with promising properties. But their mechanism of action is in most cases not fully understood. One of these peptides, called V4, is a cyclized 19 amino acid peptide whose amino acid sequence has been modeled upon the hydrophobic/cationic binding pattern found in Factor C of the horseshoe crab (Carcinoscorpius rotundicauda). In this work we used a combination of biophysical techniques to elucidate the mechanism of action of V4. Langmuir-Blodgett trough, atomic force microscopy, Fluorescence Correlation Spectroscopy, Dual Polarization Interference, and confocal microscopy experiments show how the hydrophobic and cationic properties of V4 lead to a) selective binding of the peptide to anionic lipids (POPG) versus zwitterionic lipids (POPC), b) aggregation of vesicles, and above a certain concentration threshold to c) integration of the peptide into the bilayer and finally d) to the disruption of the bilayer structure. The understanding of the mechanism of action of this peptide in relation to the properties of its constituent amino acids is a first step in designing better peptides in the future.