大豆蚜Kazal型丝氨酸蛋白酶抑制剂基因AgKaSPI 对蜡蚧刺束梗孢菌侵染的表达响应

【目的】探究Kazal型丝氨酸蛋白酶抑制剂KaSPI在大豆蚜Aphis glycines的生长发育、消化和免疫防御等过程中的作用。【方法】基于大豆蚜转录组数据PCR克隆大豆蚜Kazal型丝氨酸蛋白酶抑制剂基因cDNA序列;qRT-PCR分别检测AgKaSPI在大豆蚜1-4龄若虫和成虫以及蜡蚧刺束梗孢菌Akanthomyces     

Cytotoxic activities of Hypericum perforatum L. extracts against 2D and 3D cancer cell models

Cytotechnology - Six extracts were obtained from plant species Hypericum perforatum L., collected at Samsun in Turkey. The aim of this study was to examine the mechanisms of the anticancer activity...     

The thermodynamics of thinking: connections between neural activity,energy metabolism and blood flow

Several current functional neuroimaging methods are sensitive to cerebral metabolism and cerebral blood flow (CBF) rather than the underlying neural activity itself. Empirically, the connections between metabolism, flow and neural activity are complex and somewhat counterintuitive: CBF and glycolysis increase more than seems to be needed to provide oxygen and pyruvate for oxidative metabolism, and the oxygen extraction fraction is relatively low in the brain and decreases when oxygen metabolism increases. This work lays a foundation for the idea that this unexpected pattern of physiological changes is consistent with basic thermodynamic considerations related to metabolism. In the context of this thermodynamic framework, the apparent mismatches in metabolic rates and CBF are related to preserving the entropy change of oxidative metabolism, specifically the O₂/CO₂ ratio in the mitochondria. However, the mechanism supporting this CBF response is likely not owing to feedback from a hypothetical O₂ sensor in tissue, but rather is consistent with feed-forward control by signals from both excitatory and inhibitory neural activity. Quantitative predictions of the thermodynamic framework, based on models of O₂ and CO₂ transport and possible neural drivers of CBF control, are in good agreement with a wide range of experimental data, including responses to neural activation, hypercapnia, hypoxia and high-altitude acclimatization.This article is part of the theme issue ‘Key relationships between non-invasive functional neuroimaging and the underlying neuronal activity’.     

Seasonal trends in morpho-physiological attributes and bioactive content of Valeriana jatamansi Jones under full sunlight and shade conditions

Valeriana jatamansi Jones, an important medicinal herb of the Himalayan region, is an essential source of many therapeutic compounds and is traded/consumed in very high volume. The hypothesis of this study was that different seasons and light conditions may affect the content of medicinally valuable components with changes in the morpho-physiological attributes of the plant. Growing plants under suitable light conditions and harvesting of appropriate plant parts in optimum season is crucial for harnessing the full potential of the crop. Thus, the study was carried out to determine the seasonal response of V. jatamansi plants (genetically identical plants of same age) in terms of growth and phytochemical content under two different light conditions (full sunlight and 50% shade). During all seasons, growth parameters (plant height, leaf number, leaf area, relative water content, plant biomass) and the principle bioactive compounds (valerenic acid) were higher under shade conditions, while total flavonoids, tannins, phenolic compounds and antioxidant activities were higher under full sunlight conditions. HPLC analysis revealed that valerenic acid and most of the phenolic content were higher during summer season, especially in leaf part of the plant. The study suggested harvesting of V. jatamansi plants (especially leaf), during summer season to harness high quality raw material and to prevent loss of belowground parts. This strategy can be adopted by farmers for large scale cultivation of species.Supplementary InformationThe online version of this article contains supplementary material available at 10.1007/s12298-021-00944-0     

不同人类干扰背景下横断山南段保护优先区规划研究

建立自然保护区是保护和维持生物多样性最有效、最基本的措施。在有限的资金和人力条件下,如何参考不同人类干扰在保护优先区建设中的影响并选择合适的保护规划方案,在更大程度上的保护本区域的生物多样性,一直以来都是保护生物学家争论的焦点。以横断山南段区为例,重点关注保护区建设过程中不同的人类干扰程度,以人类干扰的高低为切入点,基于多准则决策分析的原理和方法,以横断山南植被生态系统和人类干扰强度因子为基础,对比分析横断山南的生态系统保护价值分布、人类干扰格局和保护成效,结果显示：一是区域内森林生态系统（针阔混交林、常绿阔叶林、落叶阔叶林、落叶混交林、常绿针叶林）、湿地生态系统（湖泊、河流、草本湿地）、高山生态系统（冰川和永久积雪、高寒草甸、高寒草原）价值高且分值在21分以上;二是从人类干扰高低分析入手,基于维持和提升区域生物多样性的角度出发,提出了不同的保护优先区域和保护策略。三是识别出横断山南段区的保护优先区主要包括峨边县、马边县、石棉县、越西县、保山市、腾冲市、维西县、德钦县、察隅县等区域。     

耐高盐枯草芽孢杆菌XP合成球形纳米硒及其抑制草莓病原真菌生物活性

生物方法合成纳米材料具有低能耗、高安全性以及环境友好等优良特点,因而备受人们关注。利用细菌将硒酸盐或亚硒酸盐还原为单质硒,不仅可以降低硒毒性,而且还能获得价值更高的生物纳米材料。文中选用可耐受高盐环境胁迫的枯草芽孢杆菌亚种Bacillus subtilis subspecies stercoris strain XP构建生物模型,分别以LB液体培养基和亚硒酸钠为介质和底物 (电子受体),解析菌株XP合成纳米硒的基本规律。通过扫描电镜 (Scanning electron microscope,SEM) 观察、X射线能谱分析 (X-ray energy dispersive spectral analysis,EDAX)、X射线衍射 (X-ray diffraction,XRD) 分析、傅里叶红外变换光谱 (Fourier transform infrared spectroscopy,FTIR) 技术对合成的纳米硒进行物理化学表征分析,同时选用草莓枯萎、红叶、紫斑病病原真菌对其抗菌活性进行分析。结果表明,菌株XP介导合成的单质硒为球形纳米颗粒 (Selenium nanoparticles,SeNPs),其生成量与反应时间呈正相关 (0–48 h),且细胞形态未发生褶皱或破损等变化 (耐受力强);SeNPs为非晶态,粒径范围在135–165 nm,表面元素组成以Se为主,同时存在C、O、N、S等有机元素;颗粒表面包裹生物大分子物质,-OH、C=O、N-H、C-H等官能团与SeNPs稳定性和生物活性密切相关;高浓度纳米硒对枯萎、红叶、紫斑病病原真菌均有显著抑制活性 (P<0.05),其中对草莓红叶病与枯萎病病原真菌的抑制活性明显优于对紫斑病病原真菌的抑制活性。总而言之,菌株XP不仅耐受高盐胁迫能力强,同时还可介导合成生物SeNPs,其合成的纳米硒颗粒具有良好的稳定性和生物活性,在草莓病害防治以及绿色富硒草莓种植等领域具有潜在的应用价值。     

间斑寇蛛卵粒毒素-Ⅵ的基因克隆、异源表达与活性鉴定

间斑寇蛛Latrodectus tredecimguttatus的一个显著特点是其毒腺外组织甚至卵粒中也存在毒性成分。研究毒腺外的毒素不但可以加深对蜘蛛毒素的了解,而且可以发现具有重要应用前景的新型毒素分子。为了探究间斑寇蛛卵粒中低丰度表达的蛋白质类毒素,利用生物信息学方法从间斑寇蛛卵粒转录组中挖掘出一条编码多肽毒素的基因序列,利用基于3′-RACE和巢式PCR的策略成功克隆并异源表达了该基因。表达的多肽毒素命名为间斑寇蛛卵粒毒素-Ⅵ(Latroeggtoxin-Ⅵ,LETX-Ⅵ)。生物学活性鉴定结果表明,LETX-Ⅵ能抑制ND7/23细胞膜上的钠离子通道电流和促进PC12细胞多巴胺的释放,但对美洲蜚蠊Periplaneta americana和金黄色葡萄球菌及白色念珠菌等细菌和真菌不显示明显的毒性,说明LETX-Ⅵ是一种哺乳动物特异的神经毒素,在神经生物学研究工具试剂和相关疾病治疗药物的研发等方面具有潜在的应用前景。