拟南芥转录因子GRAS 家族基因群响应渗透和干旱胁迫的初步探索

GRAS家族是一类植物特有的转录调控因子, 已有报道表明该家族基因在植物生长发育和光信号转导过程中具有重要作用。目前在拟南芥(Arabidopsis thaliana)基因组中已鉴定了33个GRAS家族基因。利用功能基因组学和生物信息学手段,通过基因芯片数据挖掘和基因功能预测, 对拟南芥GRAS家族基因在渗透和干旱胁迫过程中的应答模式进行了初步探索, 提出了一类响应渗透胁迫和干旱胁迫的拟南芥GRAS家族基因。以SCL13为例, 利用基因芯片相关性和GO分析, 对其在渗透胁迫信号转导过程中可能的调控机制进行了预测和分析。这一研究将为阐明GRAS家族基因参与水分胁迫的分子机制提供新的思路, 同时也为植物抗逆分子育种提供候选基因。     

‘Tethering’ fragment-based drug discovery to identify inhibitors of the essential respiratory membrane protein type II NADH dehydrogenase

Energy generation is a promising area of drug discovery for both bacterial pathogens and parasites. Type II NADH dehydrogenase (NDH-2), a vital respiratory membrane protein, has attracted attention as a target for the development of new antitubercular and antimalarial agents. To date, however, no potent, specific inhibitors have been identified. Here, we performed a site-directed screening technique, tethering-fragment based drug discovery, against wild-type and mutant forms of NDH-2 containing engineered active-site cysteines. Inhibitory fragments displayed IC₅₀ values between 3 and 110?μM against NDH-2 mutants. Possible binding poses were investigated by in silico modelling, providing a basis for optimisation of fragment binding and improved potency against NDH-2.     

菜用和观赏甘薯种质资源遗传多样性分析

为了发掘菜用和观赏甘薯优异种质资源,通过对国家种质徐州甘薯试管苗库中1000余份资源材料进行鉴定,筛选了96份优异种质。利用30对SSR引物对入选材料进行了遗传多样性和群体结构分析,明确了这些材料遗传差异;并对入选材料12个表型质量性状进行主成分和聚类分析。结果表明:扩增的总条带数为275条,其中多态性条带为269条,多态率97.8%;利用DPS软件计算入选材料间的Nei72遗传距离为0.15~0.76,平均遗传距离0.66;群体结构分为3个组群,与分子标记聚类结果相似,表明入选材料有较大的遗传差异性;表型质量性状主成分分析得到5个主要成分,其累计贡献率达到80.50%;利用表型质量性状,可聚为8个组群。本研究通过分子标记与表型质量性状分析为下一步杂交选育菜用和观赏甘薯新品种提供了亲本选择信息。     

低氧及酸化胁迫对大黄鱼幼鱼离子调节与鳃组织结构的影响

为探讨大黄鱼幼鱼在低氧及酸化胁迫下机体离子调节情况,本研究探讨了低氧(溶解氧量DO 3.5 mg·L-1,pH 8.1)、酸化(DO 7.0 mg·L-1,pH 7.35)以及低氧酸化协同胁迫(DO3.5 mg·L-1,pH 7.35)对大黄鱼幼鱼鳃组织结构以及离子调节相关生理指标的影响.结果 表明:低氧胁迫下,大黄鱼...     

Research progress on the effects of soil erosion on vegetation

The relationship between vegetation and soil erosion deserves attention due to its scientific importance and practical applications. A great deal of information is available about the mechanisms and benefits of vegetation in the control of soil erosion, but the effects of soil erosion on vegetation development and succession is poorly documented. Research shows that soil erosion is the most important driving force for the degradation of upland and mountain ecosystems. Soil erosion interferes with the process of plant community development and vegetation succession, commencing with seed formation and impacting throughout the whole growth phase and affecting seed availability, dispersal, germination and establishment, plant community structure and spatial distribution. There have been almost no studies on the effects of soil erosion on seed development and availability, of surface flows on seed movement and redistribution, and their influences on soil seed bank and on vegetation establishment and distribution. However, these effects may be the main cause of low vegetation cover in regions of high soil erosion activity and these issues need to be investigated. Moreover, soil erosion is not only a negative influence on vegetation succession and restoration, but also a driving force of plant adaptation and evolution. Consequently, we need to study the effects of soil erosion on ecological processes and on development and regulation of vegetation succession from the points of view of pedology and vegetation, plant and seed ecology, and to establish an integrated theory and technology for deriving practical solutions to soil erosion problems.     

Effects of grassland conversion to cropland and forest on soil organic carbon and dissolved organic carbon in the farming-pastoral ecotone of Inner Mongolia

Effects of grassland conversion to cropland and forest on soil organic carbon (SOC), dissolved organic carbon (DOC) in the farming-pastoral ecotone of Inner Mongolia were investigated by direct field sampling. SOC content and DOC content in soil decreased after grassland were shifted to forest or cropland, in the sequence of grassland soil > forest soil > cropland soil. SOC stock declined by 18% after grassland shifted from to forest. Reclamation of cropland for 10 years, 15 years and 20 years lost SOC in 0–30 cm soil layer, by 34%, 14% and 18%, respectively, compared with that of grassland. DOC in 3 soil layers was within 21.1–26.5 mg/L in grassland, 12.1–14.6 mg/L in forest soil, and 8.0–14.0 mg/L in cropland soil. Correlation analysis indicated that SOC content and DOC content were positively dependent on total nitrogen content (p < 0.05), but negatively on bulk density or land use type (p < 0.05). DOC was positively correlated SOC (p < 0.01). Moreover, SOC content could be quantitatively described by a linear combination of land use types (p = 0.000, r² = 0.712), and DOC content by a linear combination of two soil-related variables, land use types and SOC (p = 0.000, r² = 0.861).     

不同分级及转归脓毒症患者血清PCT、D-D、CRP及血小板相关参数检测的临床意义

目的:探讨不同分级及转归脓毒症患者的血清降钙素原(PCT)、D-二聚体(D-D)、C反应蛋白(CRP)及血小板相关参数检测的临床意义。方法:回顾性分析2015年3月至2018年8月期间中国人民解放军西部战区总医院收治的92例脓毒症患者的临床资料,分析不同分级及转归脓毒症患者的血清中PCT、D-D和CRP水平、急性病生理与慢性健康评价系统Ⅱ(APACHEⅡ)评分及血小板相关参数[血小板计数(PLT)、血小板平均容积(MPV)、血小板分布宽度(PDW)、大型血小板比率(P-LCR)],并分析脓毒症患者PCT、D-D、CRP水平以及血小板相关参数与APACHEⅡ评分的相关性。结果:全身炎症反应综合征组、轻度脓毒症组、严重脓毒症组、脓毒性休克组血清PCT、D-D和CRP水平、MPV、PDW、P-LCR、APACHEⅡ评分逐渐升高(P0.05),PLT逐渐降低(P0.05)。存活组患者血清PCT、D-D、CRP水平、MPV、PDW、P-LCR、APACHEⅡ评分均低于死亡组(P0.05),PLT高于死亡组(P0.05)。Pearson相关分析显示,脓毒症患者血清PCT、D-D、CRP、MPV、PDW、P-LCR与APACHE II评分呈正相关(P0.05),PLT与APACHE II评分呈负相关(P0.05)。结论:脓毒症患者血清PCT、D-D、CRP及血小板相关指标可能参与了脓毒症的发展,通过检测其血清PCT、D-D、CRP水平及血小板相关参数可评估脓毒症患者的病情和预后。     

浙北地区常见绿化树种光合固碳特征

高固碳能力的树种选择是营造优质碳汇林,发展碳汇林业的重要基础工作.以浙北地区常见的30种造林绿化树种为研究材料,利用LI-6400便携式光合测定仪,测定树木光合日变化及不同光强梯度下光合作用的光响应特性,并根据实验观测值进行计算,对30个树种的日净固碳量和光合生理拟合参数进行Ward法聚类分析和因子分析.结果表明:香樟的固碳量最大((11.374±1.020) g·m-2·d-1),其次为碧桃、垂柳、石栎、无患子,固碳量最小的为红叶李((2.178±0.605) g·m-2·d-1),香樟和红叶李的日净固碳量有极显著差异(P＜0.01);树木的生理特性指标分析进一步反映了树种在浙北地区生长适应性及固碳能力大小,同时,根据树木的生理特性指标进行因子分析和聚类分析的结果,香樟、碧桃在浙北地区生长适应性较好,其次为无患子、垂柳、女贞等;根据树种固碳量及生理指标综合测定分析,建议在浙北地区造林绿化中可以优先选用香樟、碧桃、垂柳、无患子、石栎、女贞这些树种.     

座壳孢及其有性型（子囊菌门）代谢产物研究进展

座壳孢及其有性型是一类重要的虫生真菌,隶属子囊菌门、粪菌纲、肉座菌目、麦角菌科,能寄生粉虱和蚧类昆虫,可开发成一种环境友好型的生物农药。座壳孢及其有性型属成员广泛分布于热带和亚热带地区,该类群物种、栖息环境和生态适应的多样性使它们的代谢产物化学结构及其生物活性彰显出多样性特点,结构和功能多样的真菌代谢产物已成为发现新药先导化合物的重要资源。虫生真菌因其独特的生活方式和多种生存环境形成了与众不同的适应寄主特性及代谢通路,明显提高获得新颖结构、显著活性的代谢产物的几率,目前已是药物重点研发的领域。在座壳孢及其有性型代谢产物研究中已报道了萜类、黄酮类、醌类、环肽和甾醇等多种化合物,并具有抗肿瘤、抗疟疾、抗菌和杀虫等多种生物活性,可在农业、工业和医药保健等方面应用。本文对近年座壳孢及其有性型代谢产物的化学成分和生物活性等方面的研究进展进行概述,为促进座壳孢及其有性型代谢产物的深入研究、开发利用和新药创制提供参考。     

新城疫病毒FMW株体外溶瘤作用及其机制分析

[目的]筛选出能高效抑制多种人肿瘤细胞生长增殖的新城疫(New Castle disease virus,NDV)毒株,为进一步构建重组高效靶向溶瘤毒株奠定基础.[方法]以体外噻唑蓝法测定NDV对A549、SMMC7721等肿瘤细胞及人胚干细胞L-02、人胚肾细胞HEK293等的生长抑制率,空斑试验确定病毒滴度及感染复数.利用形态学观察、Hoechst荧光染色、流式细胞术及免疫印迹等分析了NDV-FMW诱导肿瘤细胞凋亡的细胞生物学变化及其机制.[结果]从近50株NDV中筛选出NDV-FMW,以20 MOI病毒作用A549、SMMC7721等肿瘤细胞48 h,细胞生长抑制率达60%,NDV-FMW诱导肿瘤细胞发生凋亡,效应呈时间和剂量的依赖性,凋亡细胞出现核染色质断裂、浓缩及二倍体亚峰,细胞周期阻滞于GO/G1期,此外,病毒感染A549细胞16 h后开始检测到活化的Caspase-3裂解片段及PARP裂解大片段.[结论]NDV-FMW株体外能高效抑制肿瘤细胞的增殖,并经Caspase-3途径诱导肿瘤细胞凋亡.FMW株具有自主知识产权,其良好的体外溶瘤能力为进一步探讨体内抗肿瘤及临床试验的进行奠定了基础,并有可能为恶性肿瘤的治疗提供新的生物制剂.