真盐生植物盐地碱蓬根系边缘细胞在耐盐中的作用初探

以黄河三角洲潮间带盐地碱蓬种子生成的幼苗为材料,研究了NaCl胁迫对盐地碱蓬生长与根系边缘细胞的影响。盐地碱蓬的第一个边缘细胞几乎与根尖同步产生,当根长达到13mm时,边缘细胞数目达到最大值。NaCl胁迫抑制边缘细胞的活性,但低浓度的NaCl处理增加边缘细胞的数目。低浓度NaCl处理时果胶甲基酯酶（PME）的活性比对照有明显增加,超氧化物歧化酶（SOD）活性随着NaCl浓度的增加呈现先上升后下降的趋势,低浓度NaCl可以增加盐地碱蓬根内过氧化氢酶（CAT）的活性,NaCl处理时间和处理浓度都对过氧化物酶（POD）活性的影响不明显。这些结果表明,盐地碱蓬至少部分通过增加调控活性氧（ROS）水平增加PME活性及根系边缘细胞数目来抵抗NaCl胁迫。     

吸虱昆虫群落数量分类及其与小兽宿主的协同进化关系

以云南省16种主要小兽宿主体表吸虱群落为分类单元,以基于共54个群落特征变量的各群落优势虱种的相对优势度D_r、染虱率R_L、虱指数I_L、总染虱率R_LT和总虱指数I_LT及各群落的结构参数（平均丰富度 、平均均匀度 、平均多样性指数 及平均优势度指数 ）来探讨云南省吸虱昆虫与其宿主协同进化的关系。运用SPSS12.0统计软件中的系统聚类分析,对16种主要小兽宿主体表吸虱群落进行数量分析。结果将16种小兽宿主体表吸虱群落分为8个类群。隶属同一个属的小兽,其体表吸虱群落相似程度高,在系统聚类分析中聚为一类; 大多数吸虱群落相似性大小与相应小兽宿主在动物分类上的近缘性高低呈高度一致。结果提示： 吸虱昆虫与其所寄生的小兽宿主存在同步进化的关系,特定的小兽宿主,其体表吸虱群落的构成比较稳定,宿主动物的近缘关系越近,其体表吸虱群落的相似性越高,这是吸虱昆虫与小兽宿主协同进化的一个重要生态学证据。     

A20 plays a critical role in the immunoregulatory function of mesenchymal stem cells

Mesenchymal stem cells (MSCs) possess an immunoregulatory capacity and are a therapeutic target for many inflammation‐related diseases. However, the detailed mechanisms of MSC‐mediated immunosuppression remain unclear. In this study, we provide new information to partly explain the molecular mechanisms of immunoregulation by MSCs. Specifically, we found that A20 expression was induced in MSCs by inflammatory cytokines. Knockdown of A20 in MSCs resulted in increased proliferation and reduced adipogenesis, and partly reversed the suppressive effect of MSCs on T cell proliferation in vitro and inhibited tumour growth in vivo. Mechanistic studies indicated that knockdown of A20 in MSCs inhibited activation of the p38 mitogen‐activated protein kinase (MAPK) pathway, which potently promoted the production of tumour necrosis factor (TNF)‐α and inhibited the production of interleukin (IL)‐10. Collectively, these data reveal a crucial role of A20 in regulating the immunomodulatory activities of MSCs by controlling the expression of TNF‐α and IL‐10 in an inflammatory environment. These findings provide novel insights into the pathogenesis of various inflammatory‐associated diseases, and are a new reference for the future development of treatments for such afflictions.     

逆境下拟南芥野生型和突变体sex1游离态水杨酸含量及根形态差异

以拟南芥野生型(WT)和突变体sex1为材料,采用HPLC、显微观察等方法,研究了WT在10个不同生长期时游离态水杨酸(SA)含量的变化,比较了在丁香假单胞菌番茄致病变种(Pst.DC3000)、H2O2、甲基紫精(MV)和SA处理环境下WT和sex1中游离态SA含量及幼苗根形态的差异.结果表明:在花序继续开放期(6.30、6.50)以及长角果出现期(8.0),WT中游离态SA含量处在更低水平;2 mmol·L-1 SA处理能够极显著提高WT和突变体sex1中游离态SA的积累,且突变体sex1中游离态SA水平增加更明显,是其他处理游离态SA水平的10倍左右;在MV和H2O2处理下,WT和sex1主根生长受抑制的程度没有明显差异,而突变体sex1幼苗的根毛在低浓度MV环境中比WT更长但密度差异不明显,且WT和sex1根毛在低浓度H2O2环境中差异情况与对照组相似,但外源SA处理使WT和突变体sex1的主根生长均受到明显的抑制,两者的根毛密度随SA增加逐渐降低甚至消失,且突变体sex1比WT受到的抑制作用更明显.研究发现:拟南芥的开花和结果过程与SA依赖途径有一定关系;外源添加SA比Pst.DC3000、H2O2和MV处理更能直接促使拟南芥突变体sex1产生更多的游离态SA;突变体sex1根的生长发育比WT更易受到生长环境条件的影响,且sex1根形态的生长存在一定的SA浓度依赖模式.     

应用性外激素监测马尾松毛虫发生数量的初步研究

本研究采用持效期达 3 0天以上的复合橡胶载体的新型诱芯诱捕器对马尾松毛虫进行林间监测 ,发现诱蛾数量与田间调查的幼虫数量有很大的关联性 ,各乡镇每诱捕点平均诱蛾数与 1代、2代幼虫虫株率、平均虫口的变化趋势基本相同     

河北省南大港农场2002年夏蝗发生特点及原因浅析

进入 90年代以来 ,南大港蝗区东亚飞蝗Locustamigratoriamanilensis(Meyen)大发生 6次 ,2 0 0 1年夏秋蝗发生面积达 2 6万hm2 ,5龄蝗蝻最高密度为 1 0 0 0 0头 m2 。 2 0 0 2年形势更为严峻 ,仅夏蝗发生面积超过 2万hm2 ;分别造成 1 3 0 0hm2 和 2 70 0hm2 的芦苇被吃成光杆和被啃食的严重破叶。出土时间早、孵化时间长、龄期悬殊大是今年夏蝗发生的主要特点。主要原因是去年越冬卵块基数大 ,其次是受气候条件和农业环境的影响     

寄主植物对棉铃虫越冬蛹抗寒能力的影响

通过对滞育蛹过冷却点的测定 ,初步明确寄主对棉铃虫Helicoverpaarmigera的越冬抗寒性有影响 ,幼虫取食棉花时产生的滞育蛹的过冷却点低于取食玉米的滞育蛹的过冷却点 ,即前者的抗寒能力高于后者 ;但用Bt棉喂养后的棉铃虫滞育蛹抗寒能力下降     

独岛枝芽胞杆菌MCCC 1A00493产生的4-乙烯基苯酚鉴定和作用南方根结线虫特性研究

[目的]根结线虫危害严重,难防难控,前期研究发现一株深海来源的独岛枝芽胞杆菌(Virgibacillus dokdonensis)MCCC 1A00493对南方根结线虫具有良好的体外拮抗效果,本研究分离鉴定菌株发酵液中杀线虫活性物质,对其作用线虫的多种模式进行研究,为菌株有效控制植物病原线虫的应用奠定理论基础.[方法]...     

Protein kinase C delta null mice exhibit structural alterations in articular surface,intra-articular and subchondral compartments

IntroductionStructural alterations in intra-articular and subchondral compartments are hallmarks of osteoarthritis, a degenerative disease that causes pain and disability in the aging population. Protein kinase C delta (PKC-δ) plays versatile functions in cell growth and differentiation, but its role in the articular cartilage and subchondral bone is not known.MethodsHistological analysis including alcian blue, safranin O staining and fluorochrome labeling were used to reveal structural alterations at the articular cartilage surface and bone–cartilage interface in PKC-δ knockout (KO) mice. The morphology and organization of chondrocytes were studied using confocal microscopy. Glycosaminoglycan content was studied by micromass culture of chondrocytes of PKC-δ KO mice.ResultsWe uncovered atypical structural demarcation between articular cartilage and subchondral bone of PKC-δ KO mice. Histology analyses revealed a thickening of the articular cartilage and calcified bone–cartilage interface, and decreased safranin O staining accompanied by an increase in the number of hypertrophic chondrocytes in the articular cartilage of PKC-δ KO mice. Interestingly, loss of demarcation between articular cartilage and bone was concomitant with irregular chondrocyte morphology and arrangement. Consistently, in vivo calcein labeling assay showed an increased intensity of calcein labeling in the interface of the growth plate and metaphysis in PKC-δ KO mice. Furthermore, in vitro culture of chondrocyte micromass showed a decreased alcian blue staining of chondrocyte micromass in the PKC-δ KO mice, indicative of a reduced level of glycosaminoglycan production.ConclusionsOur data imply a role for PKC-δ in the osteochondral plasticity of the interface between articular cartilage and the osteochondral junction.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0720-4) contains supplementary material, which is available to authorized users.     

沙地植被碳氮磷化学计量特征与物种多样性的关系

植被化学计量特征表征植物营养限制.它是否会影响物种多样性需要进一步探究.本研究以宁夏哈巴湖国家级自然保护区沙地油蒿群落和沙柳群落为对象,计算了植被碳(C)、氮(N)、磷(P)含量,分析了植被C、N、P生态化学计量特征对沙地植物群落物种多样性的影响.结果表明: 在流动沙丘和半固定沙丘生境中的沙柳群落,物种多样性Simpson指数与植被C/N值存在显著的负相关关系,而与植被N/P值的相关性不显著;在半固定沙丘和固定沙丘生境中的油蒿群落,物种多样性Shannon指数与N/P值存在显著正相关关系,而与C/N值存在显著负相关关系.结合C、N、P生态化学计量特征与冗余分析可知,油蒿群落和沙柳群落的植被P含量对物种多样性的影响不同,导致两个群落的植被N/P值对物种多样性产生不同的影响.