黄精凝集素PCL-2诱导人前列腺癌LNCap细胞凋亡及机制研究

研究黄精凝集素PCL-2对人前列腺癌LNCap细胞生物活性和可能的抗肿瘤机制。从黄精药材中提取分离得到黄精凝集素PCL-2,体外培养LNCap细胞,采用WST-1和集落形成实验评价PCL-2对LNCap细胞的增殖作用;2,7-二氯荧光黄双乙酸盐(DCFH-DA)荧光探针法检测LNCap细胞内ROS含量;qRT-PCR和Western blot法检测PCL-2对LNCap细胞中相关基因和蛋白表达的影响。研究结果显示PCL-2能显著抑制LNCap细胞的增殖,促进细胞中ROS生成;PCL-2通过上调LNCap细胞中Bax、Caspase-3及Caspase-9基因mRNA和蛋白表达并下调Bcl-2基因mRNA和蛋白表达水平诱导LNCap细胞凋亡。本研究结果表明PCL-2诱导LNCap细胞凋亡活性作用显著,可作为抑制前列腺癌的潜在药物。     

Genetic structure in the Mediterranean seagrass Posidonia oceanica: disentangling past vicariance events from contemporary patterns of gene flow

The Mediterranean Sea is a two‐basin system, with the boundary zone restricted to the Strait of Sicily and the narrow Strait of Messina. Two main population groups are recognized in the Mediterranean endemic seagrass Posidonia oceanica, corresponding to the Western and the Eastern basins. To address the nature of the East–West cleavage in P. oceanica, the main aims of this study were: (i) to define the genetic structure within the potential contact zone (i.e. the Strait of Sicily) and clarify the extent of gene flow between the two population groups, and (ii) to investigate the role of present water circulation patterns vs. past evolutionary events on the observed genetic pattern. To achieve these goals, we utilized SSR markers and we simulated, with respect to current regime, the possible present‐day dispersal pattern of Posidonia floating fruits using 28‐day numerical Lagrangian trajectories. The results obtained confirm the presence of the two main population groups, without any indices of reproductive isolation, with the break zone located at the level of the Southern tip of Calabria. The populations in the Strait of Sicily showed higher affinity with Western than with Eastern populations. This pattern of genetic structure probably reflects historical avenues of recolonization from relict glacial areas and past vicariance events, but seems to persist as a result of the low connectivity among populations via marine currents, as suggested by our dispersal simulation analysis.     

胶州湾滨海湿地凋落物分解对土壤有机碳矿化的影响

通过室内培养试验和三维荧光光谱技术(3D-EEMs),开展了胶州湾滨海湿地碱蓬、芦苇和互花米草的分解对土壤有机碳矿化的影响研究。结果表明,凋落物的添加提高了土壤有机碳矿化速率和累积矿化量,具体表现为碱蓬互花米草芦苇空白对照;乘幂曲线模型能较好地描述有机碳矿化速率和累积矿化量的变化趋势。光谱分析表明,分解过程中类蛋白荧光强度始终大于类腐殖酸荧光强度;利用荧光区域积分进行定量分析表明,不同处理下类蛋白质物质占比最高,类腐殖质物质次之;荧光参数表明,土壤有机碳的芳香化程度在培养期间先升高后降低。凋落物分解通过增加土壤中的营养物质,提高了土壤中微生物活性,从而改变了土壤有机碳的结构和化学组分,且凋落物的植被特征决定了其对土壤有机碳矿化影响程度的大小。     

农田重金属沿植食性昆虫-天敌昆虫传递及对害虫生物防治的影响

农田重金属污染是全球农业面临的重要环境问题之一。重金属经植物吸收富集,由植食性昆虫取食并积累而产生上行效应,影响天敌昆虫的生长发育、生殖能力以及行为,进而影响天敌对害虫的控制作用。本文系统总结了农田生态系统中重金属沿植食性昆虫传递对天敌昆虫的影响,分析了农田重金属污染对害虫生物防治的直接与间接影响效应,发现重金属胁迫一般会导致天敌昆虫生长发育延缓、生殖力降低、捕食量减少等,直接影响害虫生物防治效果;但也可能导致害虫毒物兴奋效应产生和抗性能力增强,间接增加害虫防治难度。根据研究现状,对重金属污染影响天敌昆虫和生物防治的未来研究方向进行了展望。