CCM 在研究园林植物NOX 吸收能力中的应用

以湛江市6 种园林植物常绿乔木小叶榕(Ficus concinna)和人面子(Dracontomelon duperreanum), 常绿灌木龙船花(Ixora chinensis)和朱槿(Hibiscus rosa-sinensis)以及落叶乔木大花紫薇(Lagerstroemia speciosa)和黄葛榕(Ficus virens)为研究对象, 探讨叶绿素仪(CCM)在研究植物NOx 吸收能力中的应用。研究结果表明: 1)6 种植物的叶片CCI值与全氮含量均呈显著的正相关, 朱槿和人面子表现出最好的线性相关(R2 = 0.70, P < 0.001; R2 = 0.74, P < 0.001),CCI 值可以用于叶片氮含量的预测。2) 植物可以响应不同浓度的NOX 而表现出叶片氮含量的差异, 各树种的叶片CCI值均为污染区显著高于清洁区, 与叶片实测氮含量呈相同的变化趋势。3)CCI 值在植物生活型间并不存在显著差异, 宜在物种水平上进行研究; CCI 值同时受叶面积、叶片含水率和叶比重(Leaf mass per area, LMA)等因素的影响。利用CCI值可以快速、无损地测定叶片在污染区和清洁区不同NOX 浓度下叶片全氮的相对含量, 从而判断不同植物的NOX 相对吸收能力, 但这一方法的准确实施, 不仅需要更大的样本建立精准的模型, 也需要更加科学、合理的取样, 更为关键的是污染区和清洁区的CCI 差值应建立一个统一的转换尺度。     

CCM1–ICAP-1 complex controls β1 integrin–dependent endothelial contractility and fibronectin remodeling

The endothelial CCM complex regulates blood vessel stability and permeability. Loss-of-function mutations in CCM genes are responsible for human cerebral cavernous malformations (CCMs), which are characterized by clusters of hemorrhagic dilated capillaries composed of endothelium lacking mural cells and altered sub-endothelial extracellular matrix (ECM). Association of the CCM1/2 complex with ICAP-1, an inhibitor of β1 integrin, prompted us to investigate whether the CCM complex interferes with integrin signaling. We demonstrate that CCM1/2 loss resulted in ICAP-1 destabilization, which increased β1 integrin activation and led to increased RhoA-dependent contractility. The resulting abnormal distribution of forces led to aberrant ECM remodeling around lesions of CCM1- and CCM2-deficient mice. ICAP-1–deficient vessels displayed similar defects. We demonstrate that a positive feedback loop between the aberrant ECM and internal cellular tension led to decreased endothelial barrier function. Our data support that up-regulation of β1 integrin activation participates in the progression of CCM lesions by destabilizing intercellular junctions through increased cell contractility and aberrant ECM remodeling.     

Leptolyngbya CCM 4, a cyanobacterium with far-red photoacclimation from Cuatro Ciénegas Basin,México

Photosynthetica - A cyanobacterium containing phycobiliproteins with far-red acclimation was isolated from Pozas Rojas, Cuatro Ciénegas, México. It was named Leptolyngbya CCM 4 after...