Wheat genomic study for genetic improvement of traits in China

Science China Life Sciences - Bread wheat (Triticum aestivum L.) is a major crop that feeds 40% of the world’s population. Over the past several decades, advances in genomics have led to...     

Dynamically Tunable Terahertz Plasmon-Induced Transparency Analogy Based on Asymmetric Graphene Resonator Arrays

Plasmonics - A plasmon-induced transparency (PIT) effect based on an asymmetric graphene loop structure has been proposed and investigated in this paper. The microstructure consists of a pair of...     

Echinacoside inhibits the proliferation,migration, invasion and angiogenesis of ovarian cancer cells through PI3K/AKT pathway

Journal of Molecular Histology - Echinacoside is a group of natural compounds extracted from medicinal plants Cistanche and Echinacea, which has neuroprotective, antiaging, immunomodulatory and...     

Molecular dynamics simulations provide insights into the origin of gleevec’s selectivity toward human tyrosine kinases

Protein kinases are critical drug targets against cancer. Since the discovery of Gleevec, a specific inhibitor of Abl kinase, the capability of this drug to distinguish between Abl and other tyrosine kinases, such as Src, has been intensely investigated but the origin of Gleevec’s selectivity to Abl against Src is less studied. Here, we performed molecular dynamics (MD) simulations, dynamical cross-correlation matrices (DCCM), dynamical network analysis, and binding free energy calculations to explore Gleevec’s selectivity based on the crystal structures of Abl, Src, and their common ancestors (ANC-AS) and the two constructed mutation systems (AS→Abl and AS→Src). MD simulations revealed that the conformation of the phosphate-binding loop (P-loop) was altered significantly in the AS→Abl system. DCCM results unraveled that mutations increased anticorrelated motions in the AS→Abl system. Community network analysis suggested that the P-loop established special contacts in the AS→Abl system that are devoid in the AS→Src system. The binding free energy calculations unveiled that the affinity of Gleevec to AS→Abl increased to near the Abl level, whereas its affinity to AS→Src decreased to near the Src level. Analysis of individual residue contributions showed that the differences were located mainly at the P-loop. This study is valuable for understanding the sensitivity of Gleevec to human tyrosine kinases.

Communicated by Ramaswamy H. Sarma     

The Smad3-miR-29b/miR-29c axis mediates the protective effect of macrophage migration inhibitory factor against cardiac fibrosis

Although macrophage migration inhibitory factor (MIF) is known to have antioxidant property, the role of MIF in cardiac fibrosis has not been well understood. We found that MIF was markedly increased in angiotension II (Ang-II)-infused mouse myocardium. Myocardial function was impaired and cardiac fibrosis was aggravated in Mif-knockout (Mif-KO) mice. Functionally, overexpression of MIF and MIF protein could inhibit the expression of fibrosis-associated collagen (Col) 1a1, COL3A1 and α-SMA, and Smad3 activation in mouse cardiac fibroblasts (CFs). Consistently, MIF deficiency could exacerbate the expression of COL1A1, COL3A1 and α-SMA, and Smad3 activation in Ang-II-treated CFs. Interestingly, microRNA-29b-3p (miR-29b-3p) and microRNA-29c-3p (miR-29c-3p) were down-regulated in the myocardium of Ang-II-infused Mif-KO mice but upregulated in CFs with MIF overexpression or by treatment with MIF protein. MiR-29b-3p and miR-29c-3p could suppress the expression of COL1A1, COL3A1 and α-SMA in CFs through targeting the pro-fibrosis genes of transforming growth factor beta-2 (Tgfb2) and matrix metallopeptidase 2 (Mmp2). We further demonstrated that Mif inhibited reactive oxygen species (ROS) generation and Smad3 activation, and rescued the decrease of miR-29b-3p and miR-29c-3p in Ang-II-treated CFs. Smad3 inhibitors, SIS3 and Naringenin, and Smad3 siRNA could reverse the decrease of miR-29b-3p and miR-29c-3p in Ang-II-treated CFs. Taken together, our data demonstrated that the Smad3-miR-29b/miR-29c axis mediates the inhibitory effect of macrophage migration inhibitory factor on cardiac fibrosis.     

五大连池火山色木槭叶功能性状特征

植物功能性状反映了植物对生长环境的响应和适应, 是连接植物与环境的桥梁, 研究植物功能性状特征及其随坡向的变化规律, 对认识不同微地形生境下植物群落空间格局形成及适应机制具有重要意义。本文以五大连池不同历史年代的8座火山共有树种色木槭(Acer mono)为研究对象, 测定了9类叶功能性状, 研究了植物叶功能性状在火山间及火山坡向间(阴坡-阳坡)的变化规律, 以期揭示生境对火山植物主要叶功能性状的影响, 以及阴阳坡植物生存策略的变化, 初步探讨了植物对环境的适应机制。结果表明: (1)坡向的变化是造成色木槭叶功能性状差异的重要原因; (2)火山间叶功能性状的差异反映了它们具有不同的资源环境, 色木槭生长主要受氮元素的限制; (3)南北坡向及火山间叶片厚度与叶面积均呈极显著的正相关关系, 叶片厚度与比叶面积在不同火山间均呈显著的正相关关系, 这与色木槭在火山土壤条件下的自我保护密切相关, 色木槭通过这些指标间的功能调节来适应环境的变化, 并形成最佳功能组合。五大连池不同历史年代火山的色木槭采用增加植物叶片叶干物质浓度、叶面积、叶片厚度、叶氮和叶磷浓度提高固碳能力, 通过降低比叶面积和氮磷比来适应干旱、土壤养分贫瘠的环境。     

不同基质和处理对6种山茶花扦插成活率的影响

研究不同基质和处理对6个拟作为年宵花的山茶花新品种扦插成活率的影响。采用3种不同的基质配比和3种不同的处理对6个品种的山茶花进行了扦插试验。结果表明,泥炭与黄土或珍珠岩的混合基质最适合该6个品种的扦插生根,生根粉对6个山茶花品种的成活率影响不大,但插口加裹黄土后能有效提高其成活率。6个品种在最佳的扦插条件下的成活率在85%-92%之间。研究结果为快速大量地生产这些品种提供技术支持。     

环境友好型杨梅园高效栽培类型与综合效益评价

杨梅园实行精耕细作,会造成生物多样性下降、水土流失加重、杨梅病虫害加剧等不良后果。为克服或缓解这些难题,对杨梅林开展了不同类型的混交栽培模式和抚育方式的研究。结果表明:进行机械割草的杨梅园生物多样性较优,其维管束植物总计达78种,而以药剂除草的,总计仅11种,差异极显著;"杨梅针、阔、竹混交林+自然生草+机械割草"、"杨梅纯林+自然生草+机械割草"和"杨梅纯林+清耕(除草剂除草)"等三种栽培与抚育类型的主要病害有杨梅癌肿病等2种,主要虫害有白蚁类、袋蛾类、栗黄枯叶蛾等7种(类),均以针、阔、竹混交栽培模式受害最轻。对"杨梅+蓝莓"、"杨梅+蕨类(种植)"和杨梅自然生草等3种栽培模式以及机械割草、人工割草和药剂除草等3种抚育方式的"三大效益"进行了综合评价。     

Purification and characterisation of a gentisate 1,2-dioxygenase fromRalstonia solanacearum GMI 1000

The gene encoding gentisate 1,2-dioxygenase from a soil-borne Gram-negative bacterium,Ralstonia solanacearum GMI 1000, was cloned and overexpressed inEscherichia coli. The resulting product incorporated a (His) 6 tag was purified to homogeneity from the harvested cell extracts by affinity chromatography. SDS-PAGE showed that the polypeptide exhibited an approximate molecular mass of 38 kDa. The optimal temperature and pH for gentisate cleavage catalysed by the enzyme were 30 °C and 8.0, respectively. TheK _m of the enzyme was determined to be 56 μM. ThepI is 4.6–4.8. Moreover, site-directed mutagenesis revealed that His105, His 107, and His 146 are the crucial residues involved in the catalytic activity of gentisate 1,2-dioxygenase fromRalstonia solanacearum GMI 1000.