花青素合成转录因子基因在玉米中的表达研究:一种新型基因可视化跟踪表达系统

花青素是一种水溶性的黄酮类物质,可使植物呈现出红、蓝、紫和红紫等颜色.外源花青素代谢调控基因的表达可使花青素在植物细胞内积累,使植物体外观上表现出色彩的变化,易于观察,因此可作为报告基因用于植物转基因研究,快速报告细胞、组织、器官或植株是否被转化.本研究用花青素代谢调控基因Bi和C1作为报告基因,以epsp作为筛选标记基因,构建了植物表达载体pBAC9009.基因枪转化玉米自交系501的幼胚,经过除草剂草甘膦抗性筛选和分化再生,获得了转化再生植株75株,其中43株获得结实种子.T0代植株有18株在苗期或生长阶段表现局部或全紫色,8个结实果穗有零星的紫色种子,从外观上可直接确认为转化植株.结合PCR和RT-PCR的分子检测及花青素含量分析,表明叶片和籽粒为紫色的玉米植株中外源目的基因已整合并且高效表达,即紫色表型与分子检测的结果高度一致.该结果表明我们成功建立了以花青素基因作为报告基因的植物转基因可视化跟踪表达系统.该系统的应用可以大大提高工作效率,节约检测成本,对于植物转基因研究具有重要意义.     

Recent progress in room-temperature sodium-ion batteries

Room-temperature sodium-ion batteries have attracted increasing interest in recent years because of abundant sodium reserves and the low costs. Grid-scale energy storage applications are particularly rele- vant to this battery technology. Here, we present our recent progress in researching room-temperature so- dium-ion batteries, and focus on new electrode materials, including cathodes and anodes, for both non-a- queous and aqueous systems.     

A comparison of iron phthalocyanine and cobalt porphyrin on the electrochemical catalysis in Ni-MH battery

The effects of iron phthalocyanine （FePc） and cobalt porphyrin （CoPp） on inner pressure and cycle behavior of sealed Ni-MH batteries were investigated in this study. The morphology of battery electrode was observed by SEM. The electrochemical impedance spectroscopy of floating-charge/discharge battery was also measured. Experimental results show that the addition of FePc or CoPp to the alloy electrode is an effective approach to decrease the internal pressure of battery during the process of charge and overcharge. In contrast to CoPp, the battery with FePc exhibits a slower capacity decay and a smaller overpotential at the same charge-discharge rate. As an electrocatalyst, FePc may more effectively speed up the reduction of oxygen, and decrease its reduction potential. As a result, the charge process is accelerated, the gas evolution is reduced and the pulverization of electrode materials is slowed down.     

Ages and tectonic significance of the collision-related granite porphyries in the Lhunzhub Basin, Tibet, China

The Paleocene collision-related granite porphyries are identified for the first time along the western margin of the Lhunzhub Basin, Tibet. SHRIMP U-Pb zircon analysis indicates that the granite porphyries were emplaced at 58.7±1.1 Ma (MSWD = 0.79) during the Indo-Asian continental collision. The granite porphyries are peraluminous and high in K, belonging to the calc-alkaline to high-K calc-alkaline series. They are relatively enriched in LILE, Th and LREE and depletion in Ba, Nb, P and Ti, characterized by LREE-enriched patterns with slightly to moderately negative Eu anomalies. These Paleocene granite porphyries are interpreted as the products generated by partial melting of the pre-existing arc crustal rocks caused by the increase of pressures and temperatures during the crustal shortening at the early stages of the Indo-Asian continental collision since 65 Ma. Despite inherited geochemical features and tectonic settings of the arc protoliths, they are significantly different from the volcanic rocks of the Dianzhong Formation within the Linzizong Group and the Miocene granite por- phyries in the Gangdise belt.     

U-Pb zircon dating of Early Paleozoic gabbro from the Nantinghe ophiolite in the Changning-Menglian suture zone and its geological implication

The Nantinghe ophiolite is located in the northern part of the Changning-Menglian suture zone in southeast Tibet. It is composed of meta-peridotite, cumulative gabbro, meta-gabbro, plagioclase amphibolite and meta-basalt. Zircon U-Pb dating of the cumulative gabbro gives concordant ages of 473.0±3.8 Ma and 443.6±4.0 Ma respectively, indicating the early and late episodes of mafic magmatisms during the Paleo-Tethys oceanic rifting. The 16 LA-ICPMS zircon U-Pb analyses of meta-gabbro yield a weight mean age of 439±2.4Ma. The gabbro shows relatively low contents of SiO2 (46.46%-52.11%), TiO2 (0.96%-1.14%) and K2O (0.48%-0.75%). Its trace element distribution patterns are partly similar to those of the mid-ocean ridge basalts, and part is depleted in high field strength elements such as Nb, Ta, Zr, Hf and Ti. These features suggest that the mafic rocks were probably formed in a MORB-like or backarc rift basin setting. The zircon U-Pb age of gabbro is consistent with a late crystallization age of the cumulative gabbro from the Nantinghe ophiolite, suggesting that the Paleo-Tethys oceanic basin was opened during 444-439 Ma, possibly as a backarc basin. It is the first precise age which defines the formation time of the early Paleozoic ophiolite in the Changning-Menglian suture zone. These geochronological and geochemical characteristics of the Nantinghe ophiolite are consistent with those from the Guoganjianianshan and Taoxinghu of the Longmu Co-Shuanghu suture in the Qiangtang region. Thus, we suggest that the both Changning-Menglian and Longmu Co-Shuanghu sutures were probably transformed from the relic oceanic crust of the uniform Paleo-Tethys, which likely represents the original and main Paleo-Tethys oceanic basin.