特色香料作物油樟叶内生Bacillus velezensis YZ12的鉴定及拮抗病原菌活性

植物内生菌关系到植物的健康生长,且与植物产生的相关功效产物紧密关联。以我国四川宜宾油樟叶片分离筛选得到的内生细菌作为研究对象,利用传统微生物培养方法,基于形态学观察,16S rRNA和gyrA基因系统发育分析的多相分类学方法,将其鉴定为贝莱斯芽胞杆菌(Bacillus velezensis);并通过对从油樟叶片中分离的油樟真菌YZP-01以及常见植物病原真菌绳状篮状菌(Talaromyces funiculosus)、拟轮枝镰孢菌(Fusarium verticillioides)、草酸青霉(Penicillium oxalicum)四种致病菌株进行了拮抗试验,发现了该菌株具有广谱且良好的拮抗病原菌活性。使用特定引物扩增功能基因(bioA,bmyB,ituC,fenD,srfAA,srfAB,yngG和yndJ),并成功从菌株YZ12中扩增出这些基因。     

MiR-92b-3p promotes neurite growth and functional recovery via the PTEN/AKT pathway in acute spinal cord injury

Emerging evidence indicates that microRNAs play an important role in neural remodeling, including neurite growth, after acute spinal cord injury (ASCI). This study aims to identify the mechanism by which miR-92b-3p regulates neurite growth in vivo and in vitro. Adult Sprague–Dawley rats were selected to establish the ASCI model, and the expressions of miR-92b-3p and phosphate and tensin homolog deleted on chromosome ten (PTEN) were quantified at different time points. The interaction between miR-92b-3p and PTEN was further detected in the PC12 cell line and dual-luciferase reporter assay. Neurite growth proteins (GAP43 and NF-200) were assessed by western blotting after miR-92b-3p mimics treatment. The PTEN/AKT pathway-related proteins and their roles in miR-92b-3p regulation were also identified using western blotting and immunofluorescence in vitro through LY294002, an AKT inhibitor. The effect of miR-92b-3p was further determined in vivo according to the Basso-Beattie-Bresnahan (BBB) Scale and GAP43 and NF-200 expressions. miR-92b-3p was downregulated after ASCI, while PTEN showed a simultaneous opposing trend. Overexpression of miR-92b-3p downregulated PTEN expression and promoted phosphorylation of AKT, as well as the expression of GAP43 and NF-200 in PC12 cells. Furthermore, the dual-luciferase reporter assay revealed that miR-92b-3p exerted its effect by targeting PTEN's 3ʹ-untranslated regions and that this effect could be counteracted by AKT phosphorylation blocker LY294002 through western blotting and immunofluorescence. Moreover, miR-92b-3p could also improve the BBB scale as well as GAP43 and NF-200 expression levels in vivo. Collectively, these results indicate that miR-92b-3p promotes neurite growth and functional recovery through the PTEN/AKT pathway in ASCI.     

植物硫氧还蛋白系统

硫氧还蛋白是一类催化二硫键氧化还原的小蛋白,它通过调控细胞中氧化还原状态发挥重要的作用。在植物中,硫氧还蛋白系统尤为复杂,参与了植物的新陈代谢、转录翻译调控、信号传导以及植物的抗逆反应等。本文主要通过对植物硫氧还蛋白分类、活性位点、结构以及3种硫氧还蛋白系统研究现状进行概述,并对植物的硫氧还蛋白及系统进行了展望,从而较为全面地综述了植物的硫氧还蛋白系统,为进一步了解硫氧还蛋白在植物体内的作用机制奠定基础,也为今后的相关研究提供参考。     

Structures of Foot-and-mouth Disease Virus with neutralizing antibodies derived from recovered natural host reveal a mechanism for cross-serotype neutralization

The development of a universal vaccine against foot-and-mouth disease virus (FMDV) is hindered by cross-serotype antigenic diversity and by a lack of knowledge regarding neutralization of the virus in natural hosts. In this study, we isolated serotype O-specific neutralizing antibodies (NAbs) (F145 and B77) from recovered natural bovine hosts by using the single B cell antibody isolation technique. We also identified a serotype O/A cross-reacting NAb (R50) and determined virus-NAb complex structures by cryo-electron microscopy at near-atomic resolution. F145 and B77 were shown to engage the capsid of FMDV-O near the icosahedral threefold axis, binding to the BC/HI-loop of VP2. In contrast, R50 engages the capsids of both FMDV-O and FMDV-A between the 2- and 5-fold axes and binds to the BC/EF/GH-loop of VP1 and to the GH-loop of VP3 from two adjacent protomers, revealing a previously unknown antigenic site. The cross-serotype neutralizing epitope recognized by R50 is highly conserved among serotype O/A. These findings help to elucidate FMDV neutralization by natural hosts and provide epitope information for the development of a universal vaccine for cross-serotype protection against FMDV.     

FtMYB18 acts as a negative regulator of anthocyanin/proanthocyanidin biosynthesis in Tartary buckwheat

Plant Molecular Biology - FtMYB18 plays a role in the repression of anthocyanins and proanthocyanidins accumulation by strongly down-regulating the CHS and DFR genes in Tartary buckwheat, and the...     

黄曲霉素合成相关基因表达与环境因素的关系

简单介绍了黄曲霉毒素的发现、分布、危害和范围,详细叙述了黄曲霉毒素生物合成中相关基因的表达与调控,概述了黄曲霉毒素合成中的关键基因、酶和调控因子重要性,分析了影响黄曲霉毒素合成的环境因素。不仅在基础理论上对黄曲霉毒素合成机理进行了深入探讨,而且在应用研究上为减少粮食和食品受到重金属污染和黄曲霉毒素危害提供了新的思路。     

Short-term changes in the mesozooplanktonic community in theSeine ROFI (Region of Freshwater Influence)(eastern English Channel)

Discrete-depth, hourly mesozooplankton samples were collectedover a 92 h period in May 1992 at an anchor station within theSeine Region of Freshwater Influence (ROFI) (English Channel).The mesozooplankton community defined as a euryhaline marineassemblage was dominated by the calanoid copepods Acartia spp.,Temora longicornis and Centropages hamatus, the cladoceran Evadnenordmanni and the appendicularian Oikopleura dioica. The semi-diurnaltidal current was the dominant factor in determining the short-termtemporal changes in the community in terms of density and speciescomposition so that zooplankton patches displayed oscillatingmotion in relation to tidal advection. Although a few species(e.g. Pleurobrachia pileus) exhibited higher densities aroundlow tide, maximum densities were observed for most species (e.g.T.longicornis and E.nordmanni) around high tide, according tosalinity variations. Diurnal changes were only reported forcyclopoid copepods (i.e. Halicyclops sp. and Cyclopina sp.)which wer$$$ mainly endobenthic during the day and moved intothe water column at night. Besides temporal changes in depth-averageddensities, most species exhibited vertical migrations at dieland/or tidal periods. Tidal vertical migrations were reportedonly for a few taxa and could be the result of passive mechanisms(e.g. vertical mixing) rather than of active behaviour. Dielvertical migrations were observed in most of the abundant taxa.While this migration pattern did not appear to be an adaptationto predator avoidance within the Seine ROFI, it could regulatehorizontal transport of organisms and promote their retention.The consequences of the short-term mesozooplankton fluctuationsfor sampling designs are discussed.     

植物外源凝集素及其在植物基因工程中的应用

植物外源凝集素及其基因研究近年来发展迅速 ,尤其是在植物基因工程中 ,植物外源凝集素越来越受到重视。本文介绍了植物外源凝集素的分类、分布、多样性、基本组成与结构、凝集素基因同源性、表达及生物学功能等。重点讨论了凝集素基因在植物基因工程中的应用