爱德华·索亚作为当代空间研究的领军人物,在继承和发展列斐伏尔、福柯、哈维等人的空间思想的基础上,提出了独具特色的空间批判理论。本文通过分析索亚的成名著作《后现代地理学》,梳理其空间本体论的产生背景、理论构建与现实意义。首先介绍索亚关于空间理论对历史决定论反叛的出发点和进行空间重申的努力;其次,在思考其空间、时间和社会存在之间的辩证关系中,把握其社会—空间辩证法形成的理论逻辑,阐发索亚作为社会批判理论哲学基础的空间本体论思想;最后,探究索亚以空间本体论为指导,将后现代社会批判理论实证化为一种具有鲜明地理学特色的“批判性区域研究”的实践意义。As a leading figure in contemporary space research, Edward Sawyer put forward a unique critical theory of space on the basis of inheriting and developing the space thoughts of Lefebvre, Foucault, Harvey and others. By analyzing Sawyer’s famous work “postmodern geography”, this paper combs the background, theoretical construction and practical significance of his spatial ontology. Firstly, it introduces Soja’s starting point of space theory’s rebellion against historical determinism and his efforts to reiterate space. Secondly, in thinking about the dialectical relationship between space, time and social existence, we grasp the theoretical logic of the formation of its social-spatial dialectics, and elucidate the spatial ontology thought of Soja as the philosophical basis of social critical theory;finally, it explores the practical significance of Sawyer’s demonstration of postmodern social critical theory as a “critical regional study” with distinctive geographical characteristics under the guidance of spatial ontology.
Wild soybean(Glycine soja),a relative of cultivated soybean,shows high adaptability to adverse environmental conditions.We identified and characterized a wild soybean transcription factor gene,GsWRKY40,that promotes plant salt stress.GsWRKY40 was highly expressed in wild soybean roots and was up-regulated by salt treatment.GsWRKY40 was localized in nucleus and demonstrated DNA-binding activities but without transcriptional activation.Mutation and overexpression of GsWRKY40 altered salt tolerance of Arabidopsis plants.To understand the molecular mechanism of GsWRKY40 in regulating plant salt resistance,we screened a cDNA library and identified a GsWRKY40 interacting protein GsbHLH92 by using yeast two-hybrid approach.The physical interaction of GsWRKY40 and GsbHLH92 was confirmed by co-immunoprecipitation(co-IP),GST pull-down,and bimolecular fluorescence complementation(BiFC)techniques.Intriguingly,co-overexpression of GsWRKY40 and GsbHLH92 resulted in higher salt tolerance and lower ROS levels than overexpression of GsWRKY40 or GsbHLH92 in composite soybean plants,suggesting that GsWRKY40 and GsbHLH92 may synergistically regulate plant salt resistance through inhibiting ROS production.qRT-PCR data indicated that the expression level of GmSPOD1 gene encoding peroxidase was cooperatively regulated by GsWRKY40 and GsbHLH92,which was confirmed by using a dual luciferase report system and yeast one-hybrid experiment.Our study reveals a pathway that GsWRKY40 and GsbHLH92 collaboratively up-regulate plant salt resistance through impeding GmSPOD1 expression and reducing ROS levels,providing a novel perspective on the regulatory mechanisms underlying plant tolerance to abiotic stresses.
野大豆(Glycine soja Siebold&Zucc.)是一种重要的粮油兼用作物,富含多种黄酮和黄酮糖苷,具有多种药理活性。糖基化可以将黄酮苷元转化为更稳定、生物活性更强、结构更多样的糖苷。通过基因组分析和酶挖掘,报道了一种来自野大豆的黄酮UDP-糖基转移酶GsUGT1,该酶主要作用于甘草素7-OH位置,对6种黄酮受体具有催化活性。此外,在大肠杆菌中成功异源表达GsUGT1并对其纯化,酶学性质表征发现在pH为7.0、温度为35℃时,酶的催化活性达到最大,米氏动力学研究表明GsUGT1的催化效率k_(cat)/K_(m)为6.70×10^(-5)μmol/(L·s)。最后通过分子对接对GsUGT1的催化机制进行了初步探究。首次报道了野大豆来源的UDP-糖基转移酶GsUGT1,该酶有望成为酶法合成黄酮糖苷衍生物的有效工具。
