| Evaluation of Nodulation Speed by Sinorhizobium Strains
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Author:
Date:
2015-08-05
[Abstract] Rhizobia interact symbiotically with legumes to form root nodules, where by rhizobia fix atmospheric dinitrogen into ammonia in exchange for carbon produced via photosynthesis. The symbiotic interaction is agriculturally important by reducing the need for fertilizer containing nitrogen. The root and stem nodule bacteria commonly include bacteria in the genera Rhizobium, Mesorhizobium, Sinorhizobium (Ensifer), and Bradyrhizobium, although other genera of bacteria have now been shown to form root nodule symbioses with several legume species (Weir, 2012). Different rhizobial strains form different numbers of nodules on specific legume plant varieties (or cultivars), and the nitrogen fixing effectiveness of each rhizobial strain, its ability to fix ...
[摘要] 根瘤菌与豆科植物共生相互作用形成根瘤，其中根瘤菌将大气氮固定为氨，以交换通过光合作用产生的碳。共生相互作用在农业上是重要的，通过减少对含氮肥的需要。根和茎结节细菌通常包括根瘤菌属，中生根瘤菌，中华根瘤菌属（ Ensifer ）和 Bradyrhizobium >，虽然其他属的细菌现在已经显示形成根瘤与多种豆科物种的共生（Weir，2012）。不同的根瘤菌菌株在特定豆科植物品种（或品种）上形成不同数目的结节，并且每种根瘤菌菌株的氮固定效率，其固定氮并将其转移到植物的能力也是高度可变的（Toro，1996）。一些天然根瘤菌在固氮但在所生长的植物中形成大多数结节方面无效。这被称为结瘤问题的竞争（Triplett和Sadowsky，1992）。当评估大量不同的天然菌株时，竞争研究是不可行的。然而，单个菌株的结瘤速度与总体竞争性良好相关，并且可用于鉴定克服竞争问题的天然菌株（De Oliveira和Graham，1990; Bhuvaneswari等人，1980）。
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| Quantitative Evaluation of Competitive Nodulation among Different Sinorhizobium Strains
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Author:
Date:
2015-08-05
[Abstract] Legumes play a vital role in global food supply because they are uniquely capable of fixing atmospheric nitrogen (N) through symbioses with root and stem nodule bacteria, collectively called the rhizobia. These commonly include bacteria in the genera Rhizobium, Mesorhizobium, Sinorhizobium (Ensifer), and Bradyrhizobium, although other genera of bacteria have now been shown to form root nodule symbioses with several legume species (Weir, 2012). The symbiotic interaction is important for agricultural productivity, especially in less developed countries where nitrogen fertilizer is expensive. However, nodulation ability and competitiveness have practical importance in agricultural production, because the inoculation of efficient rhizobia is often ...
[摘要] 豆类在全球食物供应中起着至关重要的作用，因为它们独特地能够通过与根和茎结节细菌的共生固定大气氮（N），统称为根瘤菌。这些通常包括根瘤菌属，中生根瘤菌属，中华根瘤菌属（ Ensifer ）和 Bradyrhizobium 属中的细菌，的细菌现已显示与几种豆科物种形成根瘤共生（Weir，2012）。共生相互作用对于农业生产力是重要的，特别是在其中氮肥昂贵的欠发达国家中。然而，结瘤能力和竞争力在农业生产中具有实际重要性，因为高效根瘤菌的接种通常不成功，这主要是由于土壤中存在无效的土着根瘤菌的竞争性群体（Toro，1996; Triplett和Sadowsky， 。该协议允许我们定量评价中华根瘤菌菌株的相对结瘤竞争性。
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| Analysis of RNA-protein Interactions Using Electrophoretic Mobility Shift Assay (Gel Shift Assay)
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Author:
Date:
2013-11-20
[Abstract] RNA binding proteins (RBPs) play a crucial role in regulating gene expression at the post-transcriptional level at multiple steps including pre-mRNA splicing, polyadenylation, mRNA stability, mRNA localization and translation. RBPs regulate these processes primarily by binding to specific sequence elements in nascent or mature transcripts. There are several hundreds of RBPs in plants, but the targets of most of them are unknown. A variety of experimental methods have been developed to identify targets of an RBP. These include RNA immunoprecipitation (RIP), UV cross-linking and immunoprecipitation (CLIP) and many variations of CLIP (e.g. PAR-CLIP, iCLIP). These approaches depend on immunoprecipitation of RNAs bound to a specific RBP using an antibody to that RBP. Electrophoretic ...
[摘要] RNA结合蛋白（RBP）在包括前mRNA剪接，多聚腺苷酸化，mRNA稳定性，mRNA定位和翻译的多个步骤在调节转录后水平的基因表达中起关键作用。 RBP主要通过结合新生或成熟转录物中的特定序列元件来调节这些过程。植物中有几百个RBP，但其中大多数的目标是未知的。已经开发了各种实验方法来鉴定RBP的目标。这些包括RNA免疫沉淀（RIP），UV交联和免疫沉淀（CLIP）和CLIP的许多变体（例如PAR-CLIP，iCLIP）。这些方法取决于使用针对该RBP的抗体与特异性RBP结合的RNA的免疫沉淀。电泳迁移率变动分析（EMSA），也称为凝胶移位分析，已被用于分析蛋白质 - 核酸相互作用。它是一种简单而强大的方法来分析蛋白质-RNA/DNA相互作用。在RNA EMSA中，通过在蛋白质存在下比较RNA的迁移来可视化RNA-蛋白质复合物。通常，在RNA EMSA中，使用特异性RNA序列来分析其与蛋白质的相互作用。将具有荧光标记的体外转录的32 P标记的或化学合成的RNA与或不与目标蛋白一起温育，然后将反应混合物在天然聚丙烯酰胺凝胶电泳上运行。 RNA-蛋白复合物与游离RNA相比缓慢迁移，其可以使用成像系统可视化。除了测试RBP与RNA的结合之外，EMSA还用于绘制参与相互作用的RNA和/或蛋白质中的区域。此外，还可以使用EMSA定量结合亲和力。
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