权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Analysis of kinetics of nitrogen fixation in soybean plants by positron imaging system

正电子成像系统分析大豆植株固氮动力学

基本信息

批准号：
23780264
负责人：
ISHII Satomi
金额：
$ 2.66万
依托单位：
Japan Atomic Energy Agency
依托单位国家：
日本
项目类别：
Grant-in-Aid for Young Scientists (B)
财政年份：
2011
资助国家：
日本
起止时间：
2011 至 2012
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-23780264/
关键词：
非破壊計測ダイズ根粒窒素固定 13N標識窒素ガス

项目摘要

Nitrogen is the most important nutrient for plants. Soybean plants can utilize nitrogen (N) from atmospheric N_2 fixed by nodules which is symbiotic organ of leguminous plants with rhizobium.The purpose of our study is to visualize and analyze the N2 fixation in the nodules and transport to the aerial part noninvasively and quantitatively. A much higher radioactivity of the tracer, more than 100 MBq, was required for visualization of the transport of fixed nitrogen to the aerial part. In this study, we started to develop a fully new production method to produce a tracer gas with high radioactivity and purity by reduction of N_2O to N_2 directly.The target CO_2 gas was irradiated with proton ions as conventional methods to obtain ^<13>N nuclide through the ^<16>O (p, α) ^<13>N nuclear reaction. The irradiated gas was introduced to a line of the new purification system. The remaining CO_2 was absorbed in soda-lime, and ^<13>N_2O, a byproduct of the irradiation, was instantly reduced to ^<13>N_2 by heated Cu beads. The resultant pure ^<13>N_2 was mixed properly with nonradioactive N_2, O_2 and Ar. We fed the tracer gas to the underground part of soybean plants for 10 min and collected the serial images for one hour by PETIS. As a result, we finally obtained the image of transport to the aerial part successfully.

氮是植物最重要的营养物质。豆科植物根瘤菌是豆科植物与根瘤菌共生的器官，根瘤菌固定大气中的氮，大豆利用根瘤菌固定大气中的氮。我们研究的目的是可视化和定量分析N2在结节内的固定和向空中部分的输送。示踪剂的放射性要高得多，超过100 MBq，以显示固定氮向空中部分的运输。在这项研究中，我们开始开发一种全新的生产方法，通过直接将N_2O还原为N_2来生产高放射性和高纯度的示踪气体。用质子离子辐照靶气体CO_2，通过^<16>O (p, α) ^<13>N核反应得到^<13>N核素。辐照后的气体被引入新净化系统的一条生产线。剩余的CO_2被钠石灰吸收，辐照副产物^<13>N_2O通过加热Cu珠瞬间还原为^<13>N_2。将得到的纯净的^<13>的N_2与非放射性的N_2、O_2和Ar适当混合。将示踪气体注入大豆植株地下10分钟，用PETIS采集1小时的序列图像。最终，我们成功地获得了传输到空中部分的图像。