KATO Makoto Hamamatsu Photonics, Co.Researcher, 研究員
MATSUBAYASHI Masashi Japan Atomic Energy Research Institute, Tokai Research Establichment Researcher, 東海研究所, 研究員
MATSUMOTO Satoshi Graduate School of Agricultural & Life Sciences, University of Tokyo Professor, 大学院・農学生命科学研究所, 教授 (20032295)
|Budget Amount *help
¥17,000,000 (Direct Cost : ¥17,000,000)
Fiscal Year 1997 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1996 : ¥4,200,000 (Direct Cost : ¥4,200,000)
Fiscal Year 1995 : ¥12,000,000 (Direct Cost : ¥12,000,000)
Analysis of biological activity in intact cells or tissues is essential to understand information processing in plant. Techniques for these in vivo measuremerts have not been well developed, espeicially for roots. We studied a nondestructive method to image water in living plants to know information processing in plant using a neutron beam, as well as positron emitting nuclides to perform PET (Positron Emission Tomography. Neutron beam technique provided the highest resolution for water intissue yet ob tainable. With high specificity to water this neutonbeam technique images water movement in seeds or in roots imbedded in soil, as well as in wood and meristems during development. The resolution of the image attainable now is about 15 um.
First, we studied how this new technique allow new investigations in the field of plant research. Next, we focused on the identification of water storing function of cowpea and soybean root activity imbedded in soil. Then finally, we tried to get water
CT image of livingplant. In the case of cowpea, which is a very important crop at dryarea in Asia and Africa, we found the stem between the first leaf and the first trifoliatestored the water and when drytreatment was perfomed this water was supplied to the other plant tissue to support the activity of the plant. Water movement in this stem was studied by neutronbeam and the maintenance of the water storage function was confirmed by PET.
In the case of root, water movoment near the root, within lmmapart from the root was found to reflect the rootactivity. When vanadium was imbedded in soil, though from the growth no observablechange was shoen, the root activity was severely damaged. Since there has been no data about water movement in the vicinity of the root, we could discuss about the water absorbing model of the root. We also simulated the plant activity and growth from water movement in the soil.
To get CT image using neutron beam, we used a camation flower as an example. To set up the devise, we investigated the characteristics of neutron fluorescence converter and image processing software, espeically how to eliminate the white spots which always appear through CCD camera. We rotated the sample until 180 degree and every ldegree, we got water image. Through construsting the CT images and piled up them, three dimensional image of water in camation flower was able to get. We are now constructing the water image around the root. Less