| 研究課題/領域番号 |
26870087
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| 研究機関 | 筑波大学 |
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研究代表者 |
IRVING Louis 筑波大学, 生命環境系, 助教授 (60597178)
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| 研究期間 (年度) |
2014-04-01 – 2017-03-31
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| キーワード | Plant parasitism / Photosynthetic recovery / Phloem / xylem / Host quality |
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| 研究実績の概要 |
Although our preliminary work showed evidence of parasitism of pea plants by Orobanche, our early work on this failed to reproduce this. We have therefore changed hosts to red clover (Trifolium repens) and alfalfa (Medicago sativa). We have made excellent progress in developing our methods for plant cultivation, and can now produce plants infected with our parasite of choice with high reliability.
A preliminary study in red clover provided evidence for a temporal effect in the parasite – host relationship, which has not been previously noted in the scientific literature. Preliminary data suggests that host photosynthesis is negatively affected by parasitism by either Orobanche or Phtheirospermum, although the hosts appear to have the ability to recover in terms of photosynthetic rates. Furthermore, this is the first direct comparison of a holoparasites and hemiparasites attached to hosts of the same species. This is a very novel experiment, and we expect to publish in a high impact journal inside the next 12 months.
A second preliminary experiment using radioisotope tracers / PETIS has found an interesting accumulation of carbon / phloem blockage in alfalfa roots parasitized by Phtheirospermum. This is a novel finding, and has not been previously reported in the scientific literature. In FY2015, we will repeat this work, coupled with high resolution imaging of the plant roots via CT scanning.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
After some initial setbacks, we have now finalized our processes, and can concentrate on data collection. We have noted some interesting phenomena, which we will formalize in the first part of FY2015. We have established a good system for PETIS work, which continues improvement in 2015.
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| 今後の研究の推進方策 |
In FY2015, we aim to repeat some of the work started in 2015, and bring our data up to the level required for publishing in international level journals. Our second aim is to explore the importance of root nodule position on the carbon and nitrogen balance of the host and the parasite. We noted that in the red clover / Phtheirospermum system, when the plants were provided with nutrient solution containing N, the parasite grew well. However, when the system relied on nitrogen fixation by the host, the parasite failed to grow. We hypothesize this is due to the relative positions of the N-fixing root nodules and the point of attachment (haustoria) of the parasite. We will investigate this hypothesis over the summer of 2015. During Fall 2015, we will continue our work with JAEA to investigate the C build-up in the host roots in response to parasitism.
We aim to publish 2 papers related to this project in FY2015, and to present at the Japan Society for Plant Physiology 2016 annual meeting.
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| 次年度使用額が生じた理由 |
As part of our experiment looking at the relative positions of the parasite and the root nodules, in 2015 we will buy 14CO2 and develop a CO2 labelling system for our plant system. With this in place, we will be able to quantify fluxes to individual roots. I will hire some student labor to help in the construction of equipment and in the execution of experiments.
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| 次年度使用額の使用計画 |
As necessary depending upon project requirements.
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