2023 Fiscal Year Research-status Report
Mechanism of C/N competition between legume hosts and parasitic plants
| Project/Area Number |
23K05916
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| Research Institution | University of Tsukuba |
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Principal Investigator |
Irving Louis 筑波大学, 生命環境系, 助教 (60597178)
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| Project Period (FY) |
2023-04-01 – 2026-03-31
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| Keywords | Orobanche / parasite / nitrogen / carbon / isotope |
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| Outline of Annual Research Achievements |
I completed the first phase of the research and am preparing a manuscript for publication in a high-impact journal. Host growth and nutrient uptake were severely limited where nutrients were supplied to parasitized roots. I have started three new direction, 1) effect of N level and parasitism on host photosynthesis, 2) effect of parasite / rhizobia position on the host-parasite relationship, 3) developing a clean system for host - parasite isotope tracing studies.
For 1, we found that N supply leads to a strong suppression in both parasite establishment and parasite growth. However, low level N supply caused a decline in photosynthetic rates.
For 2, we found that parasite mass was strongly increased when grown near the bottom of the root box, although the mechanism is unknown. We have developed two plausible hypotheses, either that the parasite is directly taking nutrients up from the surrounding media, or that N fixed in the upper part of the root is being transported to the parasite.
For 3, we have established a system, although parasite necrosis is an issue. In the next few months we will develop an isotope labelling system for 13CO2 in order to quantify host to parasite carbon flux kinetics.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
There are no issues with the project, although it is generating many surprising results which require some reevaluation of the original plan.
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| Strategy for Future Research Activity |
This summer I will measure the effect of parasite number of host photosynthesis (low vs. high rate of parasitism) in collaboration with Dr. Shinya Wada (Tohoku UNiv). We will also try time-series 13C labeling to investigate host --> parasite C transfer kinetics, and the effect of environmental conditions. I will evaluate nutrient uptake and parasite capture of nutrients supplied above or below the point of attachment.
It was unexpectedly difficult to do spatial analysis of parasite / rhizobia interactions, because the rhizobia could not be contained in one part of the root system. I will improve my root box design and improve rhizobia-handling procedures to counter these issues.
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| Causes of Carryover |
In this year I have several key expenses. First, I will do some measurements at Tohoku University over the summer, so I will have expenses to take plants and materials to Tohoku university. Also, I will do 13C and 15N labeling, and will have to buy isotopes, and pay for analytical expenses (mass specctrometery). Additional expenses are basic lab expenses / chemicals, etc.
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Research Products
(1 results)
