Carbon / nitrogen interactions between legumes and parasitic plants

2015 Fiscal Year Research-status Report

• Project/Area Number: 26870087
• Research Institution: University of Tsukuba
• Principal Investigator: Irving Louis 筑波大学, 生命環境系, 助教 (60597178)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: parasite / carbon allocation / alfalfa / phtheirospermum / clover / orobanche

Outline of Annual Research Achievements

In the first year of my research project I conducted some experiments and found results which were contrary to my expectations. Over the last 18 months I have been working to try and verify the cause of this unusual data.
In summary, my experimental procedures were correct, and my original experiments were valid - my expectations based on the current literature were incorrect. In 2016 I will re-run these experiments and publish the results in a high impact journal.
Along with my collaborators at JAEA we have been working on developing a double labeling system using 11CO2 and 18F to track photoassimilate distribution and water flow in the host - parasite system. Although we have had some difficulties, we have made significant progress towards our goal, and we expect successful data generation in May this year.
I have also developed a 13CO2 labeling system allowing us to track photoassimilate distribution in plant systems. I am currently in the process of analyzing the plant material from our first experiment using this system.

Current Status of Research Progress

3: Progress in research has been slightly delayed.

Reason

As mentioned above, our expected data based upon the currently published literature was not realized. However, this is mainly due to the lack of published data in this area. We expect very smooth data collection in the following year. Significant progress has been made in plant culture, and now we are able to produce high quality plants in an extremely reliable manner.

Strategy for Future Research Activity

Experiment 1 will investigate the differential effects of the hemiparasite Phtheirospermum japonicum and Orobanche minor on the photosynthesis and growth of red clover. This is the first time a direct comparison of the effects of parasitism by hemi- and holoparasites on a single host in a single experiment has ever been conducted. I expect high quality data.
Experiment 2 will use a split root design using phtheirospermum with a ryegrass host. This will look at the relative importance of parasitized vs unparasitized roots in host plant nutrition and performance.
Experiment 3 seeks to explore a previously characterized accumulation of carbon in the host root at the point of parasite attachment. Work in the past year suggests direct carbon flux between the alfalfa host and the phtheirospemum hemiparasite. This is a new finding to the area of parasitic plant research.

Causes of Carryover

In FY2016 I have some collaborative experiments which must be conducted at JAEA Takasaki. I also have experiments in Tsukuba, and will need plant culture and experimental equipment / chemicals to conduct the experiment.

Expenditure Plan for Carryover Budget

As necessary based upon experimental needs.