2020 Fiscal Year Annual Research Report
Study on the Process of Transferring Carbohydrates from Mature bamboo to Young shoot in Moso Bamboo (Phyllostachys edulis) Forests
| Project/Area Number |
20J15519
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| Research Institution | Kyoto University |
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Principal Investigator |
WANG SHITEPHEN 京都大学, 農学研究科, 特別研究員(DC2)
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| Project Period (FY) |
2020-04-24 – 2022-03-31
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| Keywords | carbon stable isotope / Phyllostachys edulis / IRMS / 13C pulse-labelling / carbon allocation / Moso bamboo forests |
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| Outline of Annual Research Achievements |
We got two major research achievements on two topics: [1] Phyllostachys edulis, a C3 plant with C4-like carbon fixation in fast growing period, and [2] Seasonal dynamics of carbon allocation between different organs in Phyllostachys edulis (Moso bamboo) forests.
[1] Plant physiologists tend to classify a plant as one type of photosynthesis (such as C3, C2, C4, or CAM). Little is known about the different photosynthetic phenotypes of plants at different growth stages. Here we report that a typically classified C3 plant, Moso bamboo (Phyllostachys edulis), shows C4-like carbon fixation in the heterotrophic stage during the initial fast-growing period (FGP) and receiving carbohydrates from source organs of developed youths and matures, while it transforms into C3 plant as matures. This phenomenon elaborates that the evolution of plants in biosynthetic and metabolic pathways has no solidified classification in space, even in time, the stage of growth.
[2]We used pulse-labelling method to generate 13C-enriched mature bamboos in FFPRI Kansai in October 2019 and sampled different bamboo organs from October 2019 to June 2020. We analysed 13C in different organs of Moso bamboos via isotope ratio mass spectrometry (IRMS) and purified starches and structural carbohydrates. The results indicated that carbohydrates produced from mature bamboos prefer transport to the frontier of rhizomes for expansion in Autumn, and then perhaps provide strong sinks (such as bamboo shoots) in early spring. Carbohydrates for bamboo shoots re-allocated from belowground systems in Spring.
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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
The purpose of this study is to find strong evidence that mature bamboo transfers carbohydrates to young bamboos or bamboo shoots in Moso bamboo forests. So far, [1] we use the pulse-labeling method and carbon isotopic analysis to observe carbon transportation from mature bamboo to rhizome system in a Phyllostachys edulis stand. [2] We also analysed the natural bulk δ13C (‰) in different organs at autotrophic and heterotrophic stages of Moso bamboo. We got the strong evidence that bamboo shoots not directly uptake carbon from the atmosphere, but perhaps from mature and newly developed bamboo until bamboo shoots transformed into the autotrophic stage. Furthermore, [3] the side-project we developed is that a hybrid approach using machine learning and linear regression models to estimate the chaotic forest carbon sinks and stocks, and we have also written the draft already. The overall research is fairly smooth.
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| Strategy for Future Research Activity |
The further work we planning is that [1] to purify non-structural carbohydrates (NSCs) of labelling Moso bamboo samples and elaborate the seasonal dynamics of carbon allocation and relocation detailly. [2] We also purify the NSCs of natural samples in different organs at autotrophic and heterotrophic stages of Moso bamboo, and further analysis their δ13C (‰). Furthermore, [3] we will try to develop a 13-C sucrose injection method specified to rhizome system of Moso bamboo. Even if it fails, it can be used as a reference for future study. [4] In the second half of this year, we will integrate data we collect, operate statistical analysis, write research articles, and submit them to scientific journals.
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