Elucidation of the response of plants to environmental diurnal variation using the high-sensitivity photon detection technique

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K06015
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39030:Horticultural science-related
• Research Institution: Shizuoka University
• Principal Investigator: Motohashi Reiko 静岡大学, 農学部, 教授 (90332296)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 遅延蛍光 / 光合成 / シロイヌナズナ

Outline of Final Research Achievements

Delayed luminescence (DL) originates from the repopulation of excited states of chlorophyll from the stored energy after change separation. DL emission is composed of several components. The faster decaying components have been characterized as they provide information about the fate of energy absorbed by recombination of P680 with QA and QB. The slow components of DL originate in back reaction in the photosynthetic chain, Plastocyanin, and Ferredoxin after QB. We screened DL mutants in more than 2000 knockout lines that predicted chloroplast proteins. As a result, DL could monitor a wide range of photosynthetic pathway including cyclic electron transport and Calvin cycle.
Considering essential elements of nutrition are involved in photosynthesis, it is possible that DL is affected by a nutritional deficiency. DL was able to detect physiological changes in Arabidopsis thaliana under N, P, K, Fe, Mg, Mn, and Cu deficiencies, but not under S and Zn deficiencies.

Free Research Field

植物分子遺伝学

Academic Significance and Societal Importance of the Research Achievements

近年、植物工場や藻類の大量培養など光合成生物の産業利用が急速に進展しているなかで、光合成のモニタリングが重要であり、新規の光合成活性測定装置への期待は高い。本研究は、フォトン検出レベルの高感度光検出器による遅延蛍光の測定を栽培植物に適用し、光合成の生理状態を評価する。温度や光環境の植物の生理的な影響だけでなく、栄養欠乏から、乾燥ストレスの影響を遅延蛍光の減衰曲線の変化で検出でき、スマート農業や精密農業の作物生育管理手段として大きく貢献する。また、モデル植物の遺伝子変異株を用いて生理学的な基盤知見が蓄積され、遅延蛍光減衰曲線の成分が光合成のどの部分を指標としているか評価も可能である。