令和5年度 文部科学省 科学研究費補助金 学術変革領域研究（A）
■ Planning Squad
A01 Satake Group
"Gene regulatory mechanisms governing plant phenology"
Various environments exist worldwide, from high-latitude regions with long winters to tropical regions with warm temperatures year-round. The seasonal activities (phenology) of plants inhabiting each region affect the global environment. However, the genetic control that governs phenology and its responsiveness to climate and environment remains unclear. Therefore, we will perform genome sequencing of the dominant tree species in forest ecosystems. We will conduct comprehensive gene expression (molecular phenology) and phenology observations, such as BVOC emissions in diverse forest ecosystems from Hokkaido to Southeast Asian tropical forests. We will elucidate the mechanisms of phenological changes at the gene level. In addition, we will apply information on plant environmental responses obtained in a controlled laboratory environment to molecular phenology data. We will develop a phenology prediction model necessary for input into climate models by verifying predictions of leaf development, flowering, and BVOC emissions. Furthermore, the prediction results of the climate model will be fed back into the phenology prediction model. Consequently, we aim to elucidate the particulars of plant self-feedback through climate modification. Specifically, we will explore how flowering and fruiting phenology, which is sensitive to temperature and rainfall, is influenced by BVOC emissions.
Research representative
Akiko Satake
(Kyushu University, Professor)
Member of a research project
Naoki Tani (JIRCAS/ University of Tsukuba, Professor)
Ai Nagahama (National Museum of Nature and Science/Researcher)
Sachiko Isobe (The University of Tokyo Graduate School /Professor)
Hideki Hirakawa (Kazusa DNA Res.Inst./Principal Investigator)
Research collaborator
Akihiro Nakamura (Xishuang Panna Botanical Garden, Chinese Academy of Sciences,Professor)
Yoshiko Kosugi (Kyoto University,Professor)
Eriko Sasaki (Kyushu University, Associate Professor,Kyushu University)
Koji Noshita (Kyushu University, Assistant Professor)
Junko Kusumi (Kyushu University, Professor)
A02 Nagano Group
"Estimation of environmental response functions driving BVOC emissions"
We have demonstrated that temperature, light, and the circadian clock significantly affect gene expression in plants under natural environments by analyzing transcriptome data from over 10,000 field-grown plants. Furthermore, we have demonstrated that systematically acquiring learning data regarding these variables effectively estimates environmental response functions.
Based on this knowledge, we will estimate the environmental response function of BVOC synthesis and release and clarify the molecular basis of its diversity. First, we will acquire gene expression and BVOC data under conditions where temperature, light, and circadian rhythms are systematically changed using a highly functional artificial climate device that can grow various plants, including trees. Accordingly, we will estimate an environmental response function that can be applied in various environments. Next, by comparing molecular phenology and BVOC measurement data in the natural environment, we will verify the accuracy of the environmental response function and correct it, making it possible to provide input to the chemical climate model. Furthermore, we will compare environmental response functions in multiple species, analyze gene functions using synthetic biological methods and biochemistry using model plants, and perform comparative evolutionary analyses of related genes. Through this analysis, we aim to elucidate the molecular basis supporting BVOC synthesis, release, and diversity.
Research representative
(Keio University Specially Appointed Professor/
RyukokuUniversity professor)
Atsushi Nagano
Member of a research project
Kazufumi Yazaki (Kyoto University,Professor)
Ryosuke Munakata (Kyoto University, Assistant Professor)
Koji Iwayama (Shiga University, Associate Professor)
Research collaborator
Kenji Fukushima (University of Wurzburg, group leader)
Hidetoshi Matsui（Shiga University・Professor）
A03 Yamaguchi Group
"Elucidation of the epigenomic molecular basis linking BVOC release and stress tolerance"
Gene expression depends on the DNA sequence, which is the main body of the genome, and on epigenomic information such as chemical modifications of DNA and the histone proteins around which DNA is wrapped. We have previously revealed that histone modifications are essential in plants gaining tolerance in response to environmental conditions such as high temperatures and drought. Plants develop stress tolerance even after BVOC is released. However, the molecular basis of how the two interact remains unclear.
Therefore, we will clarify the epigenome-mediated gene expression control mechanism behind the acquisition of stress tolerance in plants after BVOC release. First, we will comprehensively investigate expression-variable genes using transformed plants that emit BVOC, plants grown in culture vessels that can be treated with BVOC, and plants collected in the field linked to real-time BVOC measurement data. We will identify cis sequences and trans factors present on promoters of genes with variable expression, and we will conduct a comprehensive binding analysis of trans-factors along the time series of BVOC release and epigenome analysis. We will also examine changes in stress resistance by modifying cis sequences and trans factors using model plants. We will elucidate the molecular basis that links the release of BVOCs with the acquisition of stress tolerance. Furthermore, we will compare whether cis sequences, trans elements, and epigenomic changes occur by similar mechanisms in various plant species. Therefore, we aim to elucidate the uniqueness and conservation of the pathway.
Research representative
Nobutoshi Yamaguchi
(Nara Institute of Technology, Associate Professor)
Member of a research project
Taiji Kawakatsu (NARO, senior researcher)
Haruki Nishio (Shiga University, Assistant Professor)
B01 Sekimoto Group
"Real-time measurement of multi-component BVOCs"
The type and quantity of BVOCs released by plants and their reaction behavior after release are substantially influenced by the environment, such as solar radiation and temperature. Therefore, the location and time of BVOCs emitted from trees are different within the forest, where sunlight is frequently blocked, and outside, under direct exposure to sunlight. Indeed, these emission patterns are thought to change from moment to moment. However, there have been no examples of such analysis to date.
Therefore, we will conduct research targeting dominant tree species in forest ecosystems to investigate their BVOC emission characteristics and variation factors that depend on the vertical position of trees and to clarify the effects among plants and on the climate. We will grow trees in incubators that allow us to manipulate environmental conditions, and we will measure the rate at which BVOCs are emitted from these trees using a measurement system that can simultaneously analyze the mass of multiple components in real time. Furthermore, we will measure the concentration and velocity of BVOCs emitted from each vertical position of trees in natural forests over a long period. We will input this BVOC emission data into the climate model. Consequently, we aim to elucidate how BVOCs are emitted from specific parts of the trees and which conditions affect the climate.
Research representative
Kanako Sekimoto
(Yokohama City University, Associate Professor)
Member of a research project
Takuya Saito
B02 Shiojiri Group
"Modification of BVOCs by biological interactions"
Plants coexist with other organisms by communicating with each other and changing the type and quantity of BVOCs they emit in response to environmental changes and damage. We have clarified how BVOCs affect interactions between organisms such as trees, herbs, and insects. However, when considered on a global scale, the climate and types of trees distributed vastly differ. Therefore, the interactions between BVOCs and the climate must be different, and there was a need to scale up the effects.
Thus, we will measure BVOCs in predominant forest types at a wide range of latitudes, from Hokkaido to Southeast Asian tropical forests, and clarify the actual state of BVOC-mediated interactions between organisms. First, we will investigate communication within and between forest constituent tree species in semi-field and natural forests, including insect communities, damage levels, soil microbiota, and fine root networks. Next, we will analyze the gene expression and epigenome levels to examine the extent and duration of BVOC influence on biological interactions. Conversely, we will clarify BVOC production by analyzing the systematic signals of tree species and ecological factors on the quantity and composition of BVOCs. By integrating the obtained results with global-scale tree distribution maps and soil maps, we can estimate the global quantity and composition of BVOCs emitted from trees. Additionally, we will provide input this data into climate models. Through this, we aim to estimate the actual state of BVOC-mediated interactions between organisms, changes in the quantity of BVOC released due to interactions between organisms, and the global quantity of BVOC released.
Research representative
Kaori Shiojiri
(Ryukoku University,Professor)
Member of a research project
Akira Yamao (KyotoUniversity/Professor)
Yoshihisa Suyama (Tohoku University,Professor)
Qingmin Han (Forestry and Forest Products Research Institute, Chief Researcher)
Shunsuke Matsuoka (Kyoto University, Lecturer)
Research collaborator
Masayuki Ushio (Assistant Professor The Hong Kong University of Science and Technology）
Kazumichi Fujii (Forestry and Forest Products Research Institute, Chief Researcher)
Hiroki Yamagishi (Hirosaki University, Associate Professor)
B03 Sudo Group
"Plant-climate interaction modeling and future prediction via BVOCs"
これまでに私たちは、対流圏・成層圏の大気微量成分と関連化学反応を気候モデルに組み込み、BVOCの大気中酸化や、これに伴うSOA生成、対流圏オゾン・OH・メタンへの影響を精緻にシミュレートできる化学気候モデルCHASER (MIROC) の開発を行ってきました。また、この化学気候モデルを土台としたデータ同化手法（CHASER-DAS）も構築しました。ですが、これらのモデルには植物による貢献が十分に組み込まれておらず、その改良が気候を理解する上で必要な状況でした。
そこで私たちは、化学気候モデルCHASER(MIROC)の枠組みを利用し、遺伝子・植物・気候相互作用メカニズムの表現を実装・改良する研究を行います。まず、BVOCの放出量を、植物遺伝子の環境応答の関数として表現し、CHASERに導入します。BVOCの放出量強度については、VOCsの連続・直接観測や衛星観測からのVOCs放出量推定手法に加え、BVOC酸化の中間体であるホルムアルデヒドやエアロゾル等の人工衛星等による各種リモートセンシング観測やこれを元にしたデータ同化・VOCs放出量逆推定手法も活用し、多角的に検証・調整します。そのうえで、IPCC/CMIPに準拠した過去再現および将来予測の各実験や、開花時期等をターゲットにした再現実験を実施し、温暖化やエアロゾル変動が及ぼす気温・降水量・日射量の長期的・短期的変動が及ぼす植物の環境応答や、逆に植物・BVOC変動が気象場に与える影響を定量化することを目指します。
