Identification of molecular mechanisms of plant iron sensing

2018 Fiscal Year Final Research Report

• Project/Area Number: 15H05617
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Plant nutrition/Soil science
• Research Institution: Ishikawa Prefectural University
• Principal Investigator: Kobayashi Takanori 石川県立大学, 生物資源環境学部, 准教授 (70590206)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 鉄欠乏 / イネ / 遺伝子発現 / 転写因子 / ユビキチンリガーゼ / センサー

Outline of Final Research Achievements

In order to clarify intracellular iron sensors in plants, we investigated molecular mechanisms linking metal binding and regulation of iron deficiency responses in rice transcription factor IDEF1 and ubiquitin ligase HRZs. We did not observe clear changes in DNA binding property and protein stability of IDEF1 by iron nutritional conditions. In contrast, our results suggested changes in protein stability, localization and function of HRZs by their metal binding. Proteins involved in iron-sulfur cluster biosynthesis and transport, and a bZIP transcription factor, were suggested to function downstream of HRZs. Jasmonate signaling was found to be involved in early responses to iron deficiency and HRZ-based regulation of iron homeostasis in rice.

Free Research Field

農学（植物栄養学、植物分子生物学）

Academic Significance and Societal Importance of the Research Achievements

世界の耕地の30％以上を占める石灰質土壌では、植物は鉄を吸収しにくく生育に適さないが、本研究はこのような土壌でも良好に育つ植物の開発につながる。さらに、植物が土壌中から吸収する鉄は、食物の鉄分の由来となるため、本研究は鉄栄養価の高い米などの食物の開発につながる。学術的には、植物の鉄感知を担う細胞内鉄センサーと鉄欠乏シグナルの実体は未だに明らかになっていない。本研究はこれらの解明につながる重要な知見を提供するものである。