Regulation mechanism of iron nutrition by ubiquitin ligases and iron-sulfur clusters

2021 Fiscal Year Final Research Report

• Project/Area Number: 18H02115
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 38010:Plant nutrition and soil science-related
• Research Institution: Ishikawa Prefectural University
• Principal Investigator: Kobayashi Takanori 石川県立大学, 生物資源環境学部, 教授 (70590206)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 鉄欠乏 / ユビキチンリガーゼ / 鉄硫黄クラスター / イネ

Outline of Final Research Achievements

We conducted in vitro analysis for putative substrates of rice HRZ ubiquitin ligases, including glutaredoxins (GRX), and bZIP and bHLH transcription factors. We found that GRXs and bZIP are subjected to HRZ-dependent degradation via the 26S proteasome pathway. We also produced and analyzed transgenic rice plants overexpressing or repressing these genes or iron deficiency-inducible IMA peptide genes. We found that GRXs and bZIP are novel downstream factors for HRZs, and are facilitating iron utilization in rice plants. We also found that bHLH and IMAs are novel positive regulators for rice iron deficiency responses.

Free Research Field

植物栄養学

Academic Significance and Societal Importance of the Research Achievements

本研究により、イネにおいてHRZ が鉄の吸収や蓄積を抑える際に、GRX、bZIP転写因子、bHLH転写因子、IMAペプチドを介して鉄の輸送や吸収を調節していることが明らかになった。また、植物細胞内における鉄欠乏の感知とシグナル伝達に関する知見が得られた。本研究の知見は、HRZ の働きを適切に調節し、鉄分を吸いにくい土壌でも良好に生育する植物、鉄分が豊富な作物を創出することに貢献すると期待される。