Fe sensing systems by transcription factor IDEF1

2014 Fiscal Year Final Research Report

• Project/Area Number: 23248011
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Plant nutrition/Soil science
• Research Institution: Ishikawa Prefectural University
• Principal Investigator: NISHIZAWA Naoko 石川県立大学, 生物資源環境学部, 教授 (70156066)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: 鉄欠乏 / 転写因子 / IDEF1 / HRZ / 鉄シグナル / 遺伝子制御

Outline of Final Research Achievements

In order to achieve expressional regulation in response to Fe availability, Fe sensing systems by sensors and signals must exist, but their identity has not been clarified in plants. We proposed that direct Fe binding to expressional regulators is a compelling candidate for the primary Fe sensing in plant cells. IDEF1 is a central transcriptional regulator of graminaceous genes involved in iron uptake and utilization, predominantly during early stages of iron deficiency. IDEF1 directly binds to divalent metals and sense the cellular metal ion balance caused by changes in iron availability. HRZs, novel regulators in rice, and BTS in Arabidopsis bind Fe and Zn, and possess ubiquitination activity. HRZ-knockdown rice plants show Fe efficiency and accumulation, with enhanced expression of Fe utilisation-related genes. HRZs/BTS are E3 ligases and negative regulators of iron deficiency responses in both graminaceous and non-graminaceous plants.

Free Research Field

植物栄養学・植物細胞工学