Regulation mechanisms of expression for rice Si transporter Lsi1

2016 Fiscal Year Final Research Report

• Project/Area Number: 15H06421
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Plant nutrition/Soil science
• Research Institution: Okayama University
• Principal Investigator: MITANI Namiki 岡山大学, 資源植物科学研究所, 准教授 (40581020)
• Project Period (FY): 2015-08-28 – 2017-03-31
• Keywords: 発現制御 / 輸送体 / 植物分子生理学

Outline of Final Research Achievements

Rice requires high silicon (Si) for its high and sustainable yield. Two Si transporters Lsi1 and Lsi2 are involved in this high accumulation of Si in rice. Our previous studies showed that the mRNA expression levels of these transporter genes were down-regulated by Si. In this project I investigated the mechanism underlying regulation of Lsi1 and Lsi2 expression. There was a negative correlation between the expression level of Lsi1 and Lsi2 and shoot Si accumulation. Together with the results of split-root experiments, the Si-induced down-regulation of Si transporter genes is controlled by shoot Si accumulation, not root Si. Analysis with transgenic rice carrying different lengths of Lsi1 promoter regions fused with GFP as a reporter gene revealed that the region responsible for Si response of Lsi1 expression is present between -327 to -292 in the promoter.

Free Research Field

植物栄養学