Elucidation of the novel adaptation mechanism for winter environment via vascular bundle in perennial plants

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H04801
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: University of Tsukuba
• Principal Investigator: SATOH Shinobu 筑波大学, 生命環境系(副学長), 副学長 (70196236)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: ポプラ / 導管液 / 冬季環境 / 耐性 / 根

Outline of Final Research Achievements

A xylem sap protein (XSP24), which is abundant in the xylem sap of poplar in winter, belongs to the Cupin family, and its expression is induced by short-day (SD) and ABA application to root, and is considered to contribute to the removal of ROS at low temperatures in winter. Also, XSP25 belongs to the Basic Secretory Protein family, expression of which is induced in the central cylinder of the root in SD (not induced by ABA), and XSP25 protein accumulation is observed in buds, and may protect the cells from freeze & dry. In addition, several microRNAs expressed in SD leaves and contained in the known phloem sap microRNA database such as squash were identified as candidates for signaling factors to roots.

Free Research Field

植物生理学

Academic Significance and Societal Importance of the Research Achievements

落葉性木本植物において秋の短日は、休眠芽形成と冬季環境への適応を誘導する。冬期導管液中のタンパク質（XSP25、XSP24）は根から地上部に送られて冬期の低温や乾燥に対する耐性をもたらすと考えられた。また無菌ポット栽培では、短日条件下で根の成長が低下し、根でXSP25、XSP24、ショ糖排出輸送体(SWEETs)の発現が誘導された。しかし短日において休眠芽形成を誘導するABAはXSPsとSWEETsの一部しか誘導しなかった。一方、短日の葉で発現し、篩管液に含まれる可能性のあるmicroRNA が複数同定された。この結果は、短日情報を葉から根へ伝達する新たな因子の発見につながることが期待される。