Roles of Phenolic Compounds in Mediating the Rhizosphere Formation in Woody Plant Roots

2014 Fiscal Year Final Research Report

• Project/Area Number: 23688017
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Forest science
• Research Institution: The University of Tokyo
• Principal Investigator: OSAWA Hiroki 東京大学, 農学生命科学研究科, 助教 (90401182)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: プロアントシアニジン / ボーダーライクセル / 根 / 根冠 / 根圏 / アルミニウム / 酸性土壌

Outline of Final Research Achievements

Root border-cells play a central role in root growth and development, although their formation patterns are divergent among plant species. We find novel border-like cells (BLCs) that peel from the lateral root cap, developing a sheath structure in a leguminous tree Acacia mangium. We also found that proanthocyanidins (PAs) inside the peeled BLCs were conveyed to the rhizosphere of maturing root zone. Despite the loss of membrane integrity, the PAs in the detached cells were hardly eroded for at least three days. Root-inoculation assay revealed that propagation of bacterium pathogen in root surfaces of A. mangium was restricted more than that of soybean, which lack both root PA accumulation and BLC formation. Meanwhile, the adhesion of A. mangium BLCs onto the root tip in lettuce hardly inhibited its root elongation. These results suggest that BLCs carrying PA from root surface to rhizosphere may play protective roles including a pathogen defense through a repellent dispatcher.

Free Research Field

造林学・樹木生理学