臨時生物科学セミナー（第１６０回）

　　日　時：平成２０年　１月１６日（水）　１６：３０〜１８：００

場　所：理学部２号館　第二講義室（２２３号室）

講演題目：

Control of Arabidopsis organ size by intercellular signalling - a molecular ruler?

講演者名：Dr. Michael  Lenhard（John Innes Centre）

講演概要

Plant organs grow to characteristic sizes that are genetically controlled. In animals, signaling by mobile growth factors is thought to be an effective mechanism for measuring primordium size, yet how plants gauge organ size is unclear. Here, we identify the Arabidopsis cytochrome P450 KLUH (KLU)/CYP78A5 as a stimulator of plant organ growth. While klu loss-of-function mutants form smaller organs because of a premature arrest of cell proliferation, KLU overexpression leads to larger organs with more cells. KLU promotes organ growth in a non-cell-autonomous manner, yet it does not appear to modulate the levels of known phytohormones. We therefore propose that KLU is involved in generating a mobile growth signal distinct from the classical phytohormones. The expression dynamics of KLU suggest a model of how the arrest of cell proliferation is coupled to the attainment of a certain primordium size, implying a common principle of size measurement in plants and animals.

以前、WUSで有名なLaux博士のところでCLV1-CLV3系の研究をしていたLenhard博士は、最近、BIG BROTHER (Disch et al. 2006 Curr. Bioll. 16: 272)など器官サイズを制御する仕組みについて、活発な研究を進めておられます。本セミナーの内容もAnastasiou et al. (2007) Developmental Cell 13: 843として発表されたばかりのものです。今回、来日の機会を得て、私たちの研究室への訪問希望があり、せっかくの機会なのでご講演をお願いしました。ふるってご参加ください。

問い合わせ先：塚谷　裕一（内線24047）

　東京大学理学部生物学科植物学コース