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第2日　5月16日（水）　10:25～10:45　B会場（星雲1）

2B-O1-P-1025　　PDF

陸上植物のアブシシン酸応答におけるタンパク質リン酸化ネットワークの解析

(¹農工大院BASE・ ²東農大農・ ³京大院薬・ ⁴埼玉大理・ ⁵理研CSRS・ ⁶CSIRO・ ⁷ミズーリ大生化)
天谷杏奈¹・ 本多慶匡¹・ 原百合絵¹・ 石川慎之祐¹・ 桑村真由里²・ 篠澤章久²・ 杉山直幸³・ 石濱泰³・ 坂田洋一²・ 竹澤大輔⁴・ 高橋史憲⁵・ Frank, Gubler⁶・ Jose, Barrero⁶・ Scott, Peck⁷・ 篠崎一雄⁵・ ^o梅澤泰史¹

Abscisic acid (ABA) and its signaling system are important for land plants to survive in terrestrial conditions. Protein phosphorylation/dephosphorylation has a central role in ABA signaling, mediated by protein phosphatase 2C (PP2C) and SNF1-related protein kinase 2 (SnRK2). Recently, we are taking a phosphoproteomic approach to elucidate the ABA signaling network in multi-species of land plants. For example, Physcomitrella patens is a model species of basal land plants. Our phosphoproteomic analysis detected 4,630 phosphopeptides from P. patens wild-type and two ABA-responsive mutants, such as a PP2C disruptant (ppabi1a/b), and an ARK-defective mutant (AR7), identified as an upstream regulator of SnRK2. Our data revealed: 1) the entire ABA-responsive phosphoproteome in P. patens was quite diverse, 2) P. patens PP2C regulated multiple pathways in addition to the ABA response, and 3) ARK is mainly involved in ABA signaling. Taken together, we propose that the core ABA signaling pathway is essential in all land plants; however, some ABA-responsive phosphosignaling uniquely developed in bryophytes during the evolutionary process.