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- Day 2, May 16（Wed.） Poster
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2P-61（4B-O1-P-1030） PDF
Comparative Phosphoproteomic Analysis of Fresh and After-ripened Barley seeds
Seed dormancy enables plants to adjust their germination to favorable growth conditions1,2). In barley or some other species, fresh harvested seeds show strong dormancy, but it is gradually disappeared during after-ripening process. However, the molecular mechanism of after-ripening is still unclear. Here we investigated phosphosignaling pathways in response to abscisic acid (ABA) in fresh and after-ripened (AR) barley seeds, because ABA has been known as a major dormancy regulator and ABA signals are mediated by protein phosphorylation3,4). We took a phosphoproteomic approach using barley fresh and AR seeds5,6), in combination with metal oxide chromatography for phosphopeptide enrichment and a LC-MS system (AB-SCIEX TripleTOF 5600). As a result, 1,232 and 1,073 phosphopeptides were identified in fresh and AR seeds, respectively. Although whole phosphopeptides were significantly overlapped, ABA-responsive phosphopeptides were quite different between both seeds. This result was supported by principal component analysis, clustering analysis, GO analysis and phosphorylation motif analysis, which showed different tendencies between fresh and AR seeds. These data suggested that ABA response in fresh seeds are active, but it is somehow inhibited or disappeared in after-ripened seeds at signaling level. We are going analyzing of identified phosphoproteins to find regulatory proteins of seed dormancy or after-ripening in barley.