2007 Fiscal Year Final Research Report Summary
Biochemical analysis of glycoproteins involved in gibberellin signal transduction in cereal seeds
Project/Area Number |
17380071
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Bioproduction chemistry/Bioorganic chemistry
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Research Institution | The University of Tokyo |
Principal Investigator |
SUZUKI Yoshihito The University of Tokyo, Graduate School of Agricultural Life Sciences, Associate Professor (90222067)
|
Project Period (FY) |
2005 – 2007
|
Keywords | Arabinogalactan protein / aleurone laver / defense response / gibberellin |
Research Abstract |
Arabinogalactan-proteins (AGPs) are a group of glycoproteins highly glycosylated with arabinogalactan polysaccharide and have been characterized by its specific binding to b-glucosyl Yariv reagent (b-G1cY). Another characteristics of AGPs is glycosylphosphatidylinositol (GPI)-anchoring, suggestive of their possible involvement in signal transduction. We have found that a-amylase induction by GA in barley aleurone protoplasts was inhibited by b-G1cY. Microarray analysis indicated that b-G1cY was largely effective in repressing both the GA-induced-and repressed-gene expressions. In addition, quite a number of defense-related genes were up-reguated by b-G1cY, including specific WRKYs and a protein kinase whose inhibitory effects on GA signaling had been shown. Plant defense signaling triggered by jasmonic acid or chitin elicitor could inhibit GA-inducible genes in aleurone cells. These results indicate that GA signaling in aleurone cells is under regulation of defense-related ding. It is also probable that AGPs are involved in the perception of stimuli causing defense responses. Using b-G1cY, a novel early nodulin like-protein, designated as OsENODL1, was identified as a specific AGP in aleurone layers of rice. The RNAi knockdown lines of OsENODL1 and its homologous gene were prepared and the possible role of the proteins in seed formation was shown. Yeast two hybrid screening also gave a protein which interacts with early nodulin like domain. The protein was related to defense response in plants and is induced by infection, suggesting that the interaction of the protein with OsENODL1 upon infection trigger defense signaling just as b-G1cY triggered defense signaling, and inhibit GA signaling.
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Research Products
(16 results)