This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 18/9/2326    most recent tpc.105.038844v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Chen, P.-W. Articles by Yu, S.-M. Search for Related Content PubMed PubMed Citation Articles by Chen, P.-W. Articles by Yu, S.-M. Agricola Articles by Chen, P.-W. Articles by Yu, S.-M.

Interaction between Rice MYBGA and the Gibberellin Response Element Controls Tissue-Specific Sugar Sensitivity of -Amylase Genes^[W]

^a Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 115, Republic of China
^b Taiwan Agriculture Research Institute, Wu-Fong, Taichung, Taiwan 413, Republic of China
^c Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan 402, Republic of China

² To whom correspondence should be addressed. E-mail sumay{at}imb.sinica.edu.tw; fax 886-2-2782-6085.

Expression of -amylase genes during cereal grain germination and seedling growth is regulated negatively by sugar in embryos and positively by gibberellin (GA) in endosperm through the sugar response complex (SRC) and the GA response complex (GARC), respectively. We analyzed two -amylase promoters, Amy3 containing only SRC and Amy8 containing overlapped SRC and GARC. Amy3 was sugar-sensitive but GA-nonresponsive in both rice (Oryza sativa) embryos and endosperms, whereas Amy8 was sugar-sensitive in embryos and GA-responsive in endosperms. Mutation of the GA response element (GARE) in the Amy8 promoter impaired its GA response but enhanced sugar sensitivity, and insertion of GARE in the Amy3 promoter rendered it GA-responsive but sugar-insensitive in endosperms. Expression of the GARE-interacting transcription factor MYBGA was induced by GA in endosperms, correlating with the endosperm-specific Amy8 GA response. Amy8 became sugar-sensitive in MYBGA knockout mutant endosperms, suggesting that the MYBGA–GARE interaction overrides the sugar sensitivity of Amy8. In embryos overexpressing MYBGA, Amy8 became sugar-insensitive, indicating that MYBGA affects sugar repression. -Amylase promoters active in endosperms contain GARE, whereas those active in embryos may or may not contain GARE, confirming that the GARE and GA-induced MYBGA interaction prevents sugar feedback repression of endosperm -amylase genes. We demonstrate that the MYBGA–GARE interaction affects sugar feedback control in balanced energy production during seedling growth and provide insight into the control mechanisms of tissue-specific regulation of -amylase expression by sugar and GA signaling interference.

This article has been cited by other articles:

				J. Kim, T.-G. Kim, S. H. Jung, J.-R. Kim, T. Park, P. Heslop-Harrison, and K.-H. Cho Evolutionary design principles of modules that control cellular differentiation: consequences for hysteresis and multistationarity Bioinformatics, July 1, 2008; 24(13): 1516 - 1522. [Abstract] [Full Text] [PDF]

				J. A. Punwani, D. S. Rabiger, and G. N. Drews MYB98 Positively Regulates a Battery of Synergid-Expressed Genes Encoding Filiform Apparatus Localized Proteins PLANT CELL, August 1, 2007; 19(8): 2557 - 2568. [Abstract] [Full Text] [PDF]

				C.-A. Lu, C.-C. Lin, K.-W. Lee, J.-L. Chen, L.-F. Huang, S.-L. Ho, H.-J. Liu, Y.-I. Hsing, and S.-M. Yu The SnRK1A Protein Kinase Plays a Key Role in Sugar Signaling during Germination and Seedling Growth of Rice PLANT CELL, August 1, 2007; 19(8): 2484 - 2499. [Abstract] [Full Text] [PDF]