This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 148/3/1425    most recent pp.108.125542v1 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 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 Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Matsubara, K. Articles by Yano, M. Search for Related Content PubMed PubMed Citation Articles by Matsubara, K. Articles by Yano, M. Agricola Articles by Matsubara, K. Articles by Yano, M.

DEVELOPMENT AND HORMONE ACTION

Ehd2, a Rice Ortholog of the Maize INDETERMINATE1 Gene, Promotes Flowering by Up-Regulating Ehd1^1,[C],[W]

National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305–8602, Japan (K.M., U.Y., T.I., M.Y.); and Plant Genome Center, Tsukuba, Ibaraki 305–0856, Japan (Z.-X.W., Y.M.)

Recent research into the flowering of rice (Oryza sativa) has revealed both unique and conserved genetic pathways in the photoperiodic control of flowering compared with those in Arabidopsis (Arabidopsis thaliana). We discovered an early heading date2 (ehd2) mutant that shows extremely late flowering under both short- and long-day conditions in line with a background deficient in Heading date1 (Hd1), a rice CONSTANS ortholog that belongs to the conserved pathway. This phenotype in the ehd2 mutants suggests that Ehd2 is pivotal for the floral transition in rice. Map-based cloning revealed that Ehd2 encodes a putative transcription factor with zinc finger motifs orthologous to the INDETERMINATE1 (ID1) gene, which promotes flowering in maize (Zea mays). Ehd2 mRNA in rice tissues accumulated most abundantly in developing leaves, but was present at very low levels around the shoot apex and in roots, patterns that are similar to those of ID1. To assign the position of Ehd2 within the flowering pathway of rice, we compared transcript levels of previously isolated flowering-time genes, such as Ehd1, a member of the unique pathway, Hd3a, and Rice FT-like1 (RFT1; rice florigens), between the wild-type plants and the ehd2 mutants. Severely reduced expression of these genes in ehd2 under both short- and long-day conditions suggests that Ehd2 acts as a flowering promoter mainly by up-regulating Ehd1 and by up-regulating the downstream Hd3a and RFT1 genes in the unique genetic network of photoperiodic flowering in rice.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Masahiro Yano (myano{at}nias.affrc.go.jp).

^[C] Some figures in this article are displayed in color online but in black and white in the print edition.

^[W] The online version of this article contains Web-only data.

www.plantphysiol.org/cgi/doi/10.1104/pp.108.125542

^* Corresponding author; e-mail myano{at}nias.affrc.go.jp.

Received July 7, 2008; accepted September 5, 2008; published September 12, 2008.

This article has been cited by other articles:

				Compiled by, F. Tooke, T. Chiurugwi, and N. Battey Flowering Newsletter bibliography for 2008 J. Exp. Bot., June 23, 2009; (2009) erp154v1. [Full Text] [PDF]

				A. Greenup, W. J. Peacock, E. S. Dennis, and B. Trevaskis The molecular biology of seasonal flowering-responses in Arabidopsis and the cereals Ann. Bot., June 1, 2009; 103(8): 1165 - 1172. [Abstract] [Full Text] [PDF]

				Y. Takahashi, K. M. Teshima, S. Yokoi, H. Innan, and K. Shimamoto Variations in Hd1 proteins, Hd3a promoters, and Ehd1 expression levels contribute to diversity of flowering time in cultivated rice PNAS, March 17, 2009; 106(11): 4555 - 4560. [Abstract] [Full Text] [PDF]

				Y. A. Purwestri, Y. Ogaki, S. Tamaki, H. Tsuji, and K. Shimamoto The 14-3-3 Protein GF14c Acts as a Negative Regulator of Flowering in Rice by Interacting with the Florigen Hd3a Plant Cell Physiol., March 1, 2009; 50(3): 429 - 438. [Abstract] [Full Text] [PDF]