Molecular cloning of Sdr4, a regulator involved in seed dormancy and domestication of rice
- Kazuhiko Sugimoto a ,
- Yoshinobu Takeuchi b ,
- Kaworu Ebana a ,
- Akio Miyao a ,
- Hirohiko Hirochika a ,
- Naho Hara a ,
- Kanako Ishiyama c ,
- Masatomo Kobayashi c ,
- Yoshinori Ban d ,
- Tsukaho Hattori d , and
- Masahiro Yano a , 1
- aNational Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan;
- bNational Institute of Crop Science, Tsukuba, Ibaraki 305-8518, Japan;
- cBioResources Center, RIKEN, Tsukuba, Ibaraki 305-0074, Japan; and
- dBioscience and Biotechnology Center, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
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Edited* by Maarten Koornneef, Wageningen Agricultural University, Wageningen, The Netherlands, and approved February 11, 2010 (received for review October 21, 2009)
Abstract
Seed dormancy provides a strategy for flowering plants to survive adverse natural conditions. It is also an important agronomic trait affecting grain yield, quality, and processing performance. We cloned a rice quantitative trait locus, Sdr4, which contributes substantially to differences in seed dormancy between japonica (Nipponbare) and indica (Kasalath) cultivars. Sdr4 expression is positively regulated by OsVP1, a global regulator of seed maturation, and in turn positively regulates potential regulators of seed dormancy and represses the expression of postgerminative genes, suggesting that Sdr4 acts as an intermediate regulator of dormancy in the seed maturation program. Japonica cultivars have only the Nipponbare allele (Sdr4-n), which endows reduced dormancy, whereas both the Kasalath allele (Srd4-k) and Sdr4-n are widely distributed in the indica group, indicating prevalent introgression. Srd4-k also is found in the wild ancestor Oryza rufipogon, whereas Sdr4-n appears to have been produced through at least two mutation events from the closest O. rufipogon allele among the accessions examined. These results are discussed with respect to possible selection of the allele during the domestication process.
Footnotes
- 1To whom correspondence should be addressed. E-mail: myano{at}nias.affrc.go.jp.
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Author contributions: M.Y. designed research; K.S., Y.T., K.E., A.M., H.H., N.H., K.I., M.K., Y.B., and T.H. performed research; K.E., and T.H. analyzed data; and K.S. and T.H. wrote the paper.
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The authors declare no conflict of interest.
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Data deposition: The sequences reported in this paper have been deposited in the GenBank database [accession nos. AB506455 (Sdr4-k) and AB510199 (Sdr4-n)].
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↵*This Direct Submission article had a prearranged editor.
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This article contains supporting information online at www.pnas.org/cgi/content/full/0911965107/DCSupplemental.
