Down-Regulation of OsGRF1 Gene in Rice rhd1 Mutant Results in Reduced Heading Date
Article first published online: 7 JUN 2005
Journal of Integrative Plant Biology
Volume 47, Issue 6, pages 745–752, June 2005
How to Cite
LUO, A.-D., LIU, L., TANG, Z.-S., BAI, X.-Q., CAO, S.-Y. and CHU, C.-C. (2005), Down-Regulation of OsGRF1 Gene in Rice rhd1 Mutant Results in Reduced Heading Date. Journal of Integrative Plant Biology, 47: 745–752. doi: 10.1111/j.1744-7909.2005.00071.x
Supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (KSCX2-SW-316) and the Hi-Tech Research and Development (863) Program of China (2002AAZ2001 and 2002CCA03200).
- Issue published online: 7 JUN 2005
- Article first published online: 7 JUN 2005
- Received 7 Jul. 2004 Accepted 11 Jan. 2005
- differential display polymerase chain reaction (DD-PCR);
- Oryza sativa growth-regulating factor 1 (OsGRF1);
- reduced heading date;
Abstract: A rice mutant with reduced heading date (designated rhd1) found in a transgenic line of cultivar Teqing 2 (Oryza sativa L. ssp. indica) was used to identify the genes related to rice heading and thereby to study its molecular mechanism. Genetic analysis showed that rhd1 was a dominant mutation and did not result from T-DNA insertion. By using the differential display polymerase chain reaction (DD-PCR) technique, differential gene expression between rhd1 and Teqing 2 was compared and a rhd1-down-regulated c DNA fragment was identified. Sequence analysis showed that this fragment shared 99% similarity to the OsGRF1 (O. sativa growth-regulating factor 1) gene. The OsGRF1 gene encodes a putative transcription factor, which contains two conserved regions: the QLQ (Gln, Leu, Gln) and WRC (Trp, Arg, Cys) domains. Southern analysis indicates that OsGRF1 may be encoded by single copy gene in the rice genome. RNA interference results revealed that transgenic lines with reduced OsGRF1 transcript displayed delayed growth and development, developed small leaves, and had delayed heading. The extent of the phenotypes developed was well-correlated with the OsGRF1 gene transcript. Our results clearly demonstrate that the OsGRF1 gene is not only involved in regulating growth at the juvenile stage, but that it may also be involved in the regulation of heading in rice.
(Managing editor: Li-Hui ZHAO)