Characterization and functional analysis of three wheat genes with homology to the CONSTANS flowering time gene in transgenic rice
Article first published online: 29 AUG 2003
The Plant Journal
Volume 36, Issue 1, pages 82–93, October 2003
How to Cite
Nemoto, Y., Kisaka, M., Fuse, T., Yano, M. and Ogihara, Y. (2003), Characterization and functional analysis of three wheat genes with homology to the CONSTANS flowering time gene in transgenic rice. The Plant Journal, 36: 82–93. doi: 10.1046/j.1365-313X.2003.01859.x
- Issue published online: 29 AUG 2003
- Article first published online: 29 AUG 2003
- Received 7 February 2003; revised 29 June 2003; accepted 8 July 2003.
- flowering time;
- heading date;
- hexaploid wheat;
- expression of genes from three genomes;
- transgenic rice
The CONSTANS (CO) gene of Arabidopsis plays a key role in the photoperiodic flowering pathway. To investigate photoperiod responses in cereals in more detail, we isolated three kinds of CO/Hd1 (rice ortholog of CO) homolog from hexaploid wheat, derived from the A, B, and D genomes and designated as wheat ortholog of CO from A genome (TaHd1-1), TaHd1-2, and TaHd1-3, respectively. They were highly similar to each other and to Hd1, and in addition harbored two conserved regions: two zinc finger motifs and CONSTANS, CONSTANS-LIKE and TIMING OF CAB EXPRESSION 1 (CCT) domain like CO/Hd1. They were located on the long arm of the homoeologous chromosome 6. TaHd1-2 harbored a 63-bp deletion at the promoter region containing the GATA-1 box, and consequently, we detected no subsequent transcript. The TaHd1-1 genomic clone was introduced to a rice line deficient in Hd1 function. Transgenic plants complemented the functions of rice Hd1: they promoted heading under short-day (SD) conditions and delayed it under long-day (LD)/natural conditions, indicating that Hd1 proteins from SD and LD plants share common structures and functions.