Overexpression of Wheat TaELF3-1BL Delays Flowering in Arabidopsis

EARLY FLOWERING 3 (ELF3), a light zeitnehmer (time-taker) gene, regulates circadian rhythm and photoperiodic flowering in Arabidopsis, rice, and barley. The three orthologs of ELF3 (TaELF3-1AL, TaELF3-1BL, andTaELF3-1DL) have been identified in wheat too, and one gene, TaELF3-1DL, has been associated with headingdate. However, the basic characteristics of these three genes and the roles of the other two genes, TaELF3-1BLand, TaELF3-1AL, remain unknown. Therefore, the present study obtained the coding sequences of the threeorthologs (TaELF3-1AL, TaELF3-1BL, and TaELF3-1DL) of ELF3 from bread wheat and characterized themand investigated the role of TaELF3-1BL in Arabidopsis. Protein sequence comparison revealed similarities amongthe three TaELF3 genes of wheat; however, they were different from the Arabidopsis ELF3. Real-time quantitativePCR revealed TaELF3 expression in all wheat tissues tested, with the highest expression in young spikes; the threegenes showed rhythmic expression patterns also. Furthermore, the overexpression of the TaELF3-1BL gene inArabidopsis delayed flowering, indicating their importance in flowering. Subsequent overexpression ofTaELF3-1BL in the Arabidopsis ELF3 nonfunctional mutant (elf3 mutant) eliminated its early flowering phenotype, and slightly delayed flowering. The wild-type Arabidopsis overexpressing TaELF3-1BL demonstratedreduced expression levels of flowering-related genes, such as CONSTANS (AtCO), FLOWERING LOCUS T (AtFT),and GIGANTEA (AtGI). Thus, the study characterized the three TaELF3 genes and associated TaELF3-1BL withflowering in Arabidopsis, suggesting a role in regulating flowering in wheat too. These findings provide a basis forfurther research on TaELF3 functions in wheat.