Duplication of a well-conserved homeodomain-leucine zipper transcription factor gene in barley generates a copy with more specific functions

• DOI: 10.1007/s10142-009-0134-y
• Publication Date: 2009-08-25T09:56:20Z
• Authors: Shun Sakuma; Mohammad Pourkhei...; Takashi Matsumoto; Takato Koba; Takao Komatsuda
• Keywords: Brachypodium distachyon; Triticeae; Conserved sequence

Three spikelets are formed at each rachis node of the cultivated barley (Hordeum vulgare ssp. vulgare) spike. In two-rowed barley, central one is fertile and two lateral ones sterile, whereas in six-rowed type, all three fertile. This characteristic determined by allelic constitution spike 1 (vrs1) locus on long arm chromosome 2H, with recessive allele being responsible for phenotype. The Vrs1 (HvHox1) gene encodes a homeodomain-leucine zipper (HD-Zip) transcription factor. Here, we show that evolved Poaceae via duplication, second copy gene, HvHox2, present short 2H. Micro-collinearity polypeptide sequences were both well conserved between HvHox2 its orthologs, but unique to tribe. product lacks motif which among orthologs. A phylogenetic analysis demonstrated must have diverged after separation Brachypodium distachyon from Pooideae suggests arose following duplication acquired new function during evolution was expressed organs examined predominantly immature inflorescence.