Structural Organization and Functional Activity of the Orthologous TaGLW7 Genes in Bread Wheat (Triticum aestivum L.)

Abstract

It is reported that GLW7 encoding the transcription factor OsSPL13, positively regulates grain size and shape in rice. We have limited knowledge about its orthologs in wheat. Here, based on the rice OsGLW7 we isolated and identified the TaGLW7 gene in wheat, characterized its nucleotide and protein structures, predicted the cis-elements of its promoter, analyzed its expression patterns. The orthologs in barley (HvGLW7), Brachypodium (BdGLW7), wild emmer (TtGLW7), Aegilops tauschii (AtGLW7) were also used for comparative analysis. As predicated, TaGLW7, HvGLW7, TtGLW7, and AtGLW7 were mapped onto group 2 chromosomes in the respective species. Multiple alignments indicated GLW7 possesses two exons and one intron in the analyzed species. GLW7 contains a conserved domain SBP and two neighboring low complexity regions. GLW7 was highly expressed in spike organs including wheat young spikes, barley inflorescence, and rice anthers. Additionally, biotic stress significantly down-regulated GLW7 in wheat and barley. Significant correlations between the expression patterns of predicted transcription factor ABF2 and TaGLW7 were detected. In conclusion, the conserved structure and expression of GLW7 among the investigated species and the predicted transcription factors significantly related to GLW7 are helpful for further manipulating GLW7 and uncovering its roles in plants.