GAMYB gene in rye – sequence, polymorphisms, map location, allele-specific markers and relationship with selected agronomic traits

Abstract

Background. A master GA-induced regulatory protein, crucial for development and germination of cereal grain and involved in anther formation is MYB transcription factor GAMYB, activating a vast number of genes including high-molecular-weight glutenin and α-amylase gene families. This paper presents the first attempt to characterize rye gene encoding GAMYB in relation to its sequence, polymorphisms and phenotypic effects. Results. ScGAMYB gene was identified and mapped on rye chromosome 3R using high-density DArT/DArTseq-based maps developed in two mapping populations. Comparative analysis of the gene sequence revealed its high level of homology to wheat and barley orthologues. Single nucleotide polymorphisms detected among rye inbred lines allowed developing AS-PCR markers for ScGAMYB (ten pairs of primers) which might be used to detect this gene in wide genetic stocks of rye and triticale. Segregation of ScGAMYB alleles showed significant relationship with quantitative traits including plant height, thousand grain weight, α-amylase activity, earliness per se and leaf rolling. Conclusions. The research showed the strong similarity of rye GAMYB sequence to its orthologues in other Graminae and confirmed the position in the genome consistent with the collinearity rule of cereal genomes. The statistically significant, however moderate association of ScGAMYB with many agronomic features has been pointed out, which proved that this gene is a QTL of pleiotropic character. The effect of ScGAMYB on flowering time was statistically the most significant. Developed sequence-based, allele-specific PCR markers could be useful in research and application purposes.