No abstract

Two new low-molecular-weight glutenin subunits (LMW-GS) genes from Triticum timopheevii (Zhuk.) were cloned by reverse-transcription PCR (RT-PCR). The complete open reading frames of 897 and 894 bp, corresponding to the size of LMW-GS genes were designated as TTLMW-m1 and TTLMW-m2, respectively. Multiple sequence alignment analysis indicated that these two genes showed high similarity with known LMW-m type genes, albeit possessing distinct sequence variations. A total of 10 single-nucleotide polymorphisms in the TTLMW-m1 and TTLMW-m2 genes were identified, including five non-synonymous mutations. The predicted secondary structure of the deduced mature glutenin subunits of TTLMW-m1 and TTLMW-m2 genes showed that both subunits possessed more a-helixes and b-strands than the control subunit AY263369, suggesting a more viscoelastic dough structure and a positive effect on quality. The homology tree and phylogenetic analysis showed that the two LMW-m type genes were most likely located at the Glu-G3 locus and that they diverged from the LMW-i type genes about 13 million years ago (MYA). The G genome in T. timopheevii appears to be closely related to the D and B genomes of Triticum aestivum.