The high molecular weight glutenin subunits (HMW-GSs) are a major class of common wheat storage proteins. The breadmaking quality of common wheat flour is influenced by the composition of HMW-GSs. In the present stu...The high molecular weight glutenin subunits (HMW-GSs) are a major class of common wheat storage proteins. The breadmaking quality of common wheat flour is influenced by the composition of HMW-GSs. In the present study, two unexpressed 1 By genes from Triticum aesitvum L.ssp.yunnanese AS332 and T. aesitvum ssp.tibetanurn AS908 were respectively cloned and characterized. The results indicated that both of the silenced 1By genes in AS332 and AS908 were 1Byg. In contrast to previously reported mechanisms for silenced genes lAx and lay, which was due to the insertion of transposon elements or the presence of premature stop codon via base substitution of C→T transition in trinucleotides CAA or CAG, the silence of 1By9 genes was caused by premature stop codons via the deletion of base A in trinucleotide CA.A, which lead to frameshift mutation and indirectly produced several premature stop codons (TAG) downstream of the coding sequence.展开更多
基金Supported by New Century Excellent Talents in University (NCET-04-0908)Changjiang Scholars and Innovative Research Team in University(IRT0453) of the Chinese Ministry of Educationthe Hi-Tech Researchand Development Program (863) of China (2006AA10Z1F8).
文摘The high molecular weight glutenin subunits (HMW-GSs) are a major class of common wheat storage proteins. The breadmaking quality of common wheat flour is influenced by the composition of HMW-GSs. In the present study, two unexpressed 1 By genes from Triticum aesitvum L.ssp.yunnanese AS332 and T. aesitvum ssp.tibetanurn AS908 were respectively cloned and characterized. The results indicated that both of the silenced 1By genes in AS332 and AS908 were 1Byg. In contrast to previously reported mechanisms for silenced genes lAx and lay, which was due to the insertion of transposon elements or the presence of premature stop codon via base substitution of C→T transition in trinucleotides CAA or CAG, the silence of 1By9 genes was caused by premature stop codons via the deletion of base A in trinucleotide CA.A, which lead to frameshift mutation and indirectly produced several premature stop codons (TAG) downstream of the coding sequence.