Characterization of genes encoding wheat grain hardness from Chinese cultivar GaoCheng 8901

The puroindoline-b (Pinb-D1) gene from Chinese hard wheat cultivar GaoCheng 8901 (Triticum aestivum L.) was obtained using two pairs of primers designed based on the known Pinb-D1 gene sequence and polymerase chain reaction (PCR) amplification. The PCR amplification was made using the genomic DNA of the wheat as a template and the specific fragment 450 bp in size was screened. The results indicated that the Pinb-D1 gene in GaoCheng 8901 shared 99.78% and 99.32% homology in nucleotide acid sequence and amino acid sequence, respectively, compared with the Pinb-D1 gene from hard wheat cultivars Wanser and Cheyenne. A new mutation in this Pinb-D1 gene, different from the six known mutations in the Pinb-D1 gene, was characterized with a change of a lysine to glutamic acid at position 45 in its protein sequence. This mutation, designated as Pinb-D11 in this study, might contribute to the formation of grain hardness in GaoCheng 8901. The characterization of Pinb-D1 gene would be helpful in manipulating grain hardness of wheat through genetic engineering.