Sequence analysis of alpha-amylase inhibitors genes with resistance to insects in wheat and Aegilops / 生物工程学报

ABSTRACT

The alpha-amylase inhibitors have been proposed as possibly important weapons against pests. Thus, it is of importance to identify the specificity of them. Based on the EST data of alpha-amylase inhibitor genes that were retrieved from NCBI, BBSRC and GrainGenes, two PCR primers were designed. The coding sequences of 24 kD dimeric alpha-amylase inhibitors with resistance to insects in 17 wheat and Aegilops accessions were investigated and 17 new genes were obtained. Only one 24 kD alpha-amylase inhibitor gene was found in each diploid wheat and Aegilops accession, whereas 8 genes were characterized from one hexaploid wheat variety, indicating that the 24 kD alpha-amylase inhibitors in hexaploid wheat were encoded by multi-gene. The deduced amino acid sequences of 2 genes from common wheat and 1 gene from Ae. tauschii were the same as the sequence of the inhibitor 0.19, and the deduced amino acid sequence of another gene from common wheat was similar to the inhibitor 0.53 with only one amino acid difference. The amino acid sequences of 24 kD dimeric alpha-amylase inhibitors shared very high coherence (91.2%). These results suggest that the alpha-amylase inhibitors in 24 kD family were derived from common ancestral genes by phylogenesis.