Analysis of high pI α-Amy-1 gene family members expressed in late maturity α-amylase in wheat (Triticum aestivum L.)

Late maturity α-amylase (LMA) is a genetic defect involving the synthesis of high pI isozymes of α-amylase encoded by α - Amy - 1 genes during the later stages of grain development. The aims of this investigation were to determine both the number of expressed α - Amy - 1 genes and their relative transcript abundance. Sub-cloning and sequencing of expressed high pI α-amylase genes in developing wheat seeds revealed three insertion/deletion patterns in the 3′ untranslated region and numerous single nucleotide polymorphisms at the 3′ end of α - Amy - 1. The genetic variations defined 36 α - Amy - 1 gene sequences that were expressed on the onset of LMA in doubled haploid progenies (SpM25, SpM52 and SpM127) derived from the cross Spica (LMA)/Maringa (non-LMA). Five isoelectric point groups were predicted based on the translated partial coding sequences. The potential application of quantitative real-time RT-PCR in screening wheat genotypes for LMA is discussed.