Identification of alpha-amylase inhibitors in triticale grain

In this study three complete triticales, three substituted (one gene from rye has been replaced by one gene from wheat) triticales, and parental wheat and rye were analysed for alpha-amylase inhibitory activity to evaluate whether the genetic modification influenced triticale alpha-amylase inhibitory activity. Gel filtration chromatography and thermostability analyses were performed to partially isolate and characterize alpha-amylase inhibitors. Results demonstrated that substituted triticales and wheat had higher alpha-amylase inhibitory activities and higher water-soluble protein contents than complete triticales and rye. Sodium dodecylsulfate-PAGE-electrophoresis showed that all triticales, irrespective of their classification, inherited the water-soluble protein patterns from their parents: wheat and rye. In a substituted triticale (Pony 'S'), two peaks with alpha-amylase inhibitory activity were resolved by gel filtration chromatography; they were designated T1 and T2 according to their order of elution. T1 showed a higher inhibitory activity but a lower thermostability at 70 degrees C than T2; T1 apparently comes from wheat, whereas T2 presumably comes from rye.