Molecular phylogenetic analysis of amylase trypsin inhibitors (ATIs) from a selection of ancient and modern wheat

Wheat amylase-trypsin inhibitors (ATIs) are a family of wheat proteins, which play an important role in plant defence against pest attacks. Recently, ATIs have been identified as major stimulators of human innate immune cells leading to cause Non-celiac Wheat Sensitivity. Information about ATI sequence differences among wheat species is scarce, especially considering ancient wheat genotypes. In this study, ten selected wheat accessions with different ploidy level and year of release were used for gene sequencing of four representative alpha-amylase/trypsin inhibitor genes (WMAI, WDAI, WTAI-CM3 and CMx genes). The phylogenetic analysis and the PCA analysis performed on the deduced amino acid sequences of ATI genes evidenced that the ten wheat genotypes can be differentiated on the basis of their ploidy level, but not with respect to ancient or recently developed wheat genotypes. The haplotype analysis based on Nei's genetic distances, beside confirming these results, also allowed the separation of the hulled from the naked wheat genotypes. The genetic sequence differences highlighted in this study among the ten genotypes can be the basis for further studies aimed at identifying proinflammatory sequences in ATI genes. This is the first study analyzing the ATI genetic sequences of a set of ancient and modern wheat genotypes with a different ploidy level.