Abstract
Amylase trypsin inhibitors (ATIs) are a group of proteins in all cereals' seeds, including wheat, barley, rye, and maize. Currently, ATIs are the most studied wheat components since they are linked to celiac disease and baker's asthma. The interest has increased since 2012, when they were shown to trigger the innate immune system and intestinal and extra-intestinal inflammation. Even though ATIs are present in many plant-based diets, the genetic factors underlying these proteins have not yet been investigated in barley. To this end, this study was designed to measure ten ATI proteins in a diverse barley collection grown under field conditions. Ample natural variation among the accessions in ten ATIs has been measured, which showed a substantial role in the accumulation of ATI_total, such as CMa, CMd, CMe, BTI_CMc, and AIBDAI_1. A genome-wide association scan (GWAS) utilizing a large number of molecular markers demonstrated that the accumulation of ATIs was influenced by many small to medium quantitative trait nucleotides (QTNs). Eight QTNs showed the highest association with ATIs, particularly AIBDAI, whereas these QTNs negatively influenced ATI accumulation. Genomic investigations identified Serine/threonine protein phosphatase as a putative candidate gene. Our research provides the initial analysis of the ATI proteins found in barley, which might potentially contribute to enhancing the quality of barley-based food products. As a result, the study demonstrated that cultivars with lower ATI proteins can speed up their integration to improve the quality of barley products and diminish the possibility of some diseases.