Asparagine accumulation in chicory storage roots is controlled by translocation and feedback regulation of asparagine biosynthesis in leaves

Abstract

The presence of acrylamide (AA), a potentially carcinogenic and neurotoxic compound, in food has become a major concern for public health. AA in plant-derived food mainly arises from the reaction of the amino acid asparagine (Asn) and reducing sugars during processing of foodstuffs at high temperature. Using a selection of genotypes from the chicory (Cichorium intybus L.) germplasm, we performed Asn measurements in storage roots and leaves to identify genotypes contrasting for Asn accumulation. We combined molecular analysis and grafting experiments to show that leaf to root translocation controls Asn biosynthesis and accumulation in chicory storage roots. We could demonstrate that Asn accumulation in storage roots depends on Asn biosynthesis and transport from the leaf, and that a negative feedback loop by Asn on CiASN1 expression impacts Asn biosynthesis in leaves. Our results provide a new model for Asn biosynthesis in root crop species and highlight the importance of characterizing and manipulating Asn transport to reduce AA content in processed plant-based foodstuffs.

Adding pulse flours to cereal‐based snacks and bakery products: An overview of free asparagine quantification methods and mitigation strategies of acrylamide formation in foods

“…An enzymatic method coupled with UV–Vis spectrophotometry has been technologically applied to research studies in recent years (Lecart et al., 2018). This technique involves using the enzyme asparaginase for the specific hydrolysis of ASN to yield aspartic acid and ammonia (Soares et al., 2020). Moreover, it is possible to use the Megazyme kit—including glutaminase, glutamate dehydrogenase, and asparaginase—to detect and measure free ASN in a series of four‐step enzymatic reactions (Lecart et al., 2018).…”