Understanding the Relationships between Free Asparagine in Grain and Other Traits to Breed Low-Asparagine Wheat

Abstract

Since the discovery of acrylamide in food, and the identification of free asparagine as the key determinant of acrylamide concentration in wheat products, our understanding of how grain asparagine content is regulated has improved greatly. However, the targeted reduction in grain asparagine content has not been widely implemented in breeding programmes so far. Here we summarise how free asparagine concentration relates to other quality and agronomic traits and show that these relationships are unlikely to pose major issues for the breeding of low-asparagine wheat. We also outline the strategies that are possible for the breeding of low-asparagine wheat, using both natural and induced variation.

Exploring Variability of Free Asparagine Content in the Grain of Bread Wheat (Triticum aestivum L.) Varieties Cultivated in Italy to Reduce Acrylamide-Forming Potential

“…To date, crop management strategies, including ensuring sufficient sulphur in the soil during cultivation [ 23 ] and avoiding pathogen infection [ 21 , 25 ], are the most common strategies to reduce fAsn concentrations. Nevertheless, a further crucial point to control fAsn content in wheat seeds is the identification and utilization of wheat genotypes with a strong genetic component in this trait [ 5 ]. A recent study highlighted that a natural deletion of a key gene encoding the asparagine synthetase of class 2 of the B genome (TaASN-B2) can reduce the amount of fAsn in wheat grain [ 36 ].…”

“…Today, one of the objectives of wheat breeding is the improvement of its nutritional quality and health value [ 3 , 4 ]. A major issue related to food production that can be faced through specific breeding programs is the reduction of acrylamide, which is generated in a wide range of foods, including wheat derivatives [ 5 , 6 ]. Acrylamide (C 3 H 5 NO) is a white, odourless, water-soluble molecule and is rapidly absorbed through the skin and from the gastro-intestinal tract.…”

Genetic control of grain amino acid composition in a UK soft wheat mapping population

“…In our analysis, this association mostly arose because of the effect of environment on both yield and asparagine. Environmental stress can lead to decreases in yield while increasing free asparagine, while other variables (e.g., nitrogen fertilizer) can lead to increases in both yield and free asparagine (see Oddy et al (2022) for review). Our modeling of asparagine through these variables mostly indicated environment as the driving force in our study, but there was still a slight negative association with yield and plant height as well as a slight positive association with kernel hardness.…”

Cereal grain with low acrylamide formation potential as a raw material for safer cereal-based food products in Serbia

“…However, there is a positive correlation between the amount of total proteins and free asparagine, i .e . the lower content of free asparagine the higher total protein content decrease (Žilić et al ., 2020;Oddy et al ., 2022) . Accordingly, even though cereals are not the major source of protein, cereal-based food producers must alter their recipes in order to use the genotypes with lower free asparagine content (Žilić et al .…”

“…In Serbia, regulations and recommendations concerning the content of acrylamide in food came into force in January 2020, with the Regulation on allowed maximum concentrations of certain contaminants in food, and were updated last time in December 2021 (Official Gazette RS No 81/2019, 126/2020, 90/2021, and 118/2021 . The set of benchmarks and guidelines are only applied to a small subset of food items .…”