Transformation of the US bread wheat 'Butte 86' and silencing of omega-5 gliadin genes.

Abstract

Complex groups of proteins determine the unique functional properties of wheat flour and are sometimes responsible for food intolerances and allergies in individuals that consume wheat products. Transgenic approaches can be used to explore the functions of different flour proteins, but are limited to the few wheat cultivars that can be transformed and also by the lack of detailed information about genes and proteins expressed in grain from those cultivars. The US bread wheat Butte 86 has been extensively characterized and a comprehensive proteome map was developed in which flour proteins were distinguished by mass spectrometry and associated with specific gene sequences. Here, this information has been used to design an RNA interference construct to silence the expression of genes encoding omega gliadins that trigger the food allergy wheat-dependent exercise-induced anaphylaxis (WDEIA). The construct was introduced into immature embryos from Butte 86 using biolistics and bialaphos-resistant plants were regenerated. Stable transformation and inheritance of the transgene were confirmed by PCR. Analysis of proteins in grain from transgenic plants demonstrated that the omega-5 gliadins were either absent or substantially reduced relative to non-transformed controls. The ability to genetically transform Butte 86 makes it possible to alter flour composition in a targeted manner in a commercial US wheat cultivar and should accelerate future research on flour quality and immunogenic potential.