Current Status and Perspectives on the Application of CRISPR/Cas9 Gene-Editing System to Develop a Low-Gluten, Non-Transgenic Wheat Variety.

Anil K Verma,Chiara Monachesi,Aadhya Tiwari,Sayanti Mandal,Carlo Catassi,Giulia N Catassi,Simona Gatti,Elena Lionetti,Akash Srivastava

doi:10.3390/foods10102351

Abstract

Wheat gluten contains epitopes that trigger celiac disease (CD). A life-long strict gluten-free diet is the only treatment accepted for CD. However, very low-gluten wheat may provide an alternative treatment to CD. Conventional plant breeding methods have not been sufficient to produce celiac-safe wheat. RNA interference technology, to some extent, has succeeded in the development of safer wheat varieties. However, these varieties have multiple challenges in terms of their implementation. Clustered Regularly Interspaced Short Palindromic Repeats-associated nuclease 9 (CRISPR/Cas9) is a versatile gene-editing tool that has the ability to edit immunogenic gluten genes. So far, only a few studies have applied CRISPR/Cas9 to modify the wheat genome. In this article, we reviewed the published literature that applied CRISPR/Cas9 in wheat genome editing to investigate the current status of the CRISPR/Cas9 system to produce a low-immunogenic wheat variety. We found that in recent years, the CRISPR/Cas9 system has been continuously improved to edit the complex hexaploid wheat genome. Although some reduced immunogenic wheat varieties have been reported, CRISPR/Cas9 has still not been fully explored in terms of editing the wheat genome. We conclude that further studies are required to apply the CRISPR/Cas9 gene-editing system efficiently for the development of a celiac-safe wheat variety and to establish it as a “tool to celiac safe wheat”.

Highlights

Common wheat (Triticum aestivum, 2n = 6x = 42, AABBDD) is a preferred staple food worldwide [1]
Genome-editing efficiency was validated in wheat protoplasts, and the DNA was evaluated for mutations by next-generation sequencing (NGS) followed by Agrobacterium-mediated transformation and mutant screening
The findings indicated that eating low-gliadin E82 bread for one week was well accepted by no-celiac gluten sensitivity (NCGS) patients, as the clinical effects were similar to those seen with glutenfree bread, and no variations in sensory parameters were observed

Summary

Introduction

Preliminary shreds of evidence suggest that primitive wheat (diploid or tetraploid) was safer and less immunogenic compared to currently used hexaploid wheat, as ancient wheat varieties had less immune-dominant protein fractions. This is strictly dependent on the particular genotype, not on the species [18,20]. The CRISPR/Cas gene-editing system can remove or reduce the toxic fractions of gluten, resulting in a gluten-free or low-gluten wheat [13]. This article will help in bridging the research gaps that currently exist towards the development of wheat lines devoid of immunogenic gluten

Literature Review

Genome-Editing Techniques

Role of RNAi in Modifying the Wheat Genome

Findings

12. Discussion

13. Conclusions