Why are researchers developing Low Immunogenic wheat?

 

The total global wheat consumption was 734.7 million metric tons, which increased by 759 million metric tons in 2021. As wheat was introduced into the human diet about 10,000–12,000 years ago. It has multiple health advantages such as maintaining healthy gut microbiota and obesity, in addition to it is nutritional value as it fills with vitamins, minerals, and fibers. Apart from its natural value, wheat protein's chemical structure is not fully digested by the pancreas. Wheat proteins, including non-gluten proteins, i.e., amylase/trypsin inhibitors (ATI), may trigger inflammatory immune reactions and disorders such as wheat allergies, CD, nonceliac gluten sensitivity (NCGS), fructose malabsorption, and irritable bowel syndrome (IBS). This article highlights the need for low immunogenic effect wheat that can provide a balanced and normal life.

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It was believed that the ancient varieties of wheat are healthier and safer than the recent ones. Along ages, natural breading and traditional cultivation occur among different varieties of wheat, that people use daily. However, the wheat variety doesn’t relate to its immunogenic effect, while the variety’s genome does. A genome is the full set of chromosomes in an organism, while the number of the set of chromosomes is called ploidy. Polyploidy means the organism has so many sets of chromosomes, in other words many copies of the same genome in the same organism. The one with the highest immunogenic effect is the D-genome variety as it is included the α-gliadin as it is easy to be recognized by the immune system. Gluten protein in wheat is used for storage, as it was mentioned in the previous article its content has been increases massively due to the abiotic stress subjected to the wheat plant during its cultivation. For example, using chemical pesticides and fertilizers which led to the manipulation of the genome at the sites of producing gluten genes.

Therefore, researchers have been working on developing a low-immunogenic wheat varieties using genetic editing biotechnological techniques to remove or reduce the toxic amount of gluten proteins. The most suggested techniques to be used to produce such a variety is called clustered regularly interspaced short palindromic repeats-associated nuclease 9 (CRISPR/Cas9). Recently this technique showed successful and novel second-generation genome editing procedures.

(CRISPR/Cas9) technique idea comes from the nature of the defense mechanism of bacteria attacked with a bacteriophage. Bacteriophage is a specific type of virus that infect bacteria only. After the bacterial cell invasion, the bacteriophage releases its genetic material into the bacterial chromosome. Bacteria take snippets of the viral genetic material and then synthesize DNA portions which are called CRISPR arrays, and their function is to remember the viral genetic material and work as its defense system for futural invasions with the same or similar viral genetic material. By producing RNA from the CRISPR arrays that will guide the cleavage protein called Cas9 to the viral genetic material.

This mechanism stimulation led us to synthesize the guide RNA (gRNA) which correspondent with the target DNA sequence. Then the combination of both the gRNA and Cas9 produces a complex of ribonucleoprotein (RNP). When the required cleavage occurred by restriction enzyme Cas9 it forms a DSB region double-strand break signaling the repair mechanism to repair the damage that occurred even through non-homologous joining or homologous recombination. If this is used in wheat it would alter the genetic structure of gliadin genes and suppress their immunogenic power while maintaining their functionality and organoleptic characteristics.

However, more effort should be done because of the hardship of genetic editing in wheat organisms. (CRISPR/Cas9) technique struggles with wheat’s genetic redundancy and genome complexity. Even if it is hard to be done it will take time for scientific research to find a solution.