Biosynthesis of Essential Polyunsaturated Fatty Acids in Wheat Triggered by Expression of Artificial Gene.

Daniel Mihálik,Ján Kraic,Katarína Ondreičková,Lenka Klčová,János Pauk,Milan Čertík,Marcela Gubišová,Martina Hudcovicová,Tatiana Klempová

doi:10.3390/ijms161226137

Abstract

The artificial gene D6D encoding the enzyme ∆6desaturase was designed and synthesized using the sequence of the same gene from the fungus Thamnidium elegans. The original start codon was replaced by the signal sequence derived from the wheat gene for high-molecular-weight glutenin subunit and the codon usage was completely changed for optimal expression in wheat. Synthesized artificial D6D gene was delivered into plants of the spring wheat line CY-45 and the gene itself, as well as transcribed D6D mRNA were confirmed in plants of T0 and T1 generations. The desired product of the wheat genetic modification by artificial D6D gene was the γ-linolenic acid. Its presence was confirmed in mature grains of transgenic wheat plants in the amount 0.04%–0.32% (v/v) of the total amount of fatty acids. Both newly synthesized γ-linolenic acid and stearidonic acid have been detected also in leaves, stems, roots, awns, paleas, rachillas, and immature grains of the T1 generation as well as in immature and mature grains of the T2 generation. Contents of γ-linolenic acid and stearidonic acid varied in range 0%–1.40% (v/v) and 0%–1.53% (v/v) from the total amount of fatty acids, respectively. This approach has opened the pathway of desaturation of fatty acids and production of essential polyunsaturated fatty acids in wheat.

Highlights

Wheat (Triticum aestivum L.) belongs to the most important crops and is an unreplaceable source of foods over the world
Creating of Artificial Gene The artificial gene D6D encoding the enzyme ∆6desaturase was created by the synthetic biology approach
Our study has shown that proper principles of the synthetic biology and gene transfer technologies could be an effective way to change biosynthetic pathway of polyunsaturated fatty acids in wheat plants

Summary

Introduction

Wheat (Triticum aestivum L.) belongs to the most important crops and is an unreplaceable source of foods over the world. The most substantial components of the wheat grain intended for the human diet are saccharides (starch) and proteins, but the nutrition composed primarily of wheat and other cereal grains is not optimally balanced for the consumer from the nutritional and physiological points of view. It would be highly desirable if multiple nutritional deficiencies could be tackled using engineered crops containing high levels of different minerals and organic nutrients [1]. An example could be wheat producing essential n-3 and n-6 polyunsaturated fatty acids (PUFAs), missing in mature grains. Endogenous γ-linolenic acid (6,9,12,cis,cis,cis-octadecatrienoic acid, GLA) formation, the rate limiting ∆6desaturase metabolite of linoleic acid, is low or impaired in a variety of diseases and should be supplied by diet

Objectives

Results

Conclusion