基于基因编辑技术创制高亚油酸水稻材料

[目的]亚油酸是一种人体必需的脂肪酸,能加快体内脂肪代谢与分解、减少胆固醇在血管壁上形成积存、有效预防动脉硬化的发生、提高人体免疫力、促进骨骼发育、提高记忆力、预防脑部功能退化等功能.利用基因编辑技术对控制脂肪酸合成途径的关键酶ω-3脂肪酸去饱和酶基因进行精准编辑,关闭下游产物的合成途径,以便提高水稻上游亚油酸的含量,...

Production of High Linoleic Acid Rice by Genome Editing

【Objective】 Linoleic acid is one of essential fatty acid for human, which can accelerate the metabolism and decomposition of fat in the body, reduce the accumulation of cholesterol on the wall of blood vessels, effectively prevent the occurrence of arteriosclerosis, improve human immunity, promote bone development, improve memory and prevent brain function degradation. Rice bran is a by-product of rice processing, and is an edible oil with high nutritional value. In this paper, we precisely edited the gene of ω-3 fatty acid desaturase, which is the key enzyme controlling fatty acid synthesis pathway. It can enrich the upstream linoleic acid, while closing the synthesis pathway of downstream products. 【Method】There are two copies of the key enzyme ω-3 fatty acid desaturase gene ( OsFAD3) in the fatty acid synthesis pathway in rice, which are located on chromosome 11 and chromosome 12, and their cDNA homology is 97.32%. According to the basic principles of gene editing, the specificity of edit depends on the characteristics of the guide RNA (gRNA). In this study, two gRNAs were designed and synthesized in the exon region of two homologous genes, and were constructed into editing vectors respectively. The local receptor material (Fuyuan 4) was successfully transformed by Agrobacterium mediated method. The editing efficiency and genotype of the two sites were analyzed. At the same time, the main agronomic characters of OsFAD3 double mutant were measured, such as grain width and grain length. The contents of 37 fatty acids were figured by GC-MS in the grains of OsFAD3double mutants. 【Result】The results showed two homozygous editing materials were obtained, and other editing materials with different genotypes were obtained. Compared with the control materials, the main agronomic traits such as grain width and grain length of OsFAD3 double mutant materials had no significant changes, however, the relative content of linoleic acid in rice increased by 3.36%. 【Conclusion】One gRNA vector knock out two ω-3 fatty acid desaturase genes at the same time, which improves the relative content of linoleic acid in grains without changing the main agronomic traits of seeds.