Molecular Characterization, Compositional Analysis, and Germination Evaluation of a High‐Oleic Soybean Generated by the Suppression ofFAD2‐1Expression

Abstract

ABSTRACTSoybean [Glycine max(L.) Merr.] oil is one of the most consumed and highest produced vegetable oils. However, the high percentage of polyunsaturated fatty acids in soybean oil limits its stability and shelf life. Here we report the generation and characterization of a high oleic acid soybean event (305423 soybean) that has an elevated content of monounsaturated oleic acid and reduced presence of polyunsaturated linoleic acid and linolenic acid. This transgenic event was generated by the insertion of a soybean ω‐6 desaturase (FAD2) gene fragment (gm‐fad2‐1), resulting in the suppression of endogenousFAD2‐1expression, and a modified version of the soybeanacetolactate synthase(ALS) gene (gm‐hra), used as a selectable marker. Molecular characterization revealed that 305423 soybean harbors four DNA inserts containing multiple copies of complete and partialgm‐fad2‐1gene cassettes and a single copy of the intactgm‐hragene cassette. However, these DNA inserts seemed to be inherited together without segregation. The suppression of endogenousFAD2‐1led to an increase of oleic acid (18:1) from 211 to 765 g kg–1along with concurrent reduction of both linoleic acid (18:2) from 525 to 36.2 g kg–1and linolenic acid (18:3) from 93.5 to 53.9 g kg–1out of total fatty acyl groups. The 305423 soybean was also subjected to nutrient composition analyses and phenotypic and agronomic performance evaluations and found to be comparable to the control soybean except for the expected traits.