CRISPR/Cas9-Mediated Knockout of GmFATB1 Significantly Reduced the Amount of Saturated Fatty Acids in Soybean Seeds.

Jing Ma,Huixia Shou,Shuo Sun,James Whelan

doi:10.3390/ijms22083877

Abstract

Soybean (Glycine max) oil is one of the most widely used vegetable oils across the world. Breeding of soybean to reduce the saturated fatty acid (FA) content, which is linked to cardiovascular disease, would be of great significance for nutritional improvement. Acyl-acyl carrier protein thioesterases (FATs) can release free FAs and acyl-ACP, which ultimately affects the FA profile. In this study, we identified a pair of soybean FATB coding genes, GmFATB1a and GmFATB1b. Mutants that knock out either or both of the GmFATB1 genes were obtained via CRISPR/Cas9. Single mutants, fatb1a and fatb1b, showed a decrease in leaf palmitic and stearic acid contents, ranging from 11% to 21%. The double mutant, fatb1a:1b, had a 42% and 35% decrease in palmitic and stearic acid content, displayed growth defects, and were male sterility. Analysis of the seed oil profile revealed that fatb1a and fatb1b had significant lower palmitic and stearic acid contents, 39–53% and 17–37%, respectively, while that of the unsaturated FAs were the same. The relative content of the beneficial FA, linoleic acid, was increased by 1.3–3.6%. The oil profile changes in these mutants were confirmed for four generations. Overall, our data illustrate that GmFATB1 knockout mutants have great potential in improving the soybean oil quality for human health.

Highlights

Published: 9 April 2021Soybean (Glycine max) oil is the most important vegetable oil in the world, accounting for 28% of the world’s edible oil consumption in 2019 [1]
To better understand the role of the soybean FATB proteins on the soybean oil profile, a BLAST search was performed against the soybean genome database [35], using the amino acid sequences of AtFATB
A total of four FATB proteins were found, which can be divided into two pairs, namely GmFATB1a and GmFATB1b, and GmFATB2a and

Summary

Introduction

Published: 9 April 2021Soybean (Glycine max) oil is the most important vegetable oil in the world, accounting for 28% of the world’s edible oil consumption in 2019 [1]. Soybean oil contains essential fatty acids (FAs) for human nutrition. It contains five FAs: palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), and linolenic acid (C18:3), with average contents of 10%, 4%, 18%, 55%, and 13%, respectively [2]. Oleic acid can reduce the content of total cholesterol and harmful cholesterol in the human body, and is considered as a beneficial FA. Linoleic acid is reported to have anti-cancer properties, lower blood lipids, is anti-atherosclerosis, improve immunity, and prevent and treat diabetes [6,7,8]. Increasing the content of oleic and reducing the content of saturated FAs and linolenic acid in seeds are important goals of soybean breeding

Methods

Results

Conclusion