The Potential of Genome Editing for Improving Seed Oil Content and Fatty Acid Composition in Oilseed Crops

Abstract

A continuous rise in demand for vegetable oils, which comprise mainly the storage lipid triacylglycerol, is fueling a surge in research efforts to increase seed oil content and improve fatty acid composition in oilseed crops. Progress in this area has been achieved using both conventional breeding and transgenic approaches to date. However, further advancements using traditional breeding methods will be complicated by the polyploid nature of many oilseed crops and associated time constraints, while public perception and the prohibitive cost of regulatory processes hinders the commercialization of transgenic oilseed crops. As such, genome editing using CRISPR/Cas is emerging as a breakthrough breeding tool that could provide a platform to keep pace with escalating demand while potentially minimizing regulatory burden. In this review, we discuss the technology itself and progress that has been made thus far with respect to its use in oilseed crops to improve seed oil content and quality. Furthermore, we examine a number of genes that may provide ideal targets for genome editing in this context, as well as new CRISPR-related tools that have the potential to be applied to oilseed plants and may allow additional gains to be made in the future.

The CRISPR/Cas9-Mediated Modulation of SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE 8 in Alfalfa Leads to Distinct Phenotypic Outcomes

“…This platform requires a Cas nuclease, which produces a double-stranded DNA break, and a single guide RNA (sgRNA), which includes a short user-defined sequence that guides the Cas nuclease to a highly specific chromosomal locus of choice immediately upstream of a protospacer-adjacent motif (PAM). Due to the unlinked nature of the resulting edit and the introduced transgene, this technology allows for the rapid production of non-transgenic germplasm bearing mutations that are identical in nature to those achieved spontaneously or through conventional breeding approaches such as chemical mutagenesis ( Subedi et al, 2020a , b ). While the regulatory status of crop varieties derived from genome editing is still uncertain in some countries, many others, including the United States, have concluded that in the absence of foreign DNA they are not “GM,” and will therefore not be subjected to costly and burdensome regulatory processes ( Schmidt et al, 2020 ; Singer et al, 2021a ).…”

Efficient, selectable marker free gene targeting in soybean using novel Ochrobactrum haywardense-mediated delivery

“…Modern precision breeding tools, including genome editing, present an opportunity for such targeted breeding approach. In addition, genome editing would be extremely useful in making pathway engineering needed to develop soybean varieties with enhanced protein and oil contents (Aili Bao, 2020;Subedi et al, 2020). CRISPR-Cas9 due to flexibility and ease of the design has become an important genome engineering tool for creating targeted DSBs required for precision breeding applications (Wiedenheft et al, 2011;Jinek et al, 2012;Cong et al, 2013;Xing et al, 2014).…”

Adaptation Strategies to Improve the Resistance of Oilseed Crops to Heat Stress Under a Changing Climate: An Overview

“…The success of conventional plant breeding techniques has been extensively studied to regulate heat stress tolerance mechanisms in various crops including oilseeds, but these techniques are very time consuming and cumbersome. As an alternative, genome editing using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein (CRISPR/Cas) has been raised as an innovative technique for precise and efficient genetic manipulations in plant genomes (Subedi et al, 2020 ). Although, there is a discrete lack of information regarding negative regulators within the heat stress response, and thus studies involving CRISPR/Cas-mediated enhancement of high-temperature stress tolerance mechanisms remain scarce.…”