Plant genome editing made easy: targeted mutagenesis in model and crop plants using the CRISPR/Cas system

Abstract

Targeted genome engineering (also known as genome editing) has emerged as an alternative to classical plant breeding and transgenic (GMO) methods to improve crop plants. Until recently, available tools for introducing site-specific double strand DNA breaks were restricted to zinc finger nucleases (ZFNs) and TAL effector nucleases (TALENs). However, these technologies have not been widely adopted by the plant research community due to complicated design and laborious assembly of specific DNA binding proteins for each target gene. Recently, an easier method has emerged based on the bacterial type II CRISPR (clustered regularly interspaced short palindromic repeats)/Cas (CRISPR-associated) immune system. The CRISPR/Cas system allows targeted cleavage of genomic DNA guided by a customizable small noncoding RNA, resulting in gene modifications by both non-homologous end joining (NHEJ) and homology-directed repair (HDR) mechanisms. In this review we summarize and discuss recent applications of the CRISPR/Cas technology in plants.

Genome Editing with Engineered Nucleases in Economically Important Animals and Plants: State of the Art in the Research Pipeline

“…The issue is thus not clear yet, however, a decision should be taken soon for the benefit of both the producers and the consumers (Curtin et al, 2012;Belhaj et al, 2013;Ribarits et al, 2014;Araki and Ishii, 2015;Rinaldo and Ayliffe, 2015). The regulatory systems not only ensure the safety and efficacy of the products introduced to the market but have also economic ramifications and influence the technological innovation process especially in the case of biotechnologies (Bruce et al, 2013;Smyth et al, 2014).…”

“…It is now possible to perform direct changes to the genome with an unprecedented precision and scale which can produce the desired trait without the necessity to introduce exogenous DNA (Belhaj et al, 2013;Lusser and Davies, 2013;Araki and Ishii, 2015). The approaches using SDNs are also much easier and straightforward and, in some cases, much less expensive than the traditional and/or transgenic techniques, for example CRISPR/Cas9 system can cost as little as $30 per genome change (Ledford, 2015).…”

“…Due to the very promising anticipated applications and a relatively straightforward design, the research in SDNs has been developing quickly and hundreds of studies have been published so far. Even though a large majority of the studies focus on model organisms and in vitro cultures, some also address economically important organisms, such as rice or cattle (Urnov et al, 2010;Belhaj et al, 2013;Liu et al, 2013). In this review, we give an overview of studies carried out using such organisms with focus on agronomically important traits and the outlook on market launch of such modified organisms.…”

Precision genetic modifications: a new era in molecular biology and crop improvement

“…Expressing cas9 and sgrnA(s) produces genetic modifications via the induction of DsB by cas9, followed by error-prone nhEJ or more precise hDr. With a codonoptimised version of the S. pyogenes cas9 this system has been used to modify or knock-out genes in many animal systems (supplemental Table 1) and, recently, in plant cells (Feng et al 2013;Jiang et al 2013b;li et al 2013b;mao et al 2013;miao et al 2013;nekrasov et al 2013;shan et al 2013b;Xie and Yang 2013). moreover, this system effectively targets heterochromatin in Drosophila ) and cas9 cleavage is not affected by DnA methylation (hsu et al 2013).…”

Challenges of climate change

“…These are revolutionizing the field of genome editing. 101 With their highly flexible but specific targeting, CRISPR-Cas systems can be manipulated and redirected to become powerful tools for genome editing.…”