Review
Opportunities for Products of New Plant Breeding Techniques

https://doi.org/10.1016/j.tplants.2015.11.006Get rights and content

Trends

Several NPBTs are currently being implemented and represent a significant step forward for crop improvement compared with traditional breeding.

NPBTs make use of a genetic modification step, but the resulting endproducts do not contain any foreign genes. Consequently, NPBT products are genetically similar to, or may be even indistinguishable from, traditionally bred plants.

Recent studies show the remarkable potential of NPBTs for the production of innovative crop varieties.

Various new plant breeding techniques (NPBT) have a similar aim, namely to produce improved crop varieties that are difficult to obtain through traditional breeding methods. Here, we review the opportunities for products created using NPBTs. We categorize products of these NPBTs into three product classes with a different degree of genetic modification. For each product class, recent examples are described to illustrate the potential for breeding new crops with improved traits. Finally, we touch upon the future applications of these methods, such as cisgenic potato genotypes in which specific combinations of Phytophthora infestans resistance genes have been stacked for use in durable cultivation, or the creation of new disease resistances by knocking out or removing S-genes using genome-editing techniques.

Section snippets

New Plant Breeding Techniques Facilitate Breeding of Improved Crop Varieties

Crop improvement is an important endeavor if we are to meet the demands of a growing population (a worldwide population of 9 billion people is projected for 2050), for which food production needs to be increased, while at the same time the environmental impact of food production needs to be reduced. To respond adequately, we should optimally apply all existing tools to breed improved crops and maximize any potential future applications for increasingly sustainable food production.

Plant breeding

NPBTs Produce Three Types of Improved Plant

Products from NPBTs may be grouped into three classes: (i) improved plants that contain a new DNA fragment (usually a new gene); (ii) improved plants that do not contain a new DNA fragment, but have a mutation or modification in their own DNA; and (iii) improved plants that do not contain a new DNA fragment or any modification of their DNA (Figure 1, Key Figure). Below, we describe these different product classes.

NPBT Products that Contain New DNA Fragments

Products made with cisgenesis, intragenesis and specific cases of genome editing using SSN3 technology contain new DNA fragments (Table 1, Improved plant 1). Both cisgenesis and intragenesis are concepts relevant to genetic transformation technology and concern the origin of the inserted DNA. For cisgenesis, a copy of a complete natural gene, including the promoter and terminator sequences, from the sexual compatible gene pool is introduced. This is often an allele with beneficial

NPBT Products that Contain (Small) Modifications of Their Own DNA

This class includes products made with one of the SSN technologies (an explanation of SSN-technology variants is given in Box 2) or with oligo-directed mutagenesis (ODM) (Table 1, Improved plant 2). These technologies aim to induce small modifications to existing genes in the plant genome. This may result in knockout mutations (by SSN-1 through the induction of deletions leading to reading frame-shift mutations or by SSN-2 through editing an amino acid codon into a stop codon), modified gene

NPBT Products that Do Not Contain Altered DNA

Some of this third class of products of NPBT facilitate breeding, such as by introducing recombinant genes that change the expression of one or more endogenous genes with the aim of speeding up breeding processes (reverse breeding or induced early flowering). Others aim at prolonged gene silencing (RNA-directed DNA methylation; RdDM), to replace alleles by more beneficial ones (SSN-3 for gene replacement) or is used to test the effect of novel genes (Agroinfiltration). In the absence of an

Concluding Remarks and Perspectives

The rapid developments in the field of NPBTs continuously add new and valuable tools to the plant breeder's toolbox. This enables the faster and more efficient creation of new crop varieties to meet the demand for sustainably improving agricultural productivity. All NPBTs have a similar aim, namely to enable crop improvements that are difficult (in terms of time and effort) to obtain through traditional breeding methods. The variety of approaches that are known as NPBTs complicates a comparison

Acknowledgement

This work was funded by the Ministry of Economic Affairs of The Netherlands as part of the programme ‘Sustainable plant production systems’ (BO-20-003-006).

Glossary

Agroinfiltration
a technique using Agrobacterium as a tool to achieve temporary and local expression of genes in plant tissue. Agroinfiltration is applied for testing the reaction of target plants to transgenic proteins, or for functional gene analysis in plants.
Cisgenesis
the production of plants by genetic modification using only genes from the species itself or from a species that can be crossed with this species using traditional methods (for overview of these traditional methods, see iv).

References (48)

  • H.D. Jones

    Regulatory uncertainty over genome editing

    Nat. Plants

    (2015)
  • F. Hartung et al.

    Precise plant breeding using new genome editing techniques: opportunities, safety and regulation in the EU

    Plant J.

    (2014)
  • M.M. Mahfouz

    Genome engineering via TALENs and CRISPR/Cas9 systems: challenges and perspectives

    Plant Biotechnol. J.

    (2014)
  • Y. Osakabe et al.

    Genome editing with engineered nucleases in plants

    Plant Cell Physiol.

    (2015)
  • M. Sadelain

    Safe harbours for the integration of new DNA in the human genome

    Nat. Rev. Cancer

    (2012)
  • C. Cantos

    Identification of “safe harbor” loci in indica rice genome by harnessing the property of zinc-finger nucleases to induce DNA damage and repair

    Front. Plant Sci.

    (2014)
  • V.K. Shukla

    Precise genome modification in the crop species Zea mays using zinc-finger nucleases

    Nature

    (2009)
  • W.M. Ainley

    Trait stacking via targeted genome editing

    Plant Biotechnol. J.

    (2013)
  • I.B. Holme

    Intragenesis and cisgenesis as alternatives to transgenic crop development

    Plant Biotechnol. J.

    (2013)
  • R. Chawla

    Tuber-specific silencing of asparagine synthetase-1 reduces the acrylamide-forming potential of potatoes grown in the field without affecting tuber shape and yield

    Plant Biotechnol. J.

    (2012)
  • A.J. Haverkort

    Applied biotechnology to combat late blight in potato caused by Phytophthora infestans

    Potato Res.

    (2009)
  • F.A. Krens

    Cisgenic apple trees; development, characterization, and performance

    Front. Plant Sci.

    (2015)
  • I.B. Holme

    Cisgenic barley with improved phytase activity

    Plant Biotechnol. J.

    (2012)
  • T. Li

    High-efficiency TALEN-based gene editing produces disease-resistant rice

    Nat. Biotechnol.

    (2012)
  • Cited by (0)

    View full text