Review Article

Genetic Modification for Wheat Improvement: From Transgenesis to Genome Editing

Table 1

Comparison of parameters of agrobacterial and biolistic transformation.

ParametersAgrobacterium-mediated transformationBiolistic transformationReferences

Genotype dependencyHighLess[5]

Stability of expression of transgenesHighHigh for Minimal Expression Cassettes (MEC), lower for plasmids[6, 7]

Copy number of insertsAround 50% single copy; Depends on the strain and transformation conditions<50%; Depends on the amount of DNA/shot. More multicopy inserts[7, 8]

Integration of the new genesRandom. More than one locusRandom. Often many at the same locus[6]

Maximum transformation frequency (TF) for wheat (per 100 embryos treated)Up to 90%>70%[8, 9]

Complexity of the transformation procedure in wheatSimpler. Usually requires aseptic conditionsMore complex. Requires aseptic conditions and a Biolistic Gun[8, 10]

Main explants in wheatImmature embryosImmature embryos[8, 10]

Complexity of vector construct preparation, co-transformationMore complexSimpler[11]

Maximum sizes of transferred inserts publishedUp to 200 Kb150–164 Kb[1214]

Transfer of Т-DNA bordersYesNo (for MEC)[15]

Transfer of vector DNAPossibleNo (for MEC); Yes (for plasmids)[15]

Transfer of bacterial chromosomal DNAPossibleNo (for MEC)[16]

Marker free transformation in wheatPossiblePossible[1719]

In planta transformation in wheatPossiblePossible[2022]

Delivery of RNA, proteins, nanoparticles and dyesNoPossible[23]

Transformation of chloroplasts and mitochondriaNoPossible[24, 25]

Transient gene expression in different tissues and organs of plantsEfficient for limited number of plant speciesEfficient[2628]