Skip to main content

Table 2 Potential approaches for improvement of HGT in monocots shown in this review

From: Challenges and Perspectives in Homology-Directed Gene Targeting in Monocot Plants

No.

Category

Approach

HGT mode

Tested in organism

HGT enhancement properties

References

1

homologous repair template

Homologous size and form

Extrachromosomal

Nicotiana tabacum

The longer the better; Linearized forms were much better

Baur et al. 1990

2

homologous repair template

Homologous size and form

Extrachromosomal

Nicotiana plumbaginifolia

Homologous size was preferred to be more than 456 bp

Puchta and Hohn 1991

3

homologous repair template

Homologous form

Extrachromosomal

Nicotiana tabacum

ssDNA was more preferred

Bilang et al. 1992; de Groot et al. 1992

4

HDR-related genes

EcRecA overexpression

Intrachromosomal

Nicotiana tabacum

10 folds-efficiency increase with nuclear localized EcRECA

Reiss et al. 1996

5

HDR-related genes

RuvC overexpression

Somatic crossover; Extrachromosomal; intrachromosomal

Nicotiana tabacum

Somatic crossover (12 folds); intrachromosomal recombination (11 folds); and extrachromosomal recombination (56 folds)

Shalev et al. 1999

6

HDR-related genes

yeast RAD54 overexpression

SDSA

Arabidopsis thaliana

27-fold enhancement

Shaked et al. 2005

7

NHEJ and HDR-related genes

RAD50 knockout

Intrachromosomal

Arabidopsis thaliana

8–10 folds of SSA or intrachromosomal recombination

Gherbi et al. 2001

8

NHEJ related genes

AtMLH1 knockout

Intrachromosomal

Arabidopsis thaliana

Knockout mutation reduced 72% HDR frequencies

Dion et al. 2007

9

Chromatin modeling

AtFAS1 or AtFAS2 knockout

Interchromosomal

Arabidopsis thaliana

40-fold enhancement of somatic homologous recombination

Endo et al. 2006

10

Cell Cycle Synchronization/S phase

Hydroxyurea treatment

SDSA

Yarrowia lipolytica, Arxula adeninivorans, Saccharomyces cerevisiae, Kluyveromyces lactis and Pichia pastoris

1.2- to 8-fold enhancement

Tsakraklides et al. 2015

11

Cell Cycle Synchronization/S-G2 phases

Cas9 fused with N-terminal (110a.a) of human Gemini

SDSA

Human cell lines (HEK293T)

72% enhancement of somatic homologous recombination

Gutschner et al. 2016

12

Culture conditions

Polyamines (putrescine, spermidine and spermine)

SDSA

Mouse hair follicle model and Human cell lines (U2OS and HEK293)

Polyamines promoted RAD51 loading onto ssDNAs in in vitro assays

Lee et al. 2019

13

NHEJ related genes

Suppression by chemical inhibitors

SDSA

Human cell lines (HEK293T)

KU70 and DNA ligase IV suppression by Scr7 obtained 4–5-fold increase of HR efficiency

Chu et al. 2015

14

NHEJ related genes

Suppression by chemical inhibitors

SDSA

Human cell lines and mouse

DNA ligase IV suppression by Scr7 enhanced CRISPR/Cas9-based HDR frequency up to 19 folds

Maruyama et al. 2015