Sanjay Kapoor

Friday Seminar by Dr. Pooja Verma


GKP Lab/ Friday/ September 27, 2019/ 3.30 pm/ Beyond CRISPR: Single base editing on the rise.
Category: Research
Posted by: bedineel

 

 

Beyond CRISPR: Single base editing on the rise.

 

 

 

Altering the genetic code of plants to improve survival and yield, or to study physiology, has long been the pursuit of plant scientists and breeders. A single base pair substitution in the higher eukaryotic genomes has been a challenge in the genome engineering field. Base-editing is a customized version of CRISPR/Cas9 system which generates point mutation at specific nucleotides within the genome without the need of donor DNA or double strand DNA cleavage. The technique was originally developed in mammalian cells (Liu’s lab at Harvard University) and has been adapted for plants since the year 2017. Recently, catalytically inactive CRISPR/Cas9 domain fused with cytosine deaminase domain form synthetic ribonucleoproteins identified as ‘base editors’ categorized as cytidine base editors (C-G base pair substitution to T-A) and adenine base editors (A-T base pair substitution to G-C) enabling precise base alterations in the genome with more efficiency than homologous-recombination-mediated generation of point mutations in crops. Many recent reports have developed modified base editing components to optimize base editors with enhanced efficiency for precise and expanded targeting in various plant species. Plant-tailored base editors have generated gain-of-function or loss-of -function mutations. Few genes have been successfully edited by this methodology in rice, wheat, maize and tomato like nitrate transporter, DELLA protein for plant height, a late-flowering variety in Arabidopsis, an herbicide resistance or pathogen-responsive phosphorylation sites in MPK6 gene in rice (Shimatani et al., 2017; Zong et al., 2017; Yan et al., 2018; Li et al., 2018). Base editing is a promising advanced tool for molecular breeding but for wide applications require to be examined for more plant varieties in future.
 
References

 

1-       Chen Y et al. (2017) Sci China Life Sci 60, 520–523. doi: 10.1007/s11427-017-9021-5

2-       Li C et al. (2018) Genome Biology 19:59, 1-9. doi.org/10.1186/s13059-018-1443-z

3-       Shimatani Z et al. (2017) Nat. Biotechnol. 35, 441–443.

4-       Wang M et al. (2019) Plant Biotechnology Journal, 1–3 doi: 10.1111/pbi.13124

5-       Yan F et al. (2018) Mol. Plant 11, 631-634. doi.org/10.1016/j.molp.2018.02.008

6-       Zong Y et al. (2017) Nat. Biotechnol. 35, 438–440.