Genome editing technology has revolutionized agriculture, bringing
market-ready innovations such as high oleic soybean, low pungency mustard
greens, and high GABA tomatoes. The potential of this technology to enhance
agricultural sustainability is immense.



Traditionally, the SpCas9 nuclease, with its substantial size of around 1350
amino acids, has been the most widely used tool for genome editing. However,
its large size poses significant challenges, particularly for effective
delivery inside cells, especially through viral vectors. Reducing the size
of RNA-guided genome editing nucleases is a critical goal to overcome these
limitations. Smaller nucleases not only improve delivery efficiency but also
facilitate the creation of fusion proteins, broadening the scope of genome
engineering applications.



In a pioneering study, researchers from the ICAR-National Rice Research
Institute (NRRI), Cuttack, have developed a miniature plant genome editor
that is only one-third the size of the widely used Cas9. This new genome
editor protein, derived from the transposon-associated TnpB of Deinococcus
radiodurans, has proven highly effective in editing multiple genes in both
monocot rice and dicot Arabidopsis.



Like Cas9, which requires a protospacer adjacent motif (PAM) for targeting,
TnpB requires a transposon-associated motif (TAM) adjacent to the target
sequence. TnpB can target unique regions in the genome that Cas9 cannot,
adding a new dimension to genome editing capabilities.



The study, published in the Plant Biotechnology Journal, showcases TnpB as a
hypercompact, versatile and promising tool for plant genome engineering,
marking a significant advancement in the field.



[onlinelibrary.wiley.com]