MolecularCloud February Newsletter

Are we entering an era of ternary vector system for genome editing in plants?

Dr. Qijun Chen's team published the paper "A Novel Ternary Vector System United with Morphogenic Genes Enhances CRISPR/Cas Delivery in Maize" at Plant Physical in December 2019. The plasmids of this article have been deposited on MolecularCloud.

The lack of efficient delivery methods is a major barrier to clustered regularly interspaced short palindromic repeats/CRISPR-associated protein (CRISPR/Cas)-mediated genome editing in many plant species. Combinations of morphogenic regulator (MR) genes and ternaryvector systems are promising solutions to this problem.

Dr. Chen first demonstrated that MR vectors greatly enhance maize (Zea mays) transformation. They then tested a CRISPR/Cas9 MR vector in maize and found that the MR and CRISPR/Cas9 modules have no negative influence on each other. Finally, they developed a novel ternary vector system to integrate the MR and CRISPR/Cas modules.

The ternary vector system is composed of new pGreen-like binary vectors, here named pGreen3, and a pVS1-based virulence helper plasmid, which also functions as a replication helper for the pGreen3 vectors in Agrobacterium tumefaciens The pGreen3 vectors were derived from the plasmid pRK2 and display advantages over pGreen2 vectors regarding both compatibility and stability. They demonstrated that the union of our ternary vector system with MR gene modules has additive effects in enhancing maize transformation and that this enhancement is especially evident in the transformation of recalcitrant maize inbred lines.

Collectively, the ternary vector system-based tools provide a user-friendly solution to the low efficiency of CRISPR/Cas delivery in maize and represent a basic platform for developing efficient delivery tools to use in other plant species recalcitrant to transformation.

Plasmids from this article in MolecularCloud