Preliminary results on the development of a genome editing protocol in Actinidia chinensis var. chinensis as Psa resistance approach

Since 2008, kiwifruit bacterial canker caused by Pseudomonas syringae pv. actinidiae (Psa) has spread to pandemic scale. The strong virulence of some strains, the absence of resistant cultivars and the unknown genetic basis of resistance have made it difficult to implement genetic improvement programs for PSA resistance. Currently, Psa control is based on the use of chemical and agronomic approach. Genome-editing and biotechnology approaches could be useful to overcome these limits by the modification of gene for plant-Psa interaction. Some CRISPR/Cas9 vectors were developed for the transformation of a selection of A. chinensis var. chinensis. A gene belonging to AP2/ERF transcription factors was selected as target sequence. Leaf explants were used for infection with Agrobacterium tumefaciens carrying these vectors; the regenerated shoots were analysed, and the presence of the insertion was observed. Further molecular analyses are in progress to estimate the type and the severity of the mutations. This preliminary study gives information on the feasibility of application of CRISPR/Cas9 vectors in this species to be used for future approaches for inducing Psa resistance/tolerance.