An Agrobacterium strain auxotrophic for methionine is useful for switchgrass transformation

Abstract

Auxotrophic strains of Agrobacterium tumefaciens can contribute to the development of more efficient transformation systems, especially for crops historically considered recalcitrant. Homologous recombination was used to derive methionine auxotrophs of two common A. tumefaciens strains, LBA4404 and EHA105. The EHA105 strains were more efficient for switchgrass transformation, while both the EHA105 and LBA4404 strains worked equally well for the rice control. Event quality, as measured by transgene copy number, was not affected by auxotrophy, but was higher for the LBA4404 strains than the EHA105 strains. Ultimately, the use of auxotrophs reduced bacterial overgrowth during co-cultivation and decreased the need for antibiotics.

Advances in genomics and genome editing for improving strawberry (Fragaria ×ananassa)

“…Hairy roots are valuable for functional analysis of root traits as well as for validation of transgenic and genome editing methods due to the relatively short period of root development (Ozyigit et al, 2013). Several advancements have been made to Agrobacterium-mediated transformation technologies, including improved ternary systems (Anand et al, 2018), auxotrophy of various amino acids (Aliu et al, 2020;Prías-Blanco et al, 2022), and use of a CRISPR RNA-guided integrase system (Vo et al, 2021;Aliu et al, 2022), however, there has been little application of these advanced systems in strawberry (Oosumi et al, 2006). Some transgene-free methods, such as ribonucleoprotein (RNP) bombardment and RNP transfection of protoplasts, have not been reported in strawberry but have demonstrated General workflow for trait discovery and CRISPR/Cas-mediated genome editing in strawberry.…”