Translating existing molecular tools into crop species is fundamentally important for expanding our understanding of plant development and stress responses to crop species. However, generating transgenic lines of non-model species can be labour-intensive and take a long time. We have used Agrobacterium rhizogenes-mediated hairy root transformation to rapidly generate transgenic roots in order to optimize a range of molecular tools in tomato.
We assessed gene expression patterns in tomato hairy roots, showing that the expression patterns in A. rhizogenes-transformed hairy roots are indistinguishable from roots transformed with A. tumefaciens and generating a toolbox of cell- and tissue-type specific promoters for tomato roots. We optimized two molecular methods for cell-type specific gene expression studies in tomato: Isolation of Nuclei Tagged in specific Cell-Types (INTACT) and Translating Ribosome Affinity Purification (TRAP). Finally, we tested gene function in tomato using CRISPR/Cas9 genome editing and translational reporters. Furthermore, we have used the hairy root method to generate transgenic roots in wild tomato Solanum pennelii as well as Lepidium hyssopifolium and Arabidopsis.