Split-Luciferase Complementation Imaging Assay in Virus–Plant Interactions

Protein-protein interactions constitute the interface between a virus and the cell it infects and are crucial determinants of the outcome of the viral infection. Multiple techniques have been developed to study how viral and host proteins interact in plants; among them, the split-luciferase complementation imaging assay stands out due to its capacity to detect protein-protein interactions in vivo, in the context of the infection, if desired, in an easy, fast, quantitative, and inexpensive manner. In this chapter, we use the interaction between the V2 protein from the geminivirus tomato yellow leaf curl virus (TYLCV) and Nicotiana benthamiana Argonaute 4 (AGO4) as an example to present how to perform this simple yet powerful assay using transient Agrobacterium tumefaciens-mediated transformation of N. benthamiana leaves to test the protein-protein interactions of choice.