A vector system for fast-forwardin vivostudies of the ZAR1 resistosome in the model plantNicotiana benthamiana

ABSTRACT Nicotiana benthamiana has emerged as a complementary experimental system to Arabidopsis. It enables fast-forward in vivo analyses primarily through transient gene expression and is particularly popular in the study of plant immunity. Recently, our understanding of NLR plant immune receptors has greatly advanced following the discovery of Arabidopsis ZAR1 resistosome. Here, we describe a novel vector system of 52 plasmids that enables functional studies of the ZAR1 resistosome in N. benthamiana . We showed that ZAR1 stands out among the coiled coil class of NLRs for being highly conserved across distantly related dicot plant species and confirmed NbZAR1 as the N. benthamiana ortholog of Arabidopsis ZAR1. NbZAR1 triggers autoimmune cell death in N. benthamiana and this activity is dependent on a functional N-terminal α1 helix. C-terminally tagged NbZAR1 remains functional in N. benthamiana thus enabling cell biology and biochemical studies in this plant system. We conclude that the NbZAR1 open source plasmids form an additional experimental system to Arabidopsis for in planta resistosome studies.