Investigating sequence variation in the PNPi protein gene of Puccinia striiformis f. sp. tritici and its interaction with wheat NPR1 protein

Puccinia Non-Expresser of Pathogenesis interactor Protein (PNPi) is a virulent protein secreted by Puccinia striiformis f. sp. tritici (Pst), causative agent of yellow stripe rust disease (YSRD) of wheat. Pst PNPi protein interacts with wheat host protein Non- Expresser of Pathogenesis Related Protein (NPR1) inside the host cell. This interaction may vary due to sequence polymorphisms in the Pst PNPi gene. In this study, we explored the sequence variation in the PNPi gene of Pst. Additionally, using bioinformatics tools, we predicted the molecular structure of PNPi and NPR1. DNA sequencing of multiple Pst samples suggested no sequence variation in screened exons. Structure of the FtsN domain of PNPi was predicted to be intrinsically disordered. However, molecular docking analysis showed that the region could be involved in establishing physical interaction with NPR1. The findings of the study are expected to further our understanding of disease biology of Pst which could further be exploited to develop diagnostic tools and/or preventive intervention.