Towards plant resistance to viruses using protein-only RNase P

Anthony Gobert,Mathilde Arrivé,Florent Waltz,Philippe Giegé,Isabelle Jupin,Nathalie Da Silva,Yifat Quan,Lucile Jomat,Mathias Cohen

doi:10.1038/s41467-021-21338-6

Abstract

Plant viruses cause massive crop yield loss worldwide. Most plant viruses are RNA viruses, many of which contain a functional tRNA-like structure. RNase P has the enzymatic activity to catalyze the 5′ maturation of precursor tRNAs. It is also able to cleave tRNA-like structures. However, RNase P enzymes only accumulate in the nucleus, mitochondria, and chloroplasts rather than cytosol where virus replication takes place. Here, we report a biotechnology strategy based on the re-localization of plant protein-only RNase P to the cytosol (CytoRP) to target plant viruses tRNA-like structures and thus hamper virus replication. We demonstrate the cytosol localization of protein-only RNase P in Arabidopsis protoplasts. In addition, we provide in vitro evidences for CytoRP to cleave turnip yellow mosaic virus and oilseed rape mosaic virus. However, we observe varied in vivo results. The possible reasons have been discussed. Overall, the results provided here show the potential of using CytoRP for combating some plant viral diseases.

Highlights

Plant viruses cause massive crop yield loss worldwide
Arabidopsis, three PRORP enzymes have been described: PRORP1 accumulates in both mitochondria and chloroplasts while PRORP2 and PRORP3 are both found in the nucleus[9]
When fused to eYFP and expressed in plant protoplasts, fluorescence microscopy experiments showed that CytoRP-eYFP constructs were relocated to the cytosol, while control PRORP2-eYFP and PRORP1-eYFP accumulated in the nucleus or mitochondria/chloroplasts, respectively (Fig. 1b)

Summary

Introduction

Plant viruses cause massive crop yield loss worldwide. Most plant viruses are RNA viruses, many of which contain a functional tRNA-like structure. Beyond tRNA maturation, these enzymes called PRORP participate in mRNA maturation by cleaving TLS present at the 5′ or 3′ termini of some plant mitochondria mRNAs, as shown in Arabidopsis both in vitro and in vivo[9,10] Based on this observation, we report here a strategy to induce plant resistance to viruses containing a TLS. We rationalize that an RNase P enzyme should be able to cleave TLS of plant viruses, which would impede virus replication and impair virus infection Such a process is unlikely to occur spontaneously in vivo because RNA virus infection takes place in the cell cytosol[11], while PRORP enzymes accumulate only in compartments where endogenous gene expression takes place, i.e. the nucleus, mitochondria, and chloroplasts[9]. The effect of CytoRP expression on virus levels upon infection is evaluated in planta

Methods

Results

Conclusion