Utilizing Potato Virus X to Monitor RNA Movement.

Area of Science:

• Plant molecular biology
• Virology
• RNA biology

Background:

• Non-cell-autonomous messenger RNAs move throughout plants via the phloem.
• Monitoring long-distance RNA transport is challenging and labor-intensive.
• Potato virus X (PVX) relies on its coat protein (CP) for systemic movement.

Purpose of the Study:

• To develop a simplified, virus-based assay for surveying RNA movement in plants.
• To demonstrate the utility of replacing PVX CP with mobile RNA sequences to track their movement.
• To validate the assay system using known mobile RNAs involved in plant development.

Main Methods:

• Engineered Potato Virus X (PVX) by replacing sequences critical for movement, specifically the coat protein (CP).
• Inserted phloem-mobile RNA sequences into the modified PVX genome to facilitate their long-distance transport.
• Utilized two experimental models: movement of flowering locus T RNA and StBEL5 RNA.

Main Results:

• Deletion of the PVX CP gene successfully blocked viral movement.
• Replacing the PVX CP with phloem-mobile RNA sequences restored systemic mobility.
• The assay successfully tracked the movement of flowering locus T RNA and StBEL5 RNA, demonstrating its efficacy.

Conclusions:

• The developed virus-based system provides a facile method for surveying RNA movement in plants.
• This system enables efficient monitoring of non-cell-autonomous RNAs, including those regulating flowering and tuberization.
• The findings offer a valuable tool for advancing the understanding of plant signaling pathways mediated by mobile RNAs.