Classification of the Pospiviroidae based on their structural hallmarks

Area of Science:

• Plant pathology
• Molecular biology
• Virology

Background:

• Viroids are the simplest known plant pathogens, relying on RNA sequence and structure for infection and replication.
• Selective 2 extquotesingle-hydroxyl acylation analyzed by primer extension (SHAPE) is a key method for probing RNA structures in solution.
• Previous studies utilized SHAPE for Avsunviroidae and some Pospiviroidae family members.

Purpose of the Study:

• To create a comprehensive compendium of secondary structures for all known viroid species.
• To propose a novel classification system for viroids based on structural hallmarks.
• To determine the genera of Grapevine latent viroid and Dahlia latent viroid through structural analysis.

Main Methods:

• Application of the SHAPE protocol to probe the structures of thirteen Pospiviroidae viroid species in solution.
• Elucidation of secondary structures for eleven species with known genera.
• Comparative structural analysis to propose a viroid classification system.

Main Results:

• The secondary structures of thirteen new Pospiviroidae members were mapped in solution.
• A classification system for viroids based on SHAPE-elucidated structures was proposed.
• Grapevine latent viroid and Dahlia latent viroid were assigned to the Apscaviroid and Hostuviroid genera, respectively.

Conclusions:

• This study presents the complete repertoire of mapped secondary structures for all accepted viroid species.
• The proposed classification scheme based on structural hallmarks provides a valuable tool for biological studies.
• Structural elucidation using SHAPE significantly advances viroid classification and understanding.