Cucumber mosaic virus-plant interactions: identification of 3a protein sequences affecting infectivity, cell-to-cell...

Area of Science:

• Plant virology
• Molecular biology
• Genetics

Background:

• Cucumber mosaic virus (CMV) is a significant plant pathogen.
• The viral movement protein (MP) is crucial for CMV cell-to-cell and long-distance spread.
• Understanding MP function is key to controlling CMV.

Purpose of the Study:

• To investigate the roles of specific domains within the CMV movement protein (MP).
• To analyze the effects of MP mutations on virus movement and pathogenicity in various plant hosts.
• To differentiate between cell-to-cell and long-distance movement functions of the CMV MP.

Main Methods:

• Generation and characterization of various Cucumber mosaic virus (CMV) movement protein (MP) mutants.
• In vivo analysis of mutant effects on virus movement across eight plant species.
• Complementation assays to assess the functionality of MP mutants.

Main Results:

• Mutants M1, M2, and M3 generally supported virus movement, with M3 showing altered pathogenicity in one host.
• Mutant M8 exhibited host-specific movement alterations in hypersensitive hosts.
• Mutant M9 displayed altered pathogenicity and temperature-sensitive long-distance movement, distinguishing it from cell-to-cell movement.
• Mutants M4, M5, and M6 were impaired in movement and could be complemented by wild-type MP.
• Mutant M7 was debilitated in movement and could not be complemented.

Conclusions:

• Specific sequence domains of the CMV MP are critical for distinct movement functions.
• Mutational analysis provides insights into the complex mechanisms of CMV cell-to-cell and long-distance spread.
• These findings contribute to understanding viral pathogenesis and developing strategies for CMV control.