STUDIES ON THE SONIC TREATMENT OF TOBACCO MOSAIC VIRUS

Area of Science:

• Virology
• Biophysics

Background:

• Tobacco mosaic virus (TMV) is a rod-shaped plant virus.
• Understanding TMV particle stability and biological activity is crucial for virology research.

Purpose of the Study:

• To investigate the effects of sonic treatment on TMV particle structure and biological activity.
• To determine the relationship between TMV particle size and infectivity.

Main Methods:

• TMV samples were sonically treated for varying durations (0-64 minutes).
• Viscosity, stream birefringence, and electron microscopy were used to assess structural changes.
• Biological activity was measured using the half-leaf lesion method.

Main Results:

• Sonic treatment decreased viscosity and stream birefringence, indicating particle breakage.
• Electron microscopy revealed particles breaking perpendicular to their long axis.
• Biological activity decreased exponentially with sonic treatment duration, correlating with the reduction of intact 280 µm particles.

Conclusions:

• Sonic treatment fragments TMV particles without chemical alteration.
• Only intact 280 µm TMV particles exhibit full biological activity.
• Particle aggregation affects biological activity, which can be restored by mechanical stirring or prevented by prior sonic treatment.