Infectivity of plant viruses: A case example of the generalized Poisson model for tobacco mosaic virus

This study proposes a generalized Poisson model (GPM), formulated as a stretched exponential (Weibull) function, to describe the infectivity of plant viruses, specifically tobacco mosaic virus and tomato bushy stunt virus. The GPM addresses the dimensional mismatch between virus concentration, typically measured in volumetric units (three-dimensional), and lesion formation observed on leaf surfaces (two-dimensional). By translating virus concentration into a surface-based representation, the model captures the lesion formation patterns observed under various experimental conditions. It is shown that the dimensionless form of GPM, through a normalization of lesion number and virus concentrations, converges onto a single GPM curve, suggesting that plant virus infectivity can be a simple probabilistic matter and is approximated by the well-known Weibull probability distribution.