Foxtail mosaic virus: A tool for gene function analysis in maize and other monocots

Abstract

Many plant viruses have been engineered into vectors for use in functional genomics studies, expression of heterologous proteins, and, most recently, gene editing applications. The use of viral vectors overcomes bottlenecks associated with mutagenesis and transgenesis approaches often implemented for analysis of gene function. There are several engineered viruses that are demonstrated or suggested to be useful in maize through proof‐of‐concept studies. However, foxtail mosaic virus (FoMV), which has a relatively broad host range, is emerging as a particularly useful virus for gene function studies in maize and other monocot crop or weed species. A few clones of FoMV have been independently engineered, and they have different features and capabilities for virus‐induced gene silencing (VIGS) and virus‐mediated overexpression (VOX) of proteins. In addition, FoMV can be used to deliver functional guide RNAs in maize and other plants expressing the Cas9 protein, demonstrating its potential utility in virus‐induced gene editing applications. There is a growing number of studies in which FoMV vectors are being applied for VIGS or VOX in maize and the vast majority of these are related to maize–microbe interactions. In this review, we highlight the biology and engineering of FoMV as well as its applications in maize–microbe interactions and more broadly in the context of the monocot functional genomics toolbox.

Special issue: Genetics of maize–microbe interactions

“…The use of viruses to transiently silence endogenous genes is known as virus‐induced gene silencing (VIGS), and probably the most used VIGS system in maize in recent years has been based on foxtail mosaic virus (FoMV). Beernink and Whitham review how FoMV has been used in maize and other monocots for both gene expression and gene silencing and discuss the advantages and limitations of the system (2023, this issue). Yu et al used the FoMV system, among other approaches, to identify three maize receptor‐like kinase proteins in the Feronia‐like receptor family (2022, vol.…”