A process of expressing a sequence of interest in a plant, plant part, or plant cell culture, comprising: transforming a plant, plant part, or plant cell culture with a suspension of Agrobacteria, said Agrobacteria containing in T-DNA a heterologous DNA having a sequence encoding a replicon operably linked or linkable to a transcription promoter, wherein said sequence encoding a replicon contains(i) sequences for replicon function of said replicon, said sequences being derived from a sequence of a plant virus,(ii) a sequence of interest,whereby said suspension of Agrobacteria has a concentration of cells of said Agrobacteria corresponding to a calculated optical density at 600 nm of at most 0.04.
