Methods of expressing a molecule of interest in a plant are disclosed. One method comprises contacting roots of the plant in a solution comprising at least one Geminivirus based expression construct so as to allow the at least one Geminivirus based expression construct to be absorbed by the roots, the expression construct comprising a polynucleotide encoding the molecule of interest, and further the expression construct being capable of systemic symptomless spread in a plant host, thereby expressing a molecule of interest in a plant. Expression constructs capable of systemic symptomless spread in a host plant are also disclosed.