Meristematic Tissues of Maize Plants Are Most Susceptible to Agroinfection With Maize Streak Virus

The region of whole Zea mays plants most susceptible to Agrobacterium–mediated transfer of infectious maize streak virushas been identified. Injection of a suspension of bacterial cells in meristematic tissues at or close to the apex gives a high proportion of plants showing viral symptoms, whereas inoculations in non–meri–stematic tissues give few or no symptomatic plants. We have developed a simple, reliable, sensitive and rapid assay for the transfer of DNA from Agrobacteriumto plant, which allows a large number of independent inoculations to be screened.