Treatment of maize pollen to reduce nuclease activity

Recently it has been reported that maize (Zea mays L.) pollen can be stored up to several hours in a hypertonic aqueous medium at 0°C without losing its germinability (Broglia and Brunori 1994). We found that both release and activity of pollen nucleases are diminished in a cold hypertonic aqueous medium. Nucleases can be washed off while preserving germination ability and thus preserving the possibility of passive uptake of exogeneous DNA into germinating pollen grains. Alternatively, active DNA transfer into non-germinating pollen grains in the storage medium itself may be facilitated, due to the very reduced nuclease activity in this medium.