Microsystem-Based Study of Pollen-Tube Attractants Secreted by Ovules

Microdevices are developed to resemble the in-vivo micro-environment of ovule fertilization by pollen tubes in model research plant Arabidopsis thaliana. The PDMS-based microdevices are filled with pollen germination medium (PGM) providing pollen tubes with a proper growth environment. Pollen tubes are found to grow within the microgrooves with an average rate of 130 mum/hr, reaching a final tube length of about 450 mum. Targeting ovules by pollen tubes has also been tested with an observed efficiency of about 67%. Both the pollen tube growth rate and the ovule targeting efficiency in microdevices are similar to those obtained using in-vitro plate experiments. Finally, initial results indicate that pollen tube bundles preferentially turn toward ovule containing chambers, suggesting that the pollen tubes respond to the attractants secreted by unfertilized ovules.