Establishment of Dynamic Imaging of Pollination in Arabidopsis thaliana

Pollination is the first important step in the plant reproduction system to bring together the male and female gametophytes for offspring production. While it has been studied for many years, the knowledge base about morphological aspects of sequential mid-pollination appearance, from pollen-pistil interaction to pollen tube germination, is still largely unclear. Major reason for this is technical difficulties in contiguous observation at stereoscopic and light microscopic levels. Therefore, we have focused on a morphological characterization of mid-pollination appearance, by time-series image analysis of pollination in Arabidopsis thaliana, taking established observation system in Brassica rapa (Hiroi et al 2013) into account. This approach enabled us to find that pollen exhibits various behaviours on an individual stigma on pollination, and they were classified into 4 representative patterns: Germination, Expansion, Pulsation, and No change. This result is basically consistent with that in Brassica and provides a time-series morphological evidence that pollination is a highly sophisticated and regulated mechanisms in Brassicaceae, as proposed by Dickinson (1995).