Visualization of Microfilament Distribution in Pollen Tubes through in vitro Rice Pollen Germination System

Microfilament patterns during pollen germination and pollen tube growth were observed with no pre-fixation using dimethylsulphoxide(DMSO)as a permeabilising agent and FITC-Phalloidin as the stain.The main results were:(1) Pollen germinated after hydration for 2 min and growth speed of the pollen tube was between 600-1500 μm/h.(2) In the hydration of the pollen grains without germination,a number of short fusiform microfilaments constituted a network-like structure.In the germination process,some microfilaments gradually transferred to the pollen tube as the short fusiform microfilaments were released along the pollen tube longitudinally.For pollen tube elongation,microfilaments were mainly in the middle and front region of pollen tube,but there were no obvious microfilaments in the tip of pollen tube.(3) The distribution of microfilaments was diffuse and irregular in certain non-germination pollen.Some pollen germinated at same time but were shorter,with fewer microfilaments gathered in the region near the apertures.These results indicated that the distribution of microfilament cytoskeleton affected the germination and growth of rice pollen tubes.