Abstract
We have previously showed that each component of Arabidopsis phosphatidylinositol 3-kinase (PI3K) complex, AtVps30, AtVps34, and AtVps15, is required for pollen germination. Transmission electron microscope showed that pollen grains of atvps30 and atvps15 were normal in appearance, suggesting that PI3K complex is not essential for early pollen development. However, it should be noted that several atvps34 pollen grains exhibited abnormal morphology, in accordance with the recent report by Lee et al. (2008). We suggest that reduced PI3K activity in atvps30 and atvps15 disturbs pollen germination signaling, which might include ROS production. By contrast, complete loss of PI3K activity in atvps34 may affect pollen development as well as pollen germination.
