Lifeact-mEGFP in Plant Cells Figure 3. Lifeact-mEGFP labels dynamic actin in moss and pollen. (A) Confocal micrographs of Physcomitrella patens showing the actin focal point at the apex. (B) The presence of the apical F-actin network as seen in Nicotiana tobaccum. (C) The cortical fringe in the apex of a Lilium formosanum pollen tube expressing Lifeact-mEGFP. Bar is 10 mm. See Movies S1, S2 and S3 for complete series. doi:10.1371/journal.pone.0005744.g003 spinning disc confocal instrument. This instrument scans the frame 360 times a second, instead of scanning through the frame once or twice a second. It thus eliminates some of the blurring caused by the scan of the conventional confocal instrument. This allows for dramatic, rapid alterations in actin to be more accurately imaged. We acquired a time lapse series of cortical slices in a growing cell (Figure 4). The images show the rapid remodeling of microfila- ments occurring in the cortex at the cell tip (Movie S4). Arrows point to possible buckling events seen very close to the apex. These results are very similar to recent studies from imaging of actin in PLoS ONE | www.plosone.org 5 May 2009 | Volume 4 | Issue 5 | e5744