Supplemental Data

All movies were of 3- to 4-day-old transgenic seedlings expressing either SPR1:GFP (Movies 1, 2, and 4-7) or YFP:β-TUBULIN (Movie 3) and were acquired under the same conditions at a single confocal plane with a Biorad confocal instrument. All movies were encoded at 12 frames/s for playback. Images were acquired at 3.85-s intervals.

Files in this Data Supplement:

• Supplemental Figure 1
• Supplemental Table 1
• Supplemental Movie 1 - Typical SPR1:GFP preferential labeling of the plus-ends of cortical microtubules in an interphase hypocotyl cell.
• Supplemental Movie 2 - SPR1:GFP-related fluorescence in a cotyledon guard cell.
• Supplemental Movie 3 - YFP:β-TUBULIN uniform labeling of cortical microtubules in an interphase hypocotyl cell. Note the different localization pattern compared with SPR1:GFP in Movie 1.
• Supplemental Movie 4 - De novo localization of SPR1:GFP at the cortex of a hypocotyl epidermal cell. This movie captures a SPR1:GFP-labeled structure (the tip delineated by a yellow arrowhead) appearing in a location at the cell cortex that previously contained no detectable organized label, suggesting a de novo origin of a microtubule. This is a movie of the time lapsed series of frames shown in Figure 7A.
• Supplemental Movie 5 - Dynamic growth and shrinkage of SPR1:GFP labeled microtubules in a hypocotyl epidermal cell. Two microtubules that undergo catastrophes are delineated by red arrowheads.
• Supplemental Movie 6 - A SPR1:GFP labeled microtubule (delineated by a red arrowhead) joining and traveling alongside another labeled microtubule (the second microtubule’s position is delineated by multiple yellow arrowheads), suggesting the formation and association of individual microtubules into bundles (in a hypocotyl epidermal cell).
• Supplemental Movie 7 - Two SPR1:GFP labeled microtubules (delineated by a red arrowheads) apparently detaching from the cell cortex and being displaced by the streaming cytosol (in a hypocotyl epidermal cell).
• Supplemental Movie 8 - SPR1:GFP in the mitotic spindle (Movie 8), phragmoplast (Movie 9), and preprophase band (Movie 10). Each movie is an image series acquired at a single confocal plane in epidermal cells of young leaves. The image interval is 3.8 s and the scale bars equal 10 microns.
• Supplemental Movie 9
• Supplemental Movie 10