Abstract
Stomatal movements that regulate gas exchange and water homeostasis in plants involve dynamic change in the shape and volume of the guard cell. Previous studies have been suggested an involvement of actin microfilaments (MFs) in stomatal movements, however, little is known about their rearrangements during the diurnal cycle. We have established transgenic Arabidopsis plants expressing GFP-ABD2 and obtained more than 500 microscopic images of MFs using spinning-disk confocal microscopy during the diurnal cycle. Our newly developed image analysis system could reveal various features of the MFs such as bundling and orientation from the sequential images. In addition, clustering analysis of the microscopic images clacified the guard cells into 4 classes based on the MF-status. MF dynamics was oscillated during the diurnal cycle in which bundled and organized radial array upon stomatal opening and loose and random array upon closing were observed, respectively.
