Abstract
We have been analyzing the role of actin in chloroplast photorelocation movement, using Physcomiterella protonemal cells expressing GFP-talin. However, the use of GFP is limited because blue excitation of GFP interferes photoresponses. For example, blue light chloroplast movement could not be induced under image acquisition every 1 min. In this study, actin dynamics were analyzed in the cells expressing tdTomato-talin. tdTomato is a variant of green-excitable RFP (Shaner et al., 2004) and therefore, interference on photoresponse is minimum. Blue light chloroplast movement could be induced even under image collection every 5 sec. With this transgenic line, the process of formation of actin meshwork, a characteristic structure around the photo-relocated chloroplasts was analyzed. It was found that the structure is initially organized on the area where chloroplasts locate. Further, even after the completion of meshwork formation each individual actin filament is highly dynamic, showing appearance and disappearance.
