The Functional Role and Dynamics of Actin Plaques in Wall-Less Protoplasts of Phytophthora infestans

With a focus on the function of actin plaques in wall-less protoplasts, this research examined the structure and dynamics of the actin cytoskeleton in the oomycete plant pathogen Phytophthora infestans. Researchers also aimed to learn how F-actin structures and their interactions with actin cables change in the absence of a cell wall, with respect to behavior, localization, and mobility. The movements of F-actin in the cortical cytoplasm under wall-less conditions were observed using live-cell imaging of protoplasts expressing the fluorescent actin marker Lifeact-GFP. Using microscopy, we compared the motility, lifespan, and distribution of actin plaques in walled hyphae and protoplasts. Three important findings emerged from the research. To begin, much like walled mycelium, actin plaques remained membrane-associated in protoplasts. Secondly, in the cortical cytoplasm of a few protoplasts, researchers saw revolving rings of actin cables. Thirdly, protoplast actin plaques, particularly those linked to actin rings that rotate, showed a decrease in lifespan and an increase in motility. These results shed light on the actin structure unique to oomycetes and imply that actin plaques may interact with the cell wall to anchor actin cables.