Establishment of fluorescent protein-tagged lines for investigating dynamic localization of organelle and other cell structures in rice pollen tube.

Eukaryotic cells consist of various organelles, each responsible for specific biological processes, making the understanding of protein subcellular localization essential for determining their potential functions. However, the rapid polar growth of pollen tubes requires careful consideration of organelle trafficking when analyzing subcellular localization in related studies. Fluorescence-tagged organelle markers have shown limited utility for studying pollen during the reproductive stage. In this study, we developed pollen-specific fluorescent marker sets for organelles and other cell structures using the promoter of the OsTAPE gene, which is highly expressed in mature pollen and pollen tubes of rice (Oryza sativa L.). These marker sets enable the visualization of cell membranes, nuclei, endoplasmic reticulum, Golgi apparatus, prevacuolar compartments, and filamentous actin by tagging fluorescent proteins (FP) at the amino N-terminal end. Specifically designed to accommodate the rapid tube elongation of rice pollen, this system offers a valuable resource for gene function research and colocalization analysis, helping to elucidate the pollen tube elongation process. This study expands the potential for using fluorescent labeling in monocotyledonous plants like rice during reproductive stages, facilitating gene function studies under varying environmental conditions through subcellular localization analysis in growing pollen tubes.