Phospholipase Dδ regulates pollen tube growth by modulating actin cytoskeleton organization in .

The actin cytoskeleton plays pivotal roles in pollen tube growth by regulating organelle movement, cytoplasmic streaming, and vesicle trafficking. Previous studies have reported that plasma membrane-localized phospholipase Dδ (PLDδ) binds to cortical microtubules and negatively regulates plant stress tolerance. However, it remains unknown whether or how PLDδ regulates microfilament organization. In this study, we found that loss of function led to a significant increase in pollen tube growth, whereas overexpression resulted in pollen tube growth inhibition. We also found that wild-type , rather than Arg 622-mutated , complemented the phenotype in pollen tubes. biochemical assays demonstrated that PLDδ binds directly to F-actin, and immunofluorescence assays revealed that PLDδ in pollen tubes influences actin organization. Together, these results suggest that PLDδ participates in the development of pollen tube growth by organizing actin filaments.