Incompatible stylar extract disrupts F-actin and vesicular trafficking in Nicotiana pollen tubes

JUAN A ROLDÁN; ARIEL GOLDRAIJ

Mendoza

Congreso; XLVIII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Incompatible stylar extract disrupts F-actin and vesicular trafficking in Nicotiana pollen tubes Juan A Roldán and Ariel Goldraij CIQUIBIC-CONICET. Dpto Química Biológica, Facultad de Cs. Químicas, Universidad Nacional de Córdoba   The integrity of actin filaments and vesicular trafficking is essential for pollen tube polar growth. F-actin provides the track along which organella and vesicles move, carrying the material necessary to sustain the tip growth. In the self-incompatible species Nicotiana alata pollen tube growth is inhibited after self-pollination. Using the fluorescent markers phalloidin and FM 4-64 we analyzed the alterations of F-actin cytoskeleton and vesicular trafficking in in vitro cultured pollen tubes challenged with compatible and incompatible stylar extracts. Initiallty, both compatible and incompatible pollen tubes showed similar growth and an organized pattern of F-actin cables and vesicle trafficking. However, 90 min after challenging with the stylar extract, 50% of incompatible pollen tubes showed the V-shaped zone dissapeared and large accumulations of vesicles were seen in the subapical region. In parallel, the subapical actin ring and the F-actin cables along the shank became disorganized. These changes involved almost 90% of incompatible pollen tubes after three hours of culture while most of compatible pollen tubes showed organized both F-actin cytoskeleton and the endomembrane system. A comparison between pollen tube alterations in Nicotiana and Papaver self-incompatibility systems is discussed.