INVESTIGADORES
GOLDRAIJ ariel
congresos y reuniones científicas
Título:
F-actin depolymerization precedes vacuolar breakdown cytoskeleton during pollen rejection in Nicotiana alata.
Autor/es:
JUAN A ROLDÁN; ARIEL GOLDRAIJ
Lugar:
Potrero de Funes, San Luis
Reunión:
Congreso; XLVII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2011
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)
Resumen:
F-actin
depolymerization precedes vacuolar breakdown during pollen rejection in Nicotiana alata
Juan A Roldán and
Ariel Goldraij
CIQUIBIC-CONICET
Dpto. Química Biológica, Facultad de Cs. Químicas, Universidad Nacional de
Córdoba.
We studied the in vivo changes of F-actin cytoskeleton in
pollen tubes after compatible and incompatible pollinations in Nicotiana alata.The integrity of actin
filaments is essential for polar growth in pollen tubes. F-actin provides the
track along which organelle and vesicle move, carrying the necessary material
to sustain the pollen tip growth. In a previous work we have shown that incompatible
pollen tubes underwent gradual depolymerization which continued for several
days after complete cessation of pollen growth. To assess whether F-actin
fragmentation was an early event in pollen rejection, double labeling of
F-actin and the vacuolar compartments was performed in incompatible
pollination. Vacuolar breakdown was reported as the crucial step in pollen
rejection in Nicotiana because it
releases cytotoxic S-RNase to the cytoplasm. At 1 and 3 days after pollination,
pollen tubes with depolymerized F-actin were 45% and 70%, respectively.
However, less than 10% showed disorganized both F-actin and vacuolar
compartments. At 8 d after pollination 90% of pollen tubes had disorganized the
F-actin but only 33% displayed vacuolar rupture. No pollen tubes with intact
F-actin and disorganized vacuolar compartments were seen at any time. These
results suggest that F-actin depolymerization occurs upstream in pollen
rejection and precedes S-RNase releasing from vacuole to cytoplasm.