Artículo
Disorganization of F-actin cytoskeleton precedes vacuolar disruption in pollen tubes during the in vivo self-incompatibility response in Nicotiana alata
Fecha de publicación:
09/2012
Editorial:
Oxford University Press
Revista:
Annals of Botany
ISSN:
0305-7364
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Background and Aims The integrity of actin filaments (F-actin) is essential for pollen-tube growth. In S-RNase-based self-incompatibility (SI), incompatible pollen tubes are inhibited in the style. Consequently, research efforts have focused on the alterations of pollen F-actin cytoskeleton during the SI response. However, so far, these studies were carried out in in vitro-grown pollen tubes. This study aimed to assess the timing of in vivo changes of pollen F-actin cytoskeleton taking place after compatible and incompatible pollinations in Nicotiana alata. To our knowledge, this is the first report of the in vivo F-actin alterations occurring during pollen rejection in the S-RNase-based SI system. Methods The F-actin cytoskeleton and the vacuolar endomembrane system were fluorescently labelled in compatibly and incompatibly pollinated pistils at different times after pollination. The alterations induced by the SI reaction in pollen tubes were visualized by confocal laser scanning microscopy. Key Results Early after pollination, about 70 % of both compatible and incompatible pollen tubes showed an organized pattern of F-actin cables along the main axis of the cell. While in compatible pollinations this percentage was unchanged until pollen tubes reached the ovary, pollen tubes of incompatible pollinations underwent gradual and progressive F-actin disorganization. Colocalization of the F-actin cytoskeleton and the vacuolar endomembrane system, where S-RNases are compartmentalized, revealed that by day 6 after incompatible pollination, when the pollen-tube growth was already arrested, about 80 % of pollen tubes showed disrupted F-actin but a similar percentage had intact vacuolar compartments. Conclusions The results indicate that during the SI response in Nicotiana, disruption of the F-actin cytoskeleton precedes vacuolar membrane breakdown. Thus, incompatible pollen tubes undergo a sequential disorganization process of major subcellular structures. Results also suggest that the large pool of S-RNases released from vacuoles acts late in pollen rejection, after significant subcellular changes in incompatible pollen tubes.
Palabras clave:
Confocal microcopy
,
F-actin cytoskeleton
,
Pollen tube
,
S-RNase
,
Vacuolar system
Archivos asociados
Licencia
Identificadores
Colecciones
Articulos(CIQUIBIC)
Articulos de CENTRO DE INVEST.EN QCA.BIOL.DE CORDOBA (P)
Articulos de CENTRO DE INVEST.EN QCA.BIOL.DE CORDOBA (P)
Citación
Roldán, Juan Alfredo; Rojas, Hernan Javier; Goldraij, Ariel; Disorganization of F-actin cytoskeleton precedes vacuolar disruption in pollen tubes during the in vivo self-incompatibility response in Nicotiana alata; Oxford University Press; Annals of Botany; 110; 4; 9-2012; 787-795
Compartir
Altmétricas