Double fertilization in Arabidopsis thaliana involves a polyspermy block on the egg but not the central cell.
Mol Plant
; 1(4): 611-9, 2008 Jul.
Article
em En
| MEDLINE
| ID: mdl-19825566
ABSTRACT
In animal reproduction, thousands of sperm may compete to fertilize a single egg, but polyspermy blocks prevent multiple fertilization that would otherwise lead to death of the embryo. In flowering plants, successful seed development requires that only two sperm are delivered to the embryo sac, where each must fertilize a female gamete (egg or central cell) to produce the embryo and endosperm. Therefore, polyspermy must be avoided, not only to prevent abnormalities in offspring, but to ensure double fertilization. It is not understood how each sperm fertilizes only one female gamete, nor has the existence of polyspermy barriers been directly tested in vivo. Here, we sought evidence for polyspermy blocks in angiosperms using the polyspermic tetraspore (tes) mutant of Arabidopsis, which allows in-vivo challenge of egg and central cell with multiple male gametes. We show that tes mutant pollen tubes can transmit more than one sperm pair to an embryo sac, and that sperm from more than one pair can participate in fertilization. We detected endosperms but not embryos with ploidies that could only result from multiple fertilization. Our results therefore demonstrate an in-vivo polyspermy block on the egg, but not the central cell of a flowering plant.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pólen
/
Arabidopsis
/
Óvulo Vegetal
/
Fertilização
Idioma:
En
Revista:
Mol Plant
Assunto da revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Reino Unido