ISSN:
1615-6102
Schlagwort(e):
Arabidopsis thaliana
;
Exine patterning
;
Male-sterile mutants
;
Plasma membrane
;
Pollen development
;
Sporopollenin
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Summary In order to identify factors necessary for the establishment of the reticulate pollen wall pattern, we have characterized a T-DNA tagged mutant ofArabidopsis thaliana that is defective in pattern formation. This study reports the results of an ultrastructural comparison of pollen wall formation in the mutant to wall development in wild-type plants. Pollen wall development in the mutant parallels that of wild-type until the early tetrad stage. At this point in wild-type plants, the microspore plasma membrane assumes a regular pattern of ridges and valleys. Initial sporopollenin deposition occurs on the ridges marking the beginning of probacula formation. In contrast, the plasma membrane in the mutant appears irregular with flattened protuberances and rare invaginations. As a result, the wild-type regular pattern of ridges and valleys is not formed. Sporopollenin is randomly deposited on the plasma membrane and aggregates on the locule wall; it is not anchored to the membrane. Our finding that the mutation blocks the normal invagination of the plasma membrane and disrupts the proper deposition of sporopollenin during wall formation suggests that the mutation could be in a gene responsible for pattern formation. These results also provide direct evidence that the plasma membrane plays a critical role in the establishment of the pollen wall pattern.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01282131
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