Abstract
The Brassica napus secondary embryogenesis system requires no exogenous growth regulator to stimulate embryo development. It is stable embryogenically over a long period of culture and has a distinct pre-embryogenic stage. This system was used to investigate the morphological and cellular changes occurring in the embryogenic tissue compared to non-embryogenic tissue using various microscopy techniques. A unique ultrastructural feature designated the extracellular matrix (ECM) was observed on the surface of pre-embryogenic embryoids but not on the non-embryogenic individuals. The ECM layer was found to be dominant in the pre-embryogenic stage and reduced to fragments during embryo growth and development in mature embryogenic tissue. This is a novel aspect of the phenotype previously unreported in the Brassica system. This structure might be linked to acquisition of embryogenic competence.
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Abbreviations
- ECM :
-
Extracellular matrix
- EC :
-
Embryogenic
- PEC :
-
Pre-embryogenic
- NEC :
-
Non-embryogenic
- MEC :
-
Mature embryogenic
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We are grateful to Ms. Janet Powell and Mr. Tony Burgess (Multi Imaging Centre, Department of Anatomy, University of Cambridge, UK) for technical assistance.
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Communicated by M. E. Horn
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Namasivayam, P., Skepper, J. & Hanke, D. Identification of a potential structural marker for embryogenic competency in the Brassica napus spp. oleifera embryogenic tissue. Plant Cell Rep 25, 887–895 (2006). https://doi.org/10.1007/s00299-006-0122-9
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DOI: https://doi.org/10.1007/s00299-006-0122-9