In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 106, No. 22 ( 2009-06-02), p. 8929-8934
Kurzfassung:
The debate on the origin and evolution of flowers has recently entered the field of developmental genetics, with focus on the design of the ancestral floral regulatory program. Flowers can differ dramatically among angiosperm lineages, but in general, male and female reproductive organs surrounded by a sterile perianth of sepals and petals constitute the basic floral structure. However, the basal angiosperm lineages exhibit spectacular diversity in the number, arrangement, and structure of floral organs, whereas the evolutionarily derived monocot and eudicot lineages share a far more uniform floral ground plan. Here we show that broadly overlapping transcriptional programs characterize the floral transcriptome of the basal angiosperm Persea americana (avocado), whereas floral gene expression domains are considerably more organ specific in the model eudicot Arabidopsis thaliana . Our findings therefore support the “fading borders” model for organ identity determination in basal angiosperm flowers and extend it from the action of regulatory genes to downstream transcriptional programs. Furthermore, the declining expression of components of the staminal transcriptome in central and peripheral regions of Persea flowers concurs with elements of a previous hypothesis for developmental regulation in a gymnosperm “floral progenitor.” Accordingly, in contrast to the canalized organ-specific regulatory apparatus of Arabidopsis , floral development may have been originally regulated by overlapping transcriptional cascades with fading gradients of influence from focal to bordering organs.
Materialart:
Online-Ressource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.0811476106
Sprache:
Englisch
Verlag:
Proceedings of the National Academy of Sciences
Publikationsdatum:
2009
ZDB Id:
209104-5
ZDB Id:
1461794-8
SSG:
11
SSG:
12
