Multicellular structures developing during maize microspore culture express endosperm and embryo-specific genes and show different embryogenic potentialities.
During maize pollen embryogenesis, a range of multicellular structures are formed. Using different approaches, the "nature" of these structures has been determined in terms of their embryogenic potential. In situ molecular identification techniques for gene transcripts and products, and a novel cell tracking system indicated the presence of embryogenic (embryo-like structures, ELS) and non-embryogenic (callus-like structures, CLS) structures that occurred for short periods within the cultures. Some multicellular structures with a compact appearance generated embryos. RT-PCR and fluorescence in situ hybridization (FISH) with confocal microscopy techniques using specific gene markers of the endosperm (ZmESR2, ZmAE3) and embryo (LTP2 and ZmOCL1, ZmOCL3) revealed "embryo" and "endosperm" potentialities in these various multicellular structures present in the cultures. The results presented here showed distinct and specific patterns of gene expression. Altogether, the results demonstrate the presence of different molecules on both embryonic and non-embryonic structures. Their possible roles are discussed in the context of a parallel between embryo/endosperm interactions in planta and embryonic and non-embryonic structure interrelations under in vitro conditions.
Massonneau
Agnes
A
Reproduction et Développement des Plantes, ENS Lyon, UMR5667, CNRS/INRA/ENS/LYON 1, 46 Allee d'Italie, F-69364 Lyon Cedex 07, France.
Coronado
Maria-José
MJ
Audran
Arthur
A
Bagniewska
Agnieszka
A
Mòl
Rafal
R
Testillano
Pilar S
PS
Goralski
Grzegorz
G
Dumas
Christian
C
Risueño
Maria-Carmen
MC
Matthys-Rochon
Elisabeth
E
D015415:Biomarkers; D047108:Embryonic Development; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence; D010940:Plant Proteins / Q000235:genetics; D011058:Pollen / Q000166:cytology / Q000196:embryology / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D012639:Seeds / Q000235:genetics; D003313:Zea mays / Q000166:cytology* / Q000196:embryology* / Q000235:genetics
D015415:Biomarkers; D010940:Plant Proteins; C108912:endosperm specific protein, Zea mays