title: Polar protein transport between apical and basal cells during tobacco early embryogenesis.
abstract: KEY MESSAGE                 :                                     We found that protein trafficking between apical and basal cell can be unidirectional, which reveals the different roles of the two cells in the cell-to-cell communication between them during early embryogenesis.                                                                  In most angiosperm species, asymmetric zygote division results in an apical cell and a basal cell that have distinct cell fates. Much has been speculated about possible communication between these cell types in relation to their cell fate determination. Here, we report on the use of photoactivatable green fluorescent protein (PA-GFP) in tobacco to trace intercellular communication between apical and basal cells during early embryogenesis. We found that PA-GFP was transported between apical and basal cells of a two-celled proembryo, and that protein trafficking was unidirectional toward the apical cell, highlighting different cell communication roles. Further ultrastructural analysis showed numerous plasmodesmata in the walls connecting the apical and basal cells, which may provide channels for protein trafficking. Our data show a possible unique method of cell-to-cell communication between apical and basal cells during early embryogenesis.
authors.affiliation: State Key Laboratory of Hybrid Rice, College of Life Science, Wuhan University, Wuhan 430072, China.
authors.forename: Shisheng
authors.initials: S
authors.lastname: Li
authors.forename: Yuqing
authors.initials: Y
authors.lastname: He
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Liyao
authors.initials: L
authors.lastname: Zhang
authors.forename: Meng-xiang
authors.initials: MX
authors.lastname: Sun
mesh_terms: D002450:Cell Communication; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008027:Light; D049408:Luminescent Agents / Q000378:metabolism; D018613:Microscopy, Confocal; D010940:Plant Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D031425:Plasmodesmata / Q000648:ultrastructure; D021381:Protein Transport; D014026:Nicotiana / Q000196:embryology* / Q000378:metabolism* / Q000528:radiation effects / Q000648:ultrastructure
chemical_list: D049408:Luminescent Agents; D010940:Plant Proteins; D049452:Green Fluorescent Proteins