Exit from proliferation during leaf development in Arabidopsis thaliana: a not-so-gradual process.
Early leaf growth is sustained by cell proliferation and subsequent cell expansion that initiates at the leaf tip and proceeds in a basipetal direction. Using detailed kinematic and gene expression studies to map these stages during early development of the third leaf of Arabidopsis thaliana, we showed that the cell-cycle arrest front did not progress gradually down the leaf, but rather was established and abolished abruptly. Interestingly, leaf greening and stomatal patterning followed a similar basipetal pattern, but proliferative pavement cell and formative meristemoid divisions were uncoordinated in respect to onset and persistence. Genes differentially expressed during the transition from cell proliferation to expansion were enriched in genes involved in cell cycle, photosynthesis, and chloroplast retrograde signaling. Proliferating primordia treated with norflurazon, a chemical inhibitor of retrograde signaling, showed inhibited onset of cell expansion. Hence, differentiation of the photosynthetic machinery is important for regulating the exit from proliferation.
Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.
Megan
M
Andriankaja
Stijn
S
Dhondt
Stefanie
S
De Bodt
Hannes
H
Vanhaeren
Frederik
F
Coppens
Liesbeth
L
De Milde
Per
P
Mühlenbock
Aleksandra
A
Skirycz
Nathalie
N
Gonzalez
Gerrit T S
GT
Beemster
Dirk
D
Inzé
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D002453:Cell Cycle; D002454:Cell Differentiation; D049109:Cell Proliferation; D048430:Cell Shape; D048429:Cell Size; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D007091:Image Processing, Computer-Assisted; D018519:Meristem / Q000166:cytology* / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010788:Photosynthesis; D018515:Plant Leaves / Q000166:cytology* / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics
D029681:Arabidopsis Proteins; D015415:Biomarkers; D018749:RNA, Plant