LOST MERISTEMS genes regulate cell differentiation of central zone descendants in Arabidopsis shoot meristems.
Meristems of seed plants continuously produce new cells for incorporation into maturing tissues. A tightly controlled balance between cell proliferation in the center and cell differentiation at the periphery of the shoot meristem maintains its integrity. Here, we describe the role of three GRAS genes, named LOST MERISTEMS genes, in shoot apical meristem maintenance and axillary meristem formation. Under short photoperiods, the lom1 lom2 and lom1 lom2 lom3 mutants have arrested meristems characterized by an over-proliferation of meristematic cells and loss of polar organization. They also show early arrest of axillary meristem development and formation of ectopic meristematic cell clusters within the stem. LOM1 and LOM2 transcripts accumulate in the peripheral and basal zones of the SAM and in vascular strands. We show that LOM1 and LOM2 promote cell differentiation at the periphery of shoot meristems and help to maintain their polar organization.
Max Planck Institute for Plant Breeding Research, Carl von Linné Weg 10, D-50829 Cologne, Germany.
Silke
S
Schulze
Barbara Nicole
BN
Schäfer
Eneida Abreu
EA
Parizotto
Olivier
O
Voinnet
Klaus
K
Theres
D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002455:Cell Division; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018519:Meristem / Q000166:cytology / Q000254:growth & development*; D035683:MicroRNAs / Q000378:metabolism*; D009154:Mutation; D017440:Photoperiod; D018515:Plant Leaves / Q000254:growth & development
D029681:Arabidopsis Proteins; C556248:LOM1 protein, Arabidopsis; C556249:LOM2 protein, Arabidopsis; C556250:MIRN171 microRNA, Arabidopsis; D035683:MicroRNAs