The origin, initiation and development of axillary shoot meristems in Lotus japonicus.
OBJECTIVE
Lotus japonicus 'Gifu' develops multiple axillary shoots in the cotyledonary node region throughout the growth of the plant. The origin, initiation and development of these axillary meristems were investigated.


METHODS
Morphological, histological and mRNA in situ analyses were done to characterize the ontogeny of cotyledonary axillary shoot meristems in Lotus. Morphological characterization of a putative Lotus shoot branching mutant (super-accessory branches) sac, is presented.


RESULTS
By using expression of an L. japonicus STM-like gene as a marker for meristematic tissues, it was demonstrated that groups of cells maintained in the meristematic state at the cotyledonary axil region coincide with the sites where additional axillary meristems (accessory meristems) form. A Lotus shoot branching mutant, sac, is a putative Lotus branching mutant characterized by increased proliferation of accessory shoots in all leaf axils including the cotyledons.


CONCLUSIONS
In Lotus, axillary shoot meristems continually develop at the cotyledonary node region throughout the growth of the plant. These cotyledonary primary and accessory axillaries arise from the position of a meristematic zone of tissue at the cotyledonary node axil region.
de G Alvarez
Nena
N
Grasslands Research Centre, AgResearch Private Bag 11008, Palmerston North, New Zealand.
Meeking
Roydon J
RJ
White
Derek W R
DW
D000595:Amino Acid Sequence; D018076:DNA, Complementary; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D000070116:Lotus / Q000235:genetics / Q000254:growth & development*; D018519:Meristem / Q000254:growth & development*; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D018520:Plant Shoots / Q000254:growth & development*; D012333:RNA, Messenger / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D012333:RNA, Messenger