thick tassel dwarf1 encodes a putative maize ortholog of the Arabidopsis CLAVATA1 leucine-rich repeat receptor-like kinase.
Development in higher plants depends on the activity of meristems, formative regions that continuously initiate new organs at their flanks. Meristems must maintain a balance between stem cell renewal and organ initiation. In fasciated mutants, organ initiation fails to keep pace with meristem proliferation. The thick tassel dwarf1 (td1) mutation of maize affects both male and female inflorescence development. The female inflorescence, which results in the ear, is fasciated, with extra rows of kernels. The male inflorescence, or tassel, shows an increase in spikelet density. Floral meristems are also affected in td1 mutants; for example, male florets have an increase in stamen number. These results suggest that td1 functions in the inflorescence to limit meristem size. In addition, td1 mutants are slightly shorter than normal siblings, indicating that td1 also plays a role in vegetative development. td1 encodes a leucine-rich repeat receptor-like kinase (LRR-RLK) that is a putative ortholog of the Arabidopsis CLAVATA1 protein. These results complement previous work showing that fasciated ear2 encodes a CLAVATA2-like protein, and suggest that the CLAVATA signaling pathway is conserved in monocots. td1 maps in the vicinity of quantitative trait loci that affect seed row number, spikelet density and plant height. We discuss the possible selection pressures on td1 during maize domestication.
Bommert
Peter
P
Institut für Entwicklungsbiologie, Universität zu Köln, Gyrhofstrasse 17, D-50923 Köln, Germany.
Lunde
China
C
Nardmann
Judith
J
Vollbrecht
Erik
E
Running
Mark
M
Jackson
David
D
Hake
Sarah
S
Werr
Wolfgang
W
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D035263:Flowering Tops / Q000235:genetics* / Q000254:growth & development; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism
D029681:Arabidopsis Proteins; D010940:Plant Proteins; D020794:Receptor Protein-Tyrosine Kinases; C118166:CLV1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases