D. Jackson et al., EXPRESSION OF MAIZE KNOTTED1 RELATED HOMEOBOX GENES IN THE SHOOT APICAL MERISTEM PREDICTS PATTERNS OF MORPHOGENESIS IN THE VEGETATIVE SHOOT, Development, 120(2), 1994, pp. 405-413
In this paper we describe the expression patterns of a family of homeo
box genes in maize and their relationship to organogenic domains in th
e vegetative shoot apical meristem. These genes are related by sequenc
e to KNOTTED1, a gene characterized by dominant neomorphic mutations w
hich perturb specific aspects of maize leaf development. Four members
of this gene family are expressed in shoot meristems and the developin
g stem, but not in determinate lateral organs such as leaves or floral
organs. The genes show distinct expression patterns in the vegetative
shoot apical meristem that together predict the site of leaf initiati
on and the basal limit of the vegetative 'phytomer' or segmentation un
it of the shoot. These genes are also expressed in the inflorescence a
nd floral meristems, where their patterns of expression are more simil
ar, and they are not expressed in root apical meristems. These finding
s are discussed in relation to other studies of shoot apical meristem
organization as well as possible commonality of homeobox gene function
in the animal and plant kingdoms.