Plant Physiol.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Plant Physiology Preview
Published on October 23, 2009; 10.1104/pp.109.145920

OPEN ACCESS ARTICLE
This Article
Free via Open Access: OA
Right arrow Full Text (Plant Physiology Preview (PDF))
Right arrow Supplemental Data
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Google Scholar
Right arrow Articles by Ramirez, J.
Right arrow Articles by Hake, S.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ramirez, J.
Right arrow Articles by Hake, S.
Agricola
Right arrow Articles by Ramirez, J.
Right arrow Articles by Hake, S.

Received August 13, 2009
Accepted October 18, 2009

Distal expression of knotted1 in maize leaves leads to re-establishment of proximal/distal patterning and leaf dissection

Julio Ramirez , Nathalie Bolduc , Damon Lisch , and Sarah Hake *

Department of Plant and Microbial Biology, University of California, Berkeley, 94720; Plant Gene Expression Center, USDA-ARS, 800 Buchanan St., Albany, CA 94710

* Corresponding author; email: maizesh{at}nature.berkeley.edu.

Zea mays (maize) leaves provide a useful system to study how proximal/distal patterning is established because of the distinct tissues found in the distal blade and the proximal sheath. Several mutants disrupt this pattern including the dominant knotted1-like homeobox (knox) mutants. knox genes encode homeodomain proteins of the TALE superclass of transcription factors. Class I knox genes are expressed in the meristem and down-regulated as leaves initiate. Gain-of-function phenotypes result from misexpression in leaves. We identified a new dominant allele of maize knotted1, Kn1-DL, which contains a transposon insertion in the promoter in addition to a tandem duplication of the kn1 locus. In situ hybridization shows that kn1 is misexpressed in two different parts of the blade that correlate with the different phenotypes observed. When kn1 is misexpressed along the margins, flaps of sheath-like tissue form along the margins. Expression in the distal tip leads to premature termination of the midrib into a knot and leaf bifurcation. The gain-of-function phenotypes suggest that kn1 establishes proximal/distal patterning when expressed in distal locations and lead to the hypothesis that kn1 normally participates in the establishment of proximal/distal polarity in the incipient leaf.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 2009 by the American Society of Plant Biologists