Abstract
The semidominant mutation Liguleless3-O (Lg3-O) causes a blade-to-sheath transformation at the midrib region of the maize (Zea mays L.) leaf. We isolated a full-length Ig3 cDNA containing a knotted1-like family homeobox. Six Lg3-O partial revertant alleles caused by insertion of a Mutator (Mu) transposon and two deletion derivatives were isolated and used to verify that our knotted1-like cDNA corresponds to the LG3 message. In wild-type plants the LG3 mRNA is expressed in apical regions but is not expressed in leaves. In mutant plants harboring any of three dominant Ig3 alleles (Lg3-O, -MIg, and -347), LG3 mRNA is expressed in leaf sheath tissue, indicating that the Lg3 phenotype is due to ectopic expression of the gene. The Lg3-O revertant alleles represent two classes of Lg3 phenotypes that correlate well with the level of ectopic Lg3 expression. High levels of ectopic LG3 mRNA expression results in a severe Lg3 phenotype, whereas weak ectopic Lg3 expression results in a mild Lg3 phenotype. We propose that ectopic Lg3 expression early in leaf development causes the blade-to-sheath transformation, but the level of expression determines the extent of the transformation.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 651-662 |
| Number of pages | 12 |
| Journal | Plant physiology |
| Volume | 119 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 1999 |
Bibliographical note
Funding Information:We thank M. Pettini and R. Cooke for providing their results prior to publication. We also thank J. Norris and R. Sutherland for fruitful discussion. This work has been supported in part by WPI Initiative, MEXT, Japan, and by the Grant-in-Aid for Scientific Research of the JSPS (18104003, 20540226) and MEXT (19047004, 22012003).