Journal Article

Expression differences between normal and <i>indeterminate1</i> maize suggest downstream targets of <i>ID1</i>, a floral transition regulator in maize

Viktoriya Coneva, Tong Zhu and Joseph Colasanti

in Journal of Experimental Botany

Published on behalf of Society for Experimental Biology

Volume 58, issue 13, pages 3679-3693
Published in print October 2007 | ISSN: 0022-0957
Published online October 2007 | e-ISSN: 1460-2431 | DOI:

Show Summary Details


The INDETERMINATE1 (ID1) transcription factor is a key regulator of the transition to flowering in maize. ID1 is expressed in immature leaves where it controls the production or transmission of leaf-derived florigenic signals. Loss-of-function id1 mutants make many more leaves than normal plants and produce aberrant flowers; however, they exhibit no obvious developmental defects in early growth stages. A maize oligonucleotide microarray was used to assess the molecular differences between immature leaves of wild-type and id1 mutant plants prior to the floral transition. This analysis revealed 55 genes with a significant 2-fold difference in expression; 22 are down-regulated and 33 are up-regulated in id1 mutants. Most prominent is a novel family of three β-glucosidase genes that are most closely related to sorghum dhurrinases. These genes, termed Zmdhr1, Zmdhr2, and Zmdhr3, are undetectable in immature leaves of id1 mutants and are expressed exclusively in normal immature leaves in a pattern identical to the ID1 gene. Other down-regulated genes include a group of four zinc finger protein-encoding genes that are unrelated to ID1. A significant number of genes up-regulated in id1 mutant immature leaves have potential roles in photosynthesis and carbon fixation, substantiating a possible connection between floral induction and assimilate partitioning. Finally, expression of these genes was compared in florally induced versus uninduced teosinte, a photoperiod-sensitive progenitor of day-neutral maize. Only a few genes showed expression differences, suggesting that ID1 acts in a novel autonomous floral induction pathway that is distinct from the photoperiod induction pathway.

Keywords: Comparative expression; floral regulator; long-distance signalling; maize; molecular profiling; plant metabolism; teosinte; transcription factor

Journal Article.  10082 words.  Illustrated.

Subjects: Plant Sciences and Forestry

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.