TOO MANY MOUTHS (TMM) is a gene which has been shown to regulate cell fate and control cell division in the plant leaf epidermis. TMM encodes a leucine rich repeat-receptor like protein (LRR-RLP) which has putative function as a signal transducing factor in the cell to cell signaling pathway involved in controlling proper spacing of stomata! initials throughout the leaf. This gene has been shown to be widely conserved across species of land plants ranging from bryophytes to angiosperms. Curiously, although this gene is highly conserved, stomata! installation pathways vary considerably across these species. Leaf development in both Arabidopsis and monocot grasses has been well characterized, and contrasting stomata! development pathways have been identified between them. Dioscorea bulbifera is a basal member of the monocot family, but this species forms broad leaves similar to many eudicot species. Stomata! development in this species retains some features characteristic of grass installation pathways such as few to no secondary asymmetric divisions of meristemoids. However, new epidermal cell formation occurs by fill-in between leaf veins, more closely resembling broad leaf eudicot development. A TMM ortholog has been isolated in this species and phylogenetic analysis of the sequence may help to place the signals controlling stomata! proliferation in Dioscorea bulbifera into evolutionary perspective.
| Identifer | oai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:honorstheses1990-2015-1826 |
| Date | 01 January 2009 |
| Creators | Heppert, Jennifer K. |
| Publisher | STARS |
| Source Sets | University of Central Florida |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | HIM 1990-2015 |
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