Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Zhu, Chuanmei [1], Box, Mathew [2], Goad, David [1], McKain, Michael [1], Kellogg, Elizabeth Anne [3].

Evolution and function of CLE genes and the control of meristem size in grasses.

Genes related to CLAVATA3 (CLV3) in Arabidopsis and the ESR genes in maize (CLE genes) produce proteins that are processed to release small signaling peptides of 14 amino acids. These peptides are involved in a wide variety of cell-cell signaling processes, with some of the best-characterized ones regulating meristem size. We have used model-based searches to retrieve over 1000 CLE genes from available plant genomes, and have identified sets of genes with similar sequences. We find that the CLE genes must have diversified early in the evolution of land plants; they underwent additional duplications in major clades of angiosperms. Genes with similar sequences in the CLE domain apparently share developmental roles, although this hypothesis has not been widely tested. One cluster of proteins includes CLV3, the rice protein FLORAL ORGAN NUMBER2 (FON2), and putative orthologs in various grasses. Surprisingly FON2 is in a very dynamic genomic region, such that apparently orthologous genes in maize, Setaria and Brachypodium are broadly syntenic but colinearity is disrupted. Multiple CLE genes (not just FON2-like genes) are up-regulated during inflorescence development of Setaria and maize, although the FON2 orthologs themselves are expressed at relatively low levels. If FON2-like genes are indeed involved in maintaining meristem size, as appears likely from their expression pattern and sequence similarity to CLV3, then they may play an important role in controlling inflorescence architecture and phyllotaxy. The size of branch meristems relative to the inflorescence meristem varies considerably among grasses and leads to marked differences in adult morphology. In particular, grasses related to maize and sorghum produce spikelets in pairs; the pair arises from a meristem that is notably larger than a single spikelet meristem. We suggest that CLE genes may be involved in the maintenance and possibly the evolutionary origin of the spikelet pair.

1 - Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA
2 - Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, M
3 - Donald Danforth Plant Science Center, Department Of Biology, 975 North Warson Road, St. Louis, MO, 63132, USA

Keywords:
none specified

Presentation Type: Oral Paper
Session: 2, Evolution and Development
Location: 200/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 10:45 AM
Number: 2011
Abstract ID:473
Candidate for Awards:None