| Abstract Detail
Bryological and Lichenological Section/ABLS Schuette, Scott [1]. Using Phylogenomics to Identify Putative Spore Wall Development Genes in Physcomitrella patens . Physcomitrella patens is the ideal organism for examining functional genomics and the evolution of development in land plants. Spore and pollen walls are homologous structures with elaborate architectures and morphologies. Physcomitrella spore walls have an intine, a two-layered exine, and an additional layer called the perine. Arabidopsis pollen walls have an intine and an elaborate exine divided into a nexine and sexine. These walls are undoubtedly the most complex plant cell wall and thus have complicated developmental programs. The walls are comprised of two primary domains, the intine and exine. This study employs a phylogenomic approach to identifying candidate genes involved in spore wall development in this model moss using neighbor joining and maximum likelihood algorithms. We identify putative moss spore wall development orthologs of genes involved in the pollen wall development of Arabidopsis, including DEFECTIVE EXINE (DEX1), NO EXINE FORMATION (NEF1), FACELESS POLLEN (FLP1), CALLOSE SYNTHASE 5 (CalS5), and CYP703 (CYP703A2), which all produce aberrant pollen grains in Arabidopsis. For DEX1 and NEF1 there are Physcomitrella specific orthologs with subsequent duplication events in the seed plants. FLP1 duplicated prior to the divergence of algae from land plants and again within the land plants. The CYP703A2 has duplicated in Physcomitrella independent from duplications in other land plants. The callose synthase family is large with moss and Arabidopsis specific branches, but CalS5 is directly orthologous to a single gene in Physcomitrella, and thus a likely candidate for the gene involved in callose production in the aperture. Using this approach we can address genetic mechanisms involved in spore and pollen wall development.
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1 - Southern Illinois University, Department of Plant Biology, 1125 Lincoln Drive, Carbondale, Illinois, 62901-6509, USA
Keywords:
Physcomitrella patens
spore wall
phylogenomics
pollen wall
developmental genes
developmental evolution.
Presentation Type: Oral Paper:Papers for BSA Sections
Session: 22
Location: Magpie B/Cliff Lodge - Level B
Date: Monday, July 27th, 2009
Time: 2:45 PM
Number: 22006
Abstract ID:697 |
