Within and between whorls: comparative transcriptional profiling of Aquilegia and Arabidopsis

Date

2010-03-23

Authors

Voelckel, Claudia
Borevitz, Justin O.
Kramer, Elena M.
Hodges, Scott A.

Journal Title

Journal ISSN

Volume Title

Publisher

Public Library of Science

Abstract

BACKGROUND The genus Aquilegia is an emerging model system in plant evolutionary biology predominantly because of its wide variation in floral traits and associated floral ecology. The anatomy of the Aquilegia flower is also very distinct. There are two whorls of petaloid organs, the outer whorl of sepals and the second whorl of petals that form nectar spurs, as well as a recently evolved fifth whorl of staminodia inserted between stamens and carpels. METHODOLOGY/PRINCIPAL FINDINGS We designed an oligonucleotide microarray based on EST sequences from a mixed tissue, normalized cDNA library of an A. formosa x A. pubescens F2 population representing 17,246 unigenes. We then used this array to analyze floral gene expression in late pre-anthesis stage floral organs from a natural A. formosa population. In particular, we tested for gene expression patterns specific to each floral whorl and to combinations of whorls that correspond to traditional and modified ABC model groupings. Similar analyses were performed on gene expression data of Arabidopsis thaliana whorls previously obtained using the Ath1 gene chips (data available through The Arabidopsis Information Resource). CONCLUSIONS/SIGNIFICANCE Our comparative gene expression analyses suggest that 1) petaloid sepals and petals of A. formosa share gene expression patterns more than either have organ-specific patterns, 2) petals of A. formosa and A. thaliana may be independently derived, 3) staminodia express B and C genes similar to stamens but the staminodium genetic program has also converged on aspects of the carpel program and 4) staminodia have unique up-regulation of regulatory genes and genes that have been implicated with defense against microbial infection and herbivory. Our study also highlights the value of comparative gene expression profiling and the Aquilegia microarray in particular for the study of floral evolution and ecology.

Description

Keywords

aquilegia, arabidopsis, cell cycle, dna primers, dna, complementary, evolution, molecular, expressed sequence tags, flowers, gene expression profiling, gene expression regulation, plant, nucleic acid hybridization, oligonucleotide array sequence analysis

Citation

Source

PLoS ONE

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

DOI

10.1371/journal.pone.0009735

Restricted until