Transcriptional Programs of Early Reproductive Stages in Arabidopsis  

Abstract

The life cycle of flowering plants alternates between a diploid sporophytic and a haploid gametophytic generation. After fertilization of each the egg and central cells by one male gamete, the development of both fertilization products occurs coordinated with the maternally derived seed coat and carpel tissues forming the fruit. The reproduction program is likely to involve the concerted activity of many genes. To identify genes with specific functions during reproduction, we have analyzed the expression profile of more than 22,000 genes present on the Arabidopsis ATH1 microarray during three stages of flower and fruit development. We found 1,886 genes regulated during reproductive development and 1,043 genes that were specifically expressed during reproduction. When compared to cells from an Arabidopsis suspension culture, S-phase genes were underrepresented and G2 and M-phase genes were strongly enriched in the set of specific genes, indicating that important functions during reproduction are exerted in the G2 and M phases of the cell cycle. Many potential signaling components, such as receptor-like protein kinases, phosphatases, and transcription factors, were present in both groups of genes. Members of the YABBY, MADS box, and Myb transcription factor families were significantly overrepresented in the group of specific genes, revealing an important role of these families during reproduction. Furthermore, we found a significant enrichment of predicted secreted proteins smaller than 15 kD that could function directly as signaling molecules or as precursors for peptide hormones. Our study provides a basis for targeted reverse-genetic approaches aimed to identify key genes of reproductive development in plants.

Whole Genome Analysis of Gene Expression Reveals Coordinated Activation of Signaling and Metabolic Pathways during Pollen-Pistil Interactions in Arabidopsis

“…2; Supplemental File S3). Even though it was initially thought that the success of the reproductive process would depend predominantly on down-regulation of pistil-expressed transcripts (Chen et al, 2001;Lan et al, 2004), recent genome-wide analyses in rice (Oryza sativa) and Arabidopsis contributed to change this perspective (Endo et al, 2004;Hennig et al, 2004). Our time-course analysis further reveals that pronounced transcriptional changes take place in response to pollination, and these involve the concerted activity of multiple genes that ultimately follow distinct patterns of regulation.…”

“…The transcriptional profiles of pollen (Becker et al, 2003;Twell, 2003, 2004;Pina et al, 2005; for review, see Becker and Feijó , 2007), embryo sac (Yu et al, 2005;Johnston et al, 2007;Jones-Rhoades et al, 2007;Steffen et al, 2007), pistil (Scutt et al, 2003;Tung et al, 2005), and embryo or seed developmental stages (Chen et al, 2001;Hennig et al, 2004;Yoshida et al, 2005, Le et al, 2010 were recently analyzed. More notably, recent progress in the isolation of Arabidopsis (Arabidopsis thaliana) gametes allowed genomewide expression profiling of purified sperm cells (Borges et al, 2008) as well as of isolated egg and central cells (Wuest et al, 2010).…”

Endosperm: an integrator of seed growth and development

“…This will be overcome in the future, however, by utilizing recent advances in 'genomics' tools, including new sampling techniques, such as laser-assisted micro-dissection, or mRNA-tagging approaches [43,44]. The establishment of general as well as spatial and temporal transcriptomes or proteomes is likely to lead to the generation of specific profiles for each reproductive cell type and will be a new source of information [45,46].…”

ArabidopsisRETINOBLASTOMA-RELATED Is Required for Stem Cell Maintenance, Cell Differentiation, and Lateral Organ Production

“…The arrays were scanned using an Affymetrix 3000 7G confocal scanner. Labeling of samples, hybridizations, and measurements was performed as described (Hennig et al, 2004).…”