Author
Chao, Wun | |
Dogramaci, Munevver | |
Anderson, James | |
Foley, Michael | |
Horvath, David |
Submitted to: BMC Plant Biology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/4/2014 Publication Date: 8/12/2014 Citation: Chao, W.S., Dogramaci, M., Anderson, J.V., Foley, M.E., Horvath, D.P. 2014. The resemblance and disparity of gene expression in dormant and non-dormant seeds and crown buds of leafy spurge (Euphorbia esula). Biomed Central (BMC) Plant Biology. 14:216. https://doi.org/10.1186/s12870-014-0216-4. DOI: https://doi.org/10.1186/s12870-014-0216-4 Interpretive Summary: Leafy spurge is a herbaceous perennial weed and dormancy in both buds and seeds is an important survival mechanism. Bud dormancy in leafy spurge exhibits three well-defined phases of para-, endo- and ecodormancy; however, seed dormancy for leafy spurge is classified as physiological dormancy that requires after-ripening and alternating temperature for maximal germination. Overlaps in transcriptome profiles between different phases of bud and seed dormancy have not been determined. Thus, we compared various phases of dormancy between seeds and buds to identify common genes and molecular processes. Our results indicate that common molecular mechanisms involved in dormancy transitions of buds and seeds involve processes associate with ABA and auxin signaling and transport, cell cycle, and AP2/ERF transcription factors or their up-stream regulators. Technical Abstract: Overlaps in transcriptome profiles between different phases of bud and seed dormancy have not been determined. Thus, we compared various phases of dormancy between seeds and buds to identify common genes and molecular processes. Cluster analysis of expression profiles for 201 selected genes indicated bud and seed samples clustered separately. Direct comparisons between buds and seeds is additionally complicated since seeds incubated at a constant temperature of 20°C for 21 days (21d C) could be considered paradormant (Para) because seeds may be inhibited by endosperm-generated signals, or ecodormant (Eco) because seeds germinate after being subjected to alternating temperature of 20:30°C. Since direct comparisons in gene expression between buds and seeds were problematic, we instead examined commonalities in differentially-expressed genes associated with different phases of dormancy. Comparison between buds and seeds (‘Para to Endo buds’ and ‘21d C to 1d C seeds’), using endodormant buds (Endo) and dormant seeds (1d C) as common baselines, identified transcripts associated with cell cycle (HisH4), stress response/transcription factors (ICE2, ERFB4/ABR1), ABA and auxin response (ABA1, ARF1, IAA7, TFL1), and transport (ABCB2). Comparison of transcript abundance for the ‘Eco to Endo buds’ and ‘21d C to 1d C seeds’ identified transcripts associated with ABA response (ATEM6), auxin response (ARF1), and cell cycle (HisH4). These results indicate that the physiological state of 21d C seeds is more analogous to paradormant buds than that of ecodormant buds. Combined results indicate that common molecular mechanisms involved in dormancy transitions of buds and seeds involve processes associate with ABA and auxin signaling and transport, cell cycle, and AP2/ERF transcription factors or their up-stream regulators. |