Transcriptional programs regulating seed dormancy and its release by after-ripening in common wheat (Triticum aestivum L.)
Article first published online: 1 FEB 2012
© 2012 The Authors. Plant Biotechnology Journal © 2012 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd
Plant Biotechnology Journal
Volume 10, Issue 4, pages 465–476, May 2012
How to Cite
Gao, F., Jordan, M. C. and Ayele, B. T. (2012), Transcriptional programs regulating seed dormancy and its release by after-ripening in common wheat (Triticum aestivum L.). Plant Biotechnology Journal, 10: 465–476. doi: 10.1111/j.1467-7652.2012.00682.x
- Issue published online: 2 APR 2012
- Article first published online: 1 FEB 2012
- Received 27 September 2011;accepted 13 December 2011.
- gene expression;
- seed dormancy;
- seed imbibition;
Seed dormancy is an important agronomic trait in wheat (Trticum aestivum). Seeds can be released from a physiologically dormant state by after-ripening. To understand the molecular mechanisms underlying the role of after-ripening in conferring developmental switches from dormancy to germination in wheat seeds, we performed comparative transcriptomic analyses between dormant (D) and after-ripened (AR) seeds in both dry and imbibed states. Transcriptional activation of genes represented by a core of 22 and 435 probesets was evident in the dry and imbibed states of D seeds, respectively. Furthermore, two-way ANOVA analysis identified 36 probesets as specifically regulated by dormancy. These data suggest that biological functions associated with these genes are involved in the maintenance of seed dormancy. Expression of genes encoding protein synthesis/activity inhibitors was significantly repressed during after-ripening, leading to dormancy decay. Imbibing AR seeds led to transcriptional activation of distinct biological processes, including those related to DNA replication, nitrogen metabolism, cytoplasmic membrane-bound vesicle, jasmonate biosynthesis and cell wall modification. These after-ripening-mediated transcriptional programs appear to be regulated by epigenetic mechanisms. Clustering of our microarray data produced 16 gene clusters; dormancy-specific probesets and abscisic acid (ABA)-responsive elements were significantly overrepresented in two clusters, indicating the linkage of dormancy in wheat with that of seed sensitivity to ABA. The role of ABA signalling in regulating wheat seed dormancy was further supported by the down-regulation of ABA response-related probesets in AR seeds and absence of differential expression of ABA metabolic genes between D and AR seeds.