Email updates

Keep up to date with the latest news and content from BMC Plant Biology and BioMed Central.

Open Access Research article

miRNA regulation in the early development of barley seed

Julien Curaba, Andrew Spriggs, Jen Taylor, Zhongyi Li and Chris Helliwell*

Author Affiliations

CSIRO Plant Industry, GPO Box 1600, Canberra, ACT, 2601, Australia

For all author emails, please log on.

BMC Plant Biology 2012, 12:120  doi:10.1186/1471-2229-12-120

Published: 28 July 2012

Abstract

Background

During the early stages of seed development many genes are under dynamic regulation to ensure the proper differentiation and establishment of the tissue that will constitute the mature grain. To investigate how miRNA regulation contributes to this process in barley, a combination of small RNA and mRNA degradome analyses were used to identify miRNAs and their targets.

Results

Our analysis identified 84 known miRNAs and 7 new miRNAs together with 96 putative miRNA target genes regulated through a slicing mechanism in grain tissues during the first 15 days post anthesis. We also identified many potential miRNAs including several belonging to known miRNA families. Our data gave us evidence for an increase in miRNA-mediated regulation during the transition between pre-storage and storage phases. Potential miRNA targets were found in various signalling pathways including components of four phytohormone pathways (ABA, GA, auxin, ethylene) and the defence response to powdery mildew infection. Among the putative miRNA targets we identified were two essential genes controlling the GA response, a GA3oxidase1 and a homolog of the receptor GID1, and a homolog of the ACC oxidase which catalyses the last step of ethylene biosynthesis. We found that two MLA genes are potentially miRNA regulated, establishing a direct link between miRNAs and the R gene response.

Conclusion

Our dataset provides a useful source of information on miRNA regulation during the early development of cereal grains and our analysis suggests that miRNAs contribute to the control of development of the cereal grain, notably through the regulation of phytohormone response pathways.

Keywords:
microRNA; Barley; Grain development; Plant hormones; Disease resistance; Small RNA sequencing; mRNA degradome; PARE