Post-Transcriptional Gene Regulation by MicroRNAs During Barley Malting

Barley malting is an agro-industrial process that produces malt, an essential ingredient for the brewing and distilling industries. Previously, tran-scriptome profiling has revealed mRNA changes during malting but less is known about their regulation.

The spring 2-row barley variety 'Conrad' was sampled at five stages of malt-ing. Using small RNA (sRNA)-sequencing and degradome-sequencing data from these malting stages, de novo discovery of mature microRNA (miRNA), as well as cognate mRNAs targeted for slicing, was identified. ShortStack v4.1.0 was used to map sRNA reads to the Hordeum vulgare Morex V3 genome.

In total, 33 expressed MIRs were identified, six of which may be novel. Using the degradome-sequencing data from the same malting stages, CleaveLand4 v4.5 pre-dicted 64 sliced mRNA targets, predominantly transcription factors associated with root development.

This study provides an overview of post-transcriptional modulations of miRNAs-cognate mRNA targets, as well as plausible interactions between miRNAs during barley malting.