Regulation of Spike Development through miRNAs in Barley (Hordeum vulgare L.)

Barley (Hordeum vulgare) was one of the first cultivated cereal grains, giving it nonfragile spike making it much easier to harvest. It was domesticated in the Fertile Crescent including west of Iran. Understanding the genetic mechanism that regulates spike formation is important for studying domestication and breeding for yield improvement in barley. MicroRNAs (miRNAs) play a critical role in regulation of plant architecture including spike formation. However, miRNAs are less studied in barley. To identify miRNAs involved in spike development in barley, we performed whole transcriptome profiling of spike at early developmental stages using Illumina deep sequencing technology. A total of 20 known miRNAs and 85 putative novel miRNAs belonging to 14 and 79 miRNA families were identified, respectively. MiRNA target predictions showed that most of them are transcription factors (TF), including 7 highly conserved TF families. The targets were involved in various biological functions including plant development, signal transduction, metabolic pathway, ion transportation, and environmental stresses in particular senescence genes. Our results provide new insights into the genetics of barley spike development that helps breeders to better understand the genetic determination of final yield in cereals and discovering the natural genetic resources for improving cereal yield through conventional or modern breeding approaches.

Regulation of Spike Development through miRNAs in Barley (Hordeum vulgare L.) Keywords:

miRNAs , next generation sequencing , transcription factors , shoot architecture