Abstract
The SQUAMOSA-promoter binding like (SPL) gene family encodes transcription factors that have been shown in many species to influence plant growth and development, but information about these genes in barley (Hordeum vulgare L.) is limited. This study identified 17 barley SPL genes, within eight distinct groups, that are orthologs of SPL genes described in Arabidopsis, wheat, and rice. Sixteen barley SPLs undergo alternative splicing. Seven SPLs contain a putative miR156 target site and the transcript levels of the miR156-targeted HvSPLs (HvSPL3, 13 and 23) were lower in vegetative than in reproductive phase but this was true also for some SPL genes such as HvSPL6 that were not regulated by miR156. Because SPL gene products regulate miR172, which is also involved in floral development, the expression of miR172 was studied. An antagonistic expression pattern of miR156 and miR172b during the vegetative and the reproductive phases signifies their apparent function in barley growth phase transition. Characterization of a barley mir172 mutant having an abnormal, indeterminate spikelet phenotype suggests the possible feedback role of AP2/miR172 module on HvSPL genes. This is the first comprehensive analysis of the miR156/SPL/miR172 axis in barley that provides a basis to elucidate their roles in various biological processes.
Highlights
Barley (Hordeum vulgare L.) is a widely cultivated cereal grain
Phylogenetic analysis based on amino acid sequences of conserved SBP domain from wheat, rice, and barley and from A. thaliana classified HvSPLs into eight different groups (Fig. 1)
The SBP domain binds to consensus nucleotide sequences TNCGTACAA17,50, with GTAC being an essential core sequence present on the promoter of its target genes
Summary
Barley (Hordeum vulgare L.) is a widely cultivated cereal grain. Cereal inflorescences are known as spikes. Each spike is composed of multiple spikelets formed directly on the main axis[1] During domestication, both the yield and the architecture of cereal plants have been modified. Our main research target was to explore the involvement of SPLs in barley growth phase transition from vegetative to reproductive stage. Transcription factors play important roles in plant growth and development by inducing or suppressing the expression of their target genes. Studies of A. thaliana have shown that SPL genes have diverse functions in plant growth and development. SPL8 affected reproductive development through the genes involved in GA (gibberellic acid) biosynthesis[21,22]. The miR156-targeted SPL9 promoted sesquiterpene biosynthesis by binding to the promoter region of TPS2126 and it negatively regulated anthocyanin levels by modulating the expression of the MYB-bHLH-WD40 complex[27]. Gene symbolb HORVU7Hr1G042370 HORVU6Hr1G019700 HORVU5Hr1G117190 HORVU2Hr1G097580 HORVU2Hr1G097610 HORVU0Hr1G039150 HORVU1Hr1G060770 HORVU6Hr1G031450 HORVU2Hr1G048280 HORVU7Hr1G051400 HORVU5Hr1G076380 HORVU5Hr1G073440 HORVU0Hr1G039170 HORVU7Hr1G110980 HORVU6Hr1G030490 HORVU7Hr1G110950 HORVU3Hr1G094730
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
