Title : Identification of SL-responsive transcription factors in barley
Abstract:
Strigolactones (SLs) are the youngest class of phytohormones primarily involved in shaping the architecture of plants. Barley plants harbouring the mutation in the HvD14 gene, which encodes the SL-specific receptor, produce almost twice as many tillers as wild-type (WT) plants Sebastian. Moreover, the mutant hvd14.d possesses shorter but more branched roots when compared to the WT. So far, no transcription factor (TF) that could control the response of barley to the presence of SLs has been identified. Here, by comparing the transcriptomic response of WT and hvd14.d to SLs, we typed TFs that may be involved in SL signaling transduction pathway. The RNAseq analyses were performed for both genotypes, WT and hvd14.d treated with two concentrations (1 and 10 µM) of synthetic analogue GR245DS. Overall, the analysis revealed 101 SL-responsive genes that were differentially expressed in WT but not in hvd14.d. Analyses of the promoter sequence (1500bp before the codon START) of selected SL-responsive genes allowed us identify 47 TFs that may be involved in the regulation of barley response to SLs. Six of the identified TFs may bind the promoter of more than / almost half of the genes whose expression was altered by treating plants with SLs. The obtained results revealed for the first time the set of TFs that may be involved in SL signaling pathway in barley and, on the other hand, confirm the SL-insensitivity of hvd14.d plants.
