Project description:MicroRNAs (miRNAs) are 21-24 nucleotide (nt) small non-coding RNAs that regulate a wide variety of biological processes at the posttranscriptional level. MiRNA expression often exhibits spatial and temporal specificity. However, genome-wide miRNA expression patterns in different Arabidopsis organs during plant development have not yet been fully investigated. In this study, we sequenced 59 small RNA libraries generated from different tissue types at different developmental stages of Arabidopsis. We then re-annotated Arabidopsis miRNAs based on the most recent criteria. Global analysis of miRNA expression patterns showed that most miRNAs are ubiquitously expressed in different organs or tissues. But a small set of miRNAs, either previously annotated or newly identified, show highly specific expression patterns. In addition, the expression of some miRNA members belonging to the same family is strictly regulated spatially and temporally. Unexpectedly, we found that quite a few miRNAs are produced from different arms of their hairpin precursors at different developmental stages, suggesting that arm switching could be a general and important mechanism in developmental regulation.
Project description:In order to investigate possible roles of IDL and PIP/PIPL peptides, the transcriptomic response of Arabidopsis seedlings to treatment with PIPL3 peptide was analysed. PIPL3 (At4g37295) was chosen, as no functional data was available for this peptide; furthermore, PIPL3 was expressed in leaf tissue during seedling stages. Transcriptomic responses to 3 hours PIPL3 peptide treatment suggested a role in regulation of biotic stress responses and cell wall modification. Two weeks old seedlings were treated either with 100 nM PIPL3 peptide (treated) or 100 nM mock peptide (control) and whole rosettes were harvested 3 hours after treatment. 4 biological replicates per treatment.
