Project description:Proteomic investigation of Arabidopsis thaliana ftsH12 - ftsH12 is one of 17 genes of the FtsH metallo-protease family encoded within the A. thaliana genome.
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:The nascent polypeptide-associated (NAC) complex was described in yeast as a heterodimer composed of two subunits, α and β, and was shown to bind to the nascent polypeptides newly emerging from the ribosome. Although NAC function was widely described in yeast, less is known about its role in plants. The knock down of individual NAC subunit(s) led usually to a higher sensitivity to stress. In Arabidopsis thaliana genome, there are five genes coding for NACα subunit, and two genes coding for NACβ. Double homozygous mutant in both genes coding for NACβ was acquired, which showed a delayed development compared to the wild type, had abnormal number of flower organs, shorter siliques and greatly reduced seed set. Herein, both NACβ genes were characterized by complementation analysis, overexpression, subcellular localization, and promoter analysis. Since flowers were the most affected organs by nacβ mutation, the flower buds transcriptome was identified by RNA sequencing, and their proteome by gel-free approach. The differential expression analyses of transcriptomic and proteomic datasets suggest the involvement of NACβ subunits in stress responses and male gametophyte development.
Project description:This experiment profiled a time series of gene expression in leaf 7 of Arabidopsis thaliana plants grown in a controlled environment under 8 h light: 16 h dark (i.e. short days) to compare to the profiles analysed in Breeze et al. (2011) Plant Cell 23(3):873-94 under long day conditions.
Project description:Background Long non-coding RNAs (lncRNAs) are under-studied and under-annotated in plants. In mammals, lncRNA expression has been shown to be reaching the extent of protein-coding expression and be highly variable between individuals of the same species. Using A. thaliana as a model plant organism, we aimed to understand the true scope of lncRNA transcription across plants from different regions, characterize lncRNA natural expression variability, and study the causes of this variability. Results Using RNA-seq data spanning 499 natural lines and 4 different developmental stages to create a more comprehensive annotation of lncRNAs in A. thaliana, we found over 10,000 novel loci — three times as many as in the current public annotation. We showed that, while lncRNA loci are ubiquitous in the genome, most appear to be actively silenced and their expression and repressive chromatin levels are extremely variable between natural lines. It was particularly prominent in intergenic lncRNAs, where TE-like sequences present in 50% of the loci are associated with increased silencing and variation and such lincRNAs tend to be targeted by TE silencing machinery. Conclusion lncRNAs are ubiquitous in the A. thaliana genome, but their expression is highly variable between different lines and tissues. This high expression variability is largely caused by high structural and epigenetic variability of non-coding loci, especially those containing pieces of transposable elements. We create the most comprehensive A. thaliana lncRNA annotation to date and improve our understanding of plant lncRNA biology.