In plants, microRNAs (miRNAs) comprise one of two classes of small RNAs that function primarily as negative regulators at the posttranscriptional level. Several MIRNA genes in the plant kingdom are ancient, with conservation extending between angiosperms and the mosses, whereas many others are more recently evolved. Here, we use deep...
Eukaryotes contain a diversified set of small RNA-guided pathways that control genes, repeated sequences, and viruses at the transcriptional and posttranscriptional levels. Genome-wide profiles and analyses of small RNAs, particularly the large class of 24-nucleotide (nt) short interfering RNAs (siRNAs), were done for wild-type Arabidopsis thaliana and silencing pathway mutants...
Background: Short RNAs, and in particular microRNAs, are important regulators of gene
expression both within defined regulatory pathways and at the epigenetic scale. We investigated
the short RNA (sRNA) population (18-24 nt) of the transcriptome of green leaves from the
sequenced Populus trichocarpa using a concatenation strategy in combination with...
Transacting siRNA (tasiRNA) biogenesis in Arabidopsis is initiated
by microRNA (miRNA) –guided cleavage of primary transcripts. In
the case of TAS3 tasiRNA formation, ARGONAUTE7 (AGO7)–
miR390 complexes interact with primary transcripts at two sites,
resulting in recruitment of RNA-DEPENDENT RNA POLYMERASE6
for dsRNA biosynthesis. An extensive screen for Arabidopsis mutants...
Eukaryotic small RNA (~20-30 nucleotides) are diverse regulatory molecules that repress gene expression at the transcriptional and post-transcriptional levels, defend hosts against invading viruses and defend genomes against selfish DNA elements. Small RNA populations are studied by high-throughput sequencing of the total small RNA fraction isolated from cells, however, the...
In RNA-directed silencing pathways, ternary complexes result from small RNA-guided ARGONAUTE (AGO) associating with target transcripts. Target transcripts are often silenced through direct cleavage (slicing), destabilization through slicer-independent turnover mechanisms, and translational repression. Here, wild-type and active-site defective forms of several Arabidopsis thaliana AGO proteins involved in posttranscriptional silencing were...
BACKGROUND: The wild grass Brachypodium distachyon has emerged as a model system for temperate grasses and
biofuel plants. However, the global analysis of miRNAs, molecules known to be key for eukaryotic gene regulation,
has been limited in B. distachyon to studies examining a few samples or that rely on computational...
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Arabidopsis or
Nucleotide BindingSite-Leucine-Rich Repeat (NBS-LRR)
genes in other dicot plants [21-24