Plant miRNAs and their role in suppressing NB-LRR targets via the production of secondary siRNAs (phasiRNAs)
Q. FEI (1), (1) Donald Danforth Plant Science Center

Small RNAs are a class of non-coding RNAs that are of great importance in gene silencing. Different families of small RNAs are generated via distinct biogenesis pathways. One such family specific to plants is that of phased, secondary siRNAs (phasiRNAs). Protein-encoding genes, especially NB-LRRs, are an important source of phasiRNAs in plants. We investigated their biogenesis by modulating miRNA triggers in Medicago truncatula. We found that the abundance of phasiRNAs correlates with the levels of both miRNA triggers and the target, precursor transcripts. In addition, in the miRNA-mRNA target pairing, the 3' terminal nucleotide (the 22nd position), but not the 10th position, is important for phasiRNA production, suggesting that the 22-nt length is required for phasiRNA production. Recent studies have shown that miRNAs, together with phasiRNAs, play an important role in modulating R gene accumulation during pathogenesis in diverse plant species. Therefore, studying small RNAs has expanded our understanding in plant-microbe interactions.


Abstract Number: C14-2, P10-339
Session Type: Concurrent