Plant miRNAs can trigger the production of phased, secondary siRNAs from either non-coding or protein-coding genes. In this study, at least 864 and 3,961 loci generating 21-nt and 24-nt phased siRNAs (phasiRNAs),respectively, were identified in three tissues from wild rice. Of these phasiRNA-producing loci, or PHAS genes, biogenesis of phasiRNAs in at least 160 of 21-nt and 254 of 24-nt loci could be triggered by interaction with miRNA(s). Developing seeds had more PHAS genes than leaves and roots. Genetic constrain on miRNA-triggered PHAS genes suggests that phasiRNAs might be one of the driving forces contributed to rice domestication.
Keywords: Oryza rufipogon; PHAS; TAS; miRNA; microRNA; phased siRNA; phased siRNAs (phasiRNA); phasiRNA; phasiRNA locus; rice domestication; siRNA; small RNA; small-interfering RNA; tasiRNA; tasiRNA locus; trans-acting siRNA.