Figure 5

Apple miRNA- TAS pathways and MYB -derived tasiRNA-cascaded regulatory network. (a) Schematic diagram for siRNA biogenesis along MdTAS3-1 family transcripts. Two conserved tasiARFs are flanked by a length-constant region at the 3' end and a divergent region at the 5' end. The parings between miR390 and its target sites are illustrated below. (b) List of apple TAS genes. (c) Schematic diagram of the siRNA biogenesis of MdTAS3-2 family transcripts and their conservation among plant species, including Cucumis melo (AM737743), Nicotiana tabacum (AM791738), Solanum lycopersicum (BE459870), Solanum tuberosum (BQ514736), Malus × domestica (CN928184), Populus tremuloides (DN500355), Vitis vinifera (DT023634), Gossypium hirsutum (DW502659), Helianthus exilis (EE660948), Artemisia annua (GW328601), Prunus persica (scaffold_3:16167014..16167205), and Fragaria vesca (scf0512980:217347..217557). The pairings between miR390 and its target sites are illustrated below. (d) Expression profiles for tasiRNAs in MdTAS3-1a/b and MdTAS3-2a. (e) Schematic diagram of the siRNA biogenesis of MdTAS4 and confirmation of a new gene target for TAS4-derived siR81(-) in apple. The miR828 cleavage of MdTAS4 transcripts and generation of the conserved MdTAS4-siR81(-) are marked on the transcript. The confirmed cleavage of the transcript of a gene coding for a bHLH3 factor by degradome is presented as a T-plot, and sequence pairing with cleavage site marked is shown below. (f) Location of the siRNA-biogenesis region among the ten miR828-targeted MYBs, and potential gene targeted by MYB-derived siRNAs. The number of genes or gene families targeted by siRNAs is indicated inside parentheses.