Length distributions of newly identified miRNAs from various tissues of wheat plants and the preferred 5′ start nucleotides of 21 and 24 nt miRNAs. (A) Unique counts and abundances of wheat miRNAs of different sizes. (B) Abundance of miRNAs of different sizes in various tissues. (C) Preferred 5′ start nucleotide for 21 and 24 nt miRNAs. DG: dry grain; GSE: germinating seed embryos; SH: shoots; SL: seedling leaves; SR: seedling roots; SJ: stems in the jointing stage; YS5: 0–5 mm young spikes; YS15: 10–15 mm young spikes; FL: flag leaves; GRA8: grains 8 days after pollination; GRA15: grains 15 days after pollination.