Bt 2
The construction of sRNA libraries consisted of the following successive steps: i) acrylamide gel purification of RNA fragments corresponding to sRNAs sizes (18-30 nt); ii) ligation of the 3p and 5p adapters and indexes to the RNA in two separate subsequent steps, each followed by acrylamide gel purification; iii) synthesis of cDNA followed by another acrylamide gel purification; and vi) final step of PCR amplification to generate a cDNA colony template library for Illumina sequencing. The libraries sequencing was conducted using the TruSeq SBS Kit v3-HS (Illumina) in an Illumina HiSeq 2500, with number of cycles of 1x50+7 (single-end) in one lane of the HiSeq Flow Cell v3 (Illumina).