An integrated transcriptomic atlas of smooth bromegrass (Bromus inermis) generated by PacBio Iso-Seq and Illumina RNA-Seq.

Short-read RNA sequencing was performed on the Illumina HiSeq platform (paired-end, 150 bp), and full-length transcriptome sequencing was performed on the PacBio Sequel system. For PacBio sequencing, samples comprised seeds, stems, leaves, roots, and shoots of smooth bromegrass. Seed samples were prepared by pooling five seeds from 16, 23, and 30 DAA. At 16 DAA, stems and leaves were harvested from five plants with uniform growth. Seeds were germinated in a growth chamber (16 h dark/8 h light, 15/25 degC) for 14 days; subsequently, roots and shoots were collected from 40 uniformly sized seedlings. All samples were flash-frozen in liquid nitrogen and stored at -80 degC. For Illumina sequencing, seed samples from 16, 23, and 30 DAA were categorized into 12 treatments (three time points x two grain positions [superior: SG; inferior: IG] x two conditions [control: CK; nitrogen-treated: N]), labeled as CS16, CI16, NS16, NI16, CS23, CI23, NS23, NI23, CS30, CI30, NS30, and NI30. Each treatment included eight uniform seeds with three replicates.