title: 6 h after foliar application of iron
design: Laser capture microdissection was used to collect transfer cells from grain cryosections. Twenty sections from each seed and 60 in total were laser-bombarded for each of the biological replicates. Arcturus PicoPure RNA isolation kit was used to isolate total RNA. Due to the low quantity samples ranging from 3.6 to 18 ng, linear amplification of RNAs was performed using NuGEN Ovation® RNA-Seq kit. In parallel with the amplification, the semi-random primers of the kit also enriched the RNA population of samples against ribosomal RNA. Paired end 2 × 101 bp sequencing was performed at AROS Applied Biotechnology A/S (Aarhus, Denmark) using HiSeq 2000 Illumina sequencing platform and Truseq technology. CASAVA 1.8.2 was used to convert sequencing results into fastq format.