RNA-Seq of walnut: embryo
Total RNA was extracted from the samples  using RNAprep Pure Plant kit (Tiangen, Beijing, China). RNA integrity was  measured using the RNA Nano6000 Assay Kit of Bioanalyzer 2100 system (Agilent  Technogies, CA, USA). Construction and deep-secquencing of RNA -seq libraries  were performed at Novogene Bioinformatics Technology Co., Ltd (Beijing).  Using the rRNA-depleted RNA by NEBNext RUltraTM Directional RNA library Prep  Kit for Illumina R (NEB, USA), nearly 1 g RNA per sample was used for  library preparation. Then all sequencing libraries were submitted for 150 bp  paired-end sequencing on an Illumina NovaSeq 6000 platform.