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.