RNA-Seq of PP
RNA isolation and sequencing was performed at Novogene (China). RNA-seq libraries were prepared using the TruSeq mRNA Library Prep Kit (Illumina, USA). DNA frag-ment length distributions were measured on a Fragment Analyzer (Advanced Analyt-ical/Agilent, USA) prior to pooling. Sequencing was performed on an Illumina NovaSeq 6000 Sequencing System (Illumina, USA) with the 2  150base pairs and paired-end option.