Approximately 100mg of tissue was used for RNA extraction using Spectrum Plant Total RNA Kit (Sigma-Aldrich, USA) according to the manufacturer instructions, followed by DNase treatment (On-Column DNase I Digestion Set, Sigma-Aldrich, USA). 25ng of RNA for 214 samples were aliquoted at a normalized concentration of 5 ng/μL for sequencing MIT BioMicro Center performed RNA-seq library construction and sequencing following the approach of High-Throughput 3' Digital Gene Expression with 26 + 80 bases pair-end run with 6 nucleotide index