*2.1.3. Transcriptome analysis*

The collected samples were used for transcriptome analysis. The procedure was subcontracted to Eurofins Genomics (Ebersberg, Germany). Briefly, the total RNA was extracted from the samples using RNeasy Plant Mini Kit (Qiagen Inc., Valencia, CA, USA) according to manu‐ facturer's procedure. The quality of total RNA was evaluated in terms of the degree of degradation of rRNAs with Bioanalyzer (Agilent Technologies, Santa Clara, CA, USA). Normalized cDNA library for use in Roche GS FLX Titanium sequencing was prepared as follows: poly (A) + RNA was isolated from the total RNA, and the first-strand cDNA synthesis was primed with an N6 randomized primer. Normalization was carried out by one cycle of denaturation and reassociation of the cDNA. Reassociated double-stranded (ds) cDNA was separated from the remaining single-stranded (ss) cDNA by passing the mixture through a hydroxylapatite column. The ss-cDNA was amplified by 9 PCR cycles. The cDNA library in the size range 500–700 bp was eluted from a preparative agarose gel. Emulsion PCR and sequencing were conducted according to standard protocols of Roche and the normalized cDNA library was sequenced in 1/2-plate run of GS FLX Titanium. Library preparations and their sequencing were carried out by Eurofins Genomics.
