quantitative real-time PCR (qRT-PCR)
To verify the expression levels of the DEGs, qRT-PCR amplifications of 17 randomly selected genes were performed on a LightCycler 480 II instrument (Roche Diagnostics GmbH, Germany) using the RNAs as for the library construction and illumina sequencing. Gene PU1 (Gohir.A01G131900 ) was used as internal control. The primers of these genes for the qRT-PCR analysis were designed and listed in Table S2. Relative expression of these genes were calculated according to the 2–∆∆CT method (Schmittgen & Livak, 2008). T-test was applied for significant differences among treatments at P < 0.05 level. The results were shown as the means ± standard error of three replicates.