Identification of vernalization responsive genes in the winter wheat cultivar Jing841 by transcriptome sequencing

This study aimed to identify vernalization responsive genes in the winter wheat cultivar Jing841 by comparing the transcriptome data with that of a spring wheat cultivar Liaochun10. For each cultivar, seedlings before and after the vernalization treatment were sequenced by Solexa/Illumina sequencing. Genes differentially expressed after and before vernalization were identified as differentially expressed genes (DEGs) using false discovery rate (FDR) ≤ 0.001 and |log2 (fold change)|>1 as cutoffs. The Jing841-specific DEGs were screened and subjected to functional annotation using gene ontology (GO) database. Vernalization responsive genes among the specific genes were selected for validation by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and the expression change over the time was investigated for the top 11 genes with the most significant expression differences. A total of 138,062 unigenes were obtained. Overall, 636 DEGs were identified as vernalization responsive genes including some known genes such as VRN-1 and COR14a, and some unknown contigs. The qRT-PCR validated changes in the expression of 18 DEGs that were detected by RNA-seq. Among them, 11 genes displayed four different types of expression patterns over time during the 30-day-long vernalization treatment. Genes or contigs such as VRN-A1, COR14a, IRIP, unigene1806 and Cl18953. Contig2 probably have critical roles in vernalization.