The overall aim of this study was to investigate drought responses at phenotypic and transcriptional levels in willows and to examine variation in the response among the genotypes. The plants were exposed to drought and effects of drought on plant performance were assessed. RNA from root tips and leaves from two genotypes grown in drought and well-watered conditions was sequenced with the Illumina technology (i.e. RNA-seq). The sequencing reads were assembled de novo to create a reference gene set to which the reads were mapped in order to obtain differentially expressed genes (DEGs) between the drought and well-watered conditions.