Expression profile of Populus CCCH genes under drought condition. Color bar at the top represents log2 expression values. The corresponding genes in 13 subfamilies are shown on the left side. Stage of drought treatment, organs and genotypes are showed on the top. Genotype ‘Carpaccio’ productivity is less hampered by drought than that of ‘Soligo’. EAR, a short-term water deficit by withholding irrigation 36 hours; LMI, 10-day-long response to mild stress; LMO, 10 day-long response to moderate stress.